I am fascinated by the story of Canadian Flight 143 which lost power to both engines but still landed safely.
They were able to land by using the forward slip method of slowing down but descending steeply at the same time in order to land at a safe speed on the runway.
I understand that gliders use the forward slip method and also some small planes.
My question is, has the forward slip method ever been used on a large commercial airliner such as a 747 or 767 (as with Flight 143) since that incident, and was it ever used prior to that incident on large airliner?
The forward slip (or side slip – aerodynamically, these are identical once established) method of slowing down and yet loose height fast is the basic method taught at flying schools to overcome a missed judgment in a forced or glide landing on smaller planes.
Student pilots are required to know how to do forward slips before their first solo flight. The logic is that in the event of an engine failure, the pilot will have to land on the first attempt and will not have a chance to go around if the aircraft is too high or too fast.
Such techniques are especially useful in aircraft that have neither high-drag flaps nor spoilers or in any aircraft in which the flaps cannot be extended due to a system failure. Large airliners like the B747 or B767 have high-drag flaps and spoilers and slips are rarely resorted to except in exceptional circumstances like in the case of Flight 143. If required, an experienced airline pilot would recall the use of slips to get him back on the runway quickly. However, side slips are also employed in some crosswind landings.
Yes, the captain of Flight 143 has cleverly used the slips on his B767 to get him out of a very awkward situation but I have not yet read of another B747 accident where such techniques were used before.
For those who have not seen the videos of Air Canada Flight 143, you can see them below. (When loading is slow, select “Play” on ALL Parts (1-5) to load and volume (speaker) to low. When fully loaded (red line) after a while, select ‘Replay' with volume to view without interruption)
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