How does 'noise abatement' work when airplane motors want to be quiet?

Question

How does 'noise abatement' work when airplane motors want to be quiet?

Answer 1

Noise abatement, which is mandated by the FAA, was a contributing factor in the Air Florida crash at National, ~1987. The pilots set engine pressure ratio, which readout was comprimised by ice buildup in the engine inlet. If he had applied full power, like engines prior to the jet age, they would not have crashed.

Answer 2

The pilot may not use all of the available power when taking off ( like when driving a car you can push the gas pedal all the way to the floor or just part of the way to the floor) and also may climb at a steeper angle to reach altitude quicker. Some airports that are noise sensitive also have published procedures that pilots are required to use such as a turn at a specific point after take-off to avoid the noise sensitive area.

Airline pilots believe it or not very rarely use the full power available to the engines to "save" maintenance expense and wear and tear on the engines.

Answer 3

Noise abatement concerns the noise aircraft make on departure or approaches and have to do with noise-sensitive areas near airports.

Each airport have procedures for noise abatement which consist of flight paths on departures and approaches, areas to avoid overflying, types of aircraft that can use the airport during day or night, (some airports prohibit certain aircraft from operating af night) and usually there is a request to reduce power as soon after the aircraft is airborne as safety permits. More power, more noise.

The use of less than maximum power on take-off, (on a jet powered aircraft), is something that is misunderstood. It has nothing to do with noise abatement, it has to do with performance and fuel economy.

When taking off, the pilot uses the minimum amount of power required for that specific combination of runway lenght, temperature, aircraft gross weight, winds, etc.