Runway System
YYC consists of two north/south parallel runways with two intersecting runways. The parallel runways are referred to as 17R-35L (the west runway) and 17L-35R (the east runway). The diagonal runway 11-29 is used as a ‘crosswind runway,’ meaning it is used in extreme wind conditions that prohibit parallel runway use, and is also a preferential runway for night-time arrivals. The final runway, 08-26, is almost exclusively used by light aircraft and the general aviation sector.
Modes of Operations
YYC runs parallel runway operations, which maximizes operational efficiencies and provides the opportunity to arrive and depart aircraft simultaneously from both runways. Generally, aircraft coming from or going to the west use the west runway (17R-35L) and aircraft coming from or going to the east use the east runway (17L-35R). However, weather, regularly-scheduled maintenance, and the mix of aircraft arriving and departing all play a role in determining the routes aircraft take arriving or departing an airport.
During the winter months in Calgary, cold arctic air will move in from the north which means aircraft will primarily depart and arrive on our north facing runways (35R and 35L). Through summer, with warm winds from the south, aircraft will primarily take-off and land on our south facing runways (17R and 17L). Finally, when warm westerly Chinooks roll into the city, operations will typically switch to the crosswind runways (29, and for smaller aircraft runway 26).
NAV CANADA, the organization responsible for the design and management of the airspace, ensures arrival and departure flight paths are designed according to international standards for safety:
Aircraft Arrivals
Arriving aircraft align themselves with the runway typically in three distinct segments
- The downwind leg is a flight path parallel to the landing runway in the direction opposite to landing. The typical altitude at this segment is 10,000 ft. above sea level (ASL)
- The base leg is the segment where aircraft begin to turn and prepare to line-up with the arriving runway while descending. Typical altitude is between 8,000 and 6,000 ft. ASL
- The final approach is the last segment of the arrival, where aircraft are in-line with the runway centreline and complete the final descent.
Aircraft Departures
In Canadian airports using parallel runways, there is a legal requirement for one of the departing aircraft to turn 15 degrees away to establish separation and maintain safety. YYC requested and received an exemption from NAV CANADA and Transport Canada to reduce the divergence of runway 17L (the east runway southbound) to 10 degrees. This turn is initiated to establish separation immediately after take-off and when safe to do so.
Aircraft departures are dependent on many factors such as aircraft weight, thrust settings, weather, and temperature. This means the take-off point on the runway (where aircraft become airborne) can vary. Small and light aircraft will always turn sooner than large heavy aircraft.