Originally Posted by Astro14
Originally Posted by billt460
I seem to remember a couple of fatal, (no survivors), 737 accidents that happened with several years in between, similar to this. (I'm sure Astro remembers both, and he can feel free to add or correct anything I may have gotten wrong here). Both ended up being caused by the same thing. One happened in Colorado Springs, and the other 3 or 4 years later in Pennsylvania. They never solved the Colorado Springs crash until after the Pennsylvania crash happened.
If I remember correctly, it was caused by a faulty designed hydraulic valve. That somehow managed to reverse the rudder pedal input. But only sometimes under certain rare conditions. But all 737's continued to fly with that bad valve for several years in between both crashes. Because they never discovered it until after the Pennsylvania crash. (Both were similar accidents, going in near vertically).
I hope this doesn't turn into the same thing. Not being able to solve 2 non survivable crashes involving the same aircraft is scary. (Assuming they were both caused by the same thing). And that it turns out to be mechanical. Now it's just too early to tell.
They didn't ground the 737 after the Colorado Springs crash, because some believed at the time it might have been weather related. (Rolling wind shear off the mountains, or some such occurrence). Not to mention it would have been economically devastating to so many airlines worldwide, and would have made a mess of airline travel. This appears to be shaping up differently. That said, these 2 crashes involving the 737 Max aircraft happened months in between... Not years.
That was unbelievably good work finding that bad valve, and solving the problem once and for all. I hope the same thing happens here... Assuming something in the aircraft is faulty.
You remember correctly, Bill - and the forensic analysis that revealed the design flaw in the rudder actuator is a textbook case of how to conduct an investigation.
I talked about that in this thread:
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4592998/all/Boeing_737_Max_take-off
I wasn't kind to the FAA or the 737 in my series of posts in that thread.
I'm clearly not a 737 fan, but I don't blame the 737 for either Lion Air or this crash.
We have, in both these crashes, the intersection of new design, poor communication from manufacturer, poor training by airlines, poor dissemination of updated procedures, and pilots who really don't know how to fly.
The specific crashes to which you refer were US Air 427 and United 585.
They crashed as the result of a design flaw and mechanical malfunction that slammed the rudder to the stop, and left it unresponsive to pilot input. Totally different than what we're talking about with Lion Air, and speculating about with Ethiopian.
I suspect that most of us with a little knowledge know what caused both the Lion Air and Ethiopian accidents. Having the airplane trim against you while pulling on the yoke without knowing how to turn off this automated function in a recipe for a bad outcome, as happened with these two flights.
Lion Air is a disaster factory while Ethiopian is considered the best African airline after SAA, but that's a little like being considered the best drug dealer in Dayton OH.
US carriers have much higher training and experience standards, so their pilots can recognize and avoid the potential pitfalls built into this aircraft.
We flew one of these guys MCO-SJU on 2/15/19. It was a gorgeous new machine with a really nice interior. I'd fly on another tomorrow with any of the US operators, who have real pilots with real skills, training and experience.
That these crews couldn't recognize and deal with what was effectively a trim runaway is what should really frighten us, not the aircraft as delivered.
I'll add that I've never bought the NTSB's probable cause WRT the US AIR accident nor that of the UAL aircraft. My reasoning is that the type had been in service without issue with too many operators over too many hours and cycles for too many years for this fatal problem to suddenly manifest. That an NTSB lab rat was able to get a rudder control valve to cycle hard over using dirty hydraulic fluid at a certain temperature does not bring any convincing finding in my opinion.
