The Lockheed F-117 Nighthawk is an American single-seat, twin-engine stealth attack aircraft that was developed by Lockheed's secretive Skunk Works division and operated by the United States Air Force (USAF). The F-117 was based on the Have Blue technology demonstrator.
The Nighthawk was the first operational aircraft to be designed around stealth technology. Its maiden flight took place in 1981 at Groom Lake, Nevada, and the aircraft achieved initial operating capability status in 1983. The Nighthawk was shrouded in secrecy until it was revealed to the public in 1988. Of the 64 F-117s built, 59 were production versions, with the other five being prototypes.
The F-117 was widely publicized for its role in the Persian Gulf War of 1991. Although it was commonly referred to as the "Stealth Fighter", it was strictly a ground-attack aircraft. F-117s took part in the conflict in Yugoslavia, where one was shot down by a surface-to-air missile (SAM) in 1999; it was the only Nighthawk to be lost in combat. The U.S. Air Force retired the F-117 in 2008, primarily due to the fielding of the F-22 Raptor.
|F-117 flying over mountains in Nevada in 2002|
|Role||Stealth attack aircraft|
|National origin||United States|
|First flight||18 June 1981|
|Retired||22 April 2008|
|Primary user||United States Air Force|
|Number built||64 (5 YF-117As, 59 F-117As)|
|Developed from||Lockheed Have Blue|
In 1964, Pyotr Ufimtsev, a Soviet mathematician, published a seminal paper titled Method of Edge Waves in the Physical Theory of Diffraction in the journal of the Moscow Institute for Radio Engineering, in which he showed that the strength of the radar return from an object is related to its edge configuration, not its size. Ufimtsev was extending theoretical work published by the German physicist Arnold Sommerfeld. Ufimtsev demonstrated that he could calculate the radar cross-section across a wing's surface and along its edge. The obvious and logical conclusion was that even a large aircraft could reduce its radar signature by exploiting this principle. However, the resulting design would make the aircraft aerodynamically unstable, and the state of computer technology in the early 1960s could not provide the kinds of flight computers which would later allow aircraft such as the F-117 and B-2 Spirit to stay airborne. By the 1970s, when Lockheed analyst Denys Overholser found Ufimtsev's paper, computers and software had advanced significantly, and the stage was set for the development of a stealthy airplane.
The F-117 was born after combat experience in the Vietnam War when increasingly sophisticated Soviet surface-to-air missiles (SAMs) downed heavy bombers. It was a black project, an ultra-secret program for much of its life: very few people in the Pentagon knew the program even existed, until the F-117s were revealed to the public in 1988. The project began in 1975 with a model called the "Hopeless Diamond" (a wordplay on the Hope Diamond because of its appearance). The following year, the Defense Advanced Research Projects Agency (DARPA) issued Lockheed Skunk Works a contract to build and test two Stealth Strike Fighters, under the code name "Have Blue". These subscale aircraft incorporated jet engines of the Northrop T-38A, fly-by-wire systems of the F-16, landing gear of the A-10, and environmental systems of the C-130. By bringing together existing technology and components, Lockheed built two demonstrators under budget, at $35 million for both aircraft, and in record time.
The maiden flight of the demonstrators occurred on 1 December 1977. Although both aircraft were lost during the demonstration program, test data proved positive. The success of Have Blue led the government to increase funding for stealth technology. Much of that increase was allocated towards the production of an operational stealth aircraft, the Lockheed F-117A, under the program code name "Senior Trend".
The decision to produce the F-117A was made on 1 November 1978, and a contract was awarded to Lockheed Advanced Development Projects, popularly known as the Skunk Works, in Burbank, California. The program was led by Ben Rich, with Alan Brown as manager of the project. Rich called on Bill Schroeder, a Lockheed mathematician, and Denys Overholser, a computer scientist, to exploit Ufimtsev's work. The three designed a computer program called "Echo", which made it possible to design an airplane with flat panels, called facets, which were arranged so as to scatter over 99% of a radar's signal energy "painting" the aircraft.
The first YF-117A, serial number 79-10780, made its maiden flight from Groom Lake ("Area 51"), Nevada, on 18 June 1981, only 31 months after the full-scale development decision. The first production F-117A was delivered in 1982, and operational capability was achieved in October 1983. The 4450th Tactical Group stationed at Nellis AFB, Nevada were tasked with the operational development of the early F-117, and between 1981 (prior to the arrival of the first models) and 1989 they used LTV A-7 Corsair IIs for training, to bring all pilots to a common flight training baseline and later as chase planes for F-117A tests.
