1.
Artificial Horizon (album)
–
Artificial Horizon is a compilation album of remixed tracks by rock band U2. It was released exclusively to subscribing members of U2. com, replacing Medium, the remix CD is of a similar vein to the bands 1995 release Melon, Remixes for Propaganda, which was also released exclusively to fans. A triple-vinyl edition was released to the public until 14 May 2010. Artificial Horizon includes thirteen remixed tracks spanning the most recent fifteen years of the bands career, the opening track, Elevation was taken from the 2001 single Elevation. It was produced by Brian Eno and Daniel Lanois, and includes synthesizers played by Eno, the remix was performed by Leo Pearson. Elevation was always played over the PA system as the band took the stage on the Elevation Tour, the Jacknife Lee mix of Fast Cars was first released on the 2005 single All Because of You. The original studio version, a track on some versions of the 2004 album How to Dismantle an Atomic Bomb, was produced by Steve Lillywhite. The Jacknife Lee remix includes additional keyboards played by Jacknife Lee, get on Your Boots is a previously unreleased track, the song was remixed by Declan Gaffney and Matt Paul. Vertigo was taken from the 2005 single Sometimes You Cant Make It on Your Own, produced by Lillywhite, the track was remixed by Trent Reznor. The guitar part for Native Son, a version of Vertigo, is interspersed throughout the song. Produced by Eno and Lanois, Magnificent was first released on the 2009 single Magnificent, the track was remixed by Fred Falke, who plays additional keyboards in the piece. The track was recorded by Alastair McMillan on 27 July 2009 at Croke Park in Dublin, Ireland, singer Bono includes snippets of the Frankie Goes to Hollywood songs Relax and Two Tribes at the beginning and end of the song. Beshno Az Ney/Windfall, performed by Iranian singer Sussan Deyhim, is sampled at the end as the track fades out, the David Holmes remix of Beautiful Day was included on the Elevation single. With the exception of a few backing vocals in the final minute, Staring at the Sun was first released on the 1997 single Staring at the Sun. It was produced by Flood and remixed by The Sonic Morticians, the Danny Saber mix of Happiness Is a Warm Gun was taken from the 1997 single Last Night on Earth. Produced by Flood, it was remixed by Danny Saber, get on Your Boots was originally released as a b-side to the Magnificent single. The track was remixed by the French band Justice, the Hot Chip 2006 remix of City of Blinding Lights is the third previously unreleased track. Produced by Flood, it was remixed by Hot Chip, the track If God Will Send His Angels was taken from the 1997 single Mofo
2.
Instrument landing system
–
An instrument landing system enables aircraft to land if the pilots are unable to establish visual contact with the runway. It does this by way of transmitted radio signals, an instrument approach procedure chart is published for each ILS approach to provide the information needed to fly an ILS approach during instrument flight rules operations. A chart includes the frequencies used by the ILS components or navaids. An aircraft approaching a runway is guided by the ILS receivers in the aircraft by performing modulation depth comparisons, many aircraft can route signals into the autopilot to fly the approach automatically. An ILS consists of two independent sub-systems, the localizer provides lateral guidance, the glide slope provides vertical guidance. A localizer is an antenna array normally located beyond the end of the runway. Due to the complexity of ILS localizer and glide slope systems, localizer systems are sensitive to obstructions in the signal broadcast area, such as large buildings or hangars. Glide slope systems are limited by the terrain in front of the glide slope antennas. If terrain is sloping or uneven, reflections can create an uneven glidepath, additionally, since the ILS signals are pointed in one direction by the positioning of the arrays, glide slope supports only straight-line approaches with a constant angle of descent. Installation of an ILS can be costly because of siting criteria, ILS critical areas and ILS sensitive areas are established to avoid hazardous reflections that would affect the radiated signal. The location of these areas can prevent aircraft from using certain taxiways leading to delays in takeoffs, increased hold times. Instrument guidance system - a modified ILS to accommodate a non-straight approach, in addition to the previously mentioned navigational signals, the localizer provides for ILS facility identification by periodically transmitting a 1,020 Hz Morse code identification signal. For example, the ILS for runway 4R at John F. Kennedy International Airport transmits IJFK to identify itself and this lets users know the facility is operating normally and that they are tuned to the correct ILS. The glide slope station transmits no identification signal, so ILS equipment relies on the localizer for identification and it is essential that any failure of the ILS to provide safe guidance be detected immediately by the pilot. To achieve this, monitors continually assess the characteristics of the transmissions. If any significant deviation beyond strict limits is detected, either the ILS is automatically switched off or the navigation and identification components are removed from the carrier, either of these actions will activate an indication on the instruments of an aircraft using the ILS. Modern localizer antennas are highly directional, however, usage of older, less directional antennas allows a runway to have a non-precision approach called a localizer back course. This lets aircraft land using the signal transmitted from the back of the localizer array, highly directional antennas do not provide a sufficient signal to support a back course
3.
Flight instruments
–
Flight instruments are the instruments in the cockpit of an aircraft that provide the pilot with information about the flight situation of that aircraft, such as altitude, airspeed and direction. They improve safety by allowing the pilot to fly the aircraft in level flight, visual flight rules require an airspeed indicator, an altimeter, and a compass or other suitable magnetic direction indicator. Instrument flight rules require a gyroscopic pitch-bank, direction and rate of turn indicator, plus a slip-skid indicator, adjustable altimeter. Flight into Instrument meteorological conditions require radio navigation instruments for precise takeoffs, the term is sometimes used loosely as a synonym for cockpit instruments as a whole, in which context it can include engine instruments, navigational and communication equipment. Many modern aircraft have electronic flight instrument systems, most regulated aircraft have these flight instruments as dictated by the US Code of Federal Regulations, Title 14, Part 91. They are grouped according to system, compass systems. It is adjustable for local barometric pressure which must be set correctly to obtain accurate altitude readings, as the aircraft ascends, the capsules expand and the static pressure drops, causing the altimeter to indicate a higher altitude. The opposite effect occurs when descending, with the advancement in aviation and increased altitude ceiling the altimeter dial had to be altered for use both at higher and lower altitudes. This modification was introduced in the early sixties after the recurrence of air caused by the confusion in the pilots mind. At higher altitudes the window will disappear, the airspeed indicator shows the aircrafts speed relative to the surrounding air. It works by measuring the pressure in the aircrafts Pitot tube relative to the ambient static pressure. The Indicated airspeed must be corrected for pressure and temperature in order to obtain the True airspeed. The instrument is color coded to indicate important airspeeds such as the speed, never-exceed airspeed. The VSI senses changing air pressure, and displays that information to the pilot as a rate of climb or descent in feet per minute, the compass shows the aircrafts heading relative to magnetic north. Errors include Variation, or the difference between magnetic and true direction, and Deviation, caused by the wiring in the aircraft. Additionally, the compass is subject to Dip Errors, while reliable in steady level flight it can give confusing indications when turning, climbing, descending, or accelerating due to the inclination of the Earths magnetic field. For this reason, the indicator is also used for aircraft operation. The attitude indicator shows the relation to the horizon
4.
Aircraft
–
An aircraft is a machine that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the lift of an airfoil. The human activity that surrounds aircraft is called aviation, crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as type, aircraft propulsion, usage. Each of the two World Wars led to technical advances. Consequently, the history of aircraft can be divided into five eras, Pioneers of flight, first World War,1914 to 1918. Aviation between the World Wars,1918 to 1939, Second World War,1939 to 1945. Postwar era, also called the jet age,1945 to the present day, aerostats use buoyancy to float in the air in much the same way that ships float on the water. They are characterized by one or more large gasbags or canopies, filled with a relatively low-density gas such as helium, hydrogen, or hot air, which is less dense than the surrounding air. When the weight of this is added to the weight of the aircraft structure, a balloon was originally any aerostat, while the term airship was used for large, powered aircraft designs – usually fixed-wing. In 1919 Frederick Handley Page was reported as referring to ships of the air, in the 1930s, large intercontinental flying boats were also sometimes referred to as ships of the air or flying-ships. – though none had yet been built, the advent of powered balloons, called dirigible balloons, and later of rigid hulls allowing a great increase in size, began to change the way these words were used. Huge powered aerostats, characterized by an outer framework and separate aerodynamic skin surrounding the gas bags, were produced. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, then several accidents, such as the Hindenburg disaster in 1937, led to the demise of these airships. Nowadays a balloon is an aerostat and an airship is a powered one. A powered, steerable aerostat is called a dirigible, sometimes this term is applied only to non-rigid balloons, and sometimes dirigible balloon is regarded as the definition of an airship. Non-rigid dirigibles are characterized by a moderately aerodynamic gasbag with stabilizing fins at the back and these soon became known as blimps. During the Second World War, this shape was adopted for tethered balloons, in windy weather
5.
Aircraft principal axes
–
The axes are alternatively designated as lateral, vertical, and longitudinal. These axes move with the vehicle and rotate relative to the Earth along with the craft and these definitions were analogously applied to spacecraft when the first manned spacecraft were designed in the late 1950s. These rotations are produced by torques about the principal axes, on an aircraft, these are intentionally produced by means of moving control surfaces, which vary the distribution of the net aerodynamic force about the vehicles center of mass. Elevators produce pitch, a rudder on the vertical tail produces yaw, on a spacecraft, the moments are usually produced by a reaction control system consisting of small rocket thrusters used to apply asymmetrical thrust on the vehicle. Normal axis, or yaw axis — an axis drawn from top to bottom, lateral axis, transverse axis, or pitch axis — an axis running from the pilots left to right in piloted aircraft, and parallel to the wings of a winged aircraft. Longitudinal axis, or roll axis — an axis drawn through the body of the vehicle from tail to nose in the direction of flight. Normally, these axes are represented by the letters X, Y and Z in order to them with some reference frame. Normally, this is made in such a way that the X is used for the longitudinal axis, but there are other possibilities to do it. The vertical yaw axis is defined to be perpendicular to the wings and to the line of flight with its origin at the center of gravity. Yaw moves the nose of the aircraft from side to side, a positive yaw, or heading angle, moves the nose to the right. The rudder is the control of yaw. The pitch axis passes through the plane from wingtip to wingtip, pitch moves the aircrafts nose up and down. A positive pitch angle raises the nose and lowers the tail, the elevators are the primary control of pitch. The roll axis passes through the plane from nose to tail, the angular displacement about this axis is called bank. The pilot changes bank angle by increasing the lift on one wing and decreasing it on the other, a positive roll angle lifts the left wing and lowers the right wing. The ailerons are the control of bank. The rudder also has an effect on bank. These axes are related to the axes of inertia, but are not the same
6.
