Part of the Noise Management Program is to mitigate noise created by aircraft on departure and arrival, when they’re flying over the residential areas.
Pilots are required to follow the airport noise abatement procedures unless instructed to do otherwise by air traffic control, often for safety reasons.
Departures
Pilots follow a set of standard published routes when departing from the airport called a Standard Instrument Departure (SID). SIDs are developed for each runway at Toronto Pearson, and each includes an additional set of noise abatement procedures.
Throttle back
Aircraft must throttle back soon after take-off.
This is because the most noise a plane engine will make is on take-off because that’s when it’s operating on a higher power setting to allow it to get off the ground safely. But once the aircraft is safely off the ground, it needs less power to keep it climbing.
3,000-foot elevation
Pilots must pass 3,000 feet above ground level (AGL) before making their first turn en-route to their destination.
The turn involves revving the engine and cutting through the air differently, both of which make additional noise. 3,000 feet AGL puts the aircraft high enough to limit the noise exposure for communities while allowing for safe aircraft maneuvering.
However, turns lower than 3,000 feet AGL are permitted for propeller aircraft between 6:30 am and 11:30 pm and for some small light jets between 7:00 am and 11:00 pm. These are known as early turns.
Toronto Pearson uses two departure procedures suggested by ICAO:
NADP 1
Noise Abatement Departure Procedure 1 (NADP1) reduces noise around and over the runway end by prioritizing gaining height.
NADP 2
Noise Abatement Departure Procedure 2 (NADP2) reduces noise over areas more distant from the runway end by prioritizing increasing forward speed.
Arrivals
Pilots must follow a set of procedures when arriving at the airport called the Standard Terminal Arrival Route (STAR). Every airport’s STARs are different. At Toronto Pearson, there are three noise abatement procedures built into our STARs: 2,400-foot elevation, a three-degree angle and reverse thrust.
2,400-foot elevation
Aircraft must remain at 2,400 feet above ground level (AGL) prior to lining up with the runway.
The altitude of 2,400 feet AGL gives NAV CANADA enough control over planes to land them safely and efficiently, until they have lined up for the runway, while minimizing the noise impact as best as possible.
Three-degree angle
A three-degree angle-of-descent is the typical slope configuration for the final approach to the runway.
This is because when planes approach the runway, a three-degree angle makes it a smoother, more comfortable descent for passengers on board.
A lower degree would conflict with the obstacle limitation surface that controls the height of structures, like buildings and trees close to the airport. A lower degree would also extend the point at which the aircraft intercepts the Instrument Landing System’s localizer beam, keeping them at lower altitudes for a longer amount of time.
The degree it would take to keep the planes high enough to eliminate noise on the ground would make for an uncomfortable ride for passengers onboard the aircraft. Keeping the angle at three degrees allows for a good balance between noise abatement and passenger comfort.
Reverse Thrust
Minimize the use of reverse thrust after touchdown where possible.
Even though the airfield and the land-use plans are designed to minimize the effect of on-runway noise to neighbouring communities, reverse thrusters are incredibly loud.
Aircraft do need to use reverse thrust because it helps slow down an airplane for safe and efficient runway exits, enabling a smooth flow on the airfield.
See how high aircraft are flying in this interactive map.