Ok, Im kinda new, not to FS but to the whole changing things around within FS. I am currently running FS2002, and am curious, why when I set my autopilot to any altitude over FL350 do the default aircraft struggle to it. For example I had my 777(default) climbing to FL365. As it passed say 355 I started to loose airspeed.Now I downloaded MelJet's wonderful 777-300er, put a great panel in it and set my autopilot to FL365 and the jet just cruised up and never lost airspeed....!Do I make changes to the .air file...or is it something else? Thnx.....Jeff (-:

someone else asked this on AvHistory. The AP is generally broken and requires a lot of expert hacking with. There is no general rules yet. However the less work the AP has to do the easier it will fly (probably). You may want to retune the design if the .cfg files are nominal then the .air files are the ones to be tuned. Have a look at Airfile decode in AvHistory.Ian

Going up hill is difficult for any aircraft. The best way I have found to manage a climb in a jet is to set the autopilot on HDG and ALT modes. Give it a heading to follow, an altitude you want to climb to and then set a reasonable rate of climb. You then set the throttles as needed to start the climb. During the climb as the airspeed decreases, reduce the climb rate slightly. This will work to climb to any altitude for which the aircraft is designed. It is also a very efficient way to climb, getting the highest rate at low altitude where the plane can handle it.I see no need for autothottle hear because you should set the highest thrust the engines can handle, noting that there is always a limit to N1 based on atmospheric effects. It does not help to set a speed limit on the autopilot because without a handy and complete operating manual for the aircraft, you would probably set a limit the aircraft could not handle.All realistic aircraft will lose indicated airspeed during a climb. This is partly related to Mach. Until Mach reaches 0.70, you can use any airspeed the aircraft can reach (short of VMO, the max safe operating indicated airspeed. But around 30,000 ft, most jets should establish a climb at about Mach 0.70 to 0.75. You can do this by setting the climb rate. This will require about 240 KIAS or less as you climb. Above 30,000 ft safety depends on Mach (related to true airspeed and outside temperature) while below that altitude safety depends on indicated airspeed.It does not sound to me like you need to be changing the air file. This is just pilot technique.