first post here..i'v been flying the pmdg 747 for a couple of months and hav never had this problem before, lookin at the other posts on this forum y'all seem to b very knowledgable mayb u'l be able to help me out...
ok so heres my problem..
i'm on the tarmac ready for takeoff..flaps set..fmc fully programmed V-speeds set etc and fuel/payload well within acceptable limits input using the pmdg load manager..so then wen i put the throttles forward n release brakes the aircraft starts takeoff roll as normal..but the aircraft seems to pickup speed quite slowly and once i'v finally hit V1 n Vr start to rotate but after bout 10secs in the air theres an almighty continous crunching noise which sounds engine related..on occasion i'v had the amber rpm limit warning come on for a split second but not everytime it happens..then after that the plane drops straight out of the sky:( atfirst i thought mayb i'd accidently set a failure or something but its all been resetted and clear but the problem persists..thanks for anyhelp you can give me..
im sure this isnt ur prob, but ill say just in case. are you sure the parking brake is fully off? and you dont have any autopilot speed hold on? If problem persists you could try messing around with the acceleration speed and stuff in the cfg. file but make sure you back up.
Go ask the question at the PMDG forums, they'll be more then happy to answer your question.
It sounds like over rotation. The crunching noise would be the tail strike on the runway, and the plane dropping out of the sky would be because the high AOA stalls the wings. If thats the case, it'll be cured by rotating under 10 degrees pitch up attitude until a positive ROC is established.
Can't afford such luxuries so do not have the PMDG 747 in my fleet. At a guess is the noise the stick shaker...do they replicate this noise in the sim? If so could be stick shaker then full stall...drop out of the sky!
Check your takeoff thrust settings, sounds like you're getting an engine over-speed. Ensure that you only apply thrust to the T/O thrust bug indicators.