History
Development History
The design and development of the F-22A Raptor originated from the Advanced Tactical Fighter program. It was initiated by the United States Air Force in May 1981 to gather the requirements and develop a next-generation air superiority fighter. It would have a leap in performance and technology over the F-15 Eagle to counter air-to-air threats such as the Soviet Sukhoi Su-27 and Mikoyan MiG-29 fighters and the Beriev A-50 AWACS. The requirements included advanced alloys and composite material, advanced avionics, fly-by-wire flight control, higher power propulsion systems, and stealth technology to install on the next-generation aircraft.
Responding to a request for proposals in September 1985, Lockheed and Northrop submitted their proposals and were selected as the finalists on October 31, 1986, to proceed and develop their technology demonstrator prototypes. Northrop had adequate experience with stealth technology and produced a well-refined aircraft design, while Lockheed had extensive prior stealth experience but produced an inadequate aircraft design. However, because of Lockheed’s primary focus on systems engineering and trade studies, its proposal put it into stronger consideration ahead of Northop in the competition.
Lockheed teamed up with Boeing and General Dynamics to develop the YF-22, while Northrop teamed up with McDonnell Douglas to build its YF-23. Each team was awarded the contract and undertook a 50-month demonstration and validation phase. These prototypes were not meant to perform a competitive flight or represent a production aircraft during the flight tests, and their goal was to demonstrate the viability of its concept and mitigation of risk. Pratt & Whitney and General Electric were also awarded contracts to develop the propulsion systems in the engine competition for these technology demonstrator prototypes.
During the demonstration and validation phase, the Lockheed team had to completely redesign the airframe configuration in the summer of 1987 because its design analysis showed excessive weight. It changed the wing planform from swept trapezoidal to a diamond-like delta and reduced the forebody planform area. The ATF requirements were changed and relaxed, such as deleting thrust-reversers, deleting side-looking radars, downgrading the multicolor infrared search and track system to a single-color one and then deleting as well, and downgrading the advanced ejection seat design to the existing McDonnell Douglas ACES II. Even with these changes incorporated in the designs, the takeoff gross weight estimates grew from 50,000 to 60,000 lb and prompted new engine thrust requirements to increase from 30,000 to 35,000 lb.
The Lockheed team completed the construction of YF-22, and it made its first flight on September 29, 1990, in Palmdale, California. It demonstrated the supercruise, high angle-of-attack maneuvers, and the firing of air-to-air missiles from the internal weapons bay during the flight tests with successes. The first YF-22 prototype was installed with the General Electric YF120-GE-100 engines, and the second YF-22 prototype was installed with Pratt & Whitney YF119-PW-100 engines. The prototype had achieved Mach 1.58 in supercruise, while the second prototype had reached a maximum supercruise speed of Mach 1.43 with excessive maximum speed, past Mach 2.0.
On April 23, 1991, the YF-22 and Pratt & Whitney were announced as the winner of the ATF program. Although the YF-23 lost the competition, it still had met or exceeded all performance requirements and was considered stealthier and faster. The YF-22 was selected and favored as the winner because of its thrust vectoring nozzles, making it more maneuverable, and it was less expensive and risky and had flown more test flights and hours than the YF-23 did.
Production Design Features
The Lockheed team was awarded and forwarded to the full-scale production of the new F-22A Raptor design. The inadequate YF-22 design evolved to have distant differences made in its production stage. Its wing’s leading-edge sweep angle was decreased from 48 degrees to 42 degrees, and the vertical stabilizers were shifted rearward and decreased in area by 20%. The canopy was moved forward 7 inches to improve the pilot’s visibility, and the engine intakes were moved rearward 14 inches. The radome shape was changed to achieve better radar performance. Lastly, the wing and tail were restructured to improve aerodynamics, strength, and stealth. The planform and panel edges were aligned, and the surfaces had continuous curvature to minimize their radar cross-section. Its internal structural design was refined and reinforced to allow the production airframe to last a service life of 8,000 hours.
The F-22 was incorporated with the advanced, integrated avionics system and software, including the fusion of multiple sensor systems and antennas, integrated electronic warfare and communication, navigation, and identification systems. These are the Sanders/General Electric AN/ALR-94 electronic warfare system, the Martin Marietta AN/AAR-56 infrared and Missile Launch Detector, the Westinghouse/Texas Instruments AN/APG-77 active electronically scanned array radar, the TRW Communication/Navigation/Identification system, and long-range advanced IRST. These essential systems assist the pilot’s situational awareness and reduce workload.