The Air Force denied the existence of the aircraft until 10 November 1988, when Assistant Secretary of Defense J. Daniel Howard displayed a grainy photograph at a Pentagon press conference, disproving the many inaccurate rumors about the shape of the secret "F-19". After the announcement pilots could fly the F-117 during daytime and no longer needed to be associated with the A-7, flying the T-38 supersonic trainer for travel and training instead. In April 1990, two F-117 aircraft were flown into Nellis Air Force Base, Nevada, arriving during daylight and publicly displayed to a crowd of tens of thousands.
As the Air Force has stated, "Streamlined management by Aeronautical Systems Center, Wright-Patterson AFB, Ohio, combined breakthrough stealth technology with concurrent development and production to rapidly field the aircraft... The F-117A program demonstrates that a stealth aircraft can be designed for reliability and maintainability."
The operational aircraft was officially designated "F-117A". Most modern U.S. military aircraft use post-1962 designations in which the designation "F" is usually an air-to-air fighter, "B" is usually a bomber, "A" is usually a ground-attack aircraft, etc. (Examples include the F-15, the B-2, and the A-6.) The F-117 is primarily an attack aircraft, so its "F" designation is inconsistent with the DoD system. This is an inconsistency that has been repeatedly employed by the U.S. Air Force with several of its attack aircraft since the late 1950s, including the Republic F-105 Thunderchief and General Dynamics F-111 Aardvark. A televised documentary quoted project manager Alan Brown as saying that Robert J. Dixon, a four-star Air Force general who was the head of Tactical Air Command felt that the top-notch USAF fighter pilots required to fly the new aircraft were more easily attracted to an aircraft with an "F" designation for fighter, as opposed to a bomber ("B") or attack ("A") designation.
The designation "F-117" seems to indicate that it was given an official designation prior to the 1962 U.S. Tri-Service Aircraft Designation System and could be considered numerically to be a part of the earlier "Century series" of fighters. The assumption prior to the revealing of the aircraft to the public was that it would likely receive the F-19 designation as that number had not been used. However, there were no other aircraft to receive a "100" series number following the F-111. Soviet fighters obtained by the U.S. via various means under the Constant Peg program were given F-series numbers for their evaluation by U.S. pilots, and with the advent of the Teen Series fighters, most often Century Series designations.
As with other exotic military aircraft types flying in the southern Nevada area, such as captured fighters, an arbitrary radio call of "117" was assigned. This same radio call had been used by the enigmatic 4477th Test and Evaluation Squadron, also known as the "Red Hats" or "Red Eagles", that often had flown expatriated MiG jet fighters in the area, but there was no relationship to the call and the formal F-19 designation then being considered by the Air Force. Apparently, use of the "117" radio call became commonplace and when Lockheed released its first flight manual (i.e., the Air Force "dash one" manual for the aircraft), F-117A was the designation printed on the cover.
When the Air Force first approached Lockheed with the stealth concept, Skunk Works Director Kelly Johnson proposed a rounded design. He believed smoothly blended shapes offered the best combination of speed and stealth. However, his assistant, Ben Rich, showed that faceted-angle surfaces would provide significant reduction in radar signature, and the necessary aerodynamic control could be provided with computer units. A May 1975 Skunk Works report, "Progress Report No. 2, High Stealth Conceptual Studies", showed the rounded concept that was rejected in favor of the flat-sided approach.
The resulting unusual design surprised and puzzled experienced pilots; a Royal Air Force pilot, who flew it as an exchange officer while it was still a secret project, stated that when he first saw a photograph of the F-117, he "promptly giggled and thought to [himself] 'this clearly can't fly'". Early stealth aircraft were designed with a focus on minimal radar cross-section (RCS) rather than aerodynamic performance. Highly-stealthy aircraft like the F-117 Nighthawk are aerodynamically unstable in all three aircraft principal axes and require constant flight corrections from a fly-by-wire (FBW) flight system to maintain controlled flight. It is shaped to deflect radar signals and is about the size of an F-15 Eagle.
The single-seat Nighthawk is powered by two non-afterburning General Electric F404 turbofan engines. It is air refuelable and features a V-tail. The maximum speed is 623 miles per hour (1,003 km/h) at high altitude, the max rate of climb is 2,820 feet (860 m) per minute, and service ceiling is 43,000 to 45,000 feet (13,000 to 14,000 m). The cockpit was quite spacious, with ergonomic displays and controls, but the field of view was somewhat obstructed with a large blind spot to the rear.
