i have just attempted a flight from EGLL to CYQB using the V4 747F and everything was but whilst decending from FL360 to FL260 the aircraft became wild and uncotrolable. It was on autopilot and speed was set and alt set but suddenly wen overspeed 500KTS and then Stalled and dropped froom the sky, can anyone explain what may have gone wrong since the event starts next week and wouldnt like it to happen again