The APG-77 radar is a state-of-the-art technology; it has a low-observable, active-aperture, electronically scanned antenna with multiple target track-while-scan in all weather conditions. It is intended to tilt the antenna back for stealth and can focus on its emissions to overload the enemy sensors as an electronic attack capability. The radar changes frequencies more than 1,000 times per second to lower interception probability and has an estimated range of 125 to 150 miles against an 11 square feet target and 250 miles or more in narrow beams.
The F-22’s ALR-94 electronic warfare system was the most complex technical feature because it integrates more than 30 antennas blended into the wings and fuselage for all-around radar warning receiver coverage and threat geolocation. It can be used as a passive detector, searching targets at ranges of more than 285 miles and providing enough information for a radar lock.
The aircraft’s Missile Launch Detector uses six sensors to provide full spherical infrared coverage and prompt the pilot to release countermeasures. Its IRST is a narrow field-of-view sensor for long-range passive identification and targeting, installed in a stealthy wing pod. Lastly, its integrated communication, navigation, and identification system manages the tactical air navigation system, identification of friend or foe, and communication through HAVE QUICK/SATURN, Single Channel Ground and Airborne Radio System, and Joint Tactical Information Distribution System. The F-22A Raptors can ensure its stealth in the radio frequency spectrum by using the directional InterIntra-Flight Data Link.
The F-22’s dual Pratt & Whitney F119 augmented turbofan engines are closely spaced and incorporate pitch-axis thrust vectoring nozzles with a range of 20 degrees in both up and down directions. These nozzles are fully integrated into the F-22’s flight controls and vehicle management system. Each engine has a maximum thrust of 35,000 lb. The thrust-to-weight ratio at typical combat weight is nearly 1.0 in maximum military power and 1.25 in full afterburner. It grants the F-22 the ability to supercruise without using afterburners at a certain altitude. The F-22 can pull 9-g maneuvers at its takeoff gross weight with its powerful thrust-vectoring engines combined with smooth aerodynamics.
The F-22 was designed to be difficult to detect and track by radar, so it was made to reflect, absorb, and debilitate radio waves. The F-22 is not highly dependent on radar-absorbent material; instead, its airframe shape, continuous curvature of surfaces, internal carriage of weapons, and other aerodynamic shape optimizations are the bigger factors in dispersing the radio waves. These require extensive maintenance as they are susceptible to severe weather conditions. The F-22’s exact RCS calculations and stealth in-depth characteristics are classified to this day; however, they are reported to be highly effective against the high-frequency radars in the aircraft. It is possible for low-frequency radars, such as weather radars and early-warning radars, to detect the F-22 due to its considerable physical size.
The F-22A has three internal weapons bays. The large main bay on the bottom of the F-22A has six LAU-142/A launchers for mounting the AIM-120 AMRAAMs and can be replaced with two bomb racks to carry two 1,000 lb or eight 250 lb bombs. The F-22A has two small side bays, and they have an LAU-141/A launcher for the AIM-9 Sidewinders. When the missile is launched, the bay doors will immediately open in less than a second before closing again to reduce the chance of detection. The M61A2 Vulcan 20mm rotary cannon is internally mounted and embedded in the F-22’s right wing root, with the muzzle covered by a retractable door. The F-22’s wings also include four hardpoints as part of pylon attachments that can accommodate up to 5,000 lb payload, allowing the carrying of two 600-gallon external fuel tanks or four air-to-air missiles. A pair of IRST in stealthy pods can be mounted on the outboard hard points. The F-22 can jettison external tanks and pylon attachments to reduce its radar cross-section.
Production and Service Entry
The flight testing with the first-built F-22A began on September 7, 1997. It was an Engineering & Manufacturing Development (EMD) aircraft with tail number 4001; however, the end of the Cold War and the dissolution of the Soviet Union in 1991 had major impacts on F-22 program funding. One example was that the Department of Defense reduced its spending on the F-22 program since the urgency for new weapon systems was deemed unnecessary. This led to rescheduling and delaying the production of F-22. In addition, new technologies after the 1990s had emerged and were needed to augment the F-22’s capabilities, bringing cost issues and more delays.
The USAF originally had an order of 750 F-22s as outlined in the ATF program, with the production expected to start in 1994 and service entry by the late 1990s. In 1990, the number of F-22s in order was reduced to 648, with the production in 1996 and service by the early 2000s, with the decision made by Secretary of Defense Dick Cheney. The number of F-22s in the production was reduced to fewer than 400, and their service entry was delayed again. In 2004, due to the US military’s focus on asymmetric counterinsurgency warfare in Iraq and Afghanistan, Secretary Donald Rumsfeld cut the production number down to 183, later raised to 187 by 2008. It was not until March 2005 that the program finally moved out of politics and transitioned to full-scale production. It concluded its EMD phase in December 2005.
