F-22 Raptor Take-Off and Powerful Fast Vertical Climbing

The Lockheed Martin F-22 Raptor is an American single-seat, twin-engine, all-weather tactical stealth fighter aircraft developed for the United States Air Force (USAF). As a product of the USAF's Advanced Tactical Fighter (ATF) program the aircraft was designed as an air superiority fighter, but also incorporates ground attack, electronic warfare, and signals intelligence capabilities. The prime contractor, Lockheed Martin, built most of the F-22's airframe and weapons systems and conducted final assembly, while Boeing provided the wings, aft fuselage, avionics integration, and training systems.

The aircraft first flew in 1997 and was variously designated F-22 and F/A-22 before it formally entered service in December 2005 as the F-22A. Although the USAF had originally planned to buy a total of 750 ATFs, the program was cut to 187 production aircraft in 2009 due to high costs, a lack of air-to-air missions at the time of production, and the development of the more affordable and versatile F-35. The last F-22 was delivered in 2012.

While it had a protracted development and initial operational difficulties, the F-22 has become a critical component of the USAF's tactical airpower. The fighter's combination of stealth, aerodynamic performance, and mission systems enabled a leap in air combat capabilities and set the benchmark for its generation. The F-22 is expected to serve into the 2030s and eventually have its role succeeded by the USAF's Next Generation Air Dominance (NGAD) manned fighter component.

The F-22 Raptor is a fifth-generation air superiority fighter that is considered fourth generation in stealth aircraft technology by the USAF. It is the first operational aircraft to combine supercruise, supermaneuverability, stealth, and sensor fusion in a single weapons platform. The F-22 has clipped diamond-like delta wings blended into the fuselage with four empennage surfaces and leading edge root extensions running to the upper outboard corner of the caret inlets. Flight control surfaces include leading-edge flaps, flaperons, ailerons, rudders on the canted vertical stabilizers, and all-moving horizontal tails (stabilators); for speed brake function, the ailerons deflect up, flaperons down, and rudders outwards to increase drag. The aircraft has a refueling boom receptacle centered on its spine and retractable tricycle landing gear as well as an emergency tailhook.

The aircraft's dual Pratt & Whitney F119 augmented turbofan engines are closely spaced and incorporate pitch-axis thrust vectoring nozzles with a range of ±20 degrees; the nozzles are fully integrated into the F-22's flight controls and vehicle management system. Each engine has maximum thrust in the 35,000 lbf (156 kN) class. The F-22's thrust-to-weight ratio at typical combat weight is nearly at unity in maximum military power and 1.25 in full afterburner. The caret inlets generate oblique shocks with the upper inboard corners to ensure good total pressure recovery and efficient supersonic flow compression. Maximum speed without external stores is approximately Mach 1.8 at military power and greater than Mach 2 with afterburners.

The F-22's high cruise speed and operating altitude over prior fighters improve the effectiveness of its sensors and weapon systems, and increase survivability against ground defenses such as surface-to-air missiles. The ability to supercruise, or sustain supersonic flight without using afterburners, allows it to intercept targets that afterburner-dependent aircraft would lack the fuel to reach. The use of internal weapons bays permits the aircraft to maintain comparatively higher performance over most other combat-configured fighters due to a lack of parasitic drag from external stores. The F-22's thrust and aerodynamics enable regular combat speeds of Mach 1.5 at 50,000 feet (15,000 m), thus providing 50% greater employment range for air-to-air missiles and twice the effective range for JDAMs than with prior platforms. Its structure contains a significant amount of high-strength materials to withstand stress and heat of sustained supersonic flight. Respectively, titanium alloys and bismaleimide/epoxy composites comprise 42% and 24% of the structural weight.

The F-22's aerodynamics, relaxed stability, and powerful thrust-vectoring engines give it excellent maneuverability and energy potential across its flight envelope. The airplane has excellent high alpha (angle of attack) characteristics, capable of flying at trimmed alpha of over 60° while maintaining roll control and performing maneuvers such as the Herbst maneuver (J-turn) and Pugachev's Cobra. The triplex-redundant fly-by-wire control system and full-authority digital engine control (FADEC) make the aircraft highly departure resistant and controllable, thus giving the pilot carefree handling.

source text : wikipedia.org
link : https://en.wikipedia.org/wiki/Lockheed_Martin_F-22_Raptor