It has quadruple-redundant fly-by-wire flight controls. To lower development costs, the avionics, fly-by-wire systems, and other parts were derived from the General Dynamics F-16 Fighting Falcon, McDonnell Douglas F/A-18 Hornet and McDonnell Douglas F-15E Strike Eagle. The parts were originally described as spares on budgets for these aircraft, to keep the F-117 project secret.
The aircraft is equipped with sophisticated navigation and attack systems integrated into a digital avionics suite. It navigates primarily by GPS and high-accuracy inertial navigation. Missions are coordinated by an automated planning system that can automatically perform all aspects of an attack mission, including weapons release. Targets are acquired by a thermal imaging infrared system, slaved to a laser rangefinder/laser designator that finds the range and designates targets for laser-guided bombs. The F-117A's split internal bay can carry 5,000 pounds (2,300 kg) of ordnance. Typical weapons are a pair of GBU-10, GBU-12, or GBU-27 laser-guided bombs, two BLU-109 penetration bombs, or two Joint Direct Attack Munitions (JDAMs), a GPS/INS guided stand-off bomb.
The F-117 has a radar cross-section of about 0.001 m2 (0.0108 sq ft). Among the penalties for stealth are lower engine thrust due to losses in the inlet and outlet, a very low wing aspect ratio, and a high sweep angle (50°) needed to deflect incoming radar waves to the sides. With these design considerations and no afterburner, the F-117 is limited to subsonic speeds.
The F-117A carries no radar, which lowers emissions and cross-section, and whether it carries any radar detection equipment is classified.
The F-117A's faceted shape (made from 2-dimensional flat surfaces) resulted from the limitations of the 1970s-era computer technology used to calculate its radar cross-section. Later supercomputers made it possible for subsequent aircraft like the B-2 bomber to use curved surfaces while maintaining stealth, through the use of far more computational resources to perform the additional calculations.
An exhaust plume contributes a significant infrared signature. The F-117 reduces IR signature with a non-circular tail pipe (a slit shape) to minimize the exhaust cross-sectional volume and maximize the mixing of hot exhaust with cool ambient air. The F-117 lacks afterburners, because the hot exhaust would increase the infrared signature, and breaking the sound barrier would produce an obvious sonic boom, as well as surface heating of the aircraft skin which also increases the infrared footprint. As a result, its performance in air combat maneuvering required in a dogfight would never match that of a dedicated fighter aircraft. This was unimportant in the case of this aircraft since it was designed to be a bomber.
Passive (multistatic) radar, bistatic radar and especially multistatic radar systems detect some stealth aircraft better than conventional monostatic radars, since first-generation stealth technology (such as the F-117) reflects energy away from the transmitter's line of sight, effectively increasing the radar cross section (RCS) in other directions, which the passive radars monitor.
During the program's early years, from 1984 to mid-1992, the F-117A fleet was based at Tonopah Test Range Airport, Nevada, where it served under the 4450th Tactical Group. Because the F-117 was classified during this time, the unit was officially located at Nellis Air Force Base, Nevada, and equipped with A-7 Corsair II aircraft. All military personnel were permanently assigned to Nellis AFB, and most personnel and their families lived in Las Vegas. This required commercial air and trucking to transport personnel between Las Vegas and Tonopah each week. The 4450th was absorbed by the 37th Tactical Fighter Wing in 1989. In 1992, the entire fleet was transferred to Holloman Air Force Base, New Mexico, under the command of the 49th Fighter Wing. This move also eliminated the Key Air and American Trans Air contract flights to Tonopah, which flew 22,000 passenger trips on 300 flights from Nellis to Tonopah per month.
The F-117 reached initial operating capability status in 1983. The Nighthawk's pilots called themselves "Bandits". Each of the 558 Air Force pilots who have flown the F-117 has a Bandit number, such as "Bandit 52", that indicates the sequential order of their first flight in the F-117.
The F-117 has been used several times in war. Its first mission was during the United States invasion of Panama in 1989. During that invasion two F-117A Nighthawks dropped two bombs on Rio Hato airfield.
