Tricycle landing gear
Tricycle gear is a type of aircraft undercarriage, or landing gear, arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, two or more main wheels aft of the center of gravity. Tricycle gear aircraft are the easiest to take-off and taxi, the configuration is the most used on aircraft. Several early aircraft had primitive tricycle gear, notably early Antoinette planes and the Curtiss Pushers of the pre-World War I Pioneer Era of aviation. Waldo Waterman's 1929 tailless Whatsit was one of the first to have a steerable nose wheel. Tricycle gear is the reverse of conventional landing gear or taildragger. On the ground, tricycle aircraft have a visibility advantage for the pilot as the nose of the aircraft is level, whereas the high nose of the taildragger can block the view ahead. Tricycle gear aircraft are much less liable to'nose over' as can happen if a taildragger hits a bump or has the brakes applied. In a nose-over, the aircraft's tail rises and the propeller strikes the ground, causing damage.
The tricycle layout reduces the possibility of a ground loop, because the main gear lies behind the center of mass. However, tricycle aircraft can be susceptible to wheel-barrowing; the nosewheel equipped aircraft is easier to handle on the ground in high winds due to its wing negative angle of attack. Student pilots are able to safely master nosewheel equipped aircraft more quickly. Tricycle gear aircraft are easier to land because the attitude required to land on the main gear is the same as that required in the flare, they are less vulnerable to crosswinds; as a result, the majority of modern aircraft are fitted with tricycle gear. All jet-powered aircraft have been fitted with tricycle landing gear, to avoid the blast of hot, high-speed gases causing damage to the ground surface, in particular runways and taxiways; the few exceptions have included the Yakovlev Yak-15, the Supermarine Attacker, prototypes such as the Heinkel He 178 that pioneered jet flight, the first four prototypes of the Messerschmitt Me 262, the Nene powered version of the Vickers VC.1 Viking.
Outside of the United States – where the tricycle undercarriage had solidly begun to take root with its aircraft firms before that nation's World War II involvement at the end of 1941 – the Heinkel firm in World War II Germany began building airframe designs meant to use tricycle undercarriage systems from their beginnings, as early as late 1939 with the Heinkel He 280 pioneering jet fighter demonstrator series, the unexpectedly successful Heinkel He 219 twin-engined night fighter of 1942 origin. The taildragger configuration has its own advantages, is arguably more suited to rougher landing strips; the tailwheel makes the plane sit in a nose-up attitude when on the ground, useful for operations on unpaved gravel surfaces where debris could damage the propeller. The tailwheel transmits loads to the airframe in a way much less to cause airframe damage when operating on rough fields; the small tailwheel is much less vulnerable than a nosewheel. A fixed-gear taildragger exhibits less interference drag and form drag in flight than a fixed-gear tricycle aircraft whose nosewheel may sit directly in the propeller's slipstream.
Tailwheels are smaller and cheaper to buy and to maintain, manhandling a tailwheel aircraft on the ground is easier. Most tailwheel aircraft are lower in overall height and thus. Tailwheel aircraft are more suitable for fitting with skis in wintertime
Hispano Aviación was established when a Hispano-Suiza car and aircraft parts factory complex in southern Spain was taken over by Franco led "Nationalist" forces in 1939, during the Spanish Civil War. Located in Tablada, in the Triana district of Seville, the Hispano factory produced several aircraft designs, including the HA-1109 named Me-109J, Spanish licence built version of the famous Messerschmitt Bf-109G equipped with a 1,300 hp Hispano-Suiza 12Z engine, HA-1112, Hispano HA-100 Triana. Hispano Aviación was taken over by Construcciones Aeronáuticas SA in 1972, now part of Airbus
North American T-6 Texan
The North American Aviation T-6 Texan is an American single-engined advanced trainer aircraft used to train pilots of the United States Army Air Forces, United States Navy, Royal Air Force, other air forces of the British Commonwealth during World War II and into the 1970s. Designed by North American Aviation, the T-6 is known by a variety of designations depending on the model and operating air force; the United States Army Air Corps and USAAF designated it as the AT-6, the United States Navy the SNJ, British Commonwealth air forces the Harvard, the name by which it is best known outside the US. Starting in 1948, the new United States Air Force designated it the T-6, with the USN following in 1962, it remains a popular warbird aircraft used for static displays. It has been used many times to simulate various Japanese aircraft, including the Mitsubishi A6M Zero, in movies depicting World War II in the Pacific. A total of 15,495 T-6s of all variants were built; the Texan originated from the North American NA-16 prototype which, modified as the NA-26, was submitted as an entry for a USAAC "Basic Combat" aircraft competition in March 1937.
