Thread: Ethiopian air lines flight goes down all killed

Originally Posted by DiscoMick

What puzzles me is how Boeing could think it was acceptable to..

easy. money and sales.

The author of the video is a pilot of possibly more hours than you ( sorry, I have no idea how many hours you have, but he states his in subsequent vids. Maybe you should watch. However, I'll bow to your superior knowledge ), and he goes on to quote the preliminary report at length in his vids.

Hi John. It does't really matter how many hours I have, but since you asked - I've done 25 years in airlines, with around 6000 hrs on the B737 NG... Nevertheless, I don't feel I have superior knowledge to anyone, just sharing my insight and understanding of the type I fly everyday.

I did watch the videos, and most of the info he discusses I had already touched on before the videos were produced. Some info he presented was incorrect (part of which he corrected in subsequent videos, some not). Nevertheless, overall they're quite informative.

He also describes the difficulty actuating manual trim at the airspeed the aircraft had. As a layman, I can only go with what the people who actually fly the things say. He is one of them, although I believe his currency is on the 777.

He has some experience on the B737, but flies the tripler. He's not current on type (B737). I'm current (for what that's worth ). He describes and demonstrates the difficulty of manually trimming at high speed. There's no evidence to suggest that both pilots had a go at the same time to trim. The 200hr FO just said "it's not working", and they moved on and switched the Stab Trim Cutout switches back on). Whether the trim wheels were recovered (and the position of the manual knobs known) may give some insight as to whether they both had a go. Once again, a crew coordination issue (see below).

What's scary here is that the aircraft systems clearly fought the pilots. We can argue until we are blue in the face, but the system fought the pilots, and it did so due to apparently faulty inputs. MCAS used data from ONE AOA sensor, and ignored the other, if the preliminary report is to be believed. The 737/8/9 Max is grounded on the basis of the prelim report, and events prior. The MCAS system would seem, on first basis, to be at fault here. Remember, the Ethiopian flight was not the first to crash. MCAS has been blamed for the LionAir Flight 610 crash as well.

The MCAS (in its present iteration) did't ignore the other side Alpha Vane - it was designed to only use one side (once powered up), with no redundancy(!). It does switch between L and R FCC's on alternating flights (and following a power-down), but essentially if the Alpha vane data the MCAS is currently using becomes corrupt, there's nothing you can do to revert to a valid source.

The whole system was poorly designed and implemented in the first place. Other posts here reflect the underhandedness and systemic issues of Boeing. They will pay dearly...

The other John (JDNSW)

If they could not trim, and control force required prevented lifting the nose with elevator, wouldn't the only way of slowing be to reduce thrust - which I presume would cause some pitch down? In any case, by this stage the nose was well below the horizon, so this may not have made much difference.

Indeed, John. They absolutely should have slowed down. Reducing thrust and/or deploy the speed brakes may have helped. You're right about the thrust/pitch couple, but remember that slowing down would have:
a) made it easier to trim out the nose-down stab and regain some elevator authority, and;
b) moved the CP forward, possibly mitigating some of the pitching moment (remember, at that speed they were in test pilot territory).

It's noted in the report that the thrust was left at either the takeoff or climb thrust setting. There are two possibilities:
1) They took off without the autothrottle engaged (no biggie. Sometimes it's not available due to an MEL, and we do it semi-regularly), or;
2) They disengaged the autothrottle as part of the Runaway Stabilizer checklist (most likely).
The catch is that with autothrottle disengaged, you lose Vmo speed protection (and other protections), and have to operate the thrust levers manually to ensure your speed remains where you want it. This is probably a crew coordination issue that in the heat of the moment, it appears nobody was in full control of the aircraft. Having a 200hr pilot in the right seat even under normal operations can be quite a challenge (from experience).

Yes, I assume something like that - the control issue clearly had nothing to do with the thrust setting, so there would be no reason to touch it.

That's absolutely the reason they should have reduced thrust (see above).

