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A Gut Feeling Can Be Worth Plenty

As a recent Qantas Airbus A330 incident proves, technology can’t always provide all the answers.

In an era when technology has evolved as the solution to just about every problem the aviation industry confronts, it’s refreshing to hear a story in which a pilot’s hunch, a gut feeling, played a role in the safe operation of an airplane full of people. The story is worth reading because, although it all worked out fine, the results could have been much different, just as they might have been if the airplane involved was a Cirrus SR22 or a TBM, and not an airliner.

On August 4, 2016, Flight QF61, a Qantas Airbus A330, left Brisbane, Australia, for Tokyo with 246 people aboard including the crew. According to the incident report published by the Australian Transport Safety Bureau (ATSB), the airline’s dispatcher noticed one of the Airbus’ GPS units was inoperative while in the process of creating the flight plan before takeoff. The airline’s operation specifications required two operating GPS units for dispatch for the captain to use the GPS Runway 25 approach at Saipan as an alternate airport if the weather in Japan didn’t allow a safe landing. The dispatcher checked with Qantas maintenance and learned the item would be repaired before departure but never mentioned this fact to the pilot. When the captain arrived for the flight, he added extra fuel and discussed the broken GPS with the other two pilots, never realizing the unit would be working.

The captain said he thought the airplane still needed two operating GPS units for dispatch in case of a diversion, but he assumed that if maintenance and dispatch had cleared the flight he and the other pilots must have been mistaken. As it turns out, the crew wasn’t mistaken. The crew did check the minimum equipment list (MEL) for the aircraft before departure, and it clearly showed the aircraft was legal to leave with just one GPS unit working. However, the airline’s operations manual said that when using the global navigation satellite system (GNSS) and there is the possibility of using GPS for an approach, as would have been required to shoot the instrument approach at Saipan, the A330 required two operating GPS units.

What the flight crew initially missed was the interpretation needed between what the MEL claimed was OK and what the airline used as criteria to choose the alternate under potential extended overwater operations (ETOPS).

“As QF61 traveled north along the east coast of Australia, the captain was uncomfortable with their decision to accept the aircraft with GPS 2 listed as unserviceable,” the ATSB said. “Therefore, the captain reviewed the flight plan and the publications. They [the crew] concluded they had misinterpreted the MEL operational procedures reference to alternate airport requirements and that their flight plan required two serviceable GPS units to [potentially] use the Saipan Airport Runway 25 GPS approach.” The captain discussed his interpretation, and the crew changed their alternate to Guam.

While the aircraft eventually landed safely in Tokyo, it could all have been much different if the weather had turned bad in Japan with the crew not being aware they actually had two operating GPS units. GA pilots, of course, need to interpret and completely understand all the operation issues themselves surrounding flight in IMC conditions.

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