More MAX information

[Vraciu]

Nothing except the two crashes.

#Burn


Right on. 


The trolls may wind up being correct, but they would only be beneficiaries of a lucky guess, because that’s all any of this is: a guess.    (Which is why all this speculation from the peanut gallery is so unseemly.   Let the facts speak when they’re available.)

[Oldman731]

This thread is rapidly becoming INflamed.  Another one about to bite the dust, Stab Cutout Switches or not.

True.  Remarkable that it stayed polite for so many pages, though.

- oldman

[Vraciu]

True.  Remarkable that it stayed polite for so many pages, though.

- oldman

Even professionals have a limit. 

[Vraciu]

This is probably the greatest mini-series on the subject of aviation safety ever made.   The American-narrator versions are I believe the originals.

Well worth your time.  They’re absolutely riveting.

Survival In The Sky Part 1

“BLAMING THE PILOT”

https://m.youtube.com/watch?v=ivSG5eiH_5w

[Toad]

Never would be.

Really?

Well, I'm going to make an assumption that you've heard of and understand the concept of accident chain. If not, let me know.

Let's take the Lion Air.

https://www.mro-network.com/airlines/preliminary-report-points-lion-air-safety-mro-shortcomings

A preliminary report on the Oct. 29 crash of Lion Air Flight 610 (JT610) confirms that the accident aircraft was not airworthy on at least its last two flights, spotlighting gaps in the airline's maintenance practices and safety culture.

Much of the probe's focus has been on how the JT610 flight crew responded to flight-control issues during an 11-min. flight that ended when the Boeing 737 MAX8 dove into the Java Sea, killing all 189 onboard. But early findings by Indonesia National Transportation Safety Committee (NTSC) confirm that mechanics with Lion Air subsidiary Bantam Aero Technic tasked with correcting problems on the aircraft failed to do so. As a result, both the JT610 pilots and the crew that flew the aircraft's previous flight, an Oct. 28 leg from Denpasar to Jakarta, were assigned aircraft that never should have flown.

So....all Boeing's fault right? Boeing's fault that Lion Air scheduled an aircraft that was not airworthy? Not once but TWICE.

The above information is why I replied the way I did to this statement by you:

True. I guessing it’ll be pretty hefty considering they didn’t fix the issue the first go around.

There never ever would have been a "first go around" had Bantam Aero Technic done their job. Probably the key link in the accident chain.

Maybe you understand that, maybe you don't. I guarantee you that the people in this industry fully understand that.

[Vraciu]

Really?

Well, I'm going to make an assumption that you've heard of and understand the concept of accident chain. If not, let me know.

Let's take the Lion Air.

So....all Boeing's fault right? Boeing's fault that Lion Air scheduled an aircraft that was not airworthy? Not once but TWICE.

The above information is why I replied the way I did to this statement by you:

Which is why, for example, any airplane registered as 5N immediately loses 90% of its value.   Also why we expats regularly shook our heads and said, "T-I-A."   This Is Africa. 

The things I encountered and refused to fly on crew change with some of these guys would blow your mind.  That's why the rich and politicians over there would not fly a plane crewed with two Nigerians for example.   They insisted on at least one American or European or white South African (their distinction not mine)  in the cockpit.  I guess they were just bigots.  /sarcasm

I flew most of the top officials of their government and an ex-President.   It was not negotiable with them.

Racists? 

Maybe they just didn't want to die and were playing the odds.   But yeah.  Blame the jet. 

[Toad]

OK, anyone have anything definitive on whether or not the Stab Trim Cutouts were re-egnaged?

https://abcnews.go.com/International/damaged-sensor-ethiopian-airlines-737-max-triggered-fatal/story?id=62139860

Two aviation sources familiar with the probe told ABC News that the Ethiopian Airlines flight suffered a damaged angle-of-attack sensor upon takeoff from a bird or foreign object, triggering erroneous data and the activation an anti-stall system -- called MCAS -- sending the pitch of the plane downward and ultimately crashing into the ground.