The other serious issue is that they offered an "AOA disagree warning" system as an extra cost option. Surely this shows that as a company, they did not realise the issue. Neither of the aircraft involved in these two disasters had this option. I suspect most of the ones flying without incident may have this fitted - which would lead to early detection and rectification of a sensor starting to go bad.

Excellent point, John. None of the 737NG's on the civil register in OZ have either the AoA gauge or AoA Disagree monitoring installed, as far as I'm aware. The RAAF may have it on their variants (unsure).


I think the human factors aspect has played a bigger part in the prangs than we know (at the moment). Experience, cockpit gradient, personalities, fatigue, health etc will take some time to be established.

Another John.

Originally Posted by Hugh Jars

Hi John. It does't really matter how many hours I have, but since you asked - I've done 25 years in airlines, with around 6000 hrs on the B737 NG... Nevertheless, I don't feel I have superior knowledge to anyone, just sharing my insight and understanding of the type I fly everyday.

I did watch the videos, and most of the info he discusses I had already touched on before the videos were produced. Some info he presented was incorrect (part of which he corrected in subsequent videos, some not). Nevertheless, overall they're quite informative.



He has some experience on the B737, but flies the tripler. He's not current on type (B737). I'm current (for what that's worth ). He describes and demonstrates the difficulty of manually trimming at high speed. There's no evidence to suggest that both pilots had a go at the same time to trim. The 200hr FO just said "it's not working", and they moved on and switched the Stab Trim Cutout switches back on). Whether the trim wheels were recovered (and the position of the manual knobs known) may give some insight as to whether they both had a go. Once again, a crew coordination issue (see below).



The MCAS (in its present iteration) did't ignore the other side Alpha Vane - it was designed to only use one side (once powered up), with no redundancy(!). It does switch between L and R FCC's on alternating flights (and following a power-down), but essentially if the Alpha vane data the MCAS is currently using becomes corrupt, there's nothing you can do to revert to a valid source.

The whole system was poorly designed and implemented in the first place. Other posts here reflect the underhandedness and systemic issues of Boeing. They will pay dearly...

The other John (JDNSW)
Indeed, John. They absolutely should have slowed down. Reducing thrust and/or deploy the speed brakes may have helped. You're right about the thrust/pitch couple, but remember that slowing down would have:
a) made it easier to trim out the nose-down stab and regain some elevator authority, and;
b) moved the CP forward, possibly mitigating some of the pitching moment (remember, at that speed they were in test pilot territory).

It's noted in the report that the thrust was left at either the takeoff or climb thrust setting. There are two possibilities:
1) They took off without the autothrottle engaged (no biggie. Sometimes it's not available due to an MEL, and we do it semi-regularly), or;
2) They disengaged the autothrottle as part of the Runaway Stabilizer checklist (most likely).
The catch is that with autothrottle disengaged, you lose Vmo speed protection (and other protections), and have to operate the thrust levers manually to ensure your speed remains where you want it. This is probably a crew coordination issue that in the heat of the moment, it appears nobody was in full control of the aircraft. Having a 200hr pilot in the right seat even under normal operations can be quite a challenge (from experience).

That's absolutely the reason they should have reduced thrust (see above).



Excellent point, John. None of the 737NG's on the civil register in OZ have either the AoA gauge or AoA Disagree monitoring installed, as far as I'm aware. The RAAF may have it on their variants (unsure).


I think the human factors aspect has played a bigger part in the prangs than we know (at the moment). Experience, cockpit gradient, personalities, fatigue, health etc will take some time to be established.

Another John.

I thank you for your detailed response, and I reiterate my layman's status here. I take the point about the MCAS not ignoring the AOA input, but surely Boeing must admit that that was a poor design. Well, I guess they have, albeit a little late. As for redundancy, surely a 'disagree' from two sensors is a red flag? Apparently Boeing didn't think so:

"essentially if the Alpha vane data the MCAS is currently using becomes corrupt, there's nothing you can do to revert to a valid source."