195 F-22s would be built as the final total before 2012. The first 9 EMD F-22s were built in the Block 1.0, Block 2.0, and Block 3.0 configurations for development and upgrade testing. All of these EMDs flew from 1997 to 2002. The production of F-22s began in the Block 10/20 configuration, with 74 units as the training aircraft, and in the Block 30/35 configuration, with 112 units as the combat aircraft. In December 2011, the final F-22 was completed and delivered to the USAF on May 2, 2012, with no plans to restart the F-22 production line due to economic, logistical, and political challenges.
The delivery of operational F-22s for pilot training began in September 2003 at Tyndall Air Force Base, Florida, and the first combat-ready F-22 arrived in January 2005 at Langley Air Force Base, Virginia, for the 1st Fighter Wing.
The F-22 initially entered USAF service in December 2005 and achieved Full Operational Capability in December 2007 as the F-22s in the 1st Fighter Wing and Virginia Air National Guard 129nd Fighter Wing were declared fully operational.
The F-22A Raptor is now the USAF’s first fifth-generation air superiority fighter with fourth-generation stealth aircraft technology. It is also the first operational aircraft to possess a combination of supercruise, supermaneuverability, stealth, and integrated avionics in a single weapons platform.
During the initial years of service, the F-22 pilots experienced symptoms as a result of oxygen system issues that included negative neurological changes and respiratory problems. The issues were so severe that it resulted in a four-month grounding in 2001 and subsequent altitude and distance flight restrictions. The Department of Defense opened the investigation in 2012 and found the BRAG valve was defective and restricted breathing. It was used to inflate the pilot’s vest during high-g maneuvers. In addition, the onboard oxygen generation system was found to reduce oxygen levels during high-g maneuvers. By April 4, 2013, the modifications to the life-support equipment and oxygen system were ordered and resulted in the lifting of the altitude flight restrictions.
The F-22 flew its first homeland defense mission in January and November 2007, where they performed their first interception of two Russian Tu-95MS bombers near American airspace in Alaska. The F-22 was first deployed overseas in February 2007 in Okinawa from the Air Force Base in Hawaii.
On September 22, 2014, F-22s performed their first combat sorties in Operation Inherent Resolve as part of the American-led intervention in Syria. They dropped 1,000-pound GPS-guided bombs on Islamic State targets near Tishrin Dam. Throughout their deployment, the F-22s flew 204 sorties over Syria, dropping 270 bombs at designated locations between September 2014 and July 2015. The F-22’s main role in the operations over the Middle East was only conducting intelligence, surveillance, and reconnaissance.
On February 4, 2023, an F-22 of the Fighter Wing managed to shoot down a suspected high-altitude balloon from China that flew across South Carolina at an altitude of 60,000 to 65,000 feet. It was marked as the F-22’s “first air-to-air kill.” Other F-22s shot down additional unknown high-altitude objects near the coast of northern Alaska on February 10 and over the Yukon on February 11.
Modernization Program
The F-22 received modernization programs in its service to receive upgrades to counter evolving threats. The F-22 received software and hardware modifications under numbered Increments.
The first Increments were for ground attack capabilities for counterinsurgency warfare before 2005. Then, the F-22s in the Block 20 configuration and onward received Increment 2 that enabled the usage of Joint Direct Attack Munitions and improved AN/APG-77(V)1 radar and incorporated air-to-ground modes consisting of synthetic aperture radar mapping and ground moving target indication/track. The APG-77 was fitted on F-22 airframes from Lot 5 onward.
Increment 3.1 was implemented for the F-22s with Block 30/35 configuration in 2011 to improve ground-attack capabilities through synthetic aperture radar and Small Diameter Bomb integration. F-22s were fitted with an automatic backup oxygen system and a modified life support system in 2012 to address oxygen deprivation issues investigated by the Department of Defense.
Increment 3.2 was the definitive upgrade for air combat capabilities and was implemented into the F-22s with the Block 30/35 configuration. It came with two parts: 3.2A with temporary AIM-9X and AIM-120D capability and electronic warfare capability and 3.2B with full integration of the AIM-9X and AIM-120D and avionics improvements. Lockheed Martin had completed and delivered 100% of Increment 3.2B/Update 6 to the fleet of F-22s with the Block 30/35 configuration as of June 2022.
Additional upgrades for integration of the new AIM-260 JATM and the dedicated advanced IRST are currently being tested and planned to be released in the new Increment.
As of August 2022, the USAF has 183 F-22s in its inventory, and the F-22 is planned to remain a fundamental asset of the USAF’s advanced fighter fleet until its replacement by the Next Generation Air Dominance sixth-generation air superiority fighter, which is expected to be unveiled in the 2030s. No F-22s have been exported to foreign customers under the ban placed by the US Congress.