Inertial frame of reference
–
In classical physics and special relativity, an inertial frame of reference is a frame of reference that describes time and space homogeneously, isotropically, and in a time-independent manner. The physics of a system in an inertial frame have no causes external to the system, all inertial frames are in a state of constant, rectilinear motion with respect to one another, an accelerometer moving with any of them would detect zero acceleration. Measurements in one frame can be converted to measurements in another by a simple transformation. In general relativity, in any region small enough for the curvature of spacetime and tidal forces to be negligible, systems in non-inertial frames in general relativity dont have external causes because of the principle of geodesic motion. Physical laws take the form in all inertial frames. For example, a ball dropped towards the ground does not go straight down because the Earth is rotating. Someone rotating with the Earth must account for the Coriolis effect—in this case thought of as a force—to predict the horizontal motion, another example of such a fictitious force associated with rotating reference frames is the centrifugal effect, or centrifugal force. The motion of a body can only be described relative to something else—other bodies, observers and these are called frames of reference. If the coordinates are chosen badly, the laws of motion may be more complex than necessary, for example, suppose a free body that has no external forces on it is at rest at some instant. In many coordinate systems, it would begin to move at the next instant, however, a frame of reference can always be chosen in which it remains stationary. Similarly, if space is not described uniformly or time independently, indeed, an intuitive summary of inertial frames can be given as, In an inertial reference frame, the laws of mechanics take their simplest form. In an inertial frame, Newtons first law, the law of inertia, is satisfied, Any free motion has a constant magnitude, the force F is the vector sum of all real forces on the particle, such as electromagnetic, gravitational, nuclear and so forth. The extra terms in the force F′ are the forces for this frame. The first extra term is the Coriolis force, the second the centrifugal force, also, fictitious forces do not drop off with distance. For example, the force that appears to emanate from the axis of rotation in a rotating frame increases with distance from the axis. All observers agree on the forces, F, only non-inertial observers need fictitious forces. The laws of physics in the frame are simpler because unnecessary forces are not present. In Newtons time the stars were invoked as a reference frame
7.
Steep turn (aviation)
–
A steep turn in aviation, performed by an aircraft, is a turn that involves a bank of more than 30 degrees. This means the angle created by the running along both wings and the horizon is more than 30 degrees. Generally, for training purposes, steep turns are demonstrated and practiced at 45 degrees, sometimes more. The purpose of learning and practicing a steep turn is to train a pilot to control of an aircraft in cases of emergency such as structural damage. For Jet training an increase of 7-8% of N1 caters, do not remember the amount of power for Cessnas now. While doing this the pilot has to no loss or gain of altitude. The pilot is expected to look outside the aircraft while keeping a close check on the Attitude indicator for angle of bank. When the aircraft is in a 45 degree bank, it is common for a amount of opposite aileron control to be required to prevent the aircraft from slipping into a steeper bank. This section would best be understood by a private pilot or someone who has studied the curriculum contained within the private pilot ground syllabus. For purposes of testing, a turn is a 360 degree turn in either direction with a 45 degree bank angle while maintaining altitude, speed. Furthermore the roll out heading must be within 10 degrees of the heading for the manoeuvre to be deemed successful by most flight training standards. A steep turn increases the load factor of an aircraft, simply put the aircraft feels heavier due to the effect of centrifugal force. At a 45 degree bank angle the load factor of an aircraft is 1.4 i. e. the aircraft effectively becomes 40% heavier. This requires the pilot to exert pressure on the flight stick or column to raise the nose. In the event that backward pressure is not exerted on the stick / column and this applies to cockpits with two seats arranged horizontally or abreast. Assuming the pilot performing the manoeuvre is positioned in the seat when a steep turn to the right is performed. Conversely, a turn to the left will make it seem like the nose is rising against the horizon. This is parallax error based purely on the vantage point
8.
Airspeed indicator
–
The airspeed indicator or airspeed gauge is an instrument used in an aircraft to display the crafts airspeed, typically in knots, to the pilot. In its simplest form, an ASI measures the difference in pressure between the air around the craft and the pressure caused by propulsion. The needle tracks pressure differential but the dial is marked off as airspeed, during instrument flight, the airspeed indicator is used in addition to the Artificial horizon as an instrument of reference for pitch control during climbs, descents and turns. The airspeed indicator is used in dead reckoning, where time, speed. Airspeed indicators in many Light and Recreational aircraft can only show the pilot Indicated Airspeed, for True Airspeed other components would have to be added by the manufacturer. Airspeed Indicator markings use a set of standardized coloured bands and lines on the face of the instrument, the white range is the normal range of operating speeds for the aircraft with the flaps extended as for landing or takeoff. The green range is the range of operating speeds for the aircraft without flaps extended. The yellow range is the range in which the aircraft may be operated in smooth air, a redline mark indicates VNE, or velocity. This is the maximum demonstrated safe airspeed that the aircraft must not exceed under any circumstances, the red line is preceded by a yellow band which is the caution area, which runs from VNO to VNE. A green band runs from VS1 to VNO, VS1 is the stall speed with flaps and landing gear retracted. A white band runs from VSO to VFE, VSO is the stall speed with flaps extended, and VFE is the highest speed at which flaps can be extended. The airspeed indicator is especially important for monitoring V-Speeds while operating an aircraft, however, in large aircraft, V-speeds can vary considerably depending on airfield elevation, temperature and aircraft weight. Jet aircraft do not have VNO and VNE like piston-engined aircraft, to observe both limits, the pilot of a jet airplane needs both an airspeed indicator and a Machmeter, each with appropriate red lines. An alternative single instrument is the maximum allowable airspeed indicator and it has a movable pointer that indicates the maximum operating limit. The movable pointer moves with altitude and temperature so that it indicates the maximum allowable speed of the aircraft. The pointer is usually striped, and thus known as a barber pole. As the aircraft climbs to altitude, such that MMO rather than VMO becomes the limiting speed. The airspeed is typically presented in the form of a strip that moves up and down
9.
Altimeter
–
An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, altitude can be determined based on the measurement of atmospheric pressure. The greater the altitude, the lower the pressure, when a barometer is supplied with a nonlinear calibration so as to indicate altitude, the instrument is called a pressure altimeter or barometric altimeter. A pressure altimeter is the altimeter found in most aircraft, hikers and mountain climbers use wrist-mounted or hand-held altimeters, in addition to other navigational tools such as a map, magnetic compass, or GPS receiver. The calibration of an altimeter follows the equation z = c T log , where c is a constant, T is the temperature, P is the pressure at altitude z. The constant c depends on the acceleration of gravity and the mass of the air. A barometric altimeter, used along with a map, can help to verify ones location. An altimeter is the most important piece of skydiving equipment, after the parachute itself, altitude awareness is crucial at all times during the jump, and determines the appropriate response to maintain safety. This is the most basic and common type, and is used by all student skydivers. The common design has a face marked from 0 to 4000m, the face plate sports sections prominently marked with yellow and red respectively, signifying the recommended deployment altitude, as well as emergency procedure decision altitude. Some advanced electronic altimeters are also available which use of the familiar analogue display. Digital visual altimeters, mounted on the wrist or hand and this type always operates electronically, and conveys the altitude as a number, rather than a pointer on a dial. An electronic altimeter is turned on on the ground before jump, if the intended landing zone is at a different elevation than the takeoff point, the user needs to input the appropriate offset by using a designated function. These are inserted into ones helmet, and emit a warning tone at a predefined altitude, audibles are strictly auxiliary devices, and do not replace, but complement a visual altimeter which remains the primary tool for maintaining altitude awareness. Audibles are not recommended and often banned from use by student skydivers and these do not show the precise altitude, but rather help maintain a general indicator in ones peripheral vision. The exact choice of altimeters depends heavily on the individual preferences, experience level, primary disciplines. On one end of the spectrum, a demonstration jump with water landing and no free fall might waive the mandated use of altimeters. Another skydiver doing similar types of jumps might wear a digital altimeter for their primary visual one, in aircraft, an aneroid barometer measures the atmospheric pressure from a static port outside the aircraft
10.
Variometer
–
It can be calibrated in feet per minute, knots or metres per second, depending on country and type of aircraft. In powered flight the pilot makes frequent use of the VSI to ascertain that level flight is being maintained, in gliding, the instrument is used almost continuously during normal flight, often with an audible output, to inform the pilot of rising or sinking air. It is usual for gliders to be equipped with more than one type of variometer, the simpler type does not need an external source of power and can therefore be relied upon to function regardless of whether a battery or power source has been fitted. The electronic type with audio needs a source to be operative during the flight. The instrument is of little interest during launching and landing, with the exception of aerotow, variometers measure the rate of change of altitude by detecting the change in air pressure as altitude changes. A simple variometer can be constructed by adding a large reservoir to augment the capacity of a common aircraft rate-of-climb instrument. In its simplest electronic form, the instrument consists of an air bottle connected to the atmosphere through a sensitive air flow meter. The faster the aircraft is ascending, the faster the air flows, air flowing out of the bottle indicates that the altitude of the aircraft is increasing. Air flowing into the bottle indicates that the aircraft is descending and these designs tend to be smaller as they do not need the air bottle. They are more reliable as there is no bottle to be affected by changes in temperature, the term vertical speed indicator or VSI is most often used for the instrument when it is installed in a powered aircraft. The term variometer is most often used when the instrument is installed in a glider or sailplane, an Inertial-lead or Instantaneous VSI uses accelerometers to provide a quicker response to changes in vertical speed. Human beings, unlike birds and other flying animals, are not able directly to sense climb, before the invention of the variometer, sailplane pilots found it very hard to soar. Although they could readily detect abrupt changes in speed, their senses did not allow them to distinguish lift from sink. The actual climb/sink rate could not even be guessed at, unless there was some clear fixed visual reference nearby, being near a fixed reference means being near to a hillside, or to the ground. Except when hill-soaring, these are generally very unprofitable positions for glider pilots to be in, the most useful forms of lift are found at higher altitudes and it is very hard for a pilot to detect or exploit them without the use of a variometer. After the variometer was invented in 1929 by Alexander Lippisch and Robert Kronfeld, variometers also became important in foot-launch hang gliding, where the open-to-air pilot hears the wind but needs the variometer to help him or her to detect regions of rising or sinking air. In early hang gliding, variometers were not needed for the short flights or flights close to ridge lift, but the variometer became key as pilots began making longer flights. The first portable variometer for use in hang gliders was the Colver Variometer by Colver Soaring Instruments which served to extend the sport into cross-country thermal flying, as the sport of gliding developed, however, it was found that these very simple uncompensated instruments had their limitations
11.
