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Of course, the actual implementation of MCAS was a disaster. Especially, that they didn't deactivate it automatically on AOA disagree, that on top of that the s
by _ph_ 5y ago
Of course, the actual implementation of MCAS was a disaster. Especially, that they didn't deactivate it automatically on AOA disagree, that on top of that the screen signal for AOA disagree was not shown due to a separate issue and of course that late in development MCAS was given more control authority than initially planned.
My point just was, a complete redesign of the 737 still would have to deal with the same aerodynamic issues as the 737 MAX, as they are rather fundamental to this kind of jets. But indeed, it would have been easier to deal with it with a new design.
It is less mentioned, that shortly after the MAX crashes, Airbus mandated that in some planes the last rows were kept empty until some software updates were deployed. So they seem to have discovered some boundary conditions they were not happy with and decided to be rather safe till they augmented the software.
- FabHK 5y ago> late in development MCAS was given more control authority than initially planned ... without triggering re-evaluation of the seriousness/consequences of failure. That meant that failures of MCAS were considered unproblematic, which meant that lower levels of redundancy were deemed acceptable. Quite a process/management failure.
- _ph_ 5y agoWell, technically the failures of MCAS should be unproblematic, as the stabilizer runaway protocol is well trained for any 737 pilot and would cope with a MCAS misfunction. The problem is: in the two crashes the pilots either completely failed to follow the protocol (Lion Air) or to late and failed to recover (Ethiopian Airlines).
- himinlomax 5y ago> a complete redesign of the 737 still would have to deal with the same aerodynamic issues as the 737 MAX, No, it would have more ground clearance, so it wouldn't need flat bottomed cowlings nor MCAS.
- _ph_ 5y agoThat is wrong. First of all, the 737 MAX doesn't have flat bottomed cowlings, that was its predecessor, which did not have MCAS. And the effect is fundamental to large engines. The effect which required MCAS would also happen if the machine had larger ground clearance and would be mounted more under the wings. Actually the way the engines are mounted on the MAX moves them closer to the longitudinal axis of the airplane and thus reduces and thrust-related tendency to pitch up.
- himinlomax 5y agoFirst result on Google: https://fr.wikipedia.org/wiki/Boeing_737_Max#/media/Fichier:WS_YYC_737_MAX_1.jpg https://fr.wikipedia.org/wiki/Boeing_737_Max#/media/Fichier:...
- nemetroid 5y agoThe MAX does have flattened cowlings, though the effect is less pronounced than on the NG. Compare the MAX (right) to the completely round cowling on the A320neo's LEAP-1A: https://leehamnews.com/wp-content/uploads/2020/11/737NG-vs-MAX-nacelles.png https://leehamnews.com/wp-content/uploads/2020/11/737NG-vs-M... https://aerocorner.com/wp-content/uploads/2020/01/Aegean-Airbus-A320neo-frontal-1140x641.jpg https://aerocorner.com/wp-content/uploads/2020/01/Aegean-Air...