Last December, AirAsia flight QZ8501 crashed into the Java Sea killing 155 passengers and seven crew members. Indonesia’s National Transportation Safety Commission has finally determined the causes. In the Guardian, Kate Lamb explains that an electrical interruption to the Rudder Travel Limiter (RTL), “happened three times in the space of thirteen minutes, eventually causing the autopilot to disengage.” Thus the co-pilot was at the controls. That’s when the problems begun to compound. Lamb:
According to information gleaned from two black boxes and a cockpit recording, the pilot instructed the co-pilot to “pull down”, an order that was taken literally, sending the plane soaring up to 38,000 feet, at a rate of 20,000 feet per second.
“[The pilot] said, ‘Pull down, pull down.’ But when you pull down [the gear controls] the plane goes up. To make the plane go down you need to push, so this order was confusing,” said accident investigator Nurcahyo Utomo.
The pilot, no doubt harried or even panicked, was using the terminology to ascend to tell the co-pilot to descend. As a result, according to the report:
… the plane went into a “prolonged stall condition that was beyond the capability of the crew to recover”. At one point the two men appeared to be pushing their controls in opposite directions, it added.
Unfathomable mistake number one: AirAsia let a plane fly with a faulty part. Lamb writes that the “problem with the RTL [was] an issue that investigators revealed had occurred 23 times on that specific plane since January 2014.”
Unfathomable mistake number two: The pilot bungled the most basic of piloting commands.
Unfathomable mistake number three: The co-pilot didn’t grasp that conditions called for a descent and that a steep ascent would stall the plane. Or, alternately, he was loathe to contradict the pilot.
At any one of these stages, tragedy could have been averted. It’s hard not to suspect that cost-cutting measures, such as repairing the RTL once and for all or grounding the plane, as well as more comprehensive training for pilots, were responsible.