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we all know that the f-22, the first fifth-generation aircraft in the united states, has a nickname called "raptor", but the f-22 is not the first model to be named "raptor". earlier, there was an unidentified aircraft. the combat aircraft in service are also called "raptors", but this "raptor" is not the other "raptor"! this "raptor" is numbered yf-118g and is a verification aircraft jointly built by mcdonnell douglas and boeing.

the "raptor" was developed in 1992 as a special project of the mysterious "area 51" in the united states. the origin of its name is said to be a reference to the "raptor" star battleship driven by the klingons in the american tv series "star trek". the launch of the "raptor" project is different from other well-known stealth fighters because it was not built for the u.s. air force. in other words, this fighter is just a verification model developed by two companies to verify stealth technology. participation in the air force tender was never considered.

the engineer who presided over the design of the aircraft was alan wichman of mcdonnell douglas's "ghost factory". although his name is not as loud as kelly johnson, who is known as the "son of the wind", he was mentioned in aviation week's aviation design in the division selection, wichman was also named one of the pioneers of stealth aviation. he designed the f-117 stealth fighter. he is also the winner of the technical achievement award of the national defense industry association. use american words to describe this person. the "low-key" designer is: wichman's achievements have given the united states an advantage in the field of stealth aviation for at least 15 years!

like lockheed's "have blue" (the predecessor of the f-117), which first flew in 1977, and northrop's "tacit blue" stealth technology demonstrator, which first flew in 1982, the yf -118g is also a low-cost verification plan, with a total investment of only us$67 million. in order to reduce costs, the predator uses a large number of off-the-shelf components to manufacture. for example, the aircraft has a built-in pratt & whitney canada jt15d-5c business jet turbofan engine with a thrust of 1.44 tons, and uses a mechanical hydraulic flight control system instead of an expensive fly-by-wire system. the flight control and ejection seat are directly taken from the av-8b "harrier" attack aircraft, the cabin is from the f/a-18, and the control system is from the a-4 "skyhawk". generally speaking, this aircraft is one of many in the u.s. air force. a "collection" of fighter aircraft.

"raptor" is a light jet aircraft with a maximum takeoff weight of only 3.3 tons. it has a length of 14.22 meters, a wingspan of 6.91 meters, a height of 2.82 meters, a wing area of ​​20.4 square meters, a maximum speed of only 482 kilometers per hour, and a ceiling of 6100. rice. although the flight performance is unremarkable, the design concept of the yf-118g is very simple. the aircraft is developed using a fully digital method to achieve a truly paperless design, and uses advanced overall composite material forming technology in manufacturing. the aircraft's aerodynamic shape design is even more unconventional. the large swept gull wings are placed on both sides of the rear rear fuselage of the lifting body's diamond-shaped cross-section with sharp edges. the upward reflection of the inner wing section and the downward reflection of the outer wing section are used to create equal forces. the effective vertical stabilizer completely eliminates the vertical tail and eliminates a large lateral radar reflection source. the aircraft's wings are equipped with elevons that also serve as rudders on the trailing edges. the ailerons adopt a "gapless" design that can be smoothly integrated into the wings to reduce radar echoes.

the single-person cockpit is placed at the nose of the aircraft and is equipped with a gold-coated one-piece canopy and zero-zero ejection seat. behind the cockpit is a piggy-back air inlet with an inverted v-shaped lip, which supplies air to the jt15d engine through an s-shaped inlet. , the engine tail nozzle is integrated into the v-shaped slit at the rear of the fuselage, which has excellent radar and infrared stealth capabilities. all flaps, fuselage and wing edges of the aircraft are designed according to the stealth alignment principle, which concentrates the reflection of incident radar waves in several directions away from the emission source. despite its weird appearance, the bird of prey is a fairly statically stable aircraft, so it can fly normally without fly-by-wire flight control. this is why the aircraft uses mechanical and hydraulic flight control.

the yf-118g began test flights in the fall of 1996, and the radar and infrared characteristics were fully tested during the subsequent 38 test flights. according to the yf-118g technical data released by boeing in october 2002,this is a stealth fighter that is a little more advanced than the current f-22 (in terms of stealth alone). in addition to conventional radar stealth, the yf-118g may have also tested an active camouflage system, which is based on the surrounding environment. technology that can match the color of the fuselage by changing the light and shade and color, which is a technology similar to visual camouflage.

the entire "raptor" project was terminated in april 1999. the only demonstration aircraft was donated by boeing to the u.s. air force museum in 2002 and has been on public display since 2003. the technology verified by the yf-118g was quickly used in the manufacture of the boeing x-32 joint strike fighter demonstrator. in addition, boeing's x-45a unmanned combat aircraft demonstrator that first flew in 2002 can basically be regarded as " an unmanned smaller version of the "raptor", but with the assistance of fly-by-wire flight control, the wings can be flattened instead of using gull wings.