One contributor to the A320 crash off Brazil in 2009 (Air France 447) was that the two pilots were making opposite inputs on their control sticks. The aircraft was in a stall, and therefore it was crucial to push the nose down, to regain airspeed. The instinctive human reaction (of untrained people) is to pull the nose up, since the airplane is falling. To oversimplify a long sequence of events drastically, pilot made the correct move, but the other pilot apparently panicked, and pulled back on his control stick. He continued to do this as they fell from 40,000 feet all the way to the Atlantic Ocean.
A new accident report says that the same thing happened in the crash of an Indonesia AirAsia Airbus A320, flight QZ8501, last year.
Board blames fatal overrun on pilot error.
Source: NTSB Issues Bedford Gulfstream IV Crash Report | Flying Magazine
Checklists were a major innovation in flying, and are now being pushed in health care. But as I research this, it’s clear that although pilots all swear by them, use is less than 100%. Perhaps less than 99% – and a 1% error rate is very high when there are hundreds of items on a flight.
It’s very hard to know the real number. But the pilots in this crash, both very experienced, did pre-takeoff control checks for less than 10% of their flights!
Data from a recorder installed in the airplane showed that in the previous 176 takeoffs, full flight control checks as called for on the GIV’s checklist were carried out only twice and partial checks only 16 times. The pilots on the evening of the accident skipped the flight control check, which might have revealed to them that the gust lock mechanism was still engaged.
This particular item – forgetting to unlock the “gust locks” – has been killing pilots since the first gust locks. Famous examples in the 1930s were the prototype B-17, and the head of the German Air Force. (Both discussed in my forthcoming chapter on standard procedures in aviation.)
Why do doctors and lawyers practice their professions as an art, while pilots treat flying as a science? Is the comparison even appropriate? For several years I have been working on a book showing how flying changed from a dangerous art, to a very safe science. On this blog I will be posting excerpts from the book as it progresses. My goal is to entertain, and to get comments, corrections, and criticisms.
100 years ago, pilots (men and women) learned to fly by doing it. If they survived the learning process, they got good. Now, computers do most of the flying. Human pilots manage the computers, and communicate with other aircraft and with the ground, but they do very little direct hands-on flying. How did this situation come about? Is it an appropriate model for other industries, or are there unique circumstances for aviation that make it different?
My first excerpt looks at the origins of the Aviation Checklist, which is advocated by famous surgeon Atul Gawande and others. This style of flying was a re-invention of what engineer Frederick Taylor had done for manufacturing about 40 years earlier. In both, the idea was that some ways of flying/manufacturing were best. The best methods could be found, and taught to everyone.