EPR at takeoff for A330 RR Trent

[nnc0]

Airbus recently changed the Takeoff procedure to require setting 1.1 EPR before selecting FLX/TOGA when the crosswind is less than 20 kt.

Prior to the change they required 1.1 EPR regardless of the crosswind.

If anything I would have thought the higher EPR would be required when the crosswind is higher, not when it is less.

What am I missing here?

[tdracer]

With a high crosswind, the higher the thrust setting the greater the risk of inlet separation and engine surge. As soon as you get some forward airspeed the risk of inlet separation drops rapidly.


Setting some 'off idle' power setting such as 1.1 EPR prior to selecting TOGA is because many engines are 'lazy' off idle. If one engine accelerates faster off idle you can get a big thrust asymmetry and resultant yaw, often resulting in an RTO.

[THR RED ACC]

With a high crosswind, the higher the thrust setting the greater the risk of inlet separation and engine surge. As soon as you get some forward airspeed the risk of inlet separation drops rapidly.


Setting some 'off idle' power setting such as 1.1 EPR prior to selecting TOGA is because many engines are 'lazy' off idle. If one engine accelerates faster off idle you can get a big thrust asymmetry and resultant yaw, often resulting in an RTO.

I do have to apologise but this is plain wrong.

They have not changed the Takeoff procedure. I have just spoke to a couple of the guys at my airline who use the 330RR and they said they have not been informed of any change to takeoff EPR.

[lomapaseo]

I do have to apologise but this is plain wrong.

I can't figure out what part is wrong since the quote above refers to multiple paragraphs of discussion :confused::confused:

[nnc0]

Airbus have responded to advise that the FCOM procedure (Dec 2015) is incorrect and will be amended. With RR Trent 700s, per the AFM, EPR should be at 1.1 before selecting FLEX or TOGA, regardless of ambient wind conditions.