EGLL LHR Heathrow Thrust Reduction and Acceleration heights as published on SIDS
 

Hi Everyone,

I have a question which I am finding difficult to gather based on EGLL published SID charts.

I understand the difference between Thrust reduction height and Acceleration height

Thrust reduction height - The height where take off thrust is changed to climb thrust

Acceleration height - The height where the nose is reduced to accelerate and to start cleaning up by retracting flaps.

What I don't understand is, how do you know what these figures are for certain airports. For example EGLL.


CAN SOMEONE PLEASE TELL ME IF THIS IS WRONG - PLEASE REFER TO ANY EGLL SID, THE INFO BELOW THE SID HAS THIS :

2 Cross Noise Monitoring Points not below 1083 QNH (1000 QFE) thereafter maintain minimum 4% climb gradient to 4000 to comply with Noise Abatement requirements.

DOES THIS MEAN THAT THR RED IS 1000 AND THE ACC ALT IS 4000?

I REALLY DON'T UNDERSTAND HOW YOU CAN FIND THIS OUT BASED ON THE SID PUBLICATIONS.

My .02
At Heathrow it means exactly what it says...comply with the noise abatement listed on the SID. Cross the noise terminal at or above the listed altitude and thereafter maintain a 4% gradient at a minimum. A 4% gradient at 250KIAS is slightly more than 1000fpm so it should be no problem using your operator's normal climb procedures.

Having said that I've seen pilots elect to use normal NADP's as a technique to ensure compliance.

I believe either is acceptable.

Please consider the effect of the aircraft behind you that complies with their SOP's and accelerates at 1000'aal. They then see this aircraft as a rather large object prior to turning on your individual SID's...:\

Cough

I agree with you that airmanship comes into play. I was only commenting on the legality of either method. I can't be expected to know every carriers SOP's and what they will do behind me. Some airports will mandate accelerating to a specific speed on the SID while at others ATC
will issue matching speeds to departure aircraft.