calculating B777 speeds

[yohan_mistry]

Wanted to know if there is an interpolating software / programme for calculating t/o speeds for the B777 as the weights are only in steps of 20 tonnes

[Old Smokey]

If you need a programme to interpolate speeds provided for 20 Tonne weight increments, invest in an EFB with OPT incorporated. That should set you back by a lot of money.

If you still fly a 'paper' B777, Boeing assume that then end-user pilots have average mathematical capability, and are capable of the rather simple interpolation involved.

Regards,

Old Smokey

[FE Hoppy]

Next you'll be asking what you need to know in the FCOM

[mutt]

Change the input parameters for BPS and you can have weights in any increments you desire, although considering that the speeds involved are relatively small, I find it scary that you can't interpolate in your head !

Mutt

[MrHorgy]

Simply? Do it like this (arbitrary figured I am not 777 rated):

WEIGHT | SPEED

100t | 150kts
120t | 160kts

160 - 150 = 10.
10 / 200 = 0.05
0.05 x difference in weight above 100t in 100kg increments = Answer.

For example. Aircraft weighs 116.2t:
162 x 0.05 = 8.1
150 + 8.1 = 158.1 kts
V1 is therefore 158kts.

Horgy

[B-HKD]

Judging from his location.... Air India.

Says it all