Heading indicator
–
The heading indicator is a flight instrument used in an aircraft to inform the pilot of the aircrafts heading. It is sometimes referred to by its names, the directional gyro or DG. To remedy this, the pilot will typically manoeuvre the airplane with reference to the indicator, as the gyroscopic heading indicator is unaffected by dip. The pilot will periodically reset the indicator to the heading shown on the magnetic compass. The heading indicator works using a gyroscope, tied by a mechanism to the aircraft yawing plane, i. e. the plane defined by the longitudinal. As such, any configuration of the yawing plane that does not match the local Earth horizontal results in an indication error. The heading indicator is arranged such that the axis is used to drive the display. The gyroscope is spun either electrically, or using filtered air flow from a pump driven from the aircrafts engine. The apparent drift is predicted by ω sin Latitude and will thus be greatest over the poles, to counter for the effect of Earth rate drift a latitude nut can be set which induces a real wander in the gyroscope. Otherwise it would be necessary to realign the direction indicator once each ten to fifteen minutes during routine in-flight checks. Failure to do this is a source of navigation errors among new pilots. Another sort of apparent drift exists in the form of transport wander, caused by the aircraft movement and it equals the course change along a great circle flight path. Some more expensive heading indicators are slaved to a magnetic sensor, the flux gate continuously senses the Earths magnetic field, and a servo mechanism constantly corrects the heading indicator. These slaved gyros reduce pilot workload by eliminating the need for manual realignment every ten to fifteen minutes, a common source of error here is the improper setting of the latitude nut. The table however allows one to gauge whether an indicator is behaving as expected, transport wander is an undesirable consequence of apparent drift
12.
Turn and slip indicator
–
In aviation, the turn and slip indicator and the turn coordinator variant are essentially two aircraft flight instruments in one device. One indicates the rate of turn, or the rate of change in the aircrafts heading, the turn and slip indicator can be referred to as the turn and bank indicator, although the instrument does not respond directly to bank angle. Neither does the turn coordinator, but it does respond to roll rate, the turn indicator is a gyroscopic instrument that works on the principle of precession. The gyro is mounted in a gimbal, the gyros rotational axis is in-line with the lateral axis of the aircraft, while the gimbal has limited freedom around the longitudinal axis of the aircraft. As the aircraft yaws, a force is applied to the gyro around the vertical axis, due to aircraft yaw. The gyro spins on an axis that is 90 degrees relative to the direction of the yaw torque force. The gyro and gimbal rotate with limited freedom against a calibrated spring, the torque force against the spring reaches an equilibrium and the angle that the gimbal and gyro become positioned is directly connected to the display needle, thereby indicating the rate of turn. In the turn coordinator, the gyro is canted 30 degrees from the horizontal so it responds to roll as well as yaw, the display contains hash marks for the pilots reference during a turn. When the needle is lined up with a mark, the aircraft is performing a standard rate turn which is defined as three degrees per second, known in some countries as rate one. This translates to two minutes per 360 degrees of turn, the supersonic Concorde jet aircraft and many military jets are examples of aircraft that use 4 min. The hash marks are called dog houses, because of their distinct shape on various makes of turn indicators. Under instrument flight rules, using these figures allows a pilot to perform timed turns in order to conform with the air traffic patterns. For a change of heading of 90 degrees, a turn lasting 30 seconds would be required to perform a standard rate or rate one turn, coordinated flight indication is obtained by using an inclinometer, which is recognized as the ball in a tube. An inclinometer contains a ball sealed inside a glass tube. The original form of the indicator is in effect a level with the tube curved in the opposite direction. In some early aircraft the indicator was merely a pendulum with a dashpot for damping, the ball gives an indication of whether the aircraft is slipping, skidding or in balanced flight. The balls movement is caused by the force of gravity and the centripetal acceleration. When the ball is centered in the middle of the tube, if the ball is on the inside of a turn, the aircraft is slipping
13.
Tachometer
–
A tachometer is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute on an analogue dial. The word comes from Greek ταχος and metron, essentially the words tachometer and speedometer have identical meaning, a device that measures speed. It is by convention that in the automotive world one is used for engine. In formal engineering nomenclature, more terms are used to distinguish the two. The first mechanical tachometers were based on measuring the centrifugal force, the inventor is assumed to be the German engineer Dietrich Uhlhorn, he used it for measuring the speed of machines in 1817. Since 1840, it has used to measure the speed of locomotives. Tachometers or revolution counters on cars, aircraft, and other vehicles show the rate of rotation of the engines crankshaft and this can assist the driver in selecting appropriate throttle and gear settings for the driving conditions. This is more applicable to manual transmissions than to automatics, the red zone is superfluous on most modern cars, since their engines typically have a revolution limiter which electronically limits engine speed to prevent damage. Tractors fitted with a take off system have tachometers showing the engine speed needed to rotate the PTO at the standardized speed required by most PTO-driven implements. In many countries, tractors are required to have a speedometer for use on a road, to save fitting a second dial, the vehicles tachometer is often marked with a second scale in units of speed. This scale is only accurate in a gear, but since many tractors only have one gear that is practical for use on-road. Tractors with multiple road gears often have tachometers with more than one speed scale, aircraft tachometers have a green arc showing the engines designed cruising speed range. This is from a connection called an AC tap which is a connection to one of the stators coil output. Tachometers driven by a cable from a drive unit fitted to the engine exist - usually on simple diesel-engined machinery with basic or no electrical systems. On recent EMS found on vehicles, the signal for the tachometer is usually generated from an ECU which derives the information from either the crankshaft or camshaft speed sensor. Tachometers are used to estimate traffic speed and volume, a vehicle is equipped with the sensor and conducts tach runs which record the traffic data. These data are a substitute or complement to loop detector data, to get statistically significant results requires a high number of runs, and bias is introduced by the time of day, day of week, and the season
14.
Gyroscope
–
A gyroscope is a spinning wheel or disc in which the axis of rotation is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum, because of this, gyroscopes are useful for measuring or maintaining orientation. Due to their precision, gyroscopes are used in gyrotheodolites to maintain direction in tunnel mining. Gyroscopes can be used to construct gyrocompasses, which complement or replace magnetic compasses, a gyroscope is a wheel mounted in two or three gimbals, which are a pivoted supports that allow the rotation of the wheel about a single axis. In the case of a gyroscope with two gimbals, the gimbal, which is the gyroscope frame, is mounted so as to pivot about an axis in its own plane determined by the support. This outer gimbal possesses one degree of freedom and its axis possesses none. The inner gimbal is mounted in the frame so as to pivot about an axis in its own plane that is always perpendicular to the pivotal axis of the gyroscope frame. This inner gimbal has two degrees of rotational freedom, the axle of the spinning wheel defines the spin axis. The rotor is constrained to spin about an axis, which is perpendicular to the axis of the inner gimbal. So the rotor possesses three degrees of freedom and its axis possesses two. The wheel responds to a force applied to the axis by a reaction force to the output axis. The behaviour of a gyroscope can be most easily appreciated by consideration of the front wheel of a bicycle. If the wheel is leaned away from the vertical so that the top of the moves to the left. In other words, rotation on one axis of the turning wheel produces rotation of the third axis, a gyroscope flywheel will roll or resist about the output axis depending upon whether the output gimbals are of a free or fixed configuration. Examples of some free-output-gimbal devices would be the attitude reference gyroscopes used to sense or measure the pitch, roll, the centre of gravity of the rotor can be in a fixed position. Some gyroscopes have mechanical equivalents substituted for one or more of the elements, for example, the spinning rotor may be suspended in a fluid, instead of being pivotally mounted in gimbals. In some special cases, the outer gimbal may be omitted so that the rotor has two degrees of freedom. Essentially, a gyroscope is a top combined with a pair of gimbals, Tops were invented in many different civilizations, including classical Greece, Rome, and China
15.
Vacuum
–
Vacuum is space void of matter. The word stems from the Latin adjective vacuus for vacant or void, an approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. In engineering and applied physics on the hand, vacuum refers to any space in which the pressure is lower than atmospheric pressure. The Latin term in vacuo is used to describe an object that is surrounded by a vacuum, the quality of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum, for example, a typical vacuum cleaner produces enough suction to reduce air pressure by around 20%. Ultra-high vacuum chambers, common in chemistry, physics, and engineering, operate below one trillionth of atmospheric pressure, outer space is an even higher-quality vacuum, with the equivalent of just a few hydrogen atoms per cubic meter on average. In the electromagnetism in the 19th century, vacuum was thought to be filled with a medium called aether, in modern particle physics, the vacuum state is considered the ground state of matter. Vacuum has been a frequent topic of debate since ancient Greek times. Evangelista Torricelli produced the first laboratory vacuum in 1643, and other techniques were developed as a result of his theories of atmospheric pressure. A torricellian vacuum is created by filling a glass container closed at one end with mercury. Vacuum became an industrial tool in the 20th century with the introduction of incandescent light bulbs and vacuum tubes. The recent development of human spaceflight has raised interest in the impact of vacuum on human health, the word vacuum comes from Latin an empty space, void, noun use of neuter of vacuus, meaning empty, related to vacare, meaning be empty. Vacuum is one of the few words in the English language that contains two consecutive letters u. Historically, there has been dispute over whether such a thing as a vacuum can exist. Ancient Greek philosophers debated the existence of a vacuum, or void, in the context of atomism, Aristotle believed that no void could occur naturally, because the denser surrounding material continuum would immediately fill any incipient rarity that might give rise to a void. Almost two thousand years after Plato, René Descartes also proposed a geometrically based alternative theory of atomism, without the problematic nothing–everything dichotomy of void, by the ancient definition however, directional information and magnitude were conceptually distinct. The explanation of a clepsydra or water clock was a topic in the Middle Ages. Although a simple wine skin sufficed to demonstrate a partial vacuum, in principle and he concluded that airs volume can expand to fill available space, and he suggested that the concept of perfect vacuum was incoherent. However, according to Nader El-Bizri, the physicist Ibn al-Haytham and the Mutazili theologians disagreed with Aristotle and Al-Farabi, using geometry, Ibn al-Haytham mathematically demonstrated that place is the imagined three-dimensional void between the inner surfaces of a containing body
16.
