Flying a Circuit
with an Airliner.
Not every approach is an instrument approach. This can cause problems for pilots when Air Traffic Control tell the Airline pilot to make a visual circuit. The problem is you cannot see behind you. The pilots therefore adopt a 45 seconds time leg on the stop watch in the late downwind leg.
The time point starts from the a point at 90 degrees level with the approach end of the runway threshold. The pilot flies for 45 seconds at 170 knots flap five degrees gear down. Ideally the aircraft wants to fly the downwind leg 2 to 3 miles from the airfield bearing in mind the aircraft takes that to turn from downwind onto final approach. If you are too close you will be through the centre line and will have to zig zag back onto final.
The height of the downwind leg is 1500ft above the airfield. As you turn at the end of 45 seconds start your descent at 600ft per min. As you roll out of the turn on final select 25 or 30 degree of flap. Note the base leg is not square like a Cessna would fly.