During the Gulf War in 1991, the F-117 flew approximately 1,300 sorties and scored direct hits on 1,600 high-value targets in Iraq over 6,905 flight hours. Leaflet drops on Iraqi forces displayed the F-117 destroying ground targets and warned "Escape now and save yourselves". Initial claims of its effectiveness were later found to be overstated. For instance it was claimed that the F-117 made up 2.5% of Coalition tactical aircraft in Iraq and they attacked more than 40% of the strategic targets; this ignored the fact that only 229 Coalition aircraft could drop and designate laser-guided bombs of which 36 F-117 represented 15.7%, and only the USAF had the I-2000 bombs intended for hardened targets, so the F-117 represented 32% of all coalition aircraft that could deliver such bombs. Initial reports of F-117s hitting 80% of their targets were later scaled back to "41–60%". On the first night, they failed to hit 40% of their assigned air-defense targets, including the Air Defense Operations Center in Baghdad, and 8 such targets remained functional out of 10 that could be assessed. In their Desert Storm white paper, the USAF claimed that "the F-117 was the only airplane that the planners dared risk over downtown Baghdad" and that this area was particularly well defended. In fact, most of the air defenses were on the outskirts of the city and many other aircraft hit targets in the downtown area, with minimal casualties when they attacked at night like the F-117. This meant they avoided the optically aimed AAA and infra-red SAMs which were the biggest threat to Coalition aircraft.
The aircraft was operated in secret from Tonopah for almost a decade, but after the Gulf War the aircraft moved to Holloman in 1992 – however its integration with the USAF's non-stealth "iron jets" occurred slowly. As one senior F-117A pilot later said: Because of ongoing secrecy others continued to see the aircraft as "none of their business, a stand-alone system". The F-117A and the men and women of the 49th Fighter Wing were deployed to Southwest Asia on multiple occasions. On their first deployment, with the aid of aerial refueling, pilots flew non-stop from Holloman to Kuwait, a flight of approximately 18.5 hours – a record for single-seat fighters that stands today.
One F-117 (AF ser. no. 82-0806) was lost to enemy action. It was downed during a mission against the Army of Yugoslavia on 27 March 1999, during Operation Allied Force. At approximately 8:15 pm local time, the aircraft was acquired by a fire control radar at a distance of 13 km and an altitude of 8 km: SA-3s were then launched by a Yugoslav version of the Soviet Isayev S-125 "Neva" (NATO name SA-3 "Goa") anti-aircraft missile system. The launcher was run by the 3rd Battalion of the 250th Air Defence Missile Brigade under the command of Colonel Zoltán Dani. According to Dani in a 2007 interview, his troops spotted the aircraft on radar when its bomb-bay doors opened, raising its radar signature. One source states one of the missiles detonated by its proximity fuze near the F-117. Dani said he kept most of his missile sites intact by frequently moving them, and had spotters looking for F-117s and other NATO aircraft. He also stated that he oversaw the modification of his targeting radar to improve its detection capability.
After the explosion, the aircraft became uncontrollable, forcing the pilot to eject. The pilot was recovered six hours later by a United States Air Force Pararescue team. Photos show that the aircraft struck the ground at low speed in an inverted position, and that the airframe remained relatively intact. The Serbs invited Russian personnel to inspect the aircraft's remains, compromising the then 25-year-old U.S. stealth technology. The F-117's pilot was initially misidentified. Though the name "Capt Ken 'Wiz' Dwelle" was painted on the canopy, it was revealed in 2007 that the pilot was Lt. Col. Dale Zelko. The stealth technology from the downed F-117 may have been acquired by Russia and China.
Use of the aircraft as part of Operation Allied Force continued, and it was later used in the Operation Enduring Freedom in 2001 and Operation Iraqi Freedom in 2003. It was operated by the U.S. Air Force.
The loss in Serbia caused the USAF to create a subsection of their existing weapons school to improve tactics. More training was done with other units, and the F-117A began to participate in Red Flag exercises. Though advanced for its time, the F-117's stealthy faceted airframe required a large amount of maintenance and was eventually superseded by streamlined shapes produced with computer-aided design. Other weapon systems began to take on the F-117's roles, such as the F-22 Raptor gaining ability to drop guided bombs. By 2005, the aircraft was used only for certain missions, such as if a pilot needed to verify that the correct target had been hit, or when minimal collateral damage was vital.
The Air Force had once planned to retire the F-117 in 2011, but Program Budget Decision 720 (PBD 720), dated 28 December 2005, proposed retiring it by October 2008 to free up an estimated $1.07 billion to buy more F-22s. PBD 720 called for 10 F-117s to be retired in FY2007 and the remaining 42 in FY2008, stating that other Air Force planes and missiles could stealthily deliver precision ordnance, including the B-2 Spirit, F-22 and JASSM. The planned introduction of the multirole F-35 Lightning II also contributed to the retirement decision.
