Boeing 737 (MAX) news

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Poiu
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Re: Boeing 737 (MAX) news

Post by Poiu »

sn26567 wrote: 20 Jan 2020, 22:49 The New York Times examines the 2009 crash of flight TK1951 of Turkish Airlines 737-800 in Amsterdam (an accident that killed several Boeing engineers) and finds parallels to the design problems that caused the MAX crashes.

https://www.nytimes.com/2020/01/20/busi ... dents.html

Excerpts:

"The Dutch investigators focused blame on the pilots for failing to react properly when an automated system malfunctioned and caused the plane to plummet into a field, killing nine people.

The fault was hardly the crew’s alone, however. Decisions by Boeing, including risky design choices and faulty safety assessments, also contributed to the accident on the Turkish Airlines flight
."
Absolute nonsense!
TK1951 had a faulty altimeter, which led to the malfunction of the auto throttle (automatic speed control), the pilots were not monitoring the speed, they didn’t notice they were slowing down and the aircraft crashed because it didn’t have enough speed to fly.
A Gulf Air Airbus crashed for the same reason, pilots failing to monitor speed and thrust after finger trouble caused the automatic system to slow down the aircraft.

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Re: Boeing 737 (MAX) news

Post by sn26567 »

Air Lease Corporation chairman Steven Udvar-Hazy called on Boeing to drop the “damaged” MAX brand to avoid it undermining the plane’s value.

IMHO, a name change will not solve any image problem. People are not stupid and will know that a new name does not hide old problems. Ryanair already changed the name of the MAX 200 to 737-8 200, but only naive people will be abused by the name change.

Air Niugini of Papua New Guinea has updated its contract with Boeing to delay the delivery of its four B737 MAX jets on order until at least 2024, to give the airline more time to complete a broader review of its fleet plans.
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Re: Boeing 737 (MAX) news

Post by jan_olieslagers »

People are not stupid
If this were wikipedia, I would ask for an encyclopedical reference :) for that.

Also: seeing the rapidity and frequency with which products and companies are rebranded today, at the impetus of highly qualified marketeers, I am not so sure the idea is wrong. Especially in a country like the USA, where the impact of publicity and public relations is overwhelming.
Last edited by jan_olieslagers on 21 Jan 2020, 13:09, edited 1 time in total.

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Re: Boeing 737 (MAX) news

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Lessor Avolon (Ireland) predicts the B737 MAX will safely return to revenue service in 2020 because the world needs more Boeing aircraft to support growing demand for air travel.
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Bracebrace
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Re: Boeing 737 (MAX) news

Post by Bracebrace »

Poiu wrote: 20 Jan 2020, 23:09 TK1951 had a faulty altimeter, which led to the malfunction of the auto throttle (automatic speed control), the pilots were not monitoring the speed, they didn’t notice they were slowing down and the aircraft crashed because it didn’t have enough speed to fly.
I believe the similarities are in the certification process, a single failure leading to a catastrophic event.

However in this case, the problem is known and has been known since the classic: the limited elevator authority compared to the horizontal stabilizer authority leading to a situation where with elevator only, you will not escape the life threatening situation. You might blame the pilots, but it's pretty lame to fly an aircraft that is not able to get out of a low airspeed situation without creating another hazard. Which is what happened here. And every pilot can get in a low speed situation, whether you want it or not. Safety depends on the fact you have a pilot that remembers it or not. Ask any B737 pilot and you will know. Some know. Some don't.

In the case of the max, the problem in "recovery" is that Boeing asks to use manual trim control however the "solution" is complex again as they refer to manual trim, but also state manual trim might not work and then you need to rollercoaster. You can throw airspeed unreliable checklists at them as much as you want, you end up in a battle. We needed two crashes to even know there was a battle hidden in there.

All this works against the 737 that it is a bit of a lego aircraft since the classic version, and it has become more and more lego ever since. A junkyard of so-called modern systems that are piled up in a round fuselage, hoping it will create something modern. But is not modern. It has become only more and more lego aircraft compared to any other modern airliner out there. It was clear already on the NG. The first rotation on an NG will tell you how disconnected pitch and roll are. The NG had to be the end of a generation.

