Last week, we noted an attempt to fix a hardware problem with software, which backfired pretty dramatically for Ford when they tried to counter the tendency for driveshafts to fall out of certain of their cars by automatically applying the electric parking brake.
This week, the story is a little different, but still illustrates how software and hardware can interact unpredictably, especially in the automotive space. The story centers on a 2015 Optima recall for a software update for the knock sensor detection system. We can’t find the specifics, but if this recall on a similar Kia model in the same model year range and a class-action lawsuit are any indication, the update looks like it would have made the KSDS more sensitive to worn connecting rod damage, and forced the car into “limp home mode” to limit damage to the engine if knocking is detected.
A clever solution to a mechanical problem? Perhaps, but because the Kia owner in the story claims not to have received the snail-mail recall notice, she got no warning when her bearings started wearing out. Result: a $6,000 bill for a new engine, which she was forced to cover out of pocket. Granted, this software fix isn’t quite as egregious as Ford’s workaround for weak driveshaft mounting bolts, and there may very well have been a lack of maintenance by the car’s owner. But if you’re a Kia mechanical engineer, wouldn’t your first instinct have been to fix the problem causing the rod bearings to wear out, rather than papering over the problem with software?
Engine failures happen, pilots train for them, and our airport infrastructure is setup to accommodate emergency landings like this. However, the timing of this reported failure is notable. This is the second engine failure on a 777 within a week, and the third to occur in a Boeing aircraft.
Reports of this morning’s emergency landing in Moscow will need to be verified and investigated, and we have not seen confirmation on what type of engine the Rossiya Airlines B777-300ER used. For comparison the 777-300ERs of the United fleet and the 777-300ERs operated by Emirates both use General Electric engines rather than Pratt & Whitney models, so it is likely the Rossiya aircraft also had a GE engine.
The fact that the flights were all able to make safe landings is a testament to the redundant engineering of these aircraft. CNET did a deep dive into last Saturday’s engine failure and notes that it was an Extended-range Operations Performance Standards (ETOPS) aircraft capable of flying long distances on a single engine — necessary if an aircraft needed to make it half-way to Hawaii on one engine for an emergency landing. They also report on two other Pratt & Whitney PW-4000 engine failures in 2018 and 2000 2020, although as mentioned before, today’s incident likely didn’t involve an engine from this maker.
[Main image source: B777-300 by Maarten Visser CC-BY-SA 2.0]