The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
An air-to-air missile is a missile fired from an aircraft for the purpose of destroying another aircraft. AAMs are powered by one or more rocket motors solid fueled but sometimes liquid fueled. Ramjet engines, as used on the Meteor are emerging as propulsion that will enable future medium-range missiles to maintain higher average speed across their engagement envelope. Air-to-air missiles are broadly put in two groups; those designed to engage opposing aircraft at ranges of less than 30 km are known as short-range or "within visual range" missiles and are sometimes called "dogfight" missiles because they are designed to optimize their agility rather than range. Most use are called heat-seeking missiles. In contrast, medium- or long-range missiles, which both fall under the category of beyond visual range missiles, tend to rely upon radar guidance, of which there are many forms; some modern ones use inertial guidance and/or "mid-course updates" to get the missile close enough to use an active homing sensor.
The air-to-air missile grew out of the unguided air-to-air rockets used during the First World War. Le Prieur rockets were sometimes attached to the struts of biplanes and fired electrically against observation balloons, by such early pilots as Albert Ball and A. M. Walters. Facing the Allied air superiority, Germany in World War II invested limited effort into missile research, leading to the deployment of the R4M unguided rocket and the development of various guided missile prototypes such as the Ruhrstahl X-4. Post-war research led the Royal Air Force to introduce Fairey Fireflash into service in 1955 but their results were unsuccessful; the US Navy and US Air Force began equipping guided missiles in 1956, deploying the USAF's AIM-4 Falcon and the USN's AIM-7 Sparrow and AIM-9 Sidewinder. The Soviet Air Force introduced its K-5 into service in 1957; as missile systems have continued to advance, modern air warfare consists entirely of missile firing. The use of Beyond Visual Range combat became so pervasive in the US that early F-4 variants were armed only with missiles in the 1960s.
High casualty rates during the Vietnam War caused the US to reintroduce autocannon and traditional dogfighting tactics but the missile remains the primary weapon in air combat. In the Falklands War British Harriers, using AIM-9L missiles were able to defeat faster Argentinian opponents. Since the late 20th century all-aspect heat-seeking designs can lock-on to a target from various angles, not just from behind, where the heat signature from the engines is strongest. Other types rely on radar guidance. A conventional explosive blast warhead, fragmentation warhead, or continuous rod warhead is used in the attempt to disable or destroy the target aircraft. Warheads are detonated by a proximity fuze or by an impact fuze if it scores a direct hit. Less nuclear warheads have been mounted on a small number of air-to-air missile types although these are not known to have been used in combat. Guided missiles operate by detecting their target, "homing" in on the target on a collision course. Although the missile may use radar or infra-red guidance to home on the target, the launching aircraft may detect and track the target before launch by other means.
Infra-red guided missiles can be "slaved" to an attack radar in order to find the target and radar-guided missiles can be launched at targets detected visually or via an infra-red search and track system, although they may require the attack radar to illuminate the target during part or all of the missile interception itself. Radar guidance is used for medium- or long-range missiles, where the infra-red signature of the target would be too faint for an infra-red detector to track. There are three major types of radar-guided missile – active, semi-active, passive. Radar-guided missiles can be countered by rapid maneuvering, deploying chaff or using electronic counter-measures. Active radar -guided missiles carry their own radar system to detect and track their target. However, the size of the radar antenna is limited by the small diameter of missiles, limiting its range which means such missiles are launched at a predicted future location of the target relying on separate guidance systems such as Global Positioning System, inertial guidance, or a mid-course update from either the launching aircraft or other system that can communicate with the missile to get the missile close to the target.
