Welcome to Gadling’s feature, Plane Answers, where our resident airline pilot, Kent Wien, answers your questions about everything from takeoff to touchdown and beyond. Have a question of your own? Ask away!
Just a note, we’re moving Plane Answers to Mondays. The question pool has been drying up a bit lately, so let’s hear from you.
I was recently on a flight from Bangkok to Singapore on an A319. As I always do (as a Private Pilot), I listen for that reassuring sound of the flaps being lowered for take off as we taxied to the runway. We got to the hold short line…nothing. My heart start beating a little faster as we crossed the first runway and still nothing…we lined up and got ready to takeoff and still NO FLAPS.
I had visions of running up to the cockpit or shouting at a stewardess and telling them. I could see myself being interviewed after we landed in a rice paddy saying “I was going to say something…!” But instead I put on my iPod and clenched my clammy fists as we screamed into the air. Is it common for a jet airliner, even with light load or short route not to use flaps for takeoff?
I can’t think of any airliners that are certified for zero flap takeoffs. But I ran your question past my resident A319/A320 expert, Chris Norton, who responded:
The most common flap setting for takeoff is flaps “1” which means leading edge and a little bit of trailing edge are extended. The trailing edge usually doesn’t travel very far, and the LE makes almost no noise.
I am not surprised that he didn’t hear the flaps, but had they tried to take off without flaps I am sure he would have heard the takeoff configuration warning up in the cockpit. The A320/319 is not approved for zero flap takeoffs.
On short runways, at heavy weights or high density altitude, we will use optimized takeoff criteria which would mean we are at balanced field length, and could use flaps 3. It is not very common though. Think Las Vegas in the summer or Orange County.
Thanks Chris, for your insight into the A319. I’ve always wondered how I’d react as a passenger if I were in the same situation as Ray–staring out the window at a wing with flaps in the up position. When riding in the back, passengers put a great deal of trust in the pilots, their checklist adherence, and the takeoff warning horn that’s installed in every airliner. The recent Spanair MD-80 accident is a rare example of the failure of all three levels of safety built into the system.
This rather scary USAToday article mentions some similar events over the past 30 years. They accurately point out that distractions and human errors happen, and if that occurs at the same time as a failure of the takeoff warning horn, the results could be disastrous.
To ensure the safety of an airliner, there are many items that are redundant. Electrical systems, hydraulics, fuel pumps and pressurization are some of the many mechanical components of an airliner that are double and triple-redundant. A single failure of any of these things isn’t disastrous, but when all the layers are compromised, accidents can happen.
There’s a certain amount of trust passengers need to have in the design of the airplane, how it’s maintained and in the pilots who fly it. If that doesn’t comfort you, just try to remember that there are 10 million flights a year, and over 10,000 flights per day in the U.S. alone.