Take off performance

[B737]

Dear all!

When we get the result for take off run via performance table or app how it is calculated in relation with thrust and brake setting?

 

1. Full thrust and brake released when spinned up? Or

2. Brake release, set 40% N1 and after 40% set take off thrust?

Because from my view it can be significant difference. Can' t be?

 

Regards

[Litjan]

According to regulations you have to perform a lineup within a short margin, spool up engines to 40% before brake release, then release brakes and press TO/GA. Calculated take-off thrust has to be achieved before 60kts groundspeed to conform with calculation.

A "static takeoff" (with brakes held and full thrust) is not recommended, because of undue stress on landing gear, danger of foreign object ingestion and danger of starting to slip (especially on wet/contaminated surfaces).

Cheers, Jan

 

[B737]

Dear Jan!

Thank you.

Which procedure is used in performance chart?

Static or the 40%?

Question is: I know in the real life is much more difference, but playing in games when the table tells you need 1500 meters for take off and the runway is 1500m.

I am not sure that both of the procedures would work.

 

[AngelOfAttack]

As pre FCTM, rolling takeoff with less than 2 seconds 40% N1 stable time have negligible impact on takeoff performance.

Edited April 28, 2022 by AngelOfAttack

[GusRodrigues]

Just as a side note, on winter ops, you have to step into the brakes and spool your engines up to 75% to have enough rotation to cause any ice buildup in the fan blades to go out with inertia. if braking power is fading, TOGA and release the brakes.

[Litjan]

6 hours ago, GusRodrigues said:

Just as a side note, on winter ops, you have to step into the brakes and spool your engines up to 75% to have enough rotation to cause any ice buildup in the fan blades to go out with inertia. if braking power is fading, TOGA and release the brakes.

And you have to do it for 30 seconds, too - so it is important to let the tower know beforehand, or this will send the next approaching aircraft into a go-around. I also made an announcement to my passengers (and crew) so they would not worry because the engines are roaring but the plane isn´t going.