British Ban the 737 Max

[Mega]

https://www.telegraph.co.uk/news/201...d-uk-airspace/


In the VERY rare move the British CAA has grounded ALL 737 Max (8 i think)..............they found a major fault. Trouble is that the engines are a lot bigger & the planes balance is affected. So they reprogram the flight computer to get round this..........that great on an F16, but not on this. Boeing is still trying to blame the crew, but everyone else has sussed...............hard to see how they can get out from under this one.

Mike

[Mega]

Re: British Ban the 737 Max

Germany, France & Ireland have also grounded them!

[FrankL]

Re: British Ban the 737 Max

This may or may not be Boeing's AF447 moment.

If it turns out that it is, I would be surprised if it cannot be addressed by a software update and/or retraining of the pilots. May be an opportunity to buy Boeing stock, as there's a big demand for fuel efficient planes.

[touchring]

Re: British Ban the 737 Max

This may or may not be Boeing's AF447 moment.

If it turns out that it is, I would be surprised if it cannot be addressed by a software update and/or retraining of the pilots. May be an opportunity to buy Boeing stock, as there's a big demand for fuel efficient planes.

Yes, but the price is still very high.

[Mega]

Re: British Ban the 737 Max

My understanding is the plane has new engines, these are much bigger than normal...........the balance of the plane was badly adjusted, thus Boeing used the trick of getting the flight computer to stop the planes new tenancy to "Pitch up" & try to stall. This system pushes the nose down, but as you can see it can go wrong.

Software is one thing, a funder-mental engineering/design problem is something else

[thriftyandboringinohio]

Re: British Ban the 737 Max

My understanding is the plane has new engines, these are much bigger than normal...........the balance of the plane was badly adjusted, thus Boeing used the trick of getting the flight computer to stop the planes new tenancy to "Pitch up" & try to stall. This system pushes the nose down, but as you can see it can go wrong.

Software is one thing, a funder-mental engineering/design problem is something else

Interesting observation Mike.
I would need to see some extraordinary evidence to support any claim that Boeing engineers have botched their freshman engineering calculations on basic flight forces for their best selling airliner. Until I see such evidence I continue to have unshakable faith that Boeing, Airbus, and Lockheed all know how to make a stable conventional aircraft that flies well. About 350 of these airplanes are flying around the clock and around the world.

[dcarrigg]

Re: British Ban the 737 Max

Interesting observation Mike.
I would need to see some extraordinary evidence to support any claim that Boeing engineers have botched their freshman engineering calculations on basic flight forces for their best selling airliner. Until I see such evidence I continue to have unshakable faith that Boeing, Airbus, and Lockheed all know how to make a stable conventional aircraft that flies well. About 350 of these airplanes are flying around the clock and around the world.

+1

[Milton Kuo]

Re: British Ban the 737 Max

Interesting observation Mike.
I would need to see some extraordinary evidence to support any claim that Boeing engineers have botched their freshman engineering calculations on basic flight forces for their best selling airliner. Until I see such evidence I continue to have unshakable faith that Boeing, Airbus, and Lockheed all know how to make a stable conventional aircraft that flies well. About 350 of these airplanes are flying around the clock and around the world.

From what I have read, this appears to be a training issue. Pilots who are fully-trained on the 737 need additional training to properly pilot a 737 Max as there are differences in the controls. It's possible that muscle memory and/or inadequate training caused the pilots to handle the 737 Max incorrectly.

If memory serves, there is historical precedence for this with another Boeing plane: the B-17 bomber. It was a very complicated airplane to operate for its time and, early on, there were a tremendous number of crashes that occurred during the take-off phase of flight. After much analysis, it was discovered that the crashes were caused by pilot error. The crashes were resolved with better training and, critically, the use of a check-list that pilots would follow to ensure that they did everything required in the proper order.

I'm no aerospace engineer so it's possible that the plane has got a fatal flaw in it. But there isn't that much new about the plane over the older 737 and I, too, would be shocked if Boeing were so sloppy as to make such a critical error.

[GRG55]

Re: British Ban the 737 Max

+1

+2

Conflating this with AF447 is to completely misunderstand what could have or might have happened.