At a predetermined point the missile's radar system is activated, the missile homes in on the target. If the range from the attacking aircraft to the target is within the range of the missile's radar system, the missile can "go active" upon launch; the great advantage of an active radar homing system is that it enables a "fire-and-forget" mode of attack, where the attacking aircraft is free to pursue other targets or escape the area after launching the missile. Semi-active radar homing guided missiles are more common, they function by detecting radar energy reflected from the target. The radar energy is emitted from the launching aircraft's own radar system. However, this means that the launch aircraft has to maintain a "lock" on the target (keep illuminating the target aircraft w
In aircraft, an ejection seat or ejector seat is a system designed to rescue the pilot or other crew of an aircraft in an emergency. In most designs, the seat is propelled out of the aircraft by an explosive charge or rocket motor, carrying the pilot with it; the concept of an ejectable escape crew capsule has been tried. Once clear of the aircraft, the ejection seat deploys a parachute. Ejection seats are common on certain types of military aircraft. A bungee-assisted escape from an aircraft took place in 1910. In 1916 Everard Calthrop, an early inventor of parachutes, patented an ejector seat using compressed air; the modern layout for an ejection seat was first proposed by Romanian inventor Anastase Dragomir in the late 1920s. The design featured a parachuted cell, it was tested on 25 August 1929 at the Paris-Orly Airport near Paris and in October 1929 at Băneasa, near Bucharest. Dragomir patented his "catapult-able cockpit" at the French Patent Office; the design was perfected during World War II.
Prior to this, the only means of escape from an incapacitated aircraft was to jump clear, in many cases this was difficult due to injury, the difficulty of egress from a confined space, g forces, the airflow past the aircraft, other factors. The first ejection seats were developed independently during World War II by Heinkel and SAAB. Early models were powered by compressed air and the first aircraft to be fitted with such a system was the Heinkel He 280 prototype jet-engined fighter in 1940. One of the He 280 test pilots, Helmut Schenk, became the first person to escape from a stricken aircraft with an ejection seat on 13 January 1942 after his control surfaces iced up and became inoperative; the fighter had been being used in tests of the Argus As 014 impulse jets for Fieseler Fi 103 missile development. It had its usual HeS 8A turbojets removed, was towed aloft from the Erprobungsstelle Rechlin central test facility of the Luftwaffe in Germany by a pair of Bf 110C tugs in a heavy snow-shower.
At 2,400 m, Schenk found he had no control, jettisoned his towline, ejected. The He 280 was never put into production status and the first operational type built anywhere, to provide ejection seats for the crew was the Heinkel He 219 Uhu night fighter in 1942; the Hungarian RMI-8 experimental interceptor fighter had two DB 605 engines in a push-pull configuration in order to achieve 800 km/h top speed. To save pilots a spring-driven catapult seat was developed in a few months time, but the prototype has been destroyed in 1944 during an air raid, shortly before its maiden flight. No one other prototype was finished before the fall of Budapest. In Sweden, a version using compressed air was tested in 1941. A gunpowder ejection seat was developed by Bofors and tested in 1943 for the Saab 21; the first test in the air was on a Saab 17 on 27 February 1944, the first real use occurred by Lt. Bengt Johansson on 29 July 1946 after a mid-air collision between a J 21 and a J 22; as the first operational military jet in late 1944 to feature one, the winner of the German Volksjäger "people's fighter" home defense jet fighter design competition.
In this system, the seat rode on wheels set between two pipes running up the back of the cockpit. When lowered into position, caps at the top of the seat fitted over the pipes to close them. Cartridges identical to shotgun shells, were placed in the bottom of the pipes, facing upward; when fired, the gases would fill the pipes, "popping" the caps off the end, thereby forcing the seat to ride up the pipes on its wheels and out of the aircraft. By the end of the war, the Dornier Do 335 Pfeil — from it having a rear-mounted engine powering a pusher propeller located at the aft end of the fuselage presenting a hazard to a normal "bailout" escape — and a few late-war prototype aircraft were fitted with ejection seats. After World War II, the need for such systems became pressing, as aircraft speeds were getting higher, it was not long before the sound barrier was broken. Manual escape at such speeds would be impossible; the United States Army Air Forces experimented with downward-ejecting systems operated by a spring, but it was the work of James Martin and his company Martin-Baker that proved crucial.