Precession
–
Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, in other words, if the axis of rotation of a body is itself rotating about a second axis, that body is said to be precessing about the second axis. A motion in which the second Euler angle changes is called nutation, in physics, there are two types of precession, torque-free and torque-induced. In astronomy, precession refers to any of several changes in an astronomical bodys rotational or orbital parameters. An important example is the change in the orientation of the axis of rotation of the Earth. Torque-free precession implies that no moment is applied to the body. In torque-free precession, the momentum is a constant. What makes this possible is a moment of inertia, or more precisely. The inertia matrix is composed of the moments of inertia of a body calculated with respect to coordinate axes. If an object is asymmetric about its axis of rotation. The result is that the component of the velocities of the body about each axis will vary inversely with each axis moment of inertia. When an object is not perfectly solid, internal vortices will tend to damp torque-free precession, R new = exp R old for the skew-symmetric matrix ×. Torque-induced precession is the phenomenon in which the axis of a spinning object describes a cone in space when a torque is applied to it. The phenomenon is seen in a spinning toy top. If the speed of the rotation and the magnitude of the external torque are constant, the spin axis will move at right angles to the direction that would intuitively result from the external torque. In the case of a toy top, its weight is acting downwards from its center of mass and these two opposite forces produce a torque which causes the top to precess. The device depicted on the right is gimbal mounted, from inside to outside there are three axes of rotation, the hub of the wheel, the gimbal axis, and the vertical pivot. To distinguish between the two axes, rotation around the wheel hub will be called spinning, and rotation around the gimbal axis will be called pitching
17.
Aerobatics
–
Aerobatics is the practice of flying maneuvers involving aircraft altitudes that are not used in normal flight. Aerobatics are performed in airplanes and gliders for training, recreation, entertainment, additionally, some helicopters, such as the MBB Bo 105, are capable of limited aerobatic maneuvers. An example of a fully aerobatic helicopter, capable of performing loops, the term is sometimes referred to as acrobatics, especially when translated. Most aerobatic maneuvers involve rotation of the aircraft about its longitudinal axis or lateral axis, other maneuvers, such as a spin, displace the aircraft about its vertical axis. Maneuvers are often combined to form a complete sequence for entertainment or competition. Aerobatic flying requires a set of piloting skills and exposes the aircraft to greater structural stress than for normal flight. In some countries, the pilot must wear a parachute when performing aerobatics, aerobatic training enhances a pilots ability to recover from unusual flight conditions, and thus is an element of many flight safety training programs for pilots. While many pilots fly aerobatics for recreation, some choose to fly in aerobatic competitions, in the early days of flying, some pilots used their aircraft as part of a flying circus to entertain. Among the earliest innovators in aerobatics the Frenchman Euclids name is foremost, maneuvers were flown for artistic reasons or to draw gasps from onlookers. In due course some of these maneuvers were found to allow aircraft to gain tactical advantage during combat or dogfights between fighter aircraft. Aerobatic aircraft fall into two categories—specialist aerobatic, and aerobatic capable, specialist designs such as the Pitts Special, the Extra 200 and 300, and the Sukhoi Su-26M and Sukhoi Su-29 aim for ultimate aerobatic performance. This comes at the expense of general use such as touring. Flight formation aerobatics are flown by teams of up to sixteen aircraft, some are state funded to reflect pride in the armed forces while others are commercially sponsored. Coloured smoke trails may be emitted to emphasise the patterns flown and/or the colours of a national flag, usually each team will use aircraft similar to one another finished in a special and dramatic colour scheme, thus emphasising their entertainment function. Teams often fly V-formations — they will not fly directly behind another aircraft because of danger from wake vortices or engine exhaust, aircraft will always fly slightly below the aircraft in front, if they have to follow in line. Aerobatic maneuvers flown in an aircraft are limited in scope as they cannot take advantage of the gyroscopic forces that a propeller driven aircraft can exploit. Jet-powered aircraft also tend to fly faster, which increases the size of the figures. Jet aerobatic teams often fly in formations, which restricts the maneuvers that can be safely flown
18.
Gimbal lock
–
The word lock is misleading, no gimbal is restrained. All three gimbals can still rotate freely about their axes of suspension. Nevertheless, because of the orientation of two of the gimbals axes there is no gimbal available to accommodate rotation along one axis. A gimbal is a ring that is suspended so it can rotate about an axis, gimbals are typically nested one within another to accommodate rotation about multiple axes. They appear in gyroscopes and in inertial measurement units to allow the inner gimbals orientation to remain fixed while the outer gimbal suspension assumes any orientation, in compasses and flywheel energy storage mechanisms they allow objects to remain upright. They are used to orient thrusters on rockets, some coordinate systems in mathematics behave as if there were real gimbals used to measure the angles, notably Euler angles. For cases of three or fewer nested gimbals, gimbal lock inevitably occurs at point in the system due to properties of covering spaces. While only two specific orientations produce exact gimbal lock, practical mechanical gimbals encounter difficulties near those orientations, when a set of gimbals is close to the locked configuration, small rotations of the gimbal platform require large motions of the surrounding gimbals. Although the ratio is only at the point of gimbal lock. Gimbal lock can occur in systems with two degrees of freedom such as a theodolite with rotations about an azimuth and elevation in two dimensions. These systems can gimbal lock at zenith and nadir, because at those points azimuth is not well-defined, consider tracking a helicopter flying towards the theodolite from the horizon. The theodolite is a telescope mounted on a tripod so that it can move in azimuth, the helicopter flies towards the theodolite and is tracked by the telescope in elevation and azimuth. The helicopter flies immediately above the tripod when it changes direction, the telescope cannot track this maneuver without a discontinuous jump in one or both of the gimbal orientations. There is no continuous motion that allows it to follow the target, so there is an infinity of directions around zenith for which the telescope cannot continuously track all movements of a target. Mathematically, this corresponds to the fact that spherical coordinates do not define a coordinate chart on the sphere at zenith, alternatively, the corresponding map T2→S2 from the torus T2 to the sphere S2 is not a covering map at these points. Consider a case of a level sensing platform on an aircraft flying due north with its three gimbal axes mutually perpendicular. If the aircraft pitches up 90 degrees, the aircraft and platforms yaw axis gimbal becomes parallel to the roll axis gimbal, and changes about yaw can no longer be compensated for. This problem may be overcome by use of a fourth gimbal, another solution is to rotate one or more of the gimbals to an arbitrary position when gimbal lock is detected and thus reset the device
19.
Glass cockpit
–
A glass cockpit is an aircraft cockpit that features electronic flight instrument displays, typically large LCD screens, rather than the traditional style of analog dials and gauges. This simplifies aircraft operation and navigation and allows pilots to focus only on the most pertinent information and they are also popular with airline companies as they usually eliminate the need for a flight engineer, saving costs. In recent years the technology has become available in small aircraft. As aircraft displays have modernized, the sensors that feed them have modernized as well, traditional gyroscopic flight instruments have been replaced by electronic attitude and heading reference systems and air data computers, improving reliability and reducing cost and maintenance. GPS receivers are usually integrated into glass cockpits, glass cockpits originated in military aircraft in the late 1960s and early 1970s, an early example is the Mark II avionics of the F-111D, which featured a multi-function display. Prior to the 1970s, air operations were not considered sufficiently demanding to require advanced equipment like electronic flight displays. Also, computer technology was not at a level where sufficiently light, the increasing complexity of transport aircraft, the advent of digital systems and the growing air traffic congestion around airports began to change that. The success of the NASA-led glass cockpit work is reflected in the acceptance of electronic flight displays beginning with the introduction of the MD-80 in 1979. Airlines and their passengers alike have benefited, the safety and efficiency of flights have been increased with improved pilot understanding of the aircrafts situation relative to its environment. By the end of the 1990s, liquid-crystal display panels were increasingly favored among aircraft manufacturers because of their efficiency, earlier LCD panels suffered from poor legibility at some viewing angles and poor response times, making them unsuitable for aviation. The glass cockpit has become standard equipment in airliners, business jets and it was fitted into NASAs Space Shuttle orbiters Atlantis, Columbia, Discovery, and Endeavour, and the current Russian Soyuz TMA model spacecraft that was launched in 2002. By the end of the century glass cockpits began appearing in general aviation aircraft as well, in 2003, Cirrus Designs SR20 and SR22 became the first light aircraft equipped with glass cockpits, which they made standard on all Cirrus aircraft. The Lockheed Martin F-35 Lightning II features a panoramic cockpit display touchscreen that replaces most of the switches and toggles found in an aircraft cockpit and they look and behave very similarly to other computers, with windows and data that can be manipulated with point-and-click devices. They also add terrain, approach charts, weather, vertical displays, the improved concepts enable aircraft makers to customize cockpits to a greater degree than previously. All of the manufacturers involved have chosen to do so in one way or another—such as using a trackball, many of the modifications offered by the aircraft manufacturers improve situational awareness and customize the human-machine interface to increase safety. Modern glass cockpits might include Synthetic Vision or Enhanced Vision systems, Enhanced Vision systems add real-time information from external sensors, such as an infrared camera. All new airliners such as the Airbus A380, Boeing 787 and private jets such as Bombardier Global Express, many modern general aviation aircraft are available with glass cockpits. Systems such as the Garmin G1000 are now available on many new GA aircraft, many small aircraft can also be modified post-production to replace analogue instruments
20.
Primary flight display
–
A primary flight display or PFD is a modern aircraft instrument dedicated to flight information. Much like multi-function displays, primary flight displays are built around an Liquid-crystal display or CRT display device, representations of older six pack or steam gauge instruments are combined on one compact display, simplifying pilot workflow and streamlining cockpit layouts. Cirrus Aircraft was the first general aviation manufacturer to add a PFD to their already existing MFD, mechanical gauges have not been completely eliminated from the cockpit with the onset of the PFD, they are retained for backup purposes in the event of total electrical failure. An air data computer analyzes the information and displays it to the pilot in a readable format, a number of manufacturers produce PFDs, varying slightly in appearance and functionality, but the information is displayed to the pilot in a similar fashion. However, the majority of PFDs follow a similar layout convention. Unlike a traditional attitude indicator, however, the gyroscope is not contained within the panel itself. The attitude indicator is designed to very much like traditional mechanical AIs. Other information that may or may not appear on or about the attitude indicator can include the angle, a runway diagram, ILS localizer and glide-path “needles”. The PFD may also show an indicator of the future path, as calculated by onboard computers, making it easier for pilots to anticipate aircraft movements. To the left and right of the indicator are usually the airspeed and altitude indicators. The airspeed indicator displays the speed of the aircraft in knots and these measurements are conducted through the aircrafts pitot system, which tracks air pressure measurements. As in the PFDs attitude indicator, these systems are merely displayed data from the mechanical systems. Both of these indicators are presented as vertical “tapes”, which scroll up and down as altitude. The vertical speed indicator, usually next to the indicator, indicates to the pilot how fast the aircraft is ascending or descending. This is usually represented with numbers in thousands of feet per minute, for example, a measurement of +2 indicates an ascent of 2000 feet per minute, while a measurement of -1.5 indicates a descent of 1500 feet per minute. There may also be a simulated needle showing the general direction, at the bottom of the PFD is the heading display, which shows the pilot the magnetic heading of the aircraft. This functions much like a magnetic heading indicator, turning as required. Often this part of the shows not only the current heading, but also the current track, current heading setting on the autopilot
21.
