Ethiopian Airlines Crash; Another 737 Max

Excerpt from that NYT article:
“The thing that is most abnormal is the speed,” said John Cox, an aviation safety consultant and former 737 pilot.

“The speed is very high,” said Mr. Cox, a former executive air safety chairman of the Air Line Pilots Association in the United States. “The question is why. The plane accelerates far faster than it should.”​

I'm just wondering if part of the control problem was too much thrust, maybe an autothrottle problem. If thrust is not derated as expected, would less nose-up trim be required -- and would this be more severe for the MAX because the airframe is so long?
 
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NoHeat said:
I'm just wondering if part of the control problem was too much thrust, maybe an autothrottle problem.
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Too much thrust? On takeoff? From a 7,657' airport?

The first time I took off from Bogata (8,360') it was in a 737-700, at max power, and it felt like we had forgotten to start one of the engines.
 
NoHeat said:
Excerpt from that NYT article:
“The thing that is most abnormal is the speed,” said John Cox, an aviation safety consultant and former 737 pilot.

“The speed is very high,” said Mr. Cox, a former executive air safety chairman of the Air Line Pilots Association in the United States. “The question is why. The plane accelerates far faster than it should.”​

I'm just wondering if part of the control problem was too much thrust, maybe an autothrottle problem. If thrust is not derated as expected, would less nose-up trim be required -- and would this be more severe for the MAX because the airframe is so long?
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I don't think the problem was too much thrust. They were very fast, yes, but they also weren't climbing. Sounds like the right amount of thrust, but the wrong pitch.
 
Larry in TN said:
Too much thrust? On takeoff? From a 7,657' airport?

The first time I took off from Bogata (8,360') it was in a 737-700, at max power, and it felt like we had forgotten to start one of the engines.
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Okay, scratch that idea.
 
Larry in TN said:
it felt like we had forgotten to start one of the engines.
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The first time I rode in an older aircraft from a high airport I thought the same. Caught a jumpseat ride in a LAB 727-200 out of LPB. 50 seconds or so later we were flying. I asked SIC what happens if lose an engine. He laughed and said fly down the valley and hope not run into something.
 
Tj1376 said:
Have you seen the data linking them? What are your thoughts? How do you draw that conclusion?

When I look at it, There is really only one oscillation that looks like LionAir. It then doesn’t look anything like LionAir to me.

It almost looks like ET caught the first downward trend of the nose, then it happened again and they reacted differently to the second nose down than the LionAir flight.

In the LionAir data you saw these consistent patterns of ups and downs, every 20 seconds. In ET you see this twice and then something else all together.

I wish the FAA would release the data they have from 3/13 which makes them think the two flights do parallel. I really hope it’s not the same flightradar data that the news has been spewing all week.

TJ


Sent from my iPhone using Tapatalk
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I drew no conclusions. I was simply speculating that there would be many who would draw parallels to the Lion Air crash, and that is exactly what has happened.
 
Bell206 said:
And the leaks have begun. NY Times reporting issue started right after takeoff. If true, this would take the MCAS system out of the picture.
"The captain of a doomed Ethiopian Airlines jetliner faced an emergency almost immediately after takeoff from Addis Ababa..."
https://www.nytimes.com/2019/03/14/world/boeing-737-max-ethiopian-airlines.html
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Except that it isn’t uncommon for some carriers to advocate engaging the autopilot as soon as allowable after takeoff. Just saying.
 
Greg Bockelman said:
Except that it isn’t uncommon for some carriers to advocate engaging the autopilot as soon as allowable after takeoff. Just saying.
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...and there are pilots for whom the autopilot is the preferred unusual attitude recovery tool.
 
I'm wondering if the result of all of this is going to be the public perception that passenger airliners are too complicated and that more automation us required to make them pilot-proof.
 
Matthew said:
I'm wondering if the result of all of this is going to be the public perception that passenger airliners are too complicated and that more automation us required to make them pilot-proof.
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I think Airbus would love that.
 
From AvWeb:

Investigators probing the wreck of Ethiopian Airlines Fight 302 have reportedly recovered the airplane’s trim jackscrew and found it set to a nose-down position. This is similar to the jackscrew position found in the Lion Air crash last October and may be the additional evidence that convinced the FAA to ground the Boeing 737 MAX 8 and 9 series aircraft.

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Matthew said:
I'm wondering if the result of all of this is going to be the public perception that passenger airliners are too complicated and that more automation us required to make them pilot-proof.
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If all of the automation is making airliners too complicated, how is adding more automation going to make them more pilot-proof????
 