The first live flight test of the Martin-Baker system took place on 24 July 1946, when fitter Bernard Lynch ejected from a Gloster Meteor Mk III jet. Shortly afterward, on 17 August 1946, 1st Sgt. Larry Lambert was the first live U. S. ejectee. Lynch demonstrated the ejection seat at the Daily Express Air Pageant in 1948, ejecting from a Meteor. Martin-Baker ejector seats were fitted to prototype and production aircraft from the late 1940s, the first emergency use of such a seat occurred in 1949 during testing of the jet-powered Armstrong Whitworth A. W.52 experimental flying wing. Early seats used a solid propellant charge to eject the pilot and seat by igniting the charge inside a telescoping tube attached to the seat; as aircraft speeds increased still further, this method proved inadequate to get the pilot sufficiently clear of the airframe. Increasing the amount of propellant risked damaging the occupant's spine, so experiments with rocket propulsion began. In 1958, the Convair F-102 Delta Dagger was the first aircraft to be fitted with a rocket-propelled seat.
Martin-Baker developed a similar design. The greater thrust from this configuration had the advantage of being able to eject the pilot to a safe height if the aircraft was on or near the ground. In the e
An interceptor aircraft, or interceptor, is a type of fighter aircraft designed to attack enemy aircraft bombers and reconnaissance aircraft, as they approach. There are two general classes of interceptor: lightweight aircraft built for high performance, heavier aircraft designed to fly at night or in adverse weather and operate over longer ranges. For daytime operations, conventional fighters fill the interceptor role, as well as many other missions. Daytime interceptors have been used in a defensive role since the World War I era, but are best known from several major actions during World War II, notably the Battle of Britain where the Supermarine Spitfire and Hawker Hurricane developed a good reputation. Few aircraft can be considered dedicated daytime interceptors. Exceptions include the Messerschmitt Me 163B—the only rocket-powered, manned military aircraft to see combat—and to a lesser degree designs like the Mikoyan-Gurevich MiG-15, which had heavy armament intended for anti-bomber missions.
Night fighters and bomber destroyers are, by definition, interceptors of the heavy type, although they were referred to as such. In the early Cold War era the combination of jet-powered bombers and nuclear weapons created air forces' demand for capable interceptors. Examples of classic interceptors of this era include the F-106 Delta Dart, Sukhoi Su-15, English Electric Lightning. Through the 1960s and 1970s, the rapid improvements in design led to most air-superiority and multirole fighters, such as the Grumman F-14 Tomcat and McDonnell Douglas F-15 Eagle, having the performance to take on the interceptor role, the strategic threat moved from bombers to intercontinental ballistic missiles. Dedicated interceptor designs became rare, with the only used examples designed after the 1960s being the Tornado F3, Mikoyan MiG-25 "Foxbat", Mikoyan MiG-31 "Foxhound", the Shenyang J-8 "Finback"; the first interceptor squadrons were formed during World War I to defend London against attacks by Zeppelins and against fixed-wing long-range bombers.
Early units used aircraft withdrawn from front-line service, notably the Sopwith Pup. They were told about their target's location before take-off from a command centre in the Horse Guards building; the Pup proved to have too low performance to intercept Gotha G. IV bombers, the superior Sopwith Camels supplanted them; the term "interceptor" was in use by 1929. Through the 1930s, bomber aircraft speeds increased so much that conventional interceptor tactics appeared impossible. Visual and acoustic detection from the ground had a range of only a few miles, which meant that an interceptor would have insufficient time to climb to altitude before the bombers reached their targets. Standing combat air patrols were only at great cost; the conclusion at the time was that "the bomber will always get through". The invention of radar made possible early, long-range detection of aircraft on the order of 100 miles, both day and night and in all weather. A typical bomber might take twenty minutes to cross the detection zone of early radar systems, time enough for interceptor fighters to start up, climb to altitude and engage the bombers.