In late 2006, the Air Force closed the F-117 formal training unit (FTU), and announced the retirement of the F-117. The first six aircraft to be retired made their last flight on 12 March 2007 after a ceremony at Holloman AFB to commemorate the aircraft's career. Brigadier General David L. Goldfein, commander of the 49th Fighter Wing, said at the ceremony, "With the launch of these great aircraft today, the circle comes to a close – their service to our nation's defense fulfilled, their mission accomplished and a job well done. We send them today to their final resting place – a home they are intimately familiar with – their first, and only, home outside of Holloman."
Unlike most other Air Force aircraft that are retired to Davis-Monthan AFB for scrapping, or dispersal to museums, most of the F-117s were placed in "Type 1000" storage in their original hangars at the Tonopah Test Range Airport. At Tonopah, their wings were removed and the aircraft are stored in their original climate-controlled hangars. The decommissioning occurred in eight phases, with the operational aircraft retired to Tonopah in seven waves beginning on 13 March 2007, and ending with the last wave's arrival on 22 April 2008. Four aircraft were kept flying beyond April by the 410th Flight Test Squadron at Palmdale for flight test. By August, two were remaining. The last F-117 (AF Serial No. 86-0831) left Palmdale to fly to Tonopah on 11 August 2008. With the last aircraft retired, the 410th was inactivated in a ceremony on 1 August 2008.
Five aircraft were placed in museums, including the first four YF-117As and some remains of the F-117 shot down over Serbia. Through 2009, one F-117 has been scrapped. F-117 AF Serial No. 79-0784 was scrapped at the Palmdale test facility on 26 April 2008. It was the last F-117 at Palmdale and was scrapped to test an effective method for destroying F-117 airframes. Although officially retired, the F-117 fleet remains intact, and photos show the aircraft carefully mothballed. F-117s have been spotted flying in the Nellis Bombing Range as recently as July 2015. Some of the aircraft are flown periodically.
Congress had ordered that all F-117s mothballed from 30 September 2006 onwards were to be maintained "in a condition that would allow recall of that aircraft to future service" as part of the 2007 National Defense Authorization Act. By April 2016, lawmakers appeared ready to "remove the requirement that certain F-117 aircraft be maintained in a condition that would allow recall of those aircraft to future service", which would move them from storage to the aerospace maintenance and regeneration yard in Arizona to be scavenged for hard-to-find parts, or completely disassembled.
On 11 September 2017, it was reported that in accordance with the National Defense Authorization Act for Fiscal Year 2017, signed into law on 23 December 2016, "the Air Force will remove four F-117s every year to fully divest them – a process known as demilitarizing aircraft".
The United States Navy tested the F-117 in 1984 but determined it was not suitable for carrier use. In the early 1990s, Lockheed proposed an upgraded, carrier-capable variant of the F-117 dubbed the "Seahawk" to the Navy as an alternative to the canceled A/F-X program. The unsolicited proposal was received poorly by the Department of Defense, which had little interest in the single mission capabilities of such an aircraft, particularly as it would take money away from the Joint Advanced Strike Technology program, which evolved into the Joint Strike Fighter. The new aircraft would have differed from the land-based F-117 in several ways, including the addition "of elevators, a bubble canopy, a less sharply swept wing and reconfigured tail". The "N" variant would also be re-engined to use General Electric F414 turbofans instead of the older General Electric F404s. The aircraft would be optionally fitted with hardpoints, allowing for an additional 8,000 lb (3,600 kg) of payload, and a new ground-attack radar with air-to-air capability. In that role the F-117N could carry AIM-120 AMRAAM air-to-air missiles.
After being rebuffed by the Navy, Lockheed submitted an updated proposal that included afterburning capability and a larger emphasis on the F-117N as a multi-mission aircraft, rather than just an attack aircraft. To boost interest, Lockheed also proposed an F-117B land-based variant that shared most of the F-117N capabilities. This variant was proposed to the USAF and the Royal Air Force. Several RAF exchange officers flew the F-117 during its service, two RAF pilots formally evaluated the aircraft in 1986 as a reward for British help with the American bombing of Libya that year, and the British declined an offer during the Reagan administration to purchase the aircraft. This renewed F-117N proposal was also known as the A/F-117X. Neither the F-117N nor the F-117B were ordered.
The aircraft's official name is "Night Hawk", however the alternative form "Nighthawk" is frequently used.
As it prioritized stealth over aerodynamics, it earned the nickname "Wobblin' Goblin" due to its alleged instability at low speeds. However, F-117 pilots have stated the nickname is undeserved. "Wobblin' (or Wobbly) Goblin" is likely a holdover from the early Have Blue / Senior Trend (FSD) days of the project when instability was a problem. In the USAF, "Goblin" (without wobbly) persists as a nickname because of the aircraft's appearance. During Operation Desert Storm, Saudis dubbed the aircraft "Shaba", which is Arabic for "Ghost". Some pilots also called the airplane the "Stinkbug".