The first model went into production and 180 were supplied to the USAAC as the BC-1 and 400 to the RAF as the Harvard I. The US Navy received 16 modified aircraft, designated the SNJ-1, a further 61 as the SNJ-2 with a different engine; the BC-1 was the production version of the NA-26 prototype, with retractable tailwheel landing gear and the provision for armament, a two-way radio, the 550-hp R-1340-47 engine as standard equipment. Production versions included the BC-1 with only minor modifications, of which 30 were modified as BC-1I instrument trainers. Three BC-2 aircraft were built before the shift to the "advanced trainer" designation, AT-6, equivalent to the BC-1A; the differences between the AT-6 and the BC-1 were new outer wing panels with a swept-forward trailing edge, squared-off wingtips, a triangular rudder, producing the canonical Texan silhouette. After a change to the rear of the canopy, the AT-6 was designated the Harvard II for RAF/RCAF orders and 1,173 were supplied by purchase or Lend Lease operating in Canada as part of the British Commonwealth Air Training Plan.
Next came the AT-6A, based on the NA-77 design and was powered by the Pratt & Whitney R-1340-49 Wasp radial engine. The USAAF received 1,549 and the US Navy 270; the AT-6B was built for gunnery training and could mount a.30 caliber machine gun on the forward fuselage. It used the R-1340-AN-1 engine, to become the standard for the remaining T-6 production. Canada's Noorduyn Aviation built an R-1340-AN-1-powered version of the AT-6A, supplied to the USAAF as the AT-16 and the RAF/RCAF as the Harvard IIB, some of which served with the Fleet Air Arm and Royal Canadian Navy. In late 1937, Mitsubushi purchased two NA-16s as technology demonstrators and a licence. However, the aircraft developed by Watanabe/Kyushu as the K10W1 bore no more than a superficial resemblance to the North American design, it featured a full monocoque fuselage as opposed to the steel tube fuselage of the T-6 and NA-16 family of aircraft, as well as being of smaller dimensions overall and had no design details in common with the T-6.
It was used in small numbers by the Imperial Japanese Navy from 1942 onwards. None survived the end of the war, after the war, the Japanese Air Self Defense Force operated Texans; the NA-88 design resulted in 2,970 AT-6C Texans and 2,400 as the SNJ-4. The RAF received 726 of the AT-6C as the Harvard IIA. Modifications to the electrical system produced the AT-6D and SNJ-5; the AT-6D, redesignated the Harvard III, was supplied to the Fleet Air Arm. When the USAF was created in 1948, its final production variant was nominated T-6G and involved major advancements including a full-time hydraulic system and a steerable tailwheel and persisted into the 1950s as the USAF advanced trainer. Subsequently, the NA-121 design with a clear rearmost section on the canopy, gave rise to 25 AT-6F Texans for the USAAF and 931, as the SNJ-6 for the US Navy; the ultimate version, the Harvard 4, was produced by Canada Car and Foundry during the 1950s, supplied to the RCAF, USAF and Bundeswehr. A total of 15,495 T-6s of all variants were built.
Twenty AT-6 Texans were employed by the 1st and 2nd fighter squadrons of the Syrian Air Force in the 1948 Arab-Israeli War, providing ground support for Syrian troops, launching air strikes against Israeli airfields and columns, losing one aircraft to antiaircraft fire. They engaged in air-to-air combat on a number of occasions, with a tail gunner shooting down an Israeli Avia S-199 fighter; the Israeli Air Force bought 17 Harvards, operated nine of them in the final stages of the 1948 Arab-Israeli War, against the Egyptian ground forces, with no losses. In the Sinai Campaign, IAF Harvards attacked Egyptian ground forces in Sinai Peninsula with two losses; the Royal Hellenic Air Force employed three squadrons of British- and American-supplied T-6D and G Texans for close air support and artillery spotting duties during the Greek Civil War, providing extensive support to the Greek army during the Battle of Gramos. Communist guerillas called these aircraft "O Galatas", because they saw them flying early in the morning.