Boeing dies right there. What an appalling indictment on what was once the greatest aircraft manufacturer ever. A software glitch... It used to be said, "if it isn't Boeing I'm not going". Sadly, it is now "if it it is a Boeing, I'm not going." What a disaster.

Bring back Concorde, I say. Tongue in cheek. Still, safest airliner ever....

It seems that some airlines, American and SouthWest amongst them, have cancelled flights that would have used the 737 /8/9 Max until mid August. I guess they are hedging their bets against re-certification of that aircraft. It could happen well before that, but maybe it couldn't. The question is, will the public accept the aircraft. My belief is, of course they will. Most people have no idea what they are getting into. I do, but I am interested. Would I fly in a 737 Max? Or wait hours for something else? If the 737 Max is re-certified then of course I'd fly in it.
However, Airbus has been uplifted through all of this. The A330neo will thrive due to this in the Asian market. Sure, not a true competitor to the 737 Max, but tell that to Boeing right now.

Originally Posted by JDNSW

The software writers almost certainly just programmed what they were told to do - they are almost certainly qualified in IT not aerospace engineering.

I seriously doubt that. Boeing just doesn't hire Silicone Valley geeks; well, they used not to. If they have then they deserve the ****storm they have coming. If Boeing compartmentalized to the extent you suggest then they will be ****ed in the courts and will die. The US court system is unforgiving, lobbyists notwhistanding. The forthcoming lawsuits are going to be massive, and bear in mind that it is reported that Boeing are losing $70 MILLION a day every day the 737 Max is grounded. It's unsure that Boeing will survive. That , of course, would be tragic.

Originally Posted by Hugh Jars

I think the human factors aspect has played a bigger part in the prangs than we know (at the moment). Experience, cockpit gradient, personalities, fatigue, health etc will take some time to be established.

Absolutely! Boeing can be rightly criticised all day long. But in the end it comes down to a simple fact "fly the bloody aircraft"! Supposedly qualified pilots that it appears didn't do that. The only thing that I would concede is the fact the problem occurred at low altitude, and in the case of not reducing thrust it would be a very hard move as the already nose down attitude would drop further.
But then I am not qualified to comment because I used to fly helicopters, and that is an entirely different ball game.

Originally Posted by johntins

I seriously doubt that. Boeing just doesn't hire Silicone Valley geeks; well, they used not to. If they have then they deserve the ****storm they have coming. If Boeing compartmentalized to the extent you suggest then they will be ****ed in the courts and will die. The US court system is unforgiving, lobbyists notwhistanding. The forthcoming lawsuits are going to be massive, and bear in mind that it is reported that Boeing are losing $70 MILLION a day every day the 737 Max is grounded. It's unsure that Boeing will survive. That , of course, would be tragic.

Boeing, since the MBAs started to run the company, and moved management away from production, have apparently been outsourcing everything they can. Presumably this includes as much software development as possible. And even if the software developers were still in house, expecting to be laid off at any time hardly improves the quality of the code.

Originally Posted by Old Farang

Absolutely! Boeing can be rightly criticised all day long. But in the end it comes down to a simple fact "fly the bloody aircraft"! Supposedly qualified pilots that it appears didn't do that. The only thing that I would concede is the fact the problem occurred at low altitude, and in the case of not reducing thrust it would be a very hard move as the already nose down attitude would drop further.
But then I am not qualified to comment because I used to fly helicopters, and that is an entirely different ball game.

While it is very likely that a better crew could have managed the situation (and there is emerging evidence that some crews have, for example the immediate previous flight of the Lion Air hull), the simple fact remains that the model was sold as needing no further crew training compared to existing 737s, and the crews involved have not been crashing these (not twice in a few months in identical circumstances, anyway) previously. And the worldwide grounding of the aircraft suggests that aviation authorities agree.

Certainly appears that systems which were optional and not fitted to the crashed aircraft should have been compulsory and standard.
Airbus will puck up a lot of orders from this, I expect.