Where can I buy good flight planning software?

The prototype YF-22 won a fly-off competition against the Northrop/McDonnell-Douglas YF-23 for the Advanced Tactical Fighter contract. In April 1992, during flight testing after contract award, the first YF-22A prototype crashed while landing at Edwards Air Force Base in California. The test pilot, Tom Morgenfeld, was not injured and the cause of the crash was found to be a flight control software error that allowed and created a pilot-induced oscillation. The YF-22 was originally given the unofficial name "Lightning II" by Lockheed, which persisted until the mid-1990s. For a short while, the plane was also dubbed "Rapier". The F-35 later received the Lightning II name on 7 July 2006.