Ring laser gyroscope
–
A ring laser gyroscope consists of a ring laser having two independent counter-propagating resonant modes over the same path, the difference in the frequencies is used to detect rotation. It operates on the principle of the Sagnac effect which shifts the nulls of the standing wave pattern in response to angular rotation. Interference between the beams, observed externally, results in motion of the standing wave pattern. The first experimental ring laser gyroscope was demonstrated in the US by Macek, various organizations worldwide subsequently developed ring-laser technology further. Ring laser gyroscopes can be used as the elements in an inertial reference system. The advantage of using an RLG is that there are no moving parts and this means there is no friction, which in turn means there will be no inherent drift terms. Additionally, the unit is compact, lightweight and virtually indestructible. Unlike a mechanical gyroscope, the device does not resist changes to its orientation and these hybrid INS/GPS units have replaced their mechanical counterparts in most applications. Where ultra accuracy is needed however, spin gyro based INSs are still in use today, a certain rate of rotation induces a small difference between the time it takes light to traverse the ring in the two directions according to the Sagnac effect. Therefore, the net shift of that interference pattern follows the rotation of the unit in the plane of the ring, rLGs, while more accurate than mechanical gyroscopes, suffer from an effect known as lock-in at very slow rotation rates. When the ring laser is hardly rotating, the frequencies of the counter-propagating laser modes become almost identical, forced dithering can largely overcome this problem. The ring laser cavity is rotated clockwise and anti-clockwise about its axis using a spring driven at its resonance frequency. This ensures that the velocity of the system is usually far from the lock-in threshold. Typical rates are 400 Hz, with a peak velocity of 1 arc-second per second. If a pure frequency oscillation is maintained, these small lock-in intervals can accumulate and this was remedied by introducing noise to the 400 Hz vibration. A related device is the fibre optic gyroscope which also operates on the basis of the Sagnac effect and this is therefore less sensitive than the RLG in which the externally observed phase shift is proportional to the accumulated rotation itself, not its derivative. However the sensitivity of the gyro is enhanced by having a long optical fiber coiled for compactness. Inertial Navigation – Forty Years of Evolution
22.
Accelerometer
–
An accelerometer is a device that measures proper acceleration, proper acceleration is not the same as coordinate acceleration. For example, an accelerometer at rest on the surface of the Earth will measure an acceleration due to Earths gravity, by contrast, accelerometers in free fall will measure zero. Accelerometers have multiple applications in industry and science, highly sensitive accelerometers are components of inertial navigation systems for aircraft and missiles. Accelerometers are used to detect and monitor vibration in rotating machinery, accelerometers are used in tablet computers and digital cameras so that images on screens are always displayed upright. Accelerometers are used in drones for flight stabilisation, coordinated accelerometers can be used to measure differences in proper acceleration, particularly gravity, over their separation in space, i. e. gradient of the gravitational field. This gravity gradiometry is useful because absolute gravity is a weak effect, micromachined accelerometers are increasingly present in portable electronic devices and video game controllers, to detect the position of the device or provide for game input. An accelerometer measures proper acceleration, which is the acceleration it experiences relative to freefall and is the acceleration felt by people and objects. Put another way, at any point in spacetime the equivalence principle guarantees the existence of an inertial frame. Such accelerations are popularly denoted g-force, i. e. in comparison to standard gravity, an accelerometer at rest relative to the Earths surface will indicate approximately 1 g upwards, because any point on the Earths surface is accelerating upwards relative to the local inertial frame. The reason for the appearance of an offset is Einsteins equivalence principle. For similar reasons, an accelerometer will read zero during any type of free fall and this includes use in a coasting spaceship in deep space far from any mass, a spaceship orbiting the Earth, an airplane in a parabolic zero-g arc, or any free-fall in vacuum. Another example is free-fall at a high altitude that atmospheric effects can be neglected. However this does not include a fall in air resistance produces drag forces that reduce the acceleration. At terminal velocity the accelerometer will indicate 1 g acceleration upwards, Acceleration is quantified in the SI unit metres per second per second, in the cgs unit gal, or popularly in terms of standard gravity. For the practical purpose of finding the acceleration of objects with respect to the Earth, such as for use in a navigation system. This can be obtained either by calibrating the device at rest, conceptually, an accelerometer behaves as a damped mass on a spring. When the accelerometer experiences an acceleration, the mass is displaced to the point that the spring is able to accelerate the mass at the rate as the casing. The displacement is measured to give the acceleration
23.
Magnetometer
–
A compass is a simple example of a magnetometer, one that measures the direction of an ambient magnetic field. Magnetometers are widely used for measuring the Earths magnetic field and in geophysical surveys to detect anomalies of various types. They are also used in the military to detect submarines, consequently, some countries, such as the United States, Canada and Australia, classify the more sensitive magnetometers as military technology, and control their distribution. Magnetic fields are vector quantities characterized by strength and direction. The strength of a field is measured in units of tesla in the SI units. 10,000 gauss are equal to one tesla, measurements of the Earths magnetic field are often quoted in units of nanotesla, also called a gamma. Gaussmeters and teslameters are magnetometers that measure in units of gauss or tesla, in some contexts, magnetometer is the term used for an instrument that measures fields of less than 1 millitesla and gaussmeter is used for those measuring greater than 1 mT. There are two types of magnetometer measurement. Vector magnetometers measure the components of a magnetic field. Total field magnetometers or scalar magnetometers measure the magnitude of the magnetic field. Magnetometers used to study the Earths magnetic field may express the components of the field in terms of declination. Absolute magnetometers measure the magnitude or vector magnetic field, using an internal calibration or known physical constants of the magnetic sensor. Relative magnetometers measure magnitude or vector magnetic field relative to a fixed but uncalibrated baseline, also called variometers, relative magnetometers are used to measure variations in magnetic field. Magnetometers may also be classified by their situation or intended use, stationary magnetometers are installed to a fixed position and measurements are taken while the magnetometer is stationary. Portable or mobile magnetometers are meant to be used while in motion, laboratory magnetometers are used to measure the magnetic field of materials placed within them and are typically stationary. The performance and capabilities of magnetometers are described through their technical specifications, major specifications include Sample rate is the amount of readings given per second. The inverse is the time in seconds per reading. Sample rate is important in mobile magnetometers, the sample rate, bandwidth or bandpass characterizes how well a magnetometer tracks rapid changes in magnetic field
24.
Microelectromechanical systems
–
Microelectromechanical systems is the technology of microscopic devices, particularly those with moving parts. It merges at the nano-scale into nanoelectromechanical systems and nanotechnology, MEMS are also referred to as micromachines in Japan, or micro systems technology in Europe. They usually consist of a unit that processes data and several components that interact with the surroundings such as microsensors. MEMS technology is distinguished from molecular nanotechnology or molecular electronics in that the latter must also consider surface chemistry, the potential of very small machines was appreciated before the technology existed that could make them. MEMS became practical once they could be fabricated using modified semiconductor device fabrication technologies and these include molding and plating, wet etching and dry etching, electro discharge machining, and other technologies capable of manufacturing small devices. An early example of a MEMS device is the resonistor – an electromechanical monolithic resonator, silicon is the material used to create most integrated circuits used in consumer electronics in the modern industry. The economies of scale, ready availability of inexpensive high-quality materials, silicon also has significant advantages engendered through its material properties. In single crystal form, silicon is an almost perfect Hookean material, meaning that when it is flexed there is virtually no hysteresis and hence almost no energy dissipation. Even though the industry provides an economy of scale for the silicon industry, crystalline silicon is still a complex. Polymers on the hand can be produced in huge volumes. Metals can also be used to create MEMS elements, while metals do not have some of the advantages displayed by silicon in terms of mechanical properties, when used within their limitations, metals can exhibit very high degrees of reliability. Metals can be deposited by electroplating, evaporation, and sputtering processes, commonly used metals include gold, nickel, aluminium, copper, chromium, titanium, tungsten, platinum, and silver. The nitrides of silicon, aluminium and titanium as well as silicon carbide, alN crystallizes in the wurtzite structure and thus shows pyroelectric and piezoelectric properties enabling sensors, for instance, with sensitivity to normal and shear forces. TiN, on the hand, exhibits a high electrical conductivity. Moreover, the resistance of TiN against biocorrosion qualifies the material for applications in biogenic environments. One of the building blocks in MEMS processing is the ability to deposit thin films of material with a thickness anywhere between a few nanometres to about 100 micrometres. There are two types of processes, as follows. Physical vapor deposition consists of a process in which a material is removed from a target, chemical deposition techniques include chemical vapor deposition, in which a stream of source gas reacts on the substrate to grow the material desired
25.
Federal Aviation Administration
–
The Federal Aviation Administration of the United States is a national authority with powers to regulate all aspects of civil aviation. The FAAs roles include, Regulating U. S, each LOB has a specific role within the FAA. Airports — plans and develops projects involving airports, overseeing their construction, Air Traffic Organization — primary duty is to safely and efficiently move air traffic within the National Airspace System. ATO employees manage air traffic facilities including Airport Traffic Control Towers, Aviation Safety — Responsible for aeronautical certification of personnel and aircraft, including pilots, airlines, and mechanics. Commercial Space Transportation — ensures protection of U. S. assets during the launch or reentry of commercial space vehicles, the FAA is headquartered in Washington, D. C. as well as the William J. The newly created Aeronautics Branch, operating under the Department of Commerce assumed primary responsibility for aviation oversight, in fulfilling its civil aviation responsibilities, the Department of Commerce initially concentrated on such functions as safety regulations and the certification of pilots and aircraft. It took over the building and operation of the system of lighted airways. The Aeronautics Branch was renamed the Bureau of Air Commerce in 1934 to reflect its status within the Department. As commercial flying increased, the Bureau encouraged a group of airlines to establish the first three centers for providing air traffic control along the airways, in 1936, the Bureau itself took over the centers and began to expand the ATC system. The pioneer air traffic controllers used maps, blackboards, and mental calculations to ensure the separation of aircraft traveling along designated routes between cities. In 1938, the Civil Aeronautics Act transferred the civil aviation responsibilities from the Commerce Department to a new independent agency. The legislation also expanded the role by giving them the authority. President Franklin D. Roosevelt split the authority into two agencies in 1940, the Civil Aeronautics Administration and the Civil Aeronautics Board, CAA was responsible for ATC, airman and aircraft certification, safety enforcement, and airway development. CAB was entrusted with safety regulation, accident investigation, and economic regulation of the airlines, the CAA was part of the Department of Commerce. The CAB was an independent federal agency, on the eve of Americas entry into World War II, CAA began to extend its ATC responsibilities to takeoff and landing operations at airports. This expanded role eventually became permanent after the war, the application of radar to ATC helped controllers in their drive to keep abreast of the postwar boom in commercial air transportation. The approaching era of jet travel, and a series of midair collisions and this legislation gave the CAAs functions to a new independent body, the Federal Aviation Agency. The act transferred air safety regulation from the CAB to the new FAA, the FAAs first administrator, Elwood R. Quesada, was a former Air Force general and adviser to President Eisenhower
26.
