Airlines and pilots are required to comply with the noise abatement procedures in effect at Montréal–Trudeau in order to reduce noise disturbances generated by air traffic.
Takeoff and landing procedures
Planes must take off and land into the wind. At Montréal–Trudeau, the prevailing winds are southwesterly, so aircraft usually land and take off in the direction of Lake St. Louis (southwest).
In addition to the exceptional procedures during restricted operating hours (see below), jet pilots are required to follow these procedures at all times:
- After takeoff, the plane must climb rapidly along a straight-line trajectory to a minimum altitude of 915 metres (3,000 feet) before starting a turn.
- While landing, the aircraft must be aligned with the runway’s centre line on final approach, respecting an angle of descent of 3 degrees or more; pilots must also adjust the thrust/drag speed on descent, to the extent that safety permits, in order to achieve a minimum noise level.
Operating restrictions during certain hours
Montréal–Trudeau Airport is open 24 hours a day to propeller planes and jets weighing less than 45,000 kilograms. As for jets weighing more than 45,000 kilograms, normal hours are between 7 a.m. and midnight for take offs and between 7 a.m. and 1 a.m. for landings.
Aéroports de Montréal (ADM) does, however, have the right and the authority to make exceptions to these restrictions for medical emergencies, delays beyond a carrier’s control and adverse weather conditions.
A strict internal policy applies in such cases. In particular, exceptions granted for scheduled flights represent a very small percentage of total traffic and they must be supported by strong operational reasons; furthermore, exceptions are contingent upon adherence to the noise abatement measures in force.
ADM grants exceptions to certain aircraft for departures before 7 a.m. and for late arrivals. However, only the quietest aircraft are eligible.
Restrictions on engine testing
Engine testing at high RPMs for inspection or maintenance purposes is forbidden between 11 p.m. and 7 a.m. Special permission may be granted in some cases, such as when aircraft must be on standby to respond to emergencies in isolated regions. Engine testing at high RPMs is performed in areas chosen in order to minimize noise disturbances for nearby residents.
Assignment of priority runways for night flights
Night-time runway use is determined by a priority runway assignment system outlined in the Canada Air Pilot (CAP). Since February 9, 2009, Montréal-Pierre Elliott Trudeau International Airport reinstated the original runway assignment system for night flights, which prioritizes the use of Runways 24 for landings and take offs when wind conditions permit.
This system had been changed in September 2006, in an attempt to minimize sound impact through the use of lower-noise flight paths among other measures. The original system was reinstated due to the suspension of the left-turn takeoff procedure from Runway 06L, which was not meeting the required performance criteria.
Original runway assignment system for night flights
Southwesterly/westerly winds (70% of the time): Runway 24L for takeoffs and 24R for landings
Easterly/northeasterly winds (30% of the time): Runway 06L or 06R for takeoffs and landings