Ground controlled interception required constant contact between the interceptor and the ground until the bombers became visible to the pilots and nationwide networks like the Dowding system were built in the late 1930s. The introduction of jet power increased speeds from 400 miles per hour to 600 miles per hour in a step and doubled operational altitudes. Although radars improved in performance, the gap between offense and defense was reduced. Large attacks could so confuse the defense's ability to communicate with pilots that the classic method of manual ground controlled interception was seen as inadequate. In the United States, this led to the introduction of the Semi-Automatic Ground Environment to computerize this task; the introduction of the first useful surface-to-air missiles in the 1950s obviated the need for fast reaction time interceptors as the missile could launch instantly and air forces turned to much larger designs, with enough fuel for longer endurance, to avoid the need for rapid reaction.
In the 1950s, during the Cold War, a strong interceptor force was crucial for the great powers as the best means to defend against an unexpected nuclear attack by strategic bombers. Hence for a brief period of time they faced rapid development. At the end of the 1960s, a nuclear attack became unstoppable with the introduction of ballistic missiles capable of approaching from outside the atmosphere at speeds as high as 5–7 km/s; the doctrine of mutually assured destruction replaced the trend of defense strengthening, making interceptors less strategically logical. The utility of interceptors waned as the role merged with that of the heavy air superiority fighter, dominant in military thinking; the interceptor mission is, by its nature, a difficult one. Consider the desire to protect a single target from attack by long-range bombers; the bombers have the advantage of being able to select the parameters of the mission – attack vector and altitude. This results in an enormous area. In the time it takes for the bombers to cross the distance from first detection to being on their targets, the interceptor must be able to start, take off, climb to altitude, maneuver for attack and attack the bomber.
A dedicated interceptor aircraft sacrifices the capabilities of the air superiority fighter and multirole fighter (i.e. countering enemy fighter airc
Naval Air Station Pensacola
Naval Air Station Pensacola or NAS Pensacola, "The Cradle of Naval Aviation", is a United States Navy base located next to Warrington, Florida, a community southwest of the Pensacola city limits. It is best known as the initial primary training base for all U. S. Navy, Marine Corps and Coast Guard officers pursuing designation as Naval Aviators and Naval Flight Officers, the advanced training base for most Naval Flight Officers, as the home base for the United States Navy Flight Demonstration Squadron, the precision-flying team known as the Blue Angels; because of contamination by heavy metals and other hazardous materials during its history, it is designated as a Superfund site needing environmental cleanup. The air station hosts the Naval Education and Training Command and the Naval Aerospace Medical Institute, the latter of which provides training for all naval Naval Flight Surgeons, Naval Aviation Physiologists, Naval Aviation Experimental Psychologists. With the closure of Naval Air Station Memphis in Millington and the transition of that facility to Naval Support Activity Mid-South, NAS Pensacola became home to the Naval Air Technical Training Center Memphis, which relocated to Pensacola and was renamed NATTC Pensacola.
NATTC provides technical training schools for nearly all enlisted aircraft maintenance and enlisted aircrew specialties in the U. S. Navy, U. S. Marine Corps and U. S. Coast Guard; the NATTC facility at NAS Pensacola is home to the USAF Detachment 1, a geographically separated unit whose home unit is the 359th Training Squadron located at nearby Eglin AFB. Detachment 1 trains over 1,100 Airmen annually in three structural maintenance disciplines: Low Observable, Non-Destructive Inspection, Aircraft Structural Maintenance. NAS Pensacola contains Forrest Sherman Field, home of Training Air Wing SIX, providing undergraduate flight training for all prospective Naval Flight Officers for the U. S. Navy and U. S. Marine Corps, flight officers/navigators for other NATO/Allied/Coalition partners. TRAWING SIX consists of the Training Squadron 4 "Warbucks," Training Squadron 10 "Wildcats" and Training Squadron 86 "Sabrehawks," flying the T-45C Goshawk and T-6A Texan II. A select number of prospective U. S. Air Force Navigator/Combat Systems Officers, destined for certain fighter/bomber or heavy aircraft, were trained via TRAWING SIX, under VT-4 or VT-10, with command of VT-10 rotating periodically to a USAF officer.