According to the sources, the pilots did not try to electronically pull the nose of the plane up before following Boeing's emergency procedures of disengaging power to the horizontal stabilizer on the rear of the aircraft. One source told ABC News they manually attempted to bring the nose of the plane back up by using the trim wheel. Soon after, the pilots restored power to the horizontal stabilizer.

With power restored, the MCAS was re-engaged, the sources said, and the pilots were unable to regain control before the crash.

I am loathe to trust a source like CBS but I have seen this on BBC and a few others. The Prelim doesn't seem to mention this unless I missed it.

The other thing is the thrust. From the Prelim: "During takeoff roll, the engines stabilized at about 94% N1, which matched the N1 Reference recorded on the DFDR. From this point for most of the flight, the N1 Reference remained about 94% and the throttles did not move."

Strange, no? No where in the Prelim did I see any definitive statement about use of A/T. Usually autothrotttles would be engaged on takeoff. If engaged, they would surely have gone to idle when the aircraft approached VMO, right? In fact, would have retarded approaching whatever speed was in the flight guidance, like 250 below 10K or whatever was programmed. Funny there's no mention of this. Were the power levers set manually at 94% for takeoff and just left there? Enquiring minds want to know.

[Zimme83]

There is a possibility that auto throttle where disengaged at some point. But such details will probably not be revealed until the final report. They where at 1000ft AGL when MCAS kicked in and got several GPWS alarms so its not surprising if they didnt want to reduce the throttles at that point.

Based on the FDR it seems like the cutoff switches where cut after the 2nd engagement of MCAS and it seems like they reengaged them towards the end of the flight. The most plausible theory is that since they couldnt use the trim wheels and probably felt that they couldnt hold the nose up for that much longer they decided to start all over. Reengage the switches, use the electric trim to get the plane under control and then cut them again. They probably thought that they would be able to counter the MCAS but once it kicked in they where just passengers. when they landed in their seats again the speed was so high that they couldnt move the elevators. FDR shows that they pulled the stick back pretty much all they way but that it didnt have any affect on the pitch.

[ACE]

There is a possibility that auto throttle where disengaged at some point. But such details will probably not be revealed until the final report. They where at 1000ft AGL when MCAS kicked in and got several GPWS alarms so its not surprising if they didnt want to reduce the throttles at that point.

Based on the FDR it seems like the cutoff switches where cut after the 2nd engagement of MCAS and it seems like they reengaged them towards the end of the flight. The most plausible theory is that since they couldnt use the trim wheels and probably felt that they couldnt hold the nose up for that much longer they decided to start all over. Reengage the switches, use the electric trim to get the plane under control and then cut them again. They probably thought that they would be able to counter the MCAS but once it kicked in they where just passengers. when they landed in their seats again the speed was so high that they couldnt move the elevators. FDR shows that they pulled the stick back pretty much all they way but that it didnt have any affect on the pitch.

Pretty solid view point here.

[Busher]

Pretty solid view point here.

I heard nothing but speculation.

[ACE]

I heard nothing but speculation.

That’s all anyone here is doing, Busher.

[Busher]

That’s all anyone here is doing, Busher.

No that's not true. I have seen no speculation from any professional aviator. But I'll defend your First Amendment rights.

[Zimme83]

No that's not true. I have seen no speculation from any professional aviator. But I'll defend your First Amendment rights.

Here is, again, a pretty good analysis:
https://leehamnews.com/2019/04/05/bjorns-corner-et302-crash-report-the-first-analysis/

[Busher]

Really?

Well, I'm going to make an assumption that you've heard of and understand the concept of accident chain. If not, let me know.

Let's take the Lion Air.

So....all Boeing's fault right? Boeing's fault that Lion Air scheduled an aircraft that was not airworthy? Not once but TWICE.

The above information is why I replied the way I did to this statement by you:

When I see cases of airplanes being dispatched that are not airworthy, (airworthy in the legal sense. examples: snags not resolved and signed off; snags not correctly deferred under the Minimum Equipment List) I wonder if the pilots agree to fly the aircraft under pressure from management or if their training and experience is not sufficient to make it clear that their airplane is unfit to fly.
North American airlines are not immune to MEL interpretation debates with their own pilots but fortunately our laws keep that decision solely in the hands of the Captain.

[ACE]

See rule #4