There is something wrong here which I don't understand...I have no problems taking off with the 747-400F but 747-8 goes into a stall after takeoff and crashes...I have all the latest updates...The one thing that puzzles me is the thrust limit in the 747-400 is something like 1.45 which can be lower according to temperature or reduce settings. In the 747-8 it is set at -1.00 and never changes at ANY setting...Somebody tell me if there is something wrong with this setting or is this correct...I understand the 747-8 uses the same config file as the 747-400X...After setting up everything with the FMS for takeoff it speeds up to V1 Rotate called then V2called after lift off it starts reducing pwr and stalls...I noticed the VNAV light goes out...I have tried double clicks on this button....NOTHING! I have raised the wheels, and the flaps at the correct pwr levels...I have tried about every setting with the 747-400 configuration file....Nothing changes the problem...I think it might have something to do with that thrust limit setting, but don't know how it can be changed or this totally off base...Please help...

Problem solved....Referring to my post above....It was all about setting the Vnav....I was reading an article written by, I believe Mr. Ray about takeoffs in the 777...So I applied that to the PMDG Boeing 747-8F....It worked....So I turned the Vnav off until I reached a confortable alt....I understand too that you don't need Vnav if you are doing step-climb...