Aircraft of comparable role, configuration and era
The 1999 F-117A shootdown was an event that took place on 27 March 1999, during the NATO bombing of Yugoslavia (i.e. Operation Allied Force or Operation Noble Anvil), when an Army of Yugoslavia unit used an S-125 Neva/Pechora to shoot down a Lockheed F-117 Nighthawk stealth aircraft of the United States Air Force. The pilot ejected and was rescued by allied search and rescue forces.The U.S. Air Force F-117A was developed in the 1970s, entering service in 1983 and officially revealed in 1988. It saw its first combat in 1989 over Panama, and was widely seen as one of the most advanced pieces of U.S. military equipment. At the same time, Yugoslav air defenses were seen as relatively obsolete.ACES II
ACES II is an ejection seat system manufactured by the United Technologies Aerospace Systems (UTAS) division of the United Technologies Corporation (UTC). ACES is an acronym for Advanced Concept Ejection Seat. It is used in Fairchild Republic A-10 Thunderbolt II, McDonnell Douglas F-15 Eagle, General Dynamics F-16 Fighting Falcon, Lockheed Martin F-22 Raptor, Lockheed F-117 Nighthawk, Rockwell B-1 Lancer, WB-57, and Northrop Grumman B-2 Spirit aircraft. Over 10,000 ACES II seats have been produced with over 5,000 actively flying throughout the world as of 2013. It is known throughout the industry as the lowest life cycle cost third generation seat due to the USAF owning the rights to the seat, facilitating competitive replacement part procurement. In addition, the buying power of 5,000 in-service seats and previous service life extension programs have further driven down support costs.The seat is considered third generation and includes advanced features. For example, it senses the conditions of the ejection (airspeed and altitude) and selects the appropriate drogue and main parachute deployments to minimize the forces on the occupant. The seat is controlled by a fully redundant digital electronic sequencer which makes the decisions and initiates the appropriate seat components to allow the seat to fly through the air and safely descend the aircrew to the ground. The sequencer includes a crash data recorder that contains ejection information that can be later analyzed during crash investigations to understand the dynamics of the ejection as well as loads on the aircrew during the event. The seat propulsion system is specially designed with technology to compensate for aircrew weight so that the 103 lb small female aircrew gets a similar acceleration to the 245 lb male pilot. The seat has been updated over the years through pre-planned product improvement programs to include digital sequencing, additional redundancy, enhance stability, limb restraints, structural upgrading, and passive head/neck restraints. The ACES II seat ejection injury rate is one of the lowest in the world as proven in over 600 live ejections. Back injury rates occur in only 1% of ACES ejections compared to 20% to 40% in most other ejection seats.The A-10, F-15, F-117, B-1, and B-2 use connected firing handles that activate both the canopy jettison systems, and the seat ejection. Both handles accomplish the same task, so pulling either one suffices. The F-22, WB-57, and F-16 have only one handle located between the pilot's legs, due to cockpit space limitations.The minimal ejection altitude for ACES II seat in inverted flight is about 140 feet (43 m) above ground level at 150 KIAS. The seat performance is in accordance with MIL-S-9479 as tailored for each aircraft application. Excellent terrain clearance performance under 250 KEAS is achieved by deploying the main parachute immediately after exiting the cockpit. It is the only ejection seat that can deploy the main parachute this early in the ejection sequence.The ACES seat was originally developed and produced in Long Beach, CA by McDonnell Douglas. Weber Aircraft company also produced the seat as part of a USAF mandated "leader/follower" program. In the late 1980s the McDonnell Douglas production line was relocated from Long Beach, CA to Titusville, FL. The Weber Aircraft ACES production line eventually closed as USAF needs for ejection seats declined. In the late 1990s, Boeing and McDonnell Douglas merged with the combined company retaining the Boeing name. In 1999, Goodrich acquired the ACES product line from Boeing and eventually relocated the production line to Colorado Springs to the Aircraft Manufactures Inc. (AMI) facility owned by Goodrich. In 2012, United Technologies acquired the Goodrich Corporation. Today the ACES seat product line continues to be manufactured in Colorado Springs, Colorado.Aircraft camouflage
Aircraft camouflage is the use of camouflage on military aircraft to make them more difficult to see, whether on the ground or in the air. Given the possible backgrounds and lighting conditions, no single scheme works in every situation. A common approach has been a form of countershading, the aircraft being painted in a disruptive pattern of ground colors such as green and brown above, sky colors below. For faster and higher-flying aircraft, sky colors have sometimes been used all over, while helicopters and fixed-wing aircraft used close to the ground are often painted entirely in ground camouflage. Aircraft flying by night have often been painted black, but this actually made them appear darker than the night sky, leading to paler night camouflage schemes. There are trade-offs between camouflage and aircraft recognition markings, and between camouflage and weight. Accordingly, visible light camouflage has been dispensed with when air superiority was not threatened or when no significant aerial opposition was anticipated.