General aviation
–
General aviation is the term for all civil aviation operations other than scheduled air services and non-scheduled air transport operations for remuneration or hire. General aviation flights range from gliders and powered parachutes to corporate business jet flights, the majority of the worlds air traffic falls into this category, and most of the worlds airports serve general aviation exclusively. General aviation covers a range of activities, both commercial and non-commercial, including flying clubs, flight training, agricultural aviation, light aircraft manufacturing. Of the 21,000 civil aircraft registered in the UK,96 per cent are engaged in GA operations, there are 28,000 Private Pilot Licence holders, and 10,000 certified glider pilots. Some of the 19,000 pilots who hold professional licences are also engaged in GA activities, GA operates from more than 1,800 airports and landing sites or aerodromes, ranging in size from large regional airports to farm strips. GA is regulated by the Civil Aviation Authority, although regulatory powers are being transferred to the European Aviation Safety Agency. The main focus is on standards of airworthiness and pilot licensing, general aviation is particularly popular in North America, with over 6,300 airports available for public use by pilots of general aviation aircraft. In comparison, scheduled flights operate from around 560 airports in the U. S, aircraft Owners and Pilots Association, general aviation provides more than one percent of the United States GDP, accounting for 1.3 million jobs in professional services and manufacturing. Most countries have authorities that oversee all civil aviation, including general aviation, Aviation accident rate statistics are necessarily estimates. In Canada, recreational flying accounted for 0.7 fatal accidents for every 1000 aircraft, while air taxi accounted for 1.1 fatal accidents for every 100,000 hours
27.
Korean Air Cargo Flight 8509
–
The aircraft crashed into Hatfield Forest near the village of Great Hallingbury, close to but clear of some houses. All four crew on board were killed, the aircraft involved was a Boeing 747-200F freighter registered HL7451. Built on 4 April 1980, the aircraft had completed 15,451 flights with a flight time of 83,011 hours before its fatal flight on 22 December 1999. The first officers ADI and a backup ADI were correct, a comparator alarm called attention to the discrepancy, the ADIs input selector was switched to the other INU and the correct indications returned. At Stansted, the engineers who attempted to repair the ADI did not have the correct Fault Isolation Manual available, one of them identified and repaired a damaged connecting plug on the ADI. When the ADI responded correctly to its Test button, they believed the fault had been corrected, although this button only tested the ADI, the ADIs input selector was left in the normal position. The flight crew consisted of 57-year-old Captain Park Duk-kyu, 33-year-old First Officer Yoon Ki-sik, 38-year-old Flight Engineer Park Hoon-kyu, the first officer, in contrast, was relatively inexperienced with just 195 hours of flying experience on the 747 and a total of 1,406 flight hours. The flight engineer, like the captain, had a lot of experience flying 747s –4,511 out of his 8,301 total flight hours were accrued in them and it was dark when the plane took off from London Stansted Airport, with the captain flying. When the captain tried to bank the plane to turn left, his ADI showed it not banking, the first officer, whose instrument would have shown the true angle of bank, said nothing, although the flight engineer called out bank. The captain made no response and continued banking farther and farther left, korean Air has not had a single fatal crash since this accident in 1999. The AAIB interim report – BBC – Friday 24 December 1999 AAIB Bulletin S2/2000 SPECIAL, – The Chosun Ilbo KAL Team Joins Flight KE-8509 Investigation
28.
International Standard Book Number
–
The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
29.
Flightglobal
–
Flightglobal is an online news and information website related to the aviation and aerospace industries. It also provides a community area for numerous distinct communities within the aviation, flightglobal is a resource for aviation history with a picture library of over 1 million images going back to the foundation of Flight in 1909. Thousands of images and back copies of Flight are searchable online, flightglobal won the prize for of Business Website of the Year at the Association of Online Publishers Digital Publishing Awards 2010. According to the contest judges, The site uses the spectrum of digital tools, with a special focus on engagement
30.
Pitot-static system
–
A pitot-static system is a system of pressure-sensitive instruments that is most often used in aviation to determine an aircrafts airspeed, Mach number, altitude, and altitude trend. A pitot-static system generally consists of a tube, a static port. Other instruments that might be connected are air data computers, flight recorders, altitude encoders, cabin pressurization controllers. Errors in pitot-static system readings can be dangerous as the information obtained from the pitot static system. Several commercial airline disasters have been traced to a failure of the pitot-static system, the pitot-static system of instruments uses the principle of air pressure gradient. It works by measuring pressures or pressure differences and using these values to assess the speed and these pressures can be measured either from the static port or the pitot tube. The static pressure is used in all measurements, while the pressure is used only to determine airspeed. The pitot pressure is obtained from the pitot tube, the pitot pressure is a measure of ram air pressure, which, under ideal conditions, is equal to stagnation pressure, also called total pressure. The pitot tube is most often located on the wing or front section of an aircraft, facing forward, by situating the pitot tube in such a location, the ram air pressure is more accurately measured since it will be less distorted by the aircrafts structure. When airspeed increases, the ram air pressure is increased, which can be translated by the airspeed indicator, the static pressure is obtained through a static port. The static port is most often a hole on the fuselage of an aircraft. Some aircraft may have a static port, while others may have more than one. In situations where an aircraft has more than one static port, with this positioning, an average pressure can be taken, which allows for more accurate readings in specific flight situations. An alternative static port may be located inside the cabin of the aircraft as a backup for when the static port are blocked. A pitot-static tube effectively integrates the static ports into the pitot probe and it incorporates a second coaxial tube with pressure sampling holes on the sides of the probe, outside the direct airflow, to measure the static pressure. When the aircraft climbs, static pressure will decrease, some pitot-static systems incorporate single probes that contain multiple pressure-transmitting ports that allow for the sensing of air pressure, angle of attack, and angle of sideslip data. Depending on the design, such air data probes may be referred to as 5-hole or 7-hole air data probes, differential pressure sensing techniques can be used to produce angle of attack and angle of sideslip indications. The pitot-static system obtains pressures for interpretation by the pitot-static instruments, while the explanations below explain traditional, mechanical instruments, many modern aircraft use an air data computer to calculate airspeed, rate of climb, altitude and Mach number
31.
Machmeter
–
A Machmeter is an aircraft pitot-static system flight instrument that shows the ratio of the true airspeed to the speed of sound, a dimensionless quantity called Mach number. This is shown on a Machmeter as a decimal fraction, an aircraft flying at the speed of sound is flying at a Mach number of one, expressed as Mach 1. The indicated airspeed for this changes with ambient temperature, which in turn changes with altitude. Therefore, indicated airspeed is not entirely adequate to warn the pilot of the impending problems, Mach number is more useful, and most high-speed aircraft are limited to a maximum operating Mach number, also known as MMO. For example, if the MMO is Mach 0.83, then at 30,000 feet where the speed of sound under standard conditions is 590 knots, the true airspeed at MMO is 489 knots. The speed of sound increases with air temperature, so at Mach 0.83 at 10,000 feet where the air is warmer than at 30,000 feet. Modern electronic Machmeters use information from an air data system which makes calculations using inputs from a pitot-static system. Some older mechanical Machmeters use an altitude aneroid and a capsule which together convert pitot-static pressure into Mach number. The Machmeter suffers from instrument and position errors, note that the inputs required are total pressure and static pressure. Air temperature input is not required, airspeed indicator Mach number Pitot-static system Instrument Flying Handbook. U. S. Government Printing Office, Washington D. C, U. S. Government Printing Office, Washington D. C. This article incorporates public domain material from the United States Government document Instrument Flying Handbook
32.
Horizontal situation indicator
–
The horizontal situation indicator is an aircraft flight instrument normally mounted below the artificial horizon in place of a conventional heading indicator. It combines a heading indicator with a VHF omnidirectional range-instrument landing system display and this reduces pilot workload by lessening the number of elements in the pilots instrument scan to the six basic flight instruments. Among other advantages, the HSI offers freedom from the confusion of reverse sensing on an instrument landing system localizer back course approach. As long as the needle is set to the front course. On the HSI, the aircraft is represented by a figure in the centre of the instrument – the VOR-ILS display is shown in relation to this figure. On a conventional VOR indicator, left–right and to–from must be interpreted in the context of the selected course, when an HSI is tuned to a VOR station, left and right always mean left and right and TO/FROM is indicated by a simple triangular arrowhead pointing to the VOR. If the arrowhead points to the side as the course selector arrow, it means TO. The HSI illustrated here is a designed for smaller airplanes and is the size of a standard 3 ¼-inch instrument. Airline and jet aircraft HSIs are larger and may include more display elements, the most modern HSI displays are electronic and often integrated with electronic flight instrument systems into so-called glass cockpit systems. Acronyms and abbreviations in avionics Flight instruments
33.
