Sully apparently knows some one and was able to get some sim time on one of the few 737 Max sims out there. He was able to recover the jet during simulations of the Lion Air and Ethiopian crashes. He was able to do so with difficulty and argues that its possible that a reasonable pilot confronted with this problem on a surprise basis would have their hands full recovering the jet. His airman certificate says he’s has a 737 type rating but I’m not sure how long ago and what model 737 he flew or how many hours he has in type. He is a pretty smart guy and is a safety consultant now. I’m not sure if he’s just a concerned person or has some other interest in this issue. He was recommending full up simulator training rather than computer based training for pilots when the Max is back operational. Hindsight is always 20/20 so blaming the pilots who were unable to recover from something that they didn’t train for is unwarranted, or so the argument goes. Sully blames the FAA certification process and Boeing for hastily implementing a flawed design. Here Sully has no problem with 20/20 hindsight. The general assumption is that Boeing prioritized cost over safety and cut corners. This remains to be seen and may be accurate. However, it’s equally likely that Boeing made a legitimate engineering assumption that turned out to be wrong.(The former being much more lucrative for selling papers and for litigation) The American Airlines pilot union president also at the hearing bristled at blaming the pilots involved in the two crashes. The pilots in both crashes were put in bad situations but that’s what a bad day in the office looks like and what airline pilots get paid to sort out. I’ll let you all know when I see it in the sim.
"equally likely that Boeing made a legitimate engineering assumption that turned out to be wrong" - when we say "Boeing" we really mean an individual or handful of individuals in Boeing's employ, right? I hope the individuals in question were not in some way incentivized to prioritize cost... but in a corporate culture that's generally difficult, isn't it?
ReplyDeleteLet's hope the time is coming soon when our advancing computer technology allows modeling precise enough to test all those "legitimate engineering decisions" in advance of risking real people's lives on the basis of false assumptions and calculations.
Many systems in commercial aircraft are dual channel, meaning either redundant systems or inputs to systems to minimize risk of a faulty input. In this case, the MCAS had only one AOA input, the Captains AOA vane located on the left side of the aircraft. A major question is why the engineers at Boeing decided to use a single channel input of AOA to the MCAS computer rather than compare both the Captains and FOs AOA vanes. It doesn’t seem like cost would be a major factor since designing the system itself was the major cost. Rather Mean time between failure data of AOA vanes, the probability of a comparator not allowing the MCAS to operate when it really was supposed to as well the existence of a long standing pilot procedure to combat runaway trim(this used to be a memory item) played into the decision. The real question is how aerodynamic modeling missed the problem that the MCAS was designed to counteract. This problem of reduced stick force per g at high angles of attack was isolated late in flight test at at the very end of the development cycle leaving the only possible solution one like the MCAS rather than a complete redesign of the aircraft which other than this glitch was performing well.
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