The F-22 Raptor was conceived in 1981, took its first test flight in 1990, and did not enter operational service until 2004.

猛禽F-22设计的提出是1981年的事，1990年首飞，直到2004年才进入实际服役。

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Introduces the analysis method for weapon system with different failure on the basis of the operational principle of weapon system and various measurement data in the actual flight test.

依据武器系统的工作原理和在实际飞行试验中得到的各种测量数据，给出了针对不同故障现象的武器系统分析方法。

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Applicants for experimental permits will need to provide a description of their program, a flight test plan, documentation showing the operational safety of the spacecraft and a plan for response in case of a mishap.

FORBES: Magazine Article

Friedman said one review his office conducted last year turned up backlogs in flight and laboratory test schedules for five of nine nuclear missile warheads and bombs in the operational stockpile.

CENTERFORSECURITYPOLICY: Center For Security Policy