Runways not only gauge for landings

Q: Can a larger aircraft land on a shorter than recommended runway in an emergency? What tactics would a pilot use to execute this?

— Steve Pontious, Beaumont, Texas

A: Yes, it can be done. Every airplane has a required runway length due to the physics of decelerating. It is much shorter than many people realize. Large airplanes have operated into short airports. The Boeing 727 was a very good short field airplane due to its remarkable wing. When landing on very short runways, the pilots will very carefully control the speed, touch down on the touchdown point and use all of the deceleration devices ( brakes, spoilers and reverse thrust).

Q: What is the position of flaps for takeoff and landing ? — Tom, Scottsdale, Ariz.

A: It varies by the airplane type, weight, airport elevation, temperature, runway length and climb requirements. Short runways usually require more flap extension to get airborne in the minimum amount of runway. Landing is the same, so as to touch down at the minimum speed and stop quickly. The ability to climb is decreased due to the extra drag of the flaps.

Q: I was recently on a flight into John Wayne Orange County Airport that had to divert to Los Angeles International. Per the captain, on approach, one flap was stuck in an incorrect position, so the landing was aborted. We landed at LAX on a longer runway without incident. I was wondering what issues pilots face when the flaps are in an incorrect position.

— Michael, Calif.

A: I can understand the decision to divert to LAX with a flap asymmetry problem. Airplanes monitor and compare flap position; if there is a significant difference between flaps, a protection system stops the movement before it causes controllability problems. In the cases where I have had asymmetric flaps, the airplane was easily controllable but we did have to counter the difference in lift caused by the flap difference. The correction was to hold opposite roll control during the approach.