This previous track for USAF Navigators was termed Joint Undergraduate Navigator Training. Today, all USAF Undergraduate CSO Training for all USAF aircraft is consolidated at NAS Pensacola as a USAF organization and operation under the 479th Flying Training Group, an Air Education and Training Command unit; the 479 FTG is a tenant activity at NAS Pensacola and a GSU of the 12th Flying Training Wing at Randolph AFB, Texas. The 479 FTG operates T-1A Jayhawk aircraft. Other tenant activities include the United States Navy Flight Demonstration Squadron, the Blue Angels, flying F/A-18 Hornets and a single USMC C-130T Hercules. A total of 131 aircraft operate out of Sherman Field, generating 110,000 flight operations each year; the National Naval Aviation Museum, the Pensacola Naval Air Station Historic District, the National Park Service-administered Fort Barrancas and its associated Advance Redoubt, the Pensacola Lighthouse and Museum are all located at NAS Pensacola, as is the Barrancas National Cemetery.
The site now occupied. In 1559, Spanish explorer Don Tristan de Luna founded a colony on Santa Rosa Island, considered the first European settlement of the Pensacola area; the Spanish built the wooden Fort San Carlos de Austria on this bluff in 1697–1698. Although besieged by Indians in 1707, the fort was not taken. Spain was competing in North America with the French, who settled lower Louisiana and the Illinois Country and areas to the North; the French destroyed this fort when they captured Pensacola in 1719. After Great Britain defeated the French in the Seven Years' War and exchanging some territory with Spain, British colonists took over this site and West Florida in 1763. In 1781, as an ally of the American rebels during the American Revolutionary War, the Spanish captured Pensacola. Britain ceded West Florida to Spain following the war; the Spanish completed the fort San Carlos de Barrancas in 1797. Barranca is a Spanish word for bluff, the natural terrain feature that makes this location ideal for the fortress.
Pensacola was taken by General Andrew Jackson in November 1814 during the War of 1812 between Great Britain and the United States. British forces destroyed Fort San Carlos; the Spanish remained in control of the region until 1821, when the Adams-Onís Treaty confirmed the purchase of Spanish Florida by the United States, Spain ceded this territory to the US. In 1825, the US designated this area for the Pensacola Navy Yard was designated and Congress appropriated $6,000 for a lighthouse. Operational that year, it "is said to be haunted by a light keeper murdered by his wife." Fort Barrancas was rebuilt, 1839–1844, the U. S. Army deactivating it on 15 April 1947. Designated a National Historic Site in 1960, control of the site was transferred to the National Park Service in 1971. After extensive re
McDonnell Douglas F-4 Phantom II
The McDonnell Douglas F-4 Phantom II is a tandem two-seat, twin-engine, all-weather, long-range supersonic jet interceptor and fighter-bomber developed for the United States Navy by McDonnell Aircraft. It first entered service in 1960 with the U. S. Navy. Proving adaptable, it was adopted by the U. S. Marine Corps and the U. S. Air Force, by the mid-1960s had become a major part of their air arms; the Phantom is a large fighter with a top speed of over Mach 2.2. It can carry more than 18,000 pounds of weapons on nine external hardpoints, including air-to-air missiles, air-to-ground missiles, various bombs; the F-4, like other interceptors of its time, was designed without an internal cannon. Models incorporated an M61 Vulcan rotary cannon. Beginning in 1959, it set 15 world records for in-flight performance, including an absolute speed record, an absolute altitude record; the F-4 was used extensively during the Vietnam War. It served as the principal air superiority fighter for the U. S. Air Force and Marine Corps and became important in the ground-attack and aerial reconnaissance roles late in the war.
