Having a problem, when downloading aircraft, panels and gauges for fs 2002, after takeoff upon climbing past 20000 feet the aircraft loses speed so therefore crashes. Its happened with Boeings 757, B767 and Airbuses A320 and A330. Any ideas??

What was your vertical climb rate, you have to decrease the vertical climb rate as you climb. Set the aircraft speed and then decrease the vertical climb rate, as necessary to maintain the aircraft speed.