After the "Milkmen", the guerillas waited for the armed Helldivers. During the Korean War and
International Standard Serial Number
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is helpful in distinguishing between serials with the same title. ISSN are used in ordering, interlibrary loans, other practices in connection with serial literature; the ISSN system was first drafted as an International Organization for Standardization international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard; when a serial with the same content is published in more than one media type, a different ISSN is assigned to each media type. For example, many serials are published both in electronic media; the ISSN system refers to these types as electronic ISSN, respectively. Conversely, as defined in ISO 3297:2007, every serial in the ISSN system is assigned a linking ISSN the same as the ISSN assigned to the serial in its first published medium, which links together all ISSNs assigned to the serial in every medium.
The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers. As an integer number, it can be represented by the first seven digits; the last code digit, which may be 0-9 or an X, is a check digit. Formally, the general form of the ISSN code can be expressed as follows: NNNN-NNNC where N is in the set, a digit character, C is in; the ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, C=5. To calculate the check digit, the following algorithm may be used: Calculate the sum of the first seven digits of the ISSN multiplied by its position in the number, counting from the right—that is, 8, 7, 6, 5, 4, 3, 2, respectively: 0 ⋅ 8 + 3 ⋅ 7 + 7 ⋅ 6 + 8 ⋅ 5 + 5 ⋅ 4 + 9 ⋅ 3 + 5 ⋅ 2 = 0 + 21 + 42 + 40 + 20 + 27 + 10 = 160 The modulus 11 of this sum is calculated. For calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, counting from the right.
The modulus 11 of the sum must be 0. There is an online ISSN checker. ISSN codes are assigned by a network of ISSN National Centres located at national libraries and coordinated by the ISSN International Centre based in Paris; the International Centre is an intergovernmental organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, the ISDS Register otherwise known as the ISSN Register. At the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept. An ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an anonymous identifier associated with a serial title, containing no information as to the publisher or its location. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change. Since the ISSN applies to an entire serial a new identifier, the Serial Item and Contribution Identifier, was built on top of it to allow references to specific volumes, articles, or other identifiable components.
Separate ISSNs are needed for serials in different media. Thus, the print and electronic media versions of a serial need separate ISSNs. A CD-ROM version and a web version of a serial require different ISSNs since two different media are involved. However, the same ISSN can be used for different file formats of the same online serial; this "media-oriented identification" of serials made sense in the 1970s. In the 1990s and onward, with personal computers, better screens, the Web, it makes sense to consider only content, independent of media; this "content-oriented identification" of serials was a repressed demand during a decade, but no ISSN update or initiative occurred. A natural extension for ISSN, the unique-identification of the articles in the serials, was the main demand application. An alternative serials' contents model arrived with the indecs Content Model and its application, the digital object identifier, as ISSN-independent initiative, consolidated in the 2000s. Only in 2007, ISSN-L was defined in the
Hispano-Suiza was a Spanish automotive/engineering company and, after World War II, a French aviation engine and components manufacturer. It is best known for its pre-World War II luxury cars and aviation engines. In 1923, its French subsidiary became a semi-autonomous partnership with the Spanish parent company. In 1946, the Spanish parent company sold all its Spanish automotive assets to Enasa. In 1968, the French arm was taken over by the aerospace company Snecma, now a part of the French Safran Group. In 1898 a Spanish artillery captain, Emilio de la Cuadra, started electric automobile production in Barcelona under the name of La Cuadra. In Paris, De la Cuadra met the Swiss engineer Marc Birkigt and hired him to work for the company in Spain. La Cuadra built their first gasoline-powered engines from a Birkigt design. At some point in 1902, the ownership changed hands to José María Castro Fernández and became Fábrica Hispano-Suiza de Automóviles but this company went bankrupt in December 1903.
Yet another restructuring took place in 1904, creating La Hispano-Suiza Fábrica de Automóviles, under Castro's direction based in Barcelona. Four new engines were introduced in a half; this company managed to avoid bankruptcy and its largest operations remained in Barcelona until 1946, where cars, buses, aero engines and weapons were produced. Other factories in Spain were at Ripoll and Guadalajara. In 1910 Jean Chassagne competed with a Hispano-Suiza together with works drivers Pilleveridier and Zucarelli in the Coupe des Voiturettes Boulogne and the Catalan Cup Races, gaining second and fourth places respectively. France was soon proving to be a larger market for Hispano-Suiza's luxury cars than Spain. In 1911, an assembly factory called Hispano France began operating in the Paris suburb of Levallois-Perret. Production was moved to larger factories at Bois-Colombes, under the name Hispano-Suiza in 1914 and soon became Hispano-Suiza's main plant for producing the largest, most costly models.
