USA TODAY US Edition

How rare is an aborted takeoff?

Ask the Captain,

- John Cox John Cox is a retired airline captain with US Airways.

Question: I rarely fly. I notice on takeoff, as the plane climbs, there’s a point where it sounds like the engine is shutting down and I get a sensation of the plane descending. Is that just my fear playing a trick on my mind or does that actually happen? Thank you!

– AC, Atlanta

Answer: No, the plane is not descending. Once the airplane is climbing and the landing gear is retracted, the thrust of the engines is reduced. This results in a decrease in engine noise. The rate of climb slows and as the flaps/slats are retracted there is a further reduction in climb rate for a few moments. All of this is normal.

Q: Why do jumbo jets ascend at a lower rate?

– Abson, Orange County, California A: Large four-engine airplanes are slower to climb than two-engine airplanes due to the amount of excess thrust of two-engine airplanes. If a twoengine airplane experience­s a loss of thrust in one engine (50% of the total thrust), it must still be able to climb and continue flight safely. A loss of thrust for a four-engine airplane only results in a 25% loss of thrust. The twin-engine plane has more excess thrust when all engines are operating and therefore climbs faster.

Q: Is it normal and safe for airplane wings to flex during takeoff?

Q: On a recent flight, while barreling down the runway for maybe 15-20 seconds, brakes were applied, the plane made an abrupt turn onto a taxiway and takeoff was aborted. We spent about 10 minutes on the taxiway before the captain alerted us to the reason for the aborted takeoff, which was a “warning light” that came on during takeoff. This was the first aborted takeoff I have experience­d, and most everyone I have spoken with has never experience­d one. Are aborted takeoffs common?

– James Matthews, Vermont

A: I would not say they are common, but they do occur. Over my career I have had to abort several takeoffs, but over nearly five decades that is not very many.

 ?? FOR USA TODAY ??
FOR USA TODAY
 ?? JEREMY DWYER-LINDGREN FOR USA TODAY ?? An Air France Airbus A380 lumbers out of Miami Internatio­nal Airport.
JEREMY DWYER-LINDGREN FOR USA TODAY An Air France Airbus A380 lumbers out of Miami Internatio­nal Airport.

Newspapers in English

Newspapers from United States