First: 3 times crash.
Second: F22 production.
Third: F22 serving six years were not on a battlefield.
First: F-22 flight 1 hour each, you need to maintain 34 hours of their surface coating.
(U.S. Department of Defense officials have criticized said: "The aircraft will only fly one hour repair time, this is really a shame.")
II: F-22 was mainly located in combat, rather than to attack;
(American intellectual Kulai Ke Lexington Institute analyst, said Thompson, 22 March, although F-22 is the world's most advanced fighter, but not suitable to participate in no-fly zone set up in Libya destroy the other air defense system similar to the task because of its The most basic task is not carried out precision strikes against ground targets, though it can carry two 450 kg weight JDAM precision-guided bombs, but can only destroy fixed targets, but can not hit moving targets; In addition, F-22 airborne radar not the same as synthetic aperture radar terrain mapping, which means it can not select ground targets alone, if it is to carry out the bombing of a target, you must fight off target before the relevant information into the onboard computer systems.)
Third: F-22 airborne communication equipment could not upgrade, can not exchange data with other aircraft;
(The original, F-22's communication ability is extremely limited, and only one squadron of F-22 fighters for other operational information exchange, and its equipment Link16 standard communication system, "Performance shrink" is very serious, only one-way received from other aircraft and combat helicopters, intelligence. in the development of F-22, the U.S. engineers are interested in limiting their communication capabilities in order to ensure the highest degree of stealth performance to ensure that their state is always in radio silence for Action to Combat .)
(U.S. Air Force Secretary before the Foreign Intelligence Jieputula, claiming that the modern world's most advanced fighter planes and other aircraft are unable to exchange of operational information, equipment, aircraft apparently did not sense this.)
Fourth: the individual defects found in test flight, forcing in fact, significantly reduced with the ceiling.
(The end of March the image of F-22 fighters have again been a significant blow to the U.S. decision to limit flying height of its more restricted, with a maximum ceiling of not more than 7600 meters. According to the U.S. F-22 previously reported the technical performance parameters, ceiling of about 20,000 meters, and so greatly limit natural surprising. Originally, the U.S. military inspection found that F-22 on-board oxygen generation system may have a serious defect, which may also contributed to the November 17, 2010 an F- 22 cause of the crash. was that F-22 aircraft test flight in Alaska may be the oxygen system failure, the system responsible for generating oxygen, and through a special helmet to ensure that pilots flying at high altitude when the demand for normal breathing, when the crash when the pilot may coma from lack of oxygen, resulting in loss of control. the U.S. military in the interpretation of F-22 flight altitude restrictions pointed out in the 15,000 m or higher flight, once the oxygen supply disruption helmet, pilots will only need 10 seconds coma, no time to be able to do an emergency lowering the height of the helmet to breathe free. 7600 meters is the most secure level, oxygen supply interrupted when the helmet, the pilots have the opportunity to complete within 10 seconds down to 5400 meters below the height, will not appeal problem.)
It must be emphasized that the above deficiencies is officially recognized by the U.S. Air Force and the Defense Department does not rule out the existence of the U.S. F-22 is also carefully concealed the possibility of other defects