With the start of World War I, Hispano-Suiza turned to the design and production of aircraft engines under the direction of Marc Birkigt. His chief engineer during this period was Louis Massuger. Traditionally, aircraft engines were manufactured by machining separate steel cylinders and bolting these assemblies directly to the crankcase. Birkigt's novel solution called for the engine block to be formed from a single piece of cast aluminum, into which thin steel liners were secured. Manufacturing an engine in this way simplified construction and resulted in a lighter, yet stronger more durable engine. Thus, Birkigt's new construction method created the first practical, what are known today as, "cast block" engines, his aluminum cast block V-8 design was noteworthy for incorporating overhead camshafts, propeller reduction gearing and other desirable features that would not appear together on competitor's engines until the late 1920s. Another major design feature, for the HS.8B line was the use of a hollow propeller shaft for both the 8B and 8C gear-reduction versions, which when used for the HS.8C versions engineered to accommodate one, to allow heavy calibre projectile firing through the hollow propeller shaft, avoiding the need for a synchronization gear, a feature used in future Hispano-Suiza military engines.
Hispano-Suiza's aero engines, produced at its own factories and under license, became the most used aero engines in the French and British air forces, powering over half the alliance's fighter aircraft. After World War I, Hispano-Suiza returned to automobile manufacturing and in 1919 they introduced the Hispano-Suiza H6; the H6 featured an inline 6-cylinder overhead camshaft engine based on the features of its V8 aluminum World War I aircraft engines and had coachwork done by well known coachbuilders like Hibbard & Darrin and D'Ieteren. Licences for Hispano-Suiza patents were much in demand from prestige car manufacturers world-wide. Rolls-Royce used a number of Hispano-Suiza patents. For instance, for many years Rolls Royce installed Hispano-Suiza designed power brakes in its vehicles. In 1923 the French arm of Hispano-Suiza was incorporated as the Société Française Hispano-Suiza, the Spanish parent company retaining control with 71% of the share capital; the French subsidiary was granted a large degree of financial and project independence to bring design and production direction into closer contact with its main markets but overall direction remained at Barcelona.
This arrangement increased the importance of the Bois-Colombes plant near Paris as Hispano-Suiza's premier luxury car plant, while the Spanish operations continued to produce luxury cars the smaller, less expensive models, production in Spain moved to the production of buses and aircraft engines at several plants located around the country. Through the 1920s and into the 1930s, Hispano-Suiza built a series of luxury cars with overhead camshaft engines of increasing performance. On the other hand, in the 1930s, Hispano-Suiza's V-12 car engines reverted to pushrod valve actuation to reduce engine noise. During this time, Hispano-Suiza released the 37.2 Hispano-Suiza car built at the Bois-Colombes works. The mascot statuette atop the radiator after World War I was the stork, the symbol of the French province of Alsace, taken from the squadron emblem painted on the side of a Hispano-Suiza powered fighter aircraft, flown by the World War I French ace Georges Guynemer. In 1925, Carlos Ballester obtained permission to represent Hispano-Suiza in Argentina.
The agreement consisted of a phase in which the chassis were impor
The Helwan HA-300 was a single-engine, delta-wing, light supersonic Interceptor aircraft developed in Egypt during the 1960s. It was designed by the famous German aircraft designer Willy Messerschmitt. At various stages and India were involved in the development program. Spain agreed to finance two projects, the HA-200 and the Hispano HA-300, but cancelled financing the HA-300 project before a prototype was built due to cost and time overruns. Egypt financed it, the program was transferred to Egypt where every part, including the engine, was made, the aircraft was flown. At a late stage India financed the Egyptian development of the Egyptian E-300 engine for use on the Indian fighter jet HF-24 Marut; the HA-300 was an ambitious and costly project for Egypt, at the time seeking to expand both its civilian and defence aviation industry. There were 6 planes in service built before termination of the project in 1969; the first prototype was a museum exhibit as of 1997. After World War II, Willy Messerschmitt was prohibited as a German citizen from undertaking any further research or development related to the German military, including the manufacture of aircraft, until 1955.
