6 ms·
The Admiral Cloudberg article is much better, particularly in its explanation of how the plane came to be flown with blank fuel gauges. The first technician not
by fwlr 3y ago
The Admiral Cloudberg article is much better, particularly in its explanation of how the plane came to be flown with blank fuel gauges. The first technician noticed an issue with the fuel gauges being blank a few flights earlier and applied a fix he happened to know: disabling one of the two channels, which restored the gauges. This was an acceptable fix - the plane was certified to fly with only one of the two channels active, as long as the lost redundancy was regained with manual checks. It was flown twice in this state (working gauges, single channel, manual backup fuel check).
When this captain handed the plane over to the captain of the incident flight, there was a misunderstanding in the conversation that led to the incoming captain believing the prior captain had been flying with blank fuel gauges and only manual fuel checks. In an unfortunate coincidence, the second technician who was checking the plane at this time disabled both channels to try and troubleshoot the issue again, but failed to return the system to the “one channel” functioning state (apparently because he was interrupted by a request to help with the manual fuel check, ironically).
The second technician’s mistake would have been noticed by the pilots, except that due to the misunderstanding, they were expecting to see blank gauges. Those were the initial conditions that allowed the “pounds, not kilograms” mistake to threaten the flight.
- libraryofbabel 3y agoDefinitely. What makes Admiral Cloudberg so good is the intense focus on details: both details of technical systems, and details of how humans (mis-)communicate with each other. Those details are where the reasons for failure reside, and so they are the place to focus if you’re interested in these stories from an incident analysis perspective. With flight 143, the sheer brilliance of the flying after the fuel ran out - plus the too-neat story of “it was all caused by metric / imperial conversion” can easily distract from the real lynchpin of the whole incident, which was as you say why the plane was flown with non-functional fuel gauges when that was contrary to the Minimum Equipment List for the aircraft. Taking off with blank fuel gauges was the core safety rule that was violated: the mistake with the unit conversions was necessary to make that violation dangerous but it wasn’t really the core of the accident.
- WalterBright 3y agoNearly all airliner crashes are due to an unexpected confluence of multiple errors. If any one of the errors had gone right, nothing bad would have happened.
- pfdietz 3y agoThe "swiss cheese" model of accidents. When all the holes line up...
- dctoedt 3y ago> If any one of the errors had gone right, nothing bad would have happened. IIRC, a cascade of human errors is also what happened at Three Mile Island and Chernobyl.
- gcoakes 3y agoWasn't there active attempts to hide the extent of the issue with Chernobyl which significantly worsened the damage? If so, that seems like saying there were cascading human errors in a murder-suicide. You're technically right on some level, but I wouldn't so much call that human error.
- IIsi50MHz 3y agoI'd classify humans hiding it as an additional human error.
- noah_buddy 3y agoIt makes you wonder how many flights take off with several errors and mistakes every day.
- ranger207 3y agoProbably most. Complex systems run in degraded mode as a matter of course. https://how.complexsystems.fail/ https://how.complexsystems.fail/