Aircraft were first camouflaged during World War I; aircraft camouflage has been widely employed since then. In World War II, disruptive camouflage became widespread for fighters and bombers, sometimes combined with countershading. Some air forces such as the German Luftwaffe varied their paint schemes to suit differing flight conditions such as the skyglow over German cities, or the sands of the Mediterranean front.
During and after World War II, the Yehudi lights project developed counter-illumination camouflage using lamps to increase the brightness of the aircraft to match the brightness of the sky. This was abandoned with improvements in radar, which seemed to render visible light camouflage redundant. However, aircraft continue to be painted in camouflage schemes; recent experiments have again explored active camouflage systems which allow colors, patterns and brightness to be changed to match the background, and some air forces have painted their fighters in digital camouflage patterns. Stealth technology, as in the Lockheed F-117 Nighthawk, aims to minimize an aircraft's radar cross-section and infrared signature, effectively providing multi-spectral camouflage at the price of reduced flying performance. Stealth may extend to avoiding or preventing vapor contrails.F-117A Nighthawk Stealth Fighter 2.0
F-117A Nighthawk Stealth Fighter 2.0 is the 1991 remake of the 1988-1990 Cold War combat flight simulator video game F-19 Stealth Fighter by MicroProse, itself a remake of the 1987's Project Stealth Fighter. The original PC version was updated with a corrected aircraft model once the Lockheed F-117 Nighthawk was declassified and with 256-color VGA graphics instead of the original's 16-color EGA, among other changes.F-117 (disambiguation)
F-117 is the Lockheed F-117 Nighthawk, an American stealth attack aircraft.
F-117 or F117 may also refer to:
Pratt & Whitney PW2000 (military designation F117), a turbofan aero engine
F-117A Nighthawk Stealth Fighter 2.0, for the IBM PC from MicroProse (1991)
F-117A Stealth Fighter, for the NES from MicroProse (1992)F-117 Night Storm
F-117 Night Storm is a Sega Mega Drive-exclusive video game that was released in 1993 by Electronic Arts.F-19
F-19 is the designation for a hypothetical US fighter aircraft that has never been officially acknowledged, and has engendered much speculation that it might refer to a type of aircraft whose existence is still classified.General Electric F404
The General Electric F404 and F412 are a family of afterburning turbofan engines in the 10,500–19,000 lbf (47–85 kN) class (static thrust). The series are produced by GE Aviation. Partners include Volvo Aero, which builds the RM12 variant. The F404 was developed into the larger F414 turbofan, as well as the experimental GE36 civil propfan.Infrared signature
Infrared signature, as used by defense scientists and the military, is the appearance of objects to infrared sensors. An infrared signature depends on many factors, including the shape and size of the object, temperature and emissivity, reflection of external sources (earthshine, sunshine, skyshine) from the object's surface, the background against which it is viewed and the waveband of the detecting sensor. As such there is no all-encompassing definition of infrared signature nor any trivial means of measuring it. For example, the infrared signature of a truck viewed against a field will vary significantly with changing weather, time of day and engine loading.
Two fairly successful examples of defining the infrared signature of an object are the apparent temperature difference at the sensor and the contrast radiant intensity (CRI) definitions.Lockheed Have Blue
Lockheed Have Blue was the code name for Lockheed's proof of concept demonstrator that preceded the production F-117 Nighthawk stealth aircraft. Have Blue was designed by Lockheed's Skunk Works division, and tested at Groom Lake, Nevada. The Have Blue was the first fixed-wing aircraft whose external shape was defined by radar engineering rather than by aerospace engineering. The aircraft's plate-like, faceted shape was designed to deflect electromagnetic waves in directions other than that of the originating radar emitter, greatly reducing its radar cross-section. Two flyable vehicles were constructed, but both crashed during the flight-test program.