He therefore moved to Spain where he joined Hispano Aviación and started designing an ultralight fighter aircraft in 1951. A lack of funds made the aircraft's development slow and Messerschmitt was able to build only a delta-shaped plywood glider without a tail. Towed by a CASA 2.111, the test flight for the glider was not completed due to instability and the airplane did not become airborne. Due to funding problems and the resultant long development time, Spain abandoned the project in 1960. Egypt acquired the design from Hispano Aviación; the design team, headed by Messerschmitt, moved to Helwan, Egypt, to continue its work on the HA-300, which now stood for Helwan Aircraft 300. Ferdinand Brandner, an Austrian jet engine expert, was invited to develop a turbojet for the new fighter. Egypt aimed to produce a lightweight supersonic, single-seat fighter that could join the Egyptian Air Force as an interceptor. Development of the Egyptian HA-300 started in the test facilities and workshops in Factory No. 36 in Helwan, southeast of Cairo, under the supervision of the Egyptian General Aero Organisation.
The first prototype of the HA-300, powered by a 2,200 kgp Orpheus Mk 703-S-10, first flew on 7 March 1964, achieved Mach 1.13. Egypt sent two Egyptian pilots to India in 1964 to prepare for the HA-300 flight development, it was followed by a second Orpheus-powered prototype which first flew on 22 July 1965. The third and last prototype was fitted with the Egyptian E-300 engine, which it was hoped would make it capable of attaining 12,000 m and Mach 2.0 within 2.5 min after takeoff. This prototype was flight-tested at least once when it achieved a speed of Mach 2.1 with the Egyptian Brandner E-300 engine. A total of 135 million Egyptian pounds was spent on the development, the E-300 engine was given to the Indian government for use in the HAL HF-24 Marut fighter; the HA-300 was designed for the afterburning Orpheus BOR 12 turbojet, but the engine did not achieve the minimum level of success Egypt required in the fighter jet. President Nasser saw from the beginning a major threat to national security by depending on a British engine, because of the hostility that time between Egypt and Great Britain after the 1956 Suez crisis.
The fighter jet was modified for the Egyptian Brandner E-300 engine, which would have an afterburning rating of 4,800 kgp, which achieved a high level of performance. India helped in the funding of the Egyptian E-300 jet engine in exchange for using it as a new powerplant for its HF-24 Marut; the E-300 jet engine ran for the first time in July 1963. The Helwan-300 project was cancelled on May 1969; the real reason why it was cancelled remains a mystery but it can be inferred that the cancellation was due to many factors varying between technical and political difficulties. The German engineers working on the design had to evacuate Egypt due to fear for their lives after they received multiple death threats from the Israeli Mossad. In order to fill the void created by the cancellation of this project, Egypt made close contacts with the Soviet Union and purchased aircraft instead of developing indigenous designs; the first HA-300 prototype registration number 51-100, construction number V1, was on display since 1997 in the Deutsches Museum Flugwerft Schleissheim at Oberschleißheim near Munich.
It was bought by Daimler-Benz Aerospace AG in 1991, airlifted to Germany for restoration at Manching. The process took MBB five and a half years to complete. Data from Deutsches Museum Flugwerft Schleissheim, airwar.ru, theaircache.com, aviationsmilitaires.netGeneral characteristics Crew: one Length: 12.40 m Wingspan: 5.84 m Height: 3.15 m Wing area: 16.70 m2 Empty weight: 2,100 kg Loaded weight: 5,443 kg Powerplant: 1 × Bristol Orpheus 703 or Brandner E-300 turbojet Dry thrust: 28 kN Thrust with afterburner: 47 kN Performance Maximum speed: Mach 1.7 projected Mach 2 with Brandner E-300 engine Range: 1,400 km Service ceiling: 18,000 m Rate of climb: 203 m/s Wing loading: 125.749 kg/m² Thrust/weight: 0.88Armament Guns: 2 × 30mm Hispano or 4 × 23mm Nudelman-Rikhter NR-23 cannon Missiles: 4 × infrared homing air-to-air missiles Aircraft of comparable role and era Dassault Mirage 5 Folland Gnat Northrop F-5 Related lists List of fighter aircraft