Gents,In the event of an engine failure in the 747, either before or after takeoff, is there a need to increase the thrust on the remaining 3 engines to MCT? Or does this occur automatically, or even not at all?During my emergency last week I was so caught up in the experience I honestly have no idea whether the thrust on the remaining engines increased or not! I certainly didn't touch it and the aircraft never got close to a low energy scenario.Thoughts appreciated, I have a EGLL-KBOS-EGLL trip planned for this weekend and who knows, I may need this advice again!Also, for those who are interested, I am working on a new html version of the kneeboard checklists that will include the non-normal procedures so that you can pull them up easily when required. Will advise once this is done and post with PMDG permission.

Hi,you can push TOGA once to cancel any derates, push again if you want max thrust but most real world SOP advise caution as a loss of control can occur due to asymetric thrust.Rob

Yup, in the real world SOP is to leave alone, as TO performance is predicated on the loss of the critical engine at V1.If you do wish to push the thrust levers forward, only do it as far as the fixed derate you are using, e.g. if you are using TO2 with an assumed temperature, you can only push the thrust levers as far as max TO2; anything above that and you lose Vmcg protection.David "jumbojock" Robertson

Thanks guys for the clarification.

Complex issue...Just to clarify..With an assumed temperature derate ONLY, you CAN firewall the throttles. Hitting TOGA will do this for you automatically. The Autothrottle can't compensate for the shortfall in thrust due to an engine failure if the current thrust mode limit is "TO" (as shown on the EICAS). As a result, the *autopilot* will give you a shallower climb at a slightly lower speed.If I remember correctly, if the engine fails when CLB thrust limit is displayed on your EICAS, you get an automatic thrust mode change to "CONT" with a greater thrust limit available (with the A/T engaged), so there should be more thrust than climb thrust.With fixed derates, you can't firewall the throttles for reasons previously stated.Hope this makes sense.Cheers.Q>

Thanks Q, good to see you're still around mate!