In the 1970s, it became increasingly apparent to U.S. planners that, in a military confrontation with Warsaw Pact forces, NATO aircraft would quickly suffer heavy losses. This came as a result of sophisticated Soviet defense networks, which used surveillance radars, radar-guided surface-to-air missiles (SAM), and anti-aircraft artillery to seek and eliminate enemy aircraft. Consequently, the Defense Advanced Research Projects Agency (DARPA) started a study on low-observability aircraft, seeking to design and produce an operational stealth aircraft. Five companies were initially invited, three of which bowed out early. The remaining two were later joined by Lockheed.
To design the aircraft, the Skunk Works' design team devised a computer program to calculate the radar cross-sections (RCS) of various designs. The eventual design characteristically featured faceted surfaces to deflect radar waves away from a radar receiver. It had highly-swept wings and inward-canted vertical stabilizers, which led to its being nicknamed "the Hopeless Diamond". The first operational aircraft made its maiden flight on 1 December 1977. The flight test program validated the feasibility of a flyable stealth aircraft. However, both prototypes were lost due to mechanical problems. Nevertheless, Have Blue was deemed a success, paving the way for the first operational stealth aircraft, Senior Trend, or Lockheed F-117 Nighthawk.Lockheed Martin Aeronautics
Lockheed Martin Aeronautics Company is a major unit of Lockheed Martin with headquarters at Air Force Plant 4 in Fort Worth, Texas.
Lockheed Martin Aeronautics is based in Marietta, Georgia and Palmdale, California. Palmdale is home to the Advanced Development Programs (ADP), informally known as the "Skunk Works". Various subassemblies are produced at locations in Florida, Mississippi, Pennsylvania, and West Virginia.
The company draws upon the history of the former Lockheed and Martin Marietta corporations. While the formation of Lockheed Martin in 1995 was a merger of equals, by far the greatest contribution to Lockheed Martin Aeronautics was the product portfolio of Lockheed. This included the C-5, C-130, and C-141 transports as well as the F-2, F-16 (purchased from General Dynamics), F-117, F-22, and F-35 Lightning II.
The most important project by far to Lockheed Martin Aeronautics is the F-35 Lightning II (JSF). Worth a potential $200bn the initial order book is approximately 3,000 excluding almost guaranteed export orders. The F-22 air dominance fighter, while smaller in terms of aircraft ordered, is still of great importance to Lockheed Martin (and partner Boeing).National Radar Cross-section Facility
The United States' National Radar Cross-section Facility (commonly abbreviated as RATSCAT) is located at Holloman AFB, New Mexico.
The Lockheed Have Blue and Lockheed F-117 Nighthawk have been tested at this site.Relaxed stability
In aviation, relaxed stability is the tendency of an aircraft to change its altitude and angle of bank spontaneously. An aircraft with relaxed stability will oscillate in simple harmonic motion around a particular attitude at an increasing amplitude.This can be contrasted with the behaviour of an aircraft with positive stability, which, when trimmed to fly at a certain attitude, will continue to do so in the absence of control input, and if perturbed will oscillate in simple harmonic motion on a decreasing scale around and eventually return to the trimmed attitude. A positively stable aircraft will also resist any bank movement. A Cessna 152 is an example of a stable aircraft. Similarly, an aircraft with neutral stability will not return to its trimmed setting without control input, but will oscillate in a stable simple harmonic motion around the trimmed setting continuously, neither increasing nor decreasing oscillation amplitude, and be susceptible to bank influences.Richard C. Scherrer
Richard C. Scherrer (1919–2018) was an aircraft designer notable for pioneering work on revolutionary aircraft designs with extremely low radar cross sections that led to the Lockheed F-117 Nighthawk and Northrop Grumman B-2 Spirit.Skunk Works
Skunk Works is an official pseudonym for Lockheed Martin's Advanced Development Programs (ADP), formerly called Lockheed Advanced Development Projects. It is responsible for a number of aircraft designs, including the U-2, the Lockheed SR-71 Blackbird, the Lockheed F-117 Nighthawk, Lockheed Martin F-22 Raptor, and the Lockheed Martin F-35 Lightning II, which are used in the air forces of several countries. Its name was taken from the moonshine factory in the comic strip Li'l Abner. The designation "skunk works" or "skunkworks" is widely used in business, engineering, and technical fields to describe a group within an organization given a high degree of autonomy and unhampered by bureaucracy, with the task of working on advanced or secret projects.Stealth ATF
Stealth ATF is a stealth fighter video game released by Activision in 1989 for the Nintendo Entertainment System. The object of the game is to take out aircraft that are trying to destroy the player's stealth fighter. The game supports up to two players.