1RTK1 said:
But there is still an auto trim cut off switch to remedy such problems.
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Yes, there are solutions, but the new system may have masked what was happening, thus confusing the pilots.
 
Stan Cooper said:
Today's AVweb Flash has an article referring to a Sunday Seattle Times article reporting the MCAS certification was flawed.

https://www.avweb.com/avwebflash/news/MCAS-Certification-Flawed-Report-232426-1.html
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This is an interesting article. This quote especially caught my eye.

"But the original specifications of the system called for MCAS to limit its ability to move the horizontal stabilizer .6 degrees at a time. By the time deliveries began, it could pitch the stabilizer 2.5 degrees, about half its total travel, in one movement, the result of flight testing tweaks aimed at finessing the flight control feel."

1RTK1 said:
But there is still an auto trim cut off switch to remedy such problems.
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There is, but there are problems with this.

Besides the fact that there was probably massive confusion in the cockpit. Perhaps airspeed disagrees and maybe the constant, un-silenceable rumble of the stick shaker. The plane is trimming nose-down uncommanded, and the pilot(s) are straining to keep the nose up against who-knows-how-much stick force.

Here's something that's not discussed... how hard it is to manually trim a heavy jet with the trim wheel.

DISCLAIMER: I do not/have not flown the 737. I am basing the below on my experience in the 707, which I believe is going to be similar to the 737 when it comes to the stabilizer trim. Hopefully, someone who is actually typed in the 737 (@kayoh190) can come along and correct any discrepancies.

We had to practice runway stabilizer trim in the 707 simulator every year or so. Until recently, the 707 (KC-135, actually) had no stab-trim brake like most modern jets. A stab trim brake is either a mechanical or electrical way to interrupt stab trim motion by opposing the trim force with the yoke. It's a natural reaction and works great. The trim starts to run away nose down, your first reaction is to pull back on the yoke. Back pressure on the yoke stops nose down trim. We didn't have that system in the KC-135 until after one crashed in Germany in 1999 (Esso 77). (The 737 has a stab-trim brake, but it does not stop MCAS trim inputs). So, pre-stab brake, we would get this runaway trim malfunction in the simulator. It was usually given to us on takeoff, during a configuration change, while the pilot flying was actually using the trim. Raise the flaps, give it some trim to relieve stick forces, trim works as advertised, until you let the switch go, and the trim continues. The pilot monitoring thinks nothing of it, as they are used to the trim running at that time. The pilot flying takes a few potatoes to figure out that the trim is indeed running, but now (s)he has a handful of airplane trying to pitch for the deck and now probably has two hands on the yoke pulling to keep the nose from falling. By that time the PF hopefully calls out "TRIM, TRIM, TRIM" and the PM realizes what's going on and reaches for the STAB TRIM CUT-OUT Switches. That stops the trim running, and things aren't getting any worse, but they are still not great. Now you have a heavy jet, close to the ground with a whole lot of nose down force and one pilot struggling to keep the nose from falling, the speed is increasing and the PF can't/doesn't want to take one hand off the yoke to pull the throttles back because of the yoke force, but has to because the faster the plane goes, the heavier the stick force is.

So now that the runway has stopped, you have to get the airplane back in trim using the manual trim wheel. This part was my the actual point of this whole post. Trimming and out-of-trim jet like this is definitely a two person operation. And it's difficult. If the PF just hold the nose level with all that pressure, there is NO WAY that stab wheel is going to turn. I'm telling you, you can't get it to budge due to the heavy air loads on the stabilizer. What has to be done is the pilot flying has to raise the nose a couple of degrees then, let the nose fall, thereby unloading the stabilizer, allowing the PM to turn the wheel as fast as they can to try to relieve some pressure. Once the nose lowers, the PF is now adding back pressure to keep the plane form getting too nose-low, jamming the manual trim wheel again. It usually took 3-4 of these oscillations to get the plane where is was back to a somewhat normal trim feel.

The runaway stabilizer trim was an exercise in CRM and teamwork and was a handful when that was the only thing you were concerned about. If you couple that with all the associated alerts, alarms, noises, startle effect, etc. in the cockpit AND an experienced Captain with a very low-time FO, this would be a difficult exercise indeed.
 
Sluggo63 said:
A stab trim brake is either a mechanical or electrical way to interrupt stab trim motion by opposing the trim force with the yoke. It's a natural reaction and works great. The trim starts to run away nose down, your first reaction is to pull back on the yoke. Back pressure on the yoke stops nose down trim. We didn't have that system in the KC-135 until after one crashed in Germany in 1999 (Esso 77). (The 737 has a stab-trim brake, but it does not stop MCAS trim inputs).
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Excellent post.

My question is, if the MCAS is causing a nose down trim input, presumably to protect the pilots from themselves to prevent a stall, what is the purpose of having an effective trim-brake that allows the pilots (whom the MCAS system has decided need to be saved) to over-ride the assumed to be necessary MCAS nose down trim input simply by pulling back in resistance to that presumably required nose down input?
 
If transition training in the MAX concerning the MCAS was not accomplished (or emphasized) the result is rather predictable if a MCAS failure was to occur. Understanding the system is key to surviving a MCAS failure. I wonder how well the pilots from Lion Air and Ethiopian Airlines were trained in the MAX or perhaps there was a language translation issue from Boeing engineering to the foreign operators of the MAX?
 
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Bell206 said:
And the leaks have begun. NY Times reporting issue started right after takeoff. If true, this would take the MCAS system out of the picture.
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I cannot wait for Boeing to be vindicated in this whole thing.. and they should go after all the media outlets for slander and misinformation (but they won't). This is an international targeting of an American company and an American regulatory body (FAA) that had long been held in high regard to the jealous esteem of other countries, especially those with dodgy safety records (read, basically any third world country). Why wouldn't you want to pile on the public shaming when you see an opportunity to blame a US company, especially one with many defense contracts? John Oliver just had a piece on this. Never forget the human element.

jallen0 said:
A great article discussing a very probable cause of both crashes
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I used to really love Jalopnik.. but recently (last 3-4 years) their articles have been very good at giving just enough information for people to take away misleading insights disguised as fact.. that's the most dangerous thing in my opinion. The article leaves out much of the human factors, trim cut off switches, training, etc., and drives the reader to think that one little sensor is killing hundreds of people (despite the best efforts of heroic pilots wrestling with an automated plane). Jalopnik has also started catering to a certain reader base, so unlike AvWeb, who is genuinely unbiased, most of Jalopnik (Gawker media group) are going to have some clear underlying biases in their publications. Their best authors, like Tyler Rogoway, have since left anyway

upload_2019-3-19_13-18-47.png
**this is the paragraph where they left out "pilots may fully disable the auto trim functions of the system and manually fly and trim the airplane if they suspect the system is not performing correctly, such as in this scenario. Boeing's existing 737 training and manuals for a runaway trim situation and subsequent trim cut off feature would still apply and work in this situation, as a false system indication can be inhibited by disabling auto trim and trimming manually. This calls into question the training that the pilots may be receiving and their handling of faulty systems in conjunction with the automated features"

1RTK1 said:
But there is still an auto trim cut off switch to remedy such problems
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Yes. No one has discussed that yet, not even one sentence in any of the articles that relate to this crash. Because the agenda out there is that Boeing, FAA, and the US are cutting costs for more profit (because corporation = evil, insert stereotypical monopoly man here) and this resulted in lost lives

Kenny Phillips said:
es, there are solutions, but the new system may have masked what was happening, thus confusing the pilots
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I mean.. that spinning black and white wheel next to the throttle quadrant is obvious, no? Isn't the FIRST thing most pilots do with unusual control pressures or inputs is go for the trim? I mean we learn that in the first 3 hrs of flight instruction to trim away the control pressure. If the dude was struggling to pull back on the stick, wouldn't he instinctively reach his right hand for the trim wheel and try to move it, or feel it spinning and hit the cut off with his left? That's second nature to most pilot.. isn't it?
 
If these two crashes do turn out out be from the same cause there is more to it than just software and training because if MCAS was the cause it was also a failure of MCAS and on two virtually brand new aircraft. Whether it was a faulty AOA or some other input there is something else going on here.
 
Tantalum said:
I cannot wait for Boeing to be vindicated in this whole thing..
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It depends on how culpable Boeing was, which hasn't been determined yet.

Tantalum said:
I mean.. that spinning black and white wheel next to the throttle quadrant is obvious, no? Isn't the FIRST thing most pilots do with unusual control pressures or inputs is go for the trim? I mean we learn that in the first 3 hrs of flight instruction to trim away the control pressure. If the dude was struggling to pull back on the stick, wouldn't he instinctively reach his right hand for the trim wheel and try to move it, or feel it spinning and hit the cut off with his left? That's second nature to most pilot.. isn't it?
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You can't equate flying a trainer to flying a highly computerized 737. Read post #107 by Sluggo63.
 
Silvaire said:
Whether it was a faulty AOA or some other input there is something else going on here
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This is where I do believe that NOT having 3 sensors was idiotic.. how else is the system going to get accurate readings, and warn the pilot of a system degradation and possible deactivation?
 
Larry in TN said:
Too much thrust? On takeoff? From a 7,657' airport?

The first time I took off from Bogata (8,360') it was in a 737-700, at max power, and it felt like we had forgotten to start one of the engines.
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Yep, I can feel the difference even in Denver.
 
Everskyward said:
You can't equate flying a trainer to flying a highly computerized 737
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The plane is not fly by wire.. do commercial airline pilots not trim the plane when they hand fly it?

Don't these serve a universal function in aircraft (see image below)? Why are we so reluctant to lay any blame at all on the pilots? Part of being a good aviator is handling situations that occur outside of the textbook. Look at Sully.. look at the guys who landed the DHL plane after a rocket went through the wing.. look at the pilots of the Sioux City DC10. I'm not saying there's nothing wrong with Boeing's design, but we're basically eliminating the possibility of any pilot culpability while laying 100% of the blame on Boeing.. before the findings are out, and based on news articles written by non aviation professionals because of "similarities" - which, to the lay person, is beautifully vague and can mean just about anything
upload_2019-3-19_14-16-2.png
 
Tantalum said:
The plane is not fly by wire.. do commercial airline pilots not trim the plane when they hand fly it?

Don't these serve a universal function in aircraft (see image below)? Why are we so reluctant to lay any blame at all on the pilots? Part of being a good aviator is handling situations that occur outside of the textbook. Look at Sully.. look at the guys who landed the DHL plane after a rocket went through the wing.. look at the pilots of the Sioux City DC10. I'm not saying there's nothing wrong with Boeing's design, but we're basically eliminating the possibility of any pilot culpability while laying 100% of the blame on Boeing.. before the findings are out, and based on news articles written by non aviation professionals because of "similarities" - which, to the lay person, is beautifully vague and can mean just about anything
View attachment 72709
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Everyone blamed Audi for "unintended acceleration" events, and cost Audi billions of dollars. The only thing anyone could come up with was that Audi's pedal spacing was different from other vehicles. IOW, pilot error (including one mother, in my hometown, who crushed her son against the back of the garage.)
We (as a society) don't want to blame people, as long as there is an inanimate object, built by a faceless corporation, upon which we can fix blame (Audi, Tesla, Boeing, Bushmaster, Ruger, etc.)
 
Kenny Phillips said:
Everyone blamed Audi for "unintended acceleration" events, and cost Audi billions of dollars. The only thing anyone could come up with was that Audi's pedal spacing was different from other vehicles.
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I wish I could give this more likes.
 
Brad Smith said:
If transition training in the MAX concerning the MCAS was not accomplished (or emphasized) the result is rather predictable if a MCAS failure was to occur. Understanding the system is key to surviving a MCAS failure. I wonder how well the pilots from Lion Air and Ethiopian Airlines were trained in the MAX or perhaps there was a language translation issue from Boeing engineering to the foreign operators of the MAX?
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There was barely any training at all and none on MCAS.

From the Seattle Times article:
Since MCAS was supposed to activate only in extreme circumstances far outside the normal flight envelope, Boeing decided that 737 pilots needed no extra training on the system — and indeed that they didn’t even need to know about it. It was not mentioned in their flight manuals.​
and
Dennis Tajer, a spokesman for the Allied Pilots Association at American Airlines, said his training on moving from the old 737 NG model cockpit to the new 737 MAX consisted of little more than a one-hour session on an iPad, with no simulator training.​
 
Tantalum said:
This is where I do believe that NOT having 3 sensors was idiotic.. how else is the system going to get accurate readings, and warn the pilot of a system degradation and possible deactivation?
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It seems like your opinions are at odds with each other...
- you say not having 3 AoA sensors is idiotic
- you say Boeing will be "vindicated" presumably because you think they're blameless

Do you realize MCAS relies only on one of the AoA sensors?
 
Everskyward said:
Read post #107 by Sluggo63.
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They had training though.. no doubt big iron flies different than a light piston single.. but to your point about Sluggo they were trained on runaway trim, and Kayoh's posts from before also indicated that they're trained on runaway trim.. so I still don't get it
 
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