Tech Question

[v1_rotate_v2]

Can someone help me with this question please...
Is this necessary to use Max Throttle to perform take-off, even the plane is not fully loaded.

Cheers...

[natops]

hi there, do you mean: is it necessary......?

d.

[WaldoPepper]

No, It's not necessary to use max thrust for take off.

Jets are generally over powered (A340 debatable !) and so they can meet the regulatory climb performance and field performance by using less than the maximum thrust available.

They can even do this at max weight. One method used to determine the thrust reduction used is called "Assumed Temperature" or "Flex Temperature". A warmer OAT is assumed which results in less thrust. This not only gives the required performance, but it also helps preserve engine life.

Another advantage is that if you suffer an engine failure, you can leave the thrust where it is and "theoretically" you will climb away. Keep in mind though, max thrust is always available and you just have to push the thrust levers forward.

[v1_rotate_v2]

No, It's not necessary to use max thrust for take off.
Jets are generally over powered (A340 debatable !) and so they can meet the regulatory climb performance and field performance by using less than the maximum thrust available.
They can even do this at max weight. One method used to determine the thrust reduction used is called "Assumed Temperature" or "Flex Temperature". A warmer OAT is assumed which results in less thrust. This not only gives the required performance, but it also helps preserve engine life.
Another advantage is that if you suffer an engine failure, you can leave the thrust where it is and "theoretically" you will climb away. Keep in mind though, max thrust is always available and you just have to push the thrust levers forward.

Cheers WaldoPepper:O
Don't you think this is a splendid idea to save fuel by not using max thrust for every take off then?

Airlines would certainly love this idea to help them saving every penny in fuel cost!:ok:

[TruBlu351]

Cheers WaldoPepper:O
Don't you think this is a splendid idea to save fuel by not using max thrust for every take off then?
Airlines would certainly love this idea to help them saving every penny in fuel cost!:ok:

It's also used to reduce the wear and stress on the engine. This in turn increases the engines life....again saving $$$.

[betaboy]

Reduced thrust does not decrease fuel burn, since time to climb to optimal altitudes increases. Plenty of discussion on this in the archives of the Tech Forum.

Also, V1, the call here is "V1, VR, V2." There is no "rotate" call!

[Bart Simson]

Hate to burst your bubble betaboy but in some operations it is Rotate.

:ok: :ok: :ok: :ok: :ok:

[betaboy]

Ok. I stand to be corrected. No bubble to be burst here. I should specify, Cx Pax SOPs use a "Vr" call, not a "rotate" call. Something I found unusual when I started but is second nature now. Happy?