Boeing big cheese repeats pledge of 737 Max software updates following fatal crashes Boeing chief exec Dennis Muilenberg has repeated earlier promises that a software update for the troubled Boeing 737 Max airliners is coming "soon". In an open letter published last night Muilenberg acknowledged the "shared grief for all those in mourning" after the separate crashes of two 737 Max 8s within a few months - …
So clearly having a "pilots licence" isn't enough, if every individual airplane has different controls and responses. Suggesting pilots need to train to the plane ?
Was this wheeze from Boeing an attempt to avoid that extra cost (thus making the plane more attractive to airlines) ?
Perhaps regulators need to take a similar approach to automobiles ?
So clearly having a "pilots licence" isn't enough, if every individual airplane has different controls and responses. Suggesting pilots need to train to the plane ?
This already happens, the extra license needed for a particular plane is known as a Type Rating.
https://en.wikipedia.org/wiki/Type_rating
Was this wheeze from Boeing an attempt to avoid that extra cost (thus making the plane more attractive to airlines) ?
It was a way for Boeing to claim that the new 737 MAX handled in a similar way to the old 737NG and 737/800, thus allowing them to bypass new type certification for the aircraft, which would have delayed the roll out and cost more.
All new planes require that pilots have to be trained in their handling and control, so that is a normal, accepted cost to the airlines.
I had a cousin who lived in Japan for 4 or 5 years and if I remember correctly the bigger the motorcycle he wanted to drive the hard the driving test was. He started out on a quite small bike. I wonder if it's similar for a car licences?
In theory, even auto drivers should have a training period as different cars have different characteristics. Truck drivers already do as here in the States, it's an "add-on". So yes, the pilots need to train to the plane as every plane has a different flight envelope. Difference between cars and planes is that one will kill you and everyone in it if you don't actually know and understand the differences.
This post has been deleted by its author
So Gareth, in essence, Boeing created a turd that was unstable and dangerous to fly and thought giving it a specific computer system to take care of known aerodynamic deficiencies with another level of autonomous machine control which was/is beyond human control ie cannot be easily over-ridden by a qualified/experienced pilot, was a good idea for safeguarding humans?
Hmmm? Bummer, man. That's brutal.
That post made sense, I don't know whether to commend or commiserate.
To me the issue is this: with a commercial aircraft there should be no actual reason for not giving it the best possible stability and ease of control. It isn't like a combat aircraft.
If this is correct:
The root cause seems to have been defective aircraft design to save money.
Contributing factor is that the sensor system doesn't seem to have been truly redundant (tripled) and wasn't integrated into other controls.
Once you've got these factors, no matter what you do with software you are at risk.
As an aside, one thing that annoys me about my car is that in auto mode the headlamps turn on when it is dark enough and auto dip, the wipers wipe when it is raining, but the headlamps do not turn on automatically when it is raining, leaving me with one case out of 4 to remember to do manually.
Your car is required (provided that you are in Europe and it has been built recently) to have daytime running lights, thus obviating the need to manually turn on your headlights if it happens to rain during the day.
Cars and CDV's with type approval gained after 06/02/11 (for sale in Europe) must have seperate daytime running lights, commercial and public service vehicles must have them if they gained type approval after 01/08/12. Nordic countries mandated DRL's in 1977.
Many vehicles do activate full headlights when the wipers are activated more than 3 times a minute, regardless of whether DRL's are fitted or not, as mentioned, the light switch has to be in the 'auto' position for this functionality to operate though. - and it certainly pre-dates DRL's, I'm fairly sure it was a Ford feature ported across to all PAG vehicles (like heated windscreens) and licenced to other manufacturers.
On many modern cars the rear lights come on with the DRLs or can be programmed to.
Personally I prefer the system my turn of the millennium Volvo uses. Headlights and taillights are on when the ignition is on. Full stop. (This can be switched so they can be turned off, but why would I? It doesn't have DRLs so its the only way to be easily visible)
If we're swapping car gripes, mine is that the speed limiter can't be configured to come on with the ignition - it requires to me manually activated every journey. I have yet to hear a valid reason why that should be (assuming "shit design" isn't a valid reason).
Cruise control is hopeless, speed limiters are a far better system. The moment I take the foot off the pedal, the car slows down. I use it all the time, set the limit to a safe speed just below the speed camera trigger speed and if necessary, I can push the pedal down to override the limiter.
The driver is still the speed limiter and needs to set an upper limit. The car won't keep the speed without a constant signal to do so, though.
Someone else might drive the car after you. If the limiter comes on automatically and they don't know about it or understand it they might end up in trouble if they try to join a motorway and find they can't get down the slip road faster than 30MPH. Requiring you to activate it each time means that you'll know because you did it.
My Peugeot forgets the position of the rear wiper switch. If it is on when the ignition is turned on they do not function. Have to turn the switch off and on again.
Guess someone forgot to call the 'check the physical switch position' routine...
And if you turn the fog lights on with headlight on auto guess what? Yup, if it gets lighter the auto headlights turn off and also cut the fog lights off. Because no one ever started driving on a foggy dark morning and it got lighter...
Don't get me started on the sound system...
I have noticed this with different makes of rental cars. It appears to be a useful feature, too, as it avoids the horrible sound of windshield wipers scraