Ethiopian Crash


#1

A few months back I posted in a rage over the LionAir accident and the mushroom treatment 737 pilots were given about the new Max. The similarities this time are hard to ignore: Brand new Max8, severe oscillations of speed and altitude before an attempt to turn back to the point of departure. The dead cannot be brought back so my selfish hope as both an American and as an [… self editing…] quite a few on order is that this accident has no relation to the previous crash. May the families of the passengers and crew find a way to push through the heartbreak and continue to live and thrive. As for Ethiopian, they are not LionAir. They are well-respected and professional. More than any other carrier in recent years, Ethiopian has helped modernize the African air service. Hopefully that will continue. But what a heartbreak for them.


#2

It is very sad. Many killed, and many families horribly impacted, and it looks like a very international flight with people from many countries.

Some early data here:

The pilot had 8000 hours, the aircraft was about 130 days from first flight, so a new Max8 like you said. As with these things, the full info will come out in time.

I don’t have much experience or knowledge in this area, but wouldn’t be shocked if the Max 8’s got grounded or reviewed now? I am not sure how that works.

Some more info here:


#3

Saw that story this morning and (of course) immediately thought of the Lion Air crash. Two early hull loses on such a widely anticipated (and ordered) plane is a tough hurdle. The news story I saw had the CEO standing in a huge crater, and one of the photos included was of a backhoe digging in to sort out wreckage. I really hope they (whoever is in charge of the investigation) don’t end up destroying any useful evidence and that they perhaps work with some authorities that have experience with this kind of investigation.


#4

Sad indeed,

But correct me if Im wrong, didn’t the lion air incident have a few red flags before its flight? AKA maintenance issues a few flights before.

All depends on the cause. Its very possible they will be grounded but for example lets say they lost an engine due to a birdstrike, that wouldnt be grounds for a grounding. Hope that makes sense.


#5

A friend of mine worked on the Max’s in Kansas (aerospace engineer specializing in composites)- just left and went to another company a couple of weeks ago. I asked her if she had any thoughts on this, so I’ll be curious to hear back.


#6

An ungrounded grounding? :grin:


#7

China has ordered its airlines and a few other carriers (Ethiopia and Cayman Islands) are grounding the MAX until something can be learned…

https://www.avweb.com/eletter/archives/101/4277-full.html


#8

It did. But the underlying cause was still a safety system called “CAS” that none of us were trained about. It trims the nose using the stab in ways that go totally against how we were trained that the stabilizer would be managed by the flight control system. “Speed Trim” and “Mach Trim” were two autopilot trim functions that have always existed in the 737 and they only make tiny applications that can easily be overridden. The CAS function on the Max was completely hidden from pilots until the Seattle Times taught all of us about it just after the LionAir crash. That’s LionAir. Ethiopian may have zero relationship with that crash. But I believe that China is making the right decision. The risk is too high and a review of the FDR will only take a day. If the Ethiopian crash is unrelated then carry on.


#9

An excerpt from a CBC article, emphasis added:

“The accident is likely to renew questions about the 737 MAX, the newest version of Boeing’s popular single-aisle airliner.

Indonesian investigators have not determined a cause for the October crash, but days after the accident Boeing sent a notice to airlines that faulty information from a sensor could cause the plane to automatically point the nose down. The notice reminded pilots of the procedure for handling such a situation.

The Lion Air cockpit data recorder showed that the jet’s airspeed indicator had malfunctioned on its last four flights, though the airline initially said problems with the aircraft had been fixed before it left the Indonesian capital of Jakarta.”

Source: https://www.cbc.ca/amp/1.5050532


#10

Update:

Data recorders found, 1 damaged.
Smoke reported from the rear of the plane before impact. “Rotations” before impact also mentioned, but didn’t say what that means.

Source: https://www.cbc.ca/news/world/ethiopian-airlines-crash-1.5051005


#11

I doubt the smoke claim. Eye-witnesses are very unreliable. I remember reading an account of the UAL Colorado Springs 737 crash where a witness claimed seeing the pilot waving a white flag before impact. However, I am not claiming that smoke/fire/bomb is unlikely. Statistically, that would be more likely than a repeat of the conditions that caused the LionAir accident.


#12

OK, Singapore and Australia were not really significant as there are very few 737 Max’s flying there, but I guess the UK is a different kettle of fish?

BBC News - Boeing: UK joins countries blocking aircraft


#13

Air Canada, WestJet and Sunwing here in Canada have yet to. They currently are of the mind that they are safe and immune to a potential fleet-wide problem.

Also, I was on a Sunwing Max8 one of the flights to/from Costa Rica (I’ll have to check which) in September. Scary thought, if it is a design/systems fault…


#14

I’ve also heard of reports of flames/smoke coming out the back of the plane. Possibly engine or cargo hold fire?


#15

It appears the UK has banned the 737 Max 8 from its airspace until further notice. Kinda wish they would have let an investigation reveal some details before they did that.


#16

My friend who worked for Spirit (sub who builds the fuselages) is of the opinion that it’s an avionics/ system fault that Boeing initially cut corners on, and has been in too much of a rush to properly address, because everything in their production process is feeling the strain from trying to catch up on demand for the Max8.


#17

IMHO they should ground them all until the investigation proves there is no design fault. It is the responsible course of action at this point. There may well be no connection between the two crashes, but at the same time, there are enough similarities that it needs to be checked out. Carrying on for what could be months while the investigation reaches a conclusion is just rolling the dice.


#18

There are definitely grounds for grounding. Regarding the offending system (at least in the case of LionAir), here is what I was told when I was on the fleet: the new Max’s did not quite meet the FAA stadards for stability at high AOA at certain weight and power configurations. Meaning that airplanes should naturally want to pitch down as AOA increases. The Max (or maybe just the Max8) doesn’t do this as definitively as Boeing and the FAA wanted. So they put in a system that rolls in continuous nose down trim until the pitch trend is acceptable to the airplane. These trim inputs are cumulative. The stab is far, far more powerful than the elevator. So if a pilot finds himself fighting the trim without disconnecting it, he will fight an ultimately loosing battle. This feature in itself is not a problem. The problem is that it totally changed the classic 737 trim logic we were all taught. And furthermore we were not told of the existence of the system. The underlying stall warning and AOA sensing may also be a problem but I’ve heard nothing. I personally doubt the smoke claims but that’s just me.

Another thing I heard is that American has already installed a Boeing fix and SWA is not far behind.


#19

From a Reddit user:

MCAS is temporarily disengaged by depressing the trim switches on the yoke; however, MCAS can activate again within five (5) seconds if it continues to detect a high AoA. It is worth noting here that a few days prior, Lion Air pilots of the same aircraft turned off the electric trim per the Runaway Stabilizer QRH checklist which disengaged MCAS. The pilots of the crashed airplane were fighting the repeated MCAS activations with the trim switch on the yoke without disabling the electric trim per the Runaway Stabilizer QRH via switches on the throttle quadrant.


I find it really insane that you can’t just press and hold the big red button on the yoke to disconnect all artificial inputs and trim movements. That the system reverts again in 5 seconds is pretty…well…confusing I’m sure in the moment with the nose pitching up and down. Yes, it is a training issue to be sure…but it is also a design that is looking for a way to help you fail. I mean, shouldn’t the procedure just be as easy as, hold the red button pitch for 5 degrees or whatever…stable flight, nothing more, nothing less. Nevermind my totally uninformed opinion though…I have zero experience with this kind of system other than the autopilot trim runaway interruption that is pretty standard on all planes.


#20

Tagging on to this thread…well…just because…the NTSB did release an update on preliminary data from the Atlas (Amazon Prime) 767 crash today:

https://www.ntsb.gov/investigations/Pages/DCA19MA086.aspx

About 12:38, the controller informed the pilots that they would be past the area of weather in about 18 miles, that they could expect a turn to the north for a base leg to the approach to runway 26L, and that weather was clear west of the precipitation area. The pilots responded, “sounds good” and “ok.” At this time, radar and ADS-B returns indicated the airplane levelled briefly at 6,200 ft and then began a slight climb to 6,300 ft.

Also, about this time, the FDR data indicated that some small vertical accelerations consistent with the airplane entering turbulence. Shortly after, when the airplane’s indicated airspeed was steady about 230 knots, the engines increased to maximum thrust, and the airplane pitch increased to about 4° nose up. The airplane then pitched nose down over the next 18 seconds to about 49° in response to nose-down elevator deflection. The stall warning (stick shaker) did not activate.

FDR, radar, and ADS-B data indicated that the airplane entered a rapid descent on a heading of 270°, reaching an airspeed of about 430 knots. A security camera video (figure 4) captured the airplane in a steep, generally wings-level attitude until impact with the swamp. FDR data indicated that the airplane gradually pitched up to about 20 degrees nose down during the descent.