A twin-engined commuter airplane with 43 passengers aboard takes off from a small Venezuelan airport, Merida, for the capitol of Caracas, The pilots are experienced and have made the flight innumerable times. Six minutes later the airplane crashes head first into one of the many rugged mountains surrounding Merida.
The airplane was way off its course. At an altitude of more than 14,000 feet the recovery team struggles but manages to recover both the cockpit voice recorder and the flight data recorder. Alas, most of the data from the flight recorder are missing.
With the help of the French manufacturers of the plane, the instruments that were recovered, and especially the cockpit voice recorder, the puzzle is gradually solved.
The two pilots were friends and had lingered in the airport cafeteria until they were running late. So they skipped the pre-flight instrument check. The central control that feeds data to most of the instruments is run by a battery. In a hurry, they turned the battery on to activate the instruments but then shut it down before it had completely booted up. The prescribed time to leave the battery on is 60 seconds. The pilots left it on for only 28 seconds.This deprived them of several vital instruments such as the gyro compass.
They weren't particularly bothered because they'd made the flight so often, but this time their luck ran out. Without a proper compass they were dependent on what they could see. But they found that this time they couldn't see anything because of clouds. They had no way of knowing just where they were, and thus the accident, In a rush, the two experienced pilots thought they could activate the instruments in flight but their confidence had tragic consequences. I was surprised to learn from this episode that professional pilots might deliberately skip all the pre-flight checks, including the walk around. If I ever find myself in Venezuela, I think I might take a train.
They spotted the mountain ahead of them too late.