Course deviation indicator
–
A course deviation indicator is an avionics instrument used in aircraft navigation to determine an aircrafts lateral position in relation to a course. If the location of the aircraft is to the left of course, the needle deflects to the right, the indicator shows the direction to steer to correct for course deviations. Correction is made until the vertical needle centers, meaning the aircraft has intercepted the given courseline, the pilot then steers to stay on that line. Only the receivers current position determines the reading, the heading, orientation. The courseline is selected by turning an omni bearing selector or OBS knob usually located in the left of the indicator. It then shows the number of degrees deviation between the current position and the radial line emanating from the signal source at the given bearing. This can be used to find and follow the desired radial, deflection is 10° deviation at full scale, with each dot on the CDI representing 2°. When used with a GPS, or other RNAV equipment, it shows actual distance left or right of the programmed courseline, sensitivity is usually programmable or automatically switched, but 5 nautical miles deviation at full scale is typical for en route operations. Approach and terminal operations have a higher sensitivity up to frequently.3 nautical miles at full scale, in this mode, the OBS knob may or may not have an effect, depending on configuration. When used for instrument approaches using a LDA or ILS the OBS knob has no function because the courseline is usually the runway heading, and is determined by the ground transmitter. A CDI might incorporate a horizontal needle to provide vertical guidance when used with a precision ILS approach where the glideslope is broadcast by another transmitter located on the ground. A CDI is not used with a direction finder, which receives information from a normal AM radio station or an NDB. The CDI was designed to interpret a signal from a VOR, LDA and these receivers output a signal composed of two AC voltages. Most older units and some newer ones integrate a converter with the CDI, CDI units with an internal converter are not compatible with GPS units. More modern units are driven by a converter that is standalone or integrated with the radio, the resolver position is sent to the converter which outputs the control signal to drive the CDI. Acronyms and abbreviations in avionics Horizontal situation indicator Flash VOR type Course Deviation Indicator Simulator
34.
Inertial navigation system
–
It is used on vehicles such as ships, aircraft, submarines, guided missiles, and spacecraft. Other terms used to refer to inertial navigation systems or closely related devices include inertial guidance system, inertial instrument, inertial measurement units, older INS systems generally used an inertial platform as their mounting point to the vehicle, and the terms are sometimes considered synonymous. Inertial measurement units typically contain three orthogonal rate-gyroscopes and three accelerometers, measuring angular velocity and linear acceleration respectively. By processing signals from these devices it is possible to track the position and orientation of a device, Inertial navigation is used in a wide range of applications including the navigation of aircraft, tactical and strategic missiles, spacecraft, submarines and ships. Recent advances in the construction of systems have made it possible to manufacture small. These advances have widened the range of applications to include areas such as human. An inertial navigation system includes at least a computer and a platform or module containing accelerometers, gyroscopes, the advantage of an INS is that it requires no external references in order to determine its position, orientation, or velocity once it has been initialized. An INS can detect a change in its position, a change in its velocity. It does this by measuring the acceleration and angular velocity applied to the system. Since it requires no external reference, it is immune to jamming, Inertial navigation systems are used in many different moving objects, including vehicles—such as aircraft, submarines, spacecraft—and guided missiles. However, their cost and complexity place constraints on the environments in which they are practical for use, Gyroscopes measure the angular velocity of the sensor frame with respect to the inertial reference frame. By using the orientation of the system in the inertial reference frame as the initial condition and integrating the angular velocity. This can be thought of as the ability of a passenger in a car to feel the car turn left and right or tilt up. Based on this alone, the passenger knows what direction the car is facing but not how fast or slow it is moving. Accelerometers measure the acceleration of the moving vehicle in the sensor or body frame. Performing integration on the inertial accelerations using the correct kinematic equations yields the inertial velocities of the system, therefore, the position must be periodically corrected by input from some other type of navigation system. The inaccuracy of a good-quality navigational system is less than 0.6 nautical miles per hour in position and on the order of tenths of a degree per hour in orientation. Accordingly, inertial navigation is used to supplement other navigation systems
35.
Compass
–
A compass is an instrument used for navigation and orientation that shows direction relative to the geographic cardinal directions, or points. Usually, a called a compass rose shows the directions north, south, east. When the compass is used, the rose can be aligned with the geographic directions, so, for example. Frequently, in addition to the rose or sometimes instead of it, North corresponds to zero degrees, and the angles increase clockwise, so east is 90 degrees, south is 180, and west is 270. These numbers allow the compass to show azimuths or bearings, which are stated in this notation. The magnetic compass was first invented as a device for divination as early as the Chinese Han Dynasty, the first usage of a compass recorded in Western Europe and the Islamic world occurred around the early 13th century. The magnetic compass is the most familiar compass type and it functions as a pointer to magnetic north, the local magnetic meridian, because the magnetized needle at its heart aligns itself with the horizontal component of the Earths magnetic field. The needle is mounted on a pivot point, in better compasses a jewel bearing. When the compass is level, the needle turns until, after a few seconds to allow oscillations to die out. In navigation, directions on maps are usually expressed with reference to geographical or true north, the direction toward the Geographical North Pole, the rotation axis of the Earth. Depending on where the compass is located on the surface of the Earth the angle between north and magnetic north, called magnetic declination can vary widely with geographic location. The local magnetic declination is given on most maps, to allow the map to be oriented with a parallel to true north. The location of the Earths magnetic poles slowly change with time, the effect of this means a map with the latest declination information should be used. Some magnetic compasses include means to compensate for the magnetic declination. The first compasses in ancient Han dynasty China were made of lodestone, the compass was later used for navigation during the Song Dynasty of the 11th century. Later compasses were made of iron needles, magnetized by striking them with a lodestone, dry compasses began to appear around 1300 in Medieval Europe and the Islamic world. This was supplanted in the early 20th century by the magnetic compass. Modern compasses usually use a needle or dial inside a capsule completely filled with a liquid
36.
Satellite navigation
–
A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning. It allows small electronic receivers to determine their location to high precision using time signals transmitted along a line of sight by radio from satellites, the system can be used for providing position, navigation or for tracking the position of something fitted with a receiver. The signals also allow the receiver to calculate the current local time to high precision. Satnav systems operate independently of any telephonic or internet reception, though these technologies can enhance the usefulness of the information generated. A satellite navigation system with global coverage may be termed a global satellite system. As of December 2016 only the United States NAVSTAR Global Positioning System, the Russian GLONASS, the European Unions Galileo GNSS is scheduled to be fully operational by 2020. China is in the process of expanding its regional BeiDou Navigation Satellite System into the global BeiDou-2 GNSS by 2020, India currently has satellite-based augmentation system, GPS Aided GEO Augmented Navigation, which enhances the accuracy of NAVSTAR GPS and GLONASS positions. India has already launched the IRNSS, with an operational name NAVIC and it is expected to be fully operational by June 2016. France and Japan are in the process of developing regional navigation systems as well, Global coverage for each system is generally achieved by a satellite constellation of 18–30 medium Earth orbit satellites spread between several orbital planes. The actual systems vary, but use orbital inclinations of >50°, Ground based augmentation is provided by systems like the Local Area Augmentation System. GNSS-2 is the generation of systems that independently provides a full civilian satellite navigation system. These systems will provide the accuracy and integrity monitoring necessary for civil navigation and this system consists of L1 and L2 frequencies for civil use and L5 for system integrity. Development is also in progress to provide GPS with civil use L2 and L5 frequencies, making it a GNSS-2 system. ¹ Core Satellite navigation systems, currently GPS, GLONASS, Galileo, Global Satellite Based Augmentation Systems such as Omnistar and StarFire. Regional SBAS including WAAS, EGNOS, MSAS and GAGAN, Regional Satellite Navigation Systems such as Chinas Beidou, Indias NAVIC, and Japans proposed QZSS. Continental scale Ground Based Augmentation Systems for example the Australian GRAS, Regional scale GBAS such as CORS networks. Local GBAS typified by a single GPS reference station operating Real Time Kinematic corrections, early predecessors were the ground based DECCA, LORAN, GEE and Omega radio navigation systems, which used terrestrial longwave radio transmitters instead of satellites. These positioning systems broadcast a radio pulse from a known master location, the delay between the reception of the master signal and the slave signals allowed the receiver to deduce the distance to each of the slaves, providing a fix. The first satellite system was Transit, a system deployed by the US military in the 1960s
37.
Electronic flight instrument system
–
An electronic flight instrument system is a flight deck instrument display system that displays flight data electronically rather than electromechanically. An EFIS normally consists of a flight display, multi-function display. Early EFIS models used cathode ray tube displays, but liquid crystal displays are now more common, the complex electromechanical attitude director indicator and horizontal situation indicator were the first candidates for replacement by EFIS. Now, however, few flight deck instruments cannot be replaced by an electronic display, a light aircraft might be equipped with one display unit that displays flight and navigation data. A large, commercial aircraft is likely to have six or more display units, typical EFIS displays and controls can be seen at this B737 technical information web site. The equivalent electromechanical instruments are shown here. EFIS installation follows the sequence, Displays Controls Data processors A basic EFIS might have all these facilities in the one unit. On the flight deck, the units are the most obvious parts of an EFIS system. The display unit that replaces the ADI is called the flight display. If a separate display replaces the HSI, it is called the navigation display, the PFD displays all information critical to flight, including calibrated airspeed, altitude, heading, attitude, vertical speed and yaw. The names Electronic Attitude Director Indicator and Electronic Horizontal Situation Indicator are used by some manufacturers, however, a simulated ADI is only the centerpiece of the PFD. Additional information is both superimposed on and arranged around this graphic, multi-function displays can render a separate navigation display unnecessary. Another option is to use one screen to show both the PFD and navigation display. The PFD and navigation display are often physically identical, the information displayed is determined by the system interfaces where the display units are fitted. Thus, spares holding is simplified, the one unit can be fitted in any position. LCD units generate less heat than CRTs, an advantage in an instrument panel. They are also lighter, and occupy a lower volume, the MFD displays navigational and weather information from multiple systems. MFDs are most frequently designed as chart-centric, where the aircrew can overlay different information over a map or chart, mFDs can also display information about aircraft systems, such as fuel and electrical systems
38.