During the Vietnam War, one U. S. Air Force pilot, two weapon systems officers, one U. S. Navy pilot and one radar intercept officer became aces by achieving five aerial kills against enemy fighter aircraft; the F-4 continued to form a major part of U. S. military air power throughout the 1970s and 1980s, being replaced by more modern aircraft such as the F-15 Eagle and F-16 Fighting Falcon in the U. S. Air Force, the F-14 Tomcat in the U. S. Navy, the F/A-18 Hornet in the U. S. Navy and U. S. Marine Corps; the F-4 Phantom II remained in use by the U. S. in the reconnaissance and Wild Weasel roles in the 1991 Gulf War leaving service in 1996. It was the only aircraft used by both U. S. flight demonstration teams: the USAF Thunderbirds and the US Navy Blue Angels. The F-4 was operated by the armed forces of 11 other nations. Israeli Phantoms saw extensive combat in several Arab–Israeli conflicts, while Iran used its large fleet of Phantoms, acquired before the fall of the Shah, in the Iran–Iraq War. Phantom production ran from 1958 to 1981, with a total of 5,195 built, making it the most produced American supersonic military aircraft.
As of 2018, 60 years after its first flight, the F-4 remains in service with Iran, South Korea and Turkey. The aircraft has most been in service against the Islamic State group in the Middle East. In 1952, McDonnell's Chief of Aerodynamics, Dave Lewis, was appointed by CEO Jim McDonnell to be the company's preliminary design manager. With no new aircraft competitions on the horizon, internal studies concluded the Navy had the greatest need for a new and different aircraft type: an attack fighter. In 1953, McDonnell Aircraft began work on revising its F3H Demon naval fighter, seeking expanded capabilities and better performance; the company developed several projects including a variant powered by a Wright J67 engine, variants powered by two Wright J65 engines, or two General Electric J79 engines. The J79-powered version promised a top speed of Mach 1.97. On 19 September 1953, McDonnell approached the United States Navy with a proposal for the "Super Demon". Uniquely, the aircraft was to be modular—it could be fitted with one- or two-seat noses for different missions, with different nose cones to accommodate radar, photo cameras, four 20 mm cannon, or 56 FFAR unguided rockets in addition to the nine hardpoints under the wings and the fuselage.
The Navy was sufficiently interested to order a full-scale mock-up of the F3H-G/H, but felt that the upcoming Grumman XF9F-9 and Vought XF8U-1 satisfied the need for a supersonic fighter. The McDonnell design was therefore reworked into an all-weather fighter-bomber with 11 external hardpoints for weapons and on 18 October 1954, the company received a letter of intent for two YAH-1 prototypes. On 26 May 1955, four Navy officers arrived at the McDonnell offices and, within an hour, presented the company with an new set of requirements; because the Navy had the Douglas A-4 Skyhawk for ground attack and F-8 Crusader for dogfighting, the project now had to fulfill the need for an all-weather fleet defense interceptor. A second crewman was added to operate the powerful radar; the XF4H-1 was designed to carry four semi-recessed AAM-N-6 Sparrow III radar-guided missiles, to be powered by two J79-GE-8 engines. As in the McDonnell F-101 Voodoo, the engines sat low in the fuselage to maximize internal fuel capacity and ingested air through fixed geometry intakes.
The thin-section wing had a leading edge sweep of 45° and was equipped with blown flaps for better low-speed handling. Wind tunnel testing had revealed lateral instability requiring the addition of 5° dihedral to the wings. To avoid redesigning the titanium central section of the aircraft, McDonnell engineers angled up only the outer portions of the wings by 12°, which averaged to the required 5° over the entire wingspan; the wings received the distinctive "dogtooth" for improved control at high angles of attack. The all-moving tailplane was given 23° of anhedral to improve control at high angles of attack while still keeping the tailplane clear of the engine exhaust. In addition, air intakes were equipped with variable geometry ramps to regulate airflow to the engines at supersonic speeds. All-weather intercept capability was achieved thanks to the AN/APQ-50 radar. To accommodate carrier operations, the landing gear was designed to withstand landings with a sink rate of 23 ft/s, while the nose strut could extend by some 20 in to increase angle of attack at takeoff.
On 25 July 1955, the Navy ordered two XF4H-1 test aircraft and five YF4H-1 pre-p