To be honest, I'm pretty curious about the 747-800 in this regard as well.
Last edited by Bracebrace on 21 Jan 2020, 16:23, edited 2 times in total.

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Re: Boeing 737 (MAX) news

Post by jan_olieslagers »

Thank you, @Bracebrace, for as little as I know about piloting the big metal this was the most enlightening information I yet saw on this matter (though all of it must have been available somewhere on the www, doubltlessly - there is so much...)

The really fearsome bit is in your
I believe the similarities are in the certification process, a single failure leading to a catastrophic event.
: I always believed airliners would be at least as reliable as, say, high-availability web- or databaseservers. But I have some professional knowledge of the latter, and the first and major point that I heard again and again is "AVOID SINGLE PONTS OF FAILURE". A rule not observed in the current story, if I read you correctly.

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Re: Boeing 737 (MAX) news

Post by jan_olieslagers »

@Jan_olieslagers, you fly small planes. What do you do when you go-around? You add power and you check you have it (although you are lucky, you'll hear it too ;) ).
Yes, if going around (for which one has always to be prepared, if there's gliders around, with their own smaller traffic pattern, and their absolute right of way) I will begin by pushing the throttle to the panel, then take back flaps according to airspeed, all the while keeping half an eye on the horizon and another half at other traffic.

But no, I'll not hear the effect, at least less than I used to, ever since I acquired these noise-cancelling headsets - not the flashy Bose stuff, from China I paid just 200 € per set - but in this somehow overpowered little machine, the rpm indication is like tied to the throttle with a string, no revving up like them lazy turbine things :) so yes if the engine doesn't follow suit I'd be quickly reminded. Would feel it in my bum, too :) in the seat of my pants, that is.

Come to think of it, "feeling what happens, in the seat of one's pants" (with apologies, and much appreciation, to any pilot wearing skirts :) ) is what you seem to be basically and badly missing, in certain pilots. I must say I'd not expected it to be so relevant still, in the airliners of the 21st century.

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Re: Boeing 737 (MAX) news

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737MAX wrote: 21 Jan 2020, 18:17All I've said here doesn't mean more protections or better systems should not be made. All I'm saying is that too many cases happened where pilots could have saved the situation. And yes, I was disappointed too when Boeing announced the MAX, I have flown other types than the 737 and since then I realized the 737 is really jurassic, and that the NG should have been the last 737. But it's too late too change this, obviously.
In all fairness, I think you have to turn the story around.

The B777 started flying commercially in 1995. It's 2020. The B737 NG first flight was 1997. Compare a brand new technology aircraft, with an "evolution". Many pilots were trained on the 777 from scratch. No recent experience on type from the start. Brand new integrated digital flightdeck. Brand new fly-by-wire. Brand new engines.

Statistics are pretty clear. When the B777 encounters a problem, it is pretty damn safe. The pilot errors you described resulted in a very limited number of fatalities. If there were many fatalities, the aircaft was shot down, or unknow cause (but it might be "pilot error" just as well as aircraft problem). If there is anything you could say, that is that the aircraft protected the pilots and passengers very well. And if there were major failures, the B777 remains an environment in which the pilots could work and the resulting fatalities were very very very limited. The best example being the BA crash in Heathrow (loss of thrust on both engines), athough there are other cases as well. But never fatalities.

NG: do we have to run the list of 737 NG hull losses because of crashes, overruns, underruns,...? And the number of fatilities this has all caused? And how many times the pilots "fucked up"?

Of course there are many more NG's flying around than 777s. But if you have a failure on the B777, the resulting situation is... easy. There could be pilot fuck-ups, yup, still the B777 will help you out.
If you have a failure on the NG, the resulting situation is... I don't know, it depends.
Last edited by Bracebrace on 21 Jan 2020, 23:16, edited 1 time in total.

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Re: Boeing 737 (MAX) news

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Boeing expects the 737 MAX to return to service in mid-2020

https://www.aviation24.be/manufacturers ... -mid-2020/

Following Boeing’s announcement regarding the 737MAX aircraft, WestJet today announced it will be updating its schedule to remove the aircraft through to June 24, 2020. Any affected guests will be proactively contacted once work is complete.