Boeing 737 has been in production since 1967.
Not a fly-by-wire airplane (unlike Airbus, the B777 and B787).
The 'maneuvering stick force' is part of the certification requirements of all aircraft. This is a safety requirement as the load needs to change and provide feedback to the pilot when trying to move aircraft pitch up or down from the stable, trimmed flight condition.
In light aircraft, such as the ones I fly, the requirement is a positive force only. In commercial aircraft, such as the 737, the certification requirement is a linear force gradient with airspeed - this is quite a complex thing to achieve in a large transport aircraft (e.g. higher stick force to move the aircraft from trimmed configuration with higher airspeed).
In addition the specific minimum amount of the stick forces across the gradient are specified for commercial certification.
The anti-stall system on the Max 8 uses payload weight, center of gravity location and airspeed, and under certain combinations of those conditions will modify the pitch trim under high angle of attack conditions (e.g. low stall margin) to modify (increase) the stick force feedback to the pilot, to signal the pitch down.
There's nothing new or untested about the system. However, it is not triple redundant. The 737 remains an airplane that still depends on the pilot, not banks of computers, to fly it. Apparently a radical approach these days, given my reading of some of the news reports.
In the event of a trim run-away or other similar system failure, it actually requires the pilot to recognize and disable the system (remember this is not a fly-by-wire airplane with computers, instead of humans, running the show).
This requirement to disable a runaway trim condition is a constant of every single Boeing 737 ever made. It is NOT a new training addition. It requires disconnecting the trim system using the disconnect switch and then shutting off power with a secondary switch or circuit disconnect (my own twin also has electric pitch trim, and requires exactly the same response, including pulling the circuit breaker to ensure electric power to the trim motor is off, in the unlikely event of a trim runaway).

Too early to tell exactly what happened, but unless something mechanically broke on the airplane, I think there is a high probability of an incorrect pilot diagnosis of the problem and incorrect response to same. If this seems implausible, suggest one read the accident investigation findings report for Turkish Airline Flight 1951, which crashed just short of the runway at Amsterdam Schiphol on 25th Feb, 2009, with nine fatalities, including the three pilots on board at the time.

I'll repeat, the 737 remains an airplane the pilot, not three redundant flight computers, has to fly in the last resort. We will find out what happened with Ethiopian Airlines Flight 302 in due course I am certain.

[jk]

Re: British Ban the 737 Max

some american pilots were quoted this morning as saying they'd had incidents of the nose suddenly going down on takeoff, and they had to disable the autopilot to correct it. it might be a software problem.

[touchring]

Re: British Ban the 737 Max

some american pilots were quoted this morning as saying they'd had incidents of the nose suddenly going down on takeoff, and they had to disable the autopilot to correct it. it might be a software problem.

In other words, the planes that crashed because the pilots didn't know how to fly the plane manually without auto-pilot?

[vt]

Re: British Ban the 737 Max

Both Lion and Ethiopian airlines had crashed of fairly new 737-800s; one in 2010 and one in 2013. Both were shown to be pilot error from poor training.

There is a pattern that doesn't affect other airlines so far.

Again, far too early as investigation on this on just commenced.

Airlines are the safest mode of transportation. The manufaturers, regulators and nations want to keep that record of safety.

[thriftyandboringinohio]

Re: British Ban the 737 Max

In other words, the planes that crashed because the pilots didn't know how to fly the plane manually without auto-pilot?

It's likely more nuanced and subtle than that. That nose-down MCAS system only actuates on rare occasions, and there are some claims that it's not obvious to the pilots when the system has engaged and how it might be working against their commands.

Mike's original post about the flight properties is based on facts. When Boeing designed this version of the 737, to get a valuable fuel economy improvement they accepted a tradeoff -the aircraft does have some tendency to pitch nose up due to the reasons Mike mentioned, engines of larger diameter mounted further forward and higher up. The nose down MCAS system was designed and installed to counteract this new handling tendency on those unusual occasions when the aircraft gets near stall. The whole situation seems like a tangled set of issues involving handling characteristics, the human factors of cockpit workload and awareness, and training and communications. Most modern air disaster require a few unusual things to happen all at the same time.

Although right now the spotlight is on that nose-down MCAS system, the investigation is not complete and we could be wildly incorrect about about what really caused this crash. That MCAS system might not have played a role at all.

[Mega]

Re: British Ban the 737 Max

Boeing thrown in its hand
https://news.sky.com/story/donald-tr...crash-11664428

[Mega]

Re: British Ban the 737 Max

It seems Trump got brief, he pulled the plug..........i hope its just software, because this has "DC 10/Comet" written all over it.

Mike