Hi all, nice to be back after having disappeared for a long time!

I am now hunting for new aircrafts to download to suit my Project AI aircrafts. I have looked at many websites where I can download aircrafts (mainly B777 and A330) and fly them but it seems that no download has perfect dynamics. I downloaded aircrafts made by meljet which have excellent textures and some from POSKY. However, it seems that all downloads have a problem, despite having downloaded aircrafts from different websites, I find climbing the most hardest part. I fly an aircraft, aim to climb to about 34,000 ft but once I reach about 22,000 ft the aircraft starts to stall as the airspeed decreases very quickly. The problem only seem to occur with downloaded aircraft because I dont face the same problem with the default aircrafts that come originally with the game (e.g. 777 landmark airlines...etc). Where could I possibly be wrong??!?!?

Depends how heavy you are.  The A330 is not a fast climber by any means, if going on a long haul you have to step climb to burn off fuel...even the powerfull 777 cant go strait to 38,000 feet when your going to be on a 14 hour flight.  Usualy climb to somewhere in the FL200-FL280 and stay there for an hour or so to burn off fuel.  Then go up to the lower 30s   If theres a strong headwind I dont even reach cruise altitude till at least 1/3 or even half way through the flight.  The A330 if fully loaded takes forever to get up. 

Real life uses step climbs...I was on a Malaysia 747 back in August.  They have the inflight information you can access on the PTVs.  We took off from LAX and leveled off around 19,000 for a half hour or so.  Then it was up to 23,000, then 29,000...we didnt reach our cruise altitude of 39,000 till we were half way over the Pacific.  To much fuel on a 14 hour flight to Taipei for going strait to FL390.  Same thing on the way back to LAX. 

Short hops in the 777, A330, or 747 you can get away with going up without much problem.  But short hops may only have you topping off at FL330 anyways. 

And make sure your only loading what fuel you will need.  You dont fly a 2 hour flight and takeoff with 95% fuel