777-300Er + Ge Engs Rotation/liftoff Problems

[Richard McDonald Woods 168]

Repeatedly having problems at rotation. On reaching Vr, rotation begins, but I then get slammed back down to ground. Only on the 3rd attempt each time am I able to get her to lift off (somewhat undignified though).

 

Flight EGLL-WSSS, with fuel 106471 kgs, ZFW 230038 kgs and ramp weight 336509 kgs, I set my trim at 5.75 (as per PFPX). Flaps 5 and V speeds 174/184/191.

 

Any ideas as to what is wrong?

 

Cheers, Richard

[James Bennett 52]

That's getting close to MTOW (not a problem but rotation will be laboured). 

 

I don't use PFPX but does it give you the same trim as the 777 does? Also have you tried a different controller?

[777cap 12]

Repeatedly having problems at rotation. On reaching Vr, rotation begins, but I then get slammed back down to ground. Only on the 3rd attempt each time am I able to get her to lift off (somewhat undignified though).

 

Flight EGLL-WSSS, with fuel 106471 kgs, ZFW 230038 kgs and ramp weight 336509 kgs, I set my trim at 5.75 (as per PFPX). Flaps 5 and V speeds 174/184/191.

 

Any ideas as to what is wrong?

 

Cheers, Richard

Yup! thats one heavy aircraft,just check the trim calculated by the aircraft itself,try using those units instead of PFPX(not saying it might be wrong...but it may not be correct :mellow: )

let the speed come close to V2 speed,while rotating add more trim by using the trim feature on the controller itself,this will help in a smooth takeoff,without having to go through a tailstrike or repeated attempts.

warm regards

[Richard McDonald Woods 168]

Hi H!

 

I shall try as you suggest and report back.

 

Once in the sky, one marvelous aircraft! And the WXR is something else.

 

Cheers, Richard

[cavaricooper 2,613]

I concur with using FMC calculated trim settings.  I do NOT advise trimming whilst rotating the a/c.  A blip or two to establish V2 + 20 is fine. I can recall many MTOW T/Os without incident....fwiw.