We thank our guests for their patience and our WestJetters for their commitment to keeping our airline moving safely and on time as we continue to adjust our schedule,” said Ed Sims, WestJet President and CEO. “We remain confident in the regulatory process undertaken by the Federal Aviation Authority (FAA) and Transport Canada to ensure the safe return of the aircraft.”

WestJet has completed more than 98 per cent of its planned departures even while its 13 MAX aircraft remain on the ground.
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Re: Boeing 737 (MAX) news

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Icelandair does not expect the B737 MAX in operation within its route network during the high season of summer 2020. This will have a minimal impact on Icelandair’s flight schedule in 2020.

Southwest Airlines is now 70% likely to acquire JetBlue, according to Stifel airline analyst Joe DeNardi. Any such deal would allow Southwest to diversify its fleet and acquire A321neo slots, while helping minimising the impact of the B737 MAX groundings.
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Re: Boeing 737 (MAX) news

Post by Bracebrace »

737MAX wrote: 21 Jan 2020, 18:18 What do you mean about the 747-8*?
Oops, missed this question.

Because these aircraft are cost effective in development because they rely on heritage certification. The development is different, the starting point is "where can we improve", then different people work in one single area, come with a solution, and it becomes a challenge to see how the improvement affects the complete product, the main question (for us) being "is it still safe?".

Many cases have shown the result is quite often "band aid work". The MD-11 crashed as well because of a smaller THS they decided to compensate with a computer. The NG has some rather strange "quirks" and this overly heavy pitch (to compensate the new engines?) compared to loosy goosy roll (new wing).

My philosophy is you can't band aid band aid... If you don't want to pay for heavy surgery, you need a new baby.

The 747-400 was indeed close to a new aircraft in a old fuselage, but still... so I'm simply curious about the 747-800.

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Re: Boeing 737 (MAX) news

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Bracebrace wrote: 23 Jan 2020, 10:57 Because these aircraft are cost effective in development because they rely on heritage certification. The development is different, the starting point is "where can we improve", then different people work in one single area, come with a solution, and it becomes a challenge to see how the improvement affects the complete product, the main question (for us) being "is it still safe?".
Do you think your theory also applies to the A320neo vs the A320? The changes were less drastic than on the 737MAX.
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Re: Boeing 737 (MAX) news

Post by Bracebrace »

That's a good question. Not that familiar with the Airbus besides basic knowledge. If an aircraft is more software based, the testing is easier to do I guess (input - black box - output). But it is true that the A320 platform/architecture will reach a limit some day as well, but it is more adaptable. The Airbus fly-by-wire setup is (my idea) a more complicated structure than the B777 (more computers, important feedback loop,...), but the fact that it is a fly-by-wire makes it easier to test and tweak. And this is only speaking of flight characteristics. But it remains similar hydraulics design, similar electrics (fixed 400hz I believe?)... etc...

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Re: Boeing 737 (MAX) news

Post by Homo Aeroportus »

A32S has fixed 400Hz indeed, with conventional CSD/IDG.
More recent programs (A380, A350) use variable frequency distribution.

Don't know much about the details on Hyd but that the AB has a Yellow circuit on the right hand side and a green circuit on the left hand side ...
And the A32S has an additional Pax entertainment system during taxi : the "Barking Dog" ;)

One thing A and B seem to have in common is to forget to inform FC fully about those little details such as MCAS on the one hand and the (less catastrophic) change in control law of the side stick when WoW is activated (see HAM crosswind landing some 8-10 years ago).


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Bracebrace
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Re: Boeing 737 (MAX) news

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Homo Aeroportus wrote: 23 Jan 2020, 14:57 And the A32S has an additional Pax entertainment system during taxi : the "Barking Dog" ;)
The PTU test? :lol: Still on the neo?

