Boeing's definition of Optimum Flap

[IRRenewal]

Hello all,

Been trying to get my head around Boeing's definition of Optimum Flap for take off, specifically on the 737NG.

Spent some time playing with the BLT (Boeing Laptop Tool) to get a feel for the numbers, and have also been reading the Flight Crew Training and Operation manuals.

Am I correct in saying that in Boeing's definition an Optimum Flap take off is the one that wil give the highest assumed temperature and therefore the lowest N1 as the only determining factor in selecting flap setting (assuming other limitations like Vmca etc are met)? Or is there more to it?

Cheers

Gerard
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There are 10 kinds of people. Those who understand binary and those who don't.

[longobard]

negative,

Opt Flap is the flap setting that gives you highest RTOW for a give OAT and WIND.

longobard

[mutt]

Longobard,

I think that you will find that there is more to it than that!

IRRenewal,

What others factors would you expect? Speed?

Mutt.

[The Puzzler]

Puzzle me this....

There is more to it, especially with the BLT as the optimium flap will be dependant on other factors you have selected for take off policy in your take off calculations. These can be accessed in the Fleet Management section of the Administration side of the BLT. This allows you to select V1 policy, bleeds policy (including improved clb options), brake type, obstacle criteria, single engine accel altitude plus a few other things. Of course, there are numerous other performance criteria that are set in other parts of the BLT which are all considered in the optimum flap setting. :ok: