There are several operations that result in ground noise generated by aircraft: the reverse thrust utilized by an aircraft to slow its speed at touch down, the run-up conducted as part of a maintenance check, the run-up of an aircraft just prior to departure, the sound generated by an aircraft taxiing or waiting to depart, and the noise of a ground power unit (GPU) or auxiliary power unit (APU) used to power a parked aircraft.
When maintenance has been performed on an aircraft, it may be necessary to perform a final test of the engine(s) at full power. Hanscom has a run-up pad a little west of the center of the field. During the run-up, the aircraft faces west. The engines are usually run at full power for about five minutes, and this can be repeated several times. The run-up pad has deflectors that direct the exhaust upward. Massport discourages maintenance run-ups between 9 p.m. and 7 a.m. Small aircraft also conduct a flight check prior to departure, which includes a brief run-up.
APUs and GPUs
APUs and GPUs provide power for a parked aircraft. They are generally used in close proximity to a hangar or the terminal when an aircraft is being prepared for a flight. Massport’s regulations restrict use of an APU or GPU to 30 minutes at Hanscom.
Aircraft must taxi to and from the runway. On occasion an aircraft will need to wait to take off. This is most likely to happen first thing in the morning or in the late afternoon or evening on weekdays.