4 ms·

That's a red herring, the MCAS issue has nothing to do with the type rating. MCAS is not something the crew was even supposed to be aware of, even less trained

by janoc 7y ago

That's a red herring, the MCAS issue has nothing to do with the type rating. MCAS is not something the crew was even supposed to be aware of, even less trained on, so no effect on type rating at all there. What it may cause problem with is the certification of the plane as such - MCAS was required to correct the behavior of the plane in high speeds/high thrust and high angle of attack situation where the new larger engines made it difficult to bring the nose down (and avoid stalling). However, that's not something that cannot be fixed. Airbuses fly full of similar augmentation systems and there is no problem with them, so it is certainly doable.

raverbashing 7y ago
Yes but the 737 is not fly by wire, you don't have the same ways of "inserting yourself" into the loop as in a fbw plane
- janoc 7y ago
  How do you "insert yourself in the loop" on a FBW plane when the computers conk out? There is manual reversion on an Airbus but it is very minimal - if you ever end up in a situation where that is needed you are having a very very bad day. On the other hand, 737 is actually fly-by-wire - literally, because actual steel wires are still connected between the cockpit controls and the control surfaces. So if the electronics dies and the hydraulics isn't working neither for whatever reason, the plane can still be controlled. These "magic boxes" are there to augment the control characteristics, such as the "feel" of the control column (which is normally lost due to the hydraulics driving the control surfaces). Or, in the case of MCAS, to help with an aerodynamic issue. Both are hardly unprecedented - the last large transport plane that didn't rely on any computers/electronics for controls was maybe the 707. The problem is the poor design of the MCAS software/system, not that it exists as such.
dna_polymerase 7y ago
> MCAS is not something the crew was even supposed to be aware of, even less trained on, so no effect on type rating at all there. Exactly this is the argument for a type rating problem. If pilots would have to undergo heavy training for the MAX there would probably have been a new type rating. There are some experts out there who argue that this is why Boeing tried to hide the existence of MCAS. Pilots should have been informed about MCAS and the reason it is there before all this started.
- janoc 7y ago
  Yes but the point is that it was thought this isn't something that was to be required - and had the system been correctly implemented (and handled by the crews), there wouldn't have been a problem. I don't think Boeing was intentionally "hiding" the existence of such a system, they just didn't consider it critical enough to bother the crews with it because it was supposed to come into play only in a very unusual flight regime - manual flight, flaps up and high angle of attack. There was no special "MCAS training" needed because any failures fall into the "runaway stabilizer" emergency procedure. It just didn't work out exactly that way, unfortunately. If I recall correctly, the system has been mentioned in the documentation - not prominently and not something the crews would have been forcibly made aware of, but given that the plane certification depended on it and it had to be certified, they couldn't exactly "hide" it from the regulators. Keep in mind that the procedure for the stabilizer problem is the same since 737 has been first introduced in the late 60s. Had it been correctly followed, likely neither of the crashes would have happened, MCAS or no MCAS. The Lion Air crew didn't identify the problem as a possible runaway in the first place for whatever reason and the Ethiopian crew made several (understandable, but still) mistakes, such as cutting the trim system out while heavily out of trim, not reducing the excessive speed and then finally re-activating the electric trim (which is against the procedure) when they couldn't re-trim the plane manually due to the resulting excessive forces. Which has directly caused the crash once the MCAS has re-activated.
inferiorhuman 7y ago
That's a red herring, the MCAS issue has nothing to do with the type rating. In the 60 Minutes Australia piece a Boeing employee explains that MCAS was set up to only use one alpha vane specifically to avoid being classed as a difference that required simulator time for pilots transitioning. Whether or not that's true (or how that even works), I couldn't tell you.

by janoc 7y ago

raverbashing 7y ago

Yes but the 737 is not fly by wire, you don't have the same ways of "inserting yourself" into the loop as in a fbw plane

janoc 7y ago
How do you "insert yourself in the loop" on a FBW plane when the computers conk out? There is manual reversion on an Airbus but it is very minimal - if you ever end up in a situation where that is needed you are having a very very bad day. On the other hand, 737 is actually fly-by-wire - literally, because actual steel wires are still connected between the cockpit controls and the control surfaces. So if the electronics dies and the hydraulics isn't working neither for whatever reason, the plane can still be controlled. These "magic boxes" are there to augment the control characteristics, such as the "feel" of the control column (which is normally lost due to the hydraulics driving the control surfaces). Or, in the case of MCAS, to help with an aerodynamic issue. Both are hardly unprecedented - the last large transport plane that didn't rely on any computers/electronics for controls was maybe the 707. The problem is the poor design of the MCAS software/system, not that it exists as such.

dna_polymerase 7y ago

> MCAS is not something the crew was even supposed to be aware of, even less trained on, so no effect on type rating at all there. Exactly this is the argument for a type rating problem. If pilots would have to undergo heavy training for the MAX there would probably have been a new type rating. There are some experts out there who argue that this is why Boeing tried to hide the existence of MCAS. Pilots should have been informed about MCAS and the reason it is there before all this started.

janoc 7y ago
Yes but the point is that it was thought this isn't something that was to be required - and had the system been correctly implemented (and handled by the crews), there wouldn't have been a problem. I don't think Boeing was intentionally "hiding" the existence of such a system, they just didn't consider it critical enough to bother the crews with it because it was supposed to come into play only in a very unusual flight regime - manual flight, flaps up and high angle of attack. There was no special "MCAS training" needed because any failures fall into the "runaway stabilizer" emergency procedure. It just didn't work out exactly that way, unfortunately. If I recall correctly, the system has been mentioned in the documentation - not prominently and not something the crews would have been forcibly made aware of, but given that the plane certification depended on it and it had to be certified, they couldn't exactly "hide" it from the regulators. Keep in mind that the procedure for the stabilizer problem is the same since 737 has been first introduced in the late 60s. Had it been correctly followed, likely neither of the crashes would have happened, MCAS or no MCAS. The Lion Air crew didn't identify the problem as a possible runaway in the first place for whatever reason and the Ethiopian crew made several (understandable, but still) mistakes, such as cutting the trim system out while heavily out of trim, not reducing the excessive speed and then finally re-activating the electric trim (which is against the procedure) when they couldn't re-trim the plane manually due to the resulting excessive forces. Which has directly caused the crash once the MCAS has re-activated.

inferiorhuman 7y ago

That's a red herring, the MCAS issue has nothing to do with the type rating. In the 60 Minutes Australia piece a Boeing employee explains that MCAS was set up to only use one alpha vane specifically to avoid being classed as a difference that required simulator time for pilots transitioning. Whether or not that's true (or how that even works), I couldn't tell you.