hi,What is the terminal velocity for an F-16, or similar fighter jet, in an unpowered dive?  Will an F-16 break the sound barrier if diving straight down with engines off?  Consider a starting altitude of about 50,000 feet.I'm developing the physics portion of a flight sim game and when I drop a fighter jet ...

hi Ken,A pilot friend told me once that when you see a vapor trail in the sky made by a passenger jet, the vapor comes from the jet engines.  Is this always true?  Can large vapor trails come from the wings or other parts of a high-flying plane?  Thanks.Gordon