[quote][b][url=/v3/forum/%C3%A9tats-unis-31/topic/f-22-news-221/?post=6452#post-6452]ex-nighthawk00[/url] a dit le 01/08/2006 à 12:39 :[/b]

Posté sur un autre forum (sans source):

[quote]When the F-22 was under development, the officially stated performance goal was to hit Mach 1.5 in dry thrust and Mach 1.8 at full afterburner. Well, the Raptor exceeded that handily. The problem now seems to be that it is capable of going too fast too easily.

[b]Gen. John P. Jumper (then USAF Chief of Staff) flew the Raptor at 1.72 Mach without afterburners on January 13, 2005. The supercruise dash started with roughly 75% fuel and with a full combat load of 8 AAMs (blue dummies, but of representative weight) and lasted for about 9 minutes. [/b]With burners lit the F-22 would very rapidly and easily shoot past Mach 2. [b]Paul Metz (former F-22 test pilot) has also stated during an interview that the F-22 has a top speed greater than 1600 mph (Mach 2.42) and its climb rate is faster than the F-15 Eagle[/b], even though specific limits are classified. The problem, according to Metz, was that the Raptor was reaching such high speeds with such ease that you have to be careful not to let the Raptor get too fast. This is especially true during development when software speed limiters tied into the FADEC were defeated for the sake of envelope exploration. The test pilots have to always be concious of not letting the Raptor get too fast.

Unlike earlier jets like the F-15, the F-22 has quasi fixed inlets. Normally, fixed inlets will not allow for speeds greater than Mach 1.8~2.0. However, the F-22's inlet -- while lacking variable ramps in the interest of Stealth -- does incorporate a series of over pressure vent doors. The most prominent of which can be seen on top of the fuselage to the left and right of the centerline as a series of saw toothed slats. These doors open and vent part of the pressure and air volume during high speed flight. It is a wasteful process, but it does protect the engines froms getting too much air and flaming out or suffering compressor shock damage because the air flow remained supersonic by the time it reaches the fan. However, the venting system can only do so much and it is very easy to push the Raptor over the its designed limits and damage the engines. [b]Production Raptors have software limiters which help prevent this from happening[/b], but developmental raptors had these turned off on many occasions during the flight test regime. Also, in order to not too second guess the pilot too much, the software limiters are not particularly draconian and it is still possible to exceed safe velocities in a production Raptor albiet not as easily and usually not in straight and level flight.[/quote]

Je ne serais pas étonné sachant que cette bête à des moteurs monstrueux  8)[/quote]