Anti-wasp plastic covers caused Malaysia Airlines flight emergency

KUALA LUMPUR: The emergency that forced a Malaysia Airlines flight to return to Brisbane last week was caused by pre-flight inspection failure, according to ABC News.

The Australian broadcaster said four plastic covers placed on vital gauges that should have been removed were mistakenly left in place and that after take-off the covers melted and blocked the pitot tubes used to calculate airspeed and altitude for the cockpit crew.

In Brisbane, the report said, there was a problem with insects, particularly wasps, that built hives inside the probes in as little as 20 minutes. Covers are fitted over the probes to stop the wasps from getting in.

The report said an Australian Transport Safety Bureau team was trying to establish who was to blame for this failure.

MH134 departed Brisbane for Kuala Lumpur on July 18 morning. As the plane climbed, the cockpit crew found they had no indication of how high they were, or how fast they were flying.

According to the report, the crew issued a pan alert, one step below a mayday call, and headed back to Brisbane. The plane is still in Brisbane undergoing inspection.

ABC quoted Steve Purvinas from the Australian Licenced Aircraft Engineers Association as saying: “We see this stuff all the time from airlines. They say: there was a minor incident that caused us to turn back in-flight; the plane’s got a minor problem; it’s on the ground for, like, three months – however long they want to have it on the ground.

“It usually means there’s something major wrong that they can’t fix, and in the case of this Malaysian aircraft, it’s certainly something a little bit more wrong than just a few pitot covers that have been left on the pitot probes.”

According to Purvinas, there are four pitot probes at the front of the aircraft that measure the air as it travels into the probe, and it feeds data into the air data computer. This is the primary source for air speed measurement.

The other piece of information needed to get the air speed is an altitude measurement, and that information comes from the side of the probe.

“It appears in this case with the Malaysia Airlines aircraft that nobody’s checked the aircraft before it’s taken off and those covers were still fitted, which means you can’t measure your air speed when you start moving,” Purvinas was quoted as saying.

ABC reported that other pilots and aircraft engineers claimed hydraulic fluid had leaked from the aircraft, either during the pre-takeoff manoeuvres or after landing.