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Hi Capt Lim,
I find your site very interesting. A quick question, at about a minute or two after take-off, you can hear the pilot reduce power in the engines from maximum to somewhat less.
Does this mean that, for the rest of the journey, the engines are not at full power? What power are they set at generally?
Many thanks.
Pascal
Hi Pascal,
I have answered this question somewhere amongst my FAQ. After take off, you would hear the engines power being reduced at between 1000 to 1500 feet above ground level. This is usually to comply with noise abatement procedures of some particular airports located around populated city area. Noise abatement is a procedure whereby the engine thrust is reduced from the usual take off power, which is fairly noisy in some airplanes, to a setting that is lower and less noisy.
I am sure you are aware that many people who live along the take-off flight path are getting very sensitive over the noise of jet planes taking off at various times of the day. Pilots and Airlines can be fined for not adhering to this requirement.
Once an airplane has reached its acceleration altitude of 3000 feet, the climb power would be maintained until the cruising phase of the flight. At this point, the power is further reduced to an economical cruising power of about 10 percent of the take off power, to achieve a speed of Mach 0.84 or around 550 mph on the Boeing 777.
So the engines are never at full power in cruise, except during the take off at the designed maximum take-off weight.
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