V speeds
–
In aviation, V-speeds are standard terms used to define airspeeds important or useful to the operation of all aircraft. Using them is considered a best practice to maximize aviation safety, the actual speeds represented by these designators are specific to a particular model of aircraft. They are expressed by the indicated airspeed, so that pilots may use them directly, without having to apply correction factors. In general aviation aircraft, the most commonly used and most safety-critical airspeeds are displayed as color-coded arcs, the lower ends of the green arc and the white arc are the stalling speed with wing flaps retracted, and stalling speed with wing flaps fully extended, respectively. These are the speeds for the aircraft at its maximum weight. The yellow range is the range in which the aircraft may be operated in air, and then only with caution to avoid abrupt control movement, and the red line is the Vne. Proper display of V speeds is a requirement for type-certificated aircraft in most countries. The most common V-speeds are often defined by a particular governments aviation regulations, in the United States, these are defined in title 14 of the United States Code of Federal Regulations, known as the Federal Aviation Regulations or FARs. In Canada, the body, Transport Canada, defines 26 commonly used V-speeds in their Aeronautical Information Manual. V-speed definitions in FAR23,25 and equivalent are for designing and certification of airplanes, the descriptions below are for use by pilots. These V-speeds are defined by regulations and they are typically defined with constraints such as weight, configuration, or phases of flight, some of these constraints have been omitted to simplify the description. Some of these V-speeds are specific to types of aircraft and are not defined by regulations. Whenever a limiting speed is expressed by a Mach number, it is expressed relative to the speed of sound, e. g. VMO, Maximum operating speed, MMO, V1 is the critical engine failure recognition speed or takeoff decision speed. It is the speed above which the takeoff will continue if a engine fails or another problem occurs. Aborting a takeoff after V1 is strongly discouraged because the aircraft will by definition not be able to stop before the end of the runway, Transport Canada defines it as, Critical engine failure recognition speed and adds, This definition is not restrictive. An operator may adopt any other definition outlined in the flight manual of TC type-approved aircraft as long as such definition does not compromise operational safety of the aircraft. Getting to grips with aircraft performance, flight Operations Support & Line Assistance
39.
Yaw string
–
The yaw string, also known as a slip string, is a simple device for indicating a slip or skid in an aircraft in flight. It performs the function as the slip-skid indicator ball, but is more sensitive. Technically, it measures sideslip angle, not yaw angle, and it is typically constructed from a short piece or tuft of yarn placed in the free air stream where it is visible to the pilot. In closed cockpit aircraft, it is taped to the aircraft canopy. It may also be mounted on the nose, either directly on the skin, or elevated on a mast. They are commonly used on gliders, but may also be found on jet aircraft, ultralight aircraft, light-sport aircraft, autogyros, airplanes and its usefulness on airplanes with a tractor configuration is limited because the propeller creates turbulence and the spiral slipstream displaces the string to one side. The yaw string is considered a primary flight reference instrument on gliders and it is valued for its high sensitivity, and the fact that it is presented in a head-up display. Even the most sophisticated modern racing sailplanes are fitted with yaw strings by their pilots, the yaw string dates from the earliest days of aviation, and actually was the first flight instrument. The Wright Brothers used a yaw string on their 1902 glider tied on their front mounted elevator, wilbur Wright is credited with its invention, having applied it concurrently with the movable rudder invented by his brother Orville in October 1902, although others may have used it before. Glenn Curtiss also used it on his early airplanes, yaw strings are also fitted to the Lockheed U-2 high-altitude surveillance aircraft. A flat spin, caused by excessive sideslip even in level flight, in a multiengine airplane with an inoperative engine, the centered ball is no longer the indicator of zero sideslip due to asymmetrical thrust. The yaw string is the only instrument that will directly tell the pilot the flight conditions for zero sideslip. Yaw strings are used on some helicopters. A variation of the yaw string is the string, used in gliders for a determination of the angle of attack. Glider Gliding Sideslip angle Slip Tell-tale Tuft Critical engine This article incorporates public domain material from the United States Government document Instrument Flying Handbook
40.
Fixed-wing aircraft
–
A fixed-wing aircraft is an aircraft, such as an aeroplane, which is capable of flight using wings that generate lift caused by the vehicles forward airspeed and the shape of the wings. Fixed-wing aircraft are distinct from rotary-wing aircraft, in which the form a rotor mounted on a spinning shaft. Glider fixed-wing aircraft, including free-flying gliders of various kinds and tethered kites, powered fixed-wing aircraft that gain forward thrust from an engine include powered paragliders, powered hang gliders and some ground effect vehicles. The wings of an aircraft are not necessarily rigid, kites, hang-gliders, variable-sweep wing aircraft. Most fixed-wing aircraft are flown by a pilot on board the aircraft, kites were used approximately 2,800 years ago in China, where materials ideal for kite building were readily available. Some authors hold that leaf kites were being flown much earlier in what is now Indonesia, by at least 549 AD paper kites were being flown, as it was recorded in that year a paper kite was used as a message for a rescue mission. Ancient and medieval Chinese sources list other uses of kites for measuring distances, testing the wind, lifting men, signaling, and communication for military operations. Stories of kites were brought to Europe by Marco Polo towards the end of the 13th century, although they were initially regarded as mere curiosities, by the 18th and 19th centuries kites were being used as vehicles for scientific research. This machine may have been suspended for its flight, some of the earliest recorded attempts with gliders were those by the 9th-century poet Abbas Ibn Firnas and the 11th-century monk Eilmer of Malmesbury, both experiments injured their pilots. In 1799, Sir George Cayley set forth the concept of the aeroplane as a fixed-wing flying machine with separate systems for lift, propulsion. Cayley was building and flying models of fixed-wing aircraft as early as 1803, in 1856, Frenchman Jean-Marie Le Bris made the first powered flight, by having his glider LAlbatros artificiel pulled by a horse on a beach. In 1884, the American John J. Montgomery made controlled flights in a glider as a part of a series of gliders built between 1883-1886, other aviators who made similar flights at that time were Otto Lilienthal, Percy Pilcher, and Octave Chanute. In the 1890s, Lawrence Hargrave conducted research on wing structures and his box kite designs were widely adopted. Although he also developed a type of aircraft engine, he did not create. Sir Hiram Maxim built a craft that weighed 3.5 tons, in 1894, his machine was tested with overhead rails to prevent it from rising. The test showed that it had enough lift to take off, the craft was uncontrollable, which Maxim, it is presumed, realized, because he subsequently abandoned work on it. By 1905, the Wright Flyer III was capable of fully controllable, stable flight for substantial periods, the flight was certified by the FAI. This was the first controlled flight, to be officially recognised, the Bleriot VIII design of 1908 was an early aircraft design that had the modern monoplane tractor configuration
41.
Airframe
–
The airframe of an aircraft is its mechanical structure. It is typically considered to include fuselage, wings and undercarriage, airframe design is a field of aerospace engineering that combines aerodynamics, materials technology and manufacturing methods to achieve balances of performance, reliability and cost. Modern airframe history began in the United States when a 1903 wood biplane made by Orville, in 1912 the Deperdussin Monocoque pioneered the light, strong and streamlined monocoque fuselage formed of thin plywood layers over a circular frame, achieving 210 km/h. Many early developments were spurred by military needs during World War I and these used hybrid wood and metal structures. In 1916 the German Albatros D. German engineer Hugo Junkers first flew all-metal airframes in 1915 with the all-metal, cantilever-wing, commercial aircraft development during the 1920s and 1930s focused on monoplane designs using Radial engines. Some were produced as single copies or in small quantity such as the Spirit of St. Louis flown across the Atlantic by Charles Lindbergh in 1927, william Stout designed the all-metal Ford Trimotors in 1926. They were among the most successful designs to emerge from the era through the use of all-metal airframes, during World War II, military needs again dominated airframe designs. The first jets were produced during the war but not made in large quantity, postwar commercial airframe design focused on airliners, on turboprop engines, and then on Jet engines, turbojets and later turbofans. The generally higher speeds and tensile stresses of turboprops and jets were major challenges, Airbus and Boeing are the dominant assemblers of large jet airliners while ATR, Bombardier and Embraer lead the regional airliner market, many manufacturers produce airframe components. It has a carbon fiber fuselage, said to replace 1,200 sheets of aluminum and 40,000 rivets. In February 2017, Airbus installed a 3D printing machine for titanium aircraft structural parts using electron beam additive manufacturing from Sciaky, airframe production has become an exacting process. Manufacturers operate under strict quality control and government regulations, departures from established standards become objects of major concern. A landmark in aeronautical design, the worlds first jet airliner, early models suffered from catastrophic airframe metal fatigue, causing a series of widely publicised accidents. The Royal Aircraft Establishment investigation at Farnborough Airport founded the science of aircraft crash reconstruction, after 3000 pressurisation cycles in a specially constructed pressure chamber, airframe failure was found to be due to stress concentration, a consequence of the square shaped windows. The windows had been engineered to be glued and riveted, but had been punch riveted only, unlike drill riveting, the imperfect nature of the hole created by punch riveting may cause the start of fatigue cracks around the rivet. The Lockheed L-188 Electra turboprop, first flown in 1957 became a lesson in controlling oscillation. Its 1959 crash of Braniff Flight 542 showed the difficulties that the airframe industry, the A300 had experienced other structural problems but none of this magnitude. Longeron Former Chord Aircraft fairing Vertical stabilizer
42.
Bracing (aeronautics)
–
In aeronautics, bracing comprises additional structural members which stiffen the functional airframe to give it rigidity and strength under load. Bracing may be applied both internally and externally, and may take the form of strut, which act in compression or tension as the need arises, and/or wires, which act only in tension. Another disadvantage of bracing wires is that they require routine checking and adjustment, or rigging, during the early years of aviation, bracing was a universal feature of all forms of aeroplane, including the monoplanes and biplanes which were then equally common. Today, bracing in the form of lift struts is still used for light commercial designs where a high wing. Bracing works by creating a triangulated truss structure which resists bending or twisting, by comparison, an unbraced cantilever structure bends easily unless it carries a lot of heavy reinforcement. Making the structure allows it to be much lighter and stiffer. To reduce weight and air resistance, the structure may be made hollow, for example, a high-wing monoplane may be given a diagonal lifting strut running from the bottom of the fuselage to a position far out towards the wingtip. This increases the depth of the wing root to the height of the fuselage. Typically, the ends of bracing struts are joined to the internal structural components such as a wing spar or a fuselage bulkhead. Bracing may be used to resist all the forces which occur in an airframe, including lift, weight, drag. A strut is a bracing component stiff enough to resist these forces whether they place it under compression or tension, a wire is a bracing component able only to resist tension, going slack under compression, and consequently is nearly always used in conjunction with struts. A square frame made of bars is not rigid but tends to bend at the corners. Bracing it with a diagonal bar would be heavy. A wire would be much lighter but would stop it collapsing only one way, to hold it rigid, two cross-bracing wires are needed. This method of cross-bracing can be clearly on early biplanes. Another way of arranging a rigid structure is to make the cross pieces solid enough to act in compression and this method was once common on monoplanes, where the wing and a central cabane or a pylon form the cross members while wire bracing forms the outer diamond. Most commonly found on biplane and other aircraft, wire bracing was also common on early monoplanes. Unlike struts, bracing wires always act in tension The thickness and profile of a wire affect the drag it causes, wires may be made of multi-stranded cable, a single strand of piano wire, or aerofoil sectioned steel
.svg)