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Re: Boeing 737 (MAX) news

Post by Homo Aeroportus »

Bracebrace wrote: 23 Jan 2020, 15:42
Homo Aeroportus wrote: 23 Jan 2020, 14:57 And the A32S has an additional Pax entertainment system during taxi : the "Barking Dog" ;)
The PTU test? :lol: Still on the neo?
No in test but during normal SETI/SETO.
Just can't help answering this way when a fellow passenger is somewhat anxiously asking what that noise is. You know those standing up in the aisle 1 sec after On Block and having to wait 10 min before disembarking.
:lol:

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Re: Boeing 737 (MAX) news

Post by Homo Aeroportus »

Homo Aeroportus wrote: 23 Jan 2020, 17:21
Bracebrace wrote: 23 Jan 2020, 15:42
Homo Aeroportus wrote: 23 Jan 2020, 14:57 And the A32S has an additional Pax entertainment system during taxi : the "Barking Dog" ;)
The PTU test? :lol: Still on the neo?
Not in test but during normal SETI/SETO.
Just can't help answering this way when a fellow passenger is somewhat anxiously asking what that noise is. You know those standing up in the aisle 1 sec after On Block and having to wait 10 min before disembarking.
:lol:

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Re: Boeing 737 (MAX) news

Post by Homo Aeroportus »

Homo Aeroportus wrote: 23 Jan 2020, 17:21
Homo Aeroportus wrote: 23 Jan 2020, 17:21
Bracebrace wrote: 23 Jan 2020, 15:42

The PTU test? :lol: Still on the neo?
Not in test but during normal SETI/SETO.
Just can't help answering this way when a fellow passenger is somewhat anxiously asking what that noise is. You know those standing up in the aisle 1 sec after On Block and having to wait 10 min before disembarking.
:lol:

H.A.
Sorry, translation of the above lingo :

PTU, Power Transfer Unit, is a pump that activates automatically to maintain the pressure in the hydraulic circuit when the engine that normally powers it has been shut off after landing.
This is the SETI, Single Engine Taxi In.
Conversely you have SETO.
This PTU produces a hoarse sound that can be heard especially near the centre of the cabin. When a Pax queries about the origin of this sound, the typical answer is : Oh, its a dog barking in the cargo hold.

SETI/SETO is used to save fuel thanks to taxiing on a single engine but I don't agree with its systematic use.


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Poiu
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Re: Boeing 737 (MAX) news

Post by Poiu »

Homo Aeroportus wrote: 23 Jan 2020, 17:35 PTU, Power Transfer Unit, is a pump that activates automatically to maintain the pressure in the hydraulic circuit when the engine that normally powers it has been shut off after landing.
This is the SETI, Single Engine Taxi In.
Conversely you have SETO.
This PTU produces a hoarse sound that can be heard especially near the centre of the cabin. When a Pax queries about the origin of this sound, the typical answer is : Oh, its a dog barking in the cargo hold.
Good try, but not entirely correct, during single engine taxi an electric pump is pressurising the relevant hydraulic system. The electric pump generates a high frequency noise which you will hear as well during operation of the cargo doors.
As Brace correctly wrote, the PTU (power transfer unit) runs briefly when the second engine is started to test its functionality. If the pilots forget to switch on the electric pump during single engine taxi you’ll hear the PTU constantly.

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Re: Boeing 737 (MAX) news

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Lessor AerCap chief executive Aengus Kelly says there is no alternative to the B737 MAX and it would be “absolutely stupid” for Boeing to launch a replacement (NMA or 797) before the next wave of technology a decade from now.

Boeing new CEO Dave Calhoun indeed said that plans to develop the NMA or 797 would be put on a back burner, the first priority being to restore confidence in the 737 MAX.

Calhoun also said simulator training for the B737 MAX prompted its decision to push back its timeline to mid 2020. There are no new technical reasons. He expects to resume B737 MAX production months before its forecasted mid-year return to service.

Air Canada said that it has now removed the B737 MAX from its operating schedule until 30 June 2020.

FlyDubai
is looking for short- to medium-term leasing options as the B737 MAX will not be cleared to fly until the middle of 2020.

SpiceJet
says the new B737 MAX delay will mean induction of more aircraft on a short-term lease for the carrier.
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