Module f14

Step 5. Data Available before Landing

Your Own Observations

Initially:

You are approaching Toronto airport, but are still about 10 minutes from landing. You are flying the instrument approach course as assigned by Air Traffic Control (ATC). You are flying IFR (instrument flight rules), for which you have much experience and the aircraft is well equipped for.

Clouds and Precipitation: Your flight path is taking you in and out of deep convective (cumuliform) clouds. Between clouds you occassionally see the ground, and you see tall convective clouds ahead in your path. When you are in the clouds, it is very dark, there is near zero visibility, heavy rain, and moderate turbulence. You see lightning ahead and all around. You see a tall thunderstorm in your path, and you ask and receive vectors from ATC to allow you to fly around it. After flying around it, you continue toward the airport.

Airborne Weather Radar: Your aircraft has two separate weather radar systems onboard, providing cockpit displays of rainfall intensity ahead of the aircraft. They are showing numerous thunderstorm cells, which agrees with the view out the cockpit window.

Radio Communications regarding other aircraft landing ahead of you. Two other commercial airliners (regional jets) are ahead of you for landing. They land successfully, but mentioned thunderstorms nearby. They also reported that the runway was wet, causing poor braking action. Because these smaller aircraft landed successfully, you anticipate that your larger aircraft can also make a successful landing.

A bit later:

About 7 minutes from touch down, you intercept the ILS localizer (the signal that the autopilot can use to steer the aircraft left or right as needed to fly directly to the runway). Then, about 3 minutes later, you also intercept the ILS glideslope (the signal that the autopilot can use to fly a gentle descent towards the runway). The runway you are aiming for is runway 24L (namely, the runway centerline points toward magnetic direction 240 degrees). The regional jet aircraft (i.e., a smaller aircraft than yours) landing two minutes ahead of you reports winds from 290° at 15 to 20 knots.

Just before landing:

You are about 1 minute from landing, flying directly toward the desired end of the runway. You are 2 to 3 nautical miles from the runway, descending through about 1,500 feet altitude above the ground. Your approach path is right where it should be, as guided by the ILS system. Your approach speed is also good, at 140 knots.

You start to see the ground between some of the lower clouds. You can see half of the runway ahead of you, and you notice that it is covered with water, producing a shiny mirror-like surface. You see lightning on both sides of the runway, and at the far end of the runway. Your airborne weather radar shows two cells of heavy rain, one just reaching the runway from the northwest, and other south of the runway.

You have a sophisticated navigation system on the aircraft that automatically compares your airspeed and direction to your actual path over the ground. It indicates that the aircraft is experiencing a 70° to 90° direct crosswind from the right at 15 to 20 knots.

UBC ATSC 113 Weather for Sailing, Flying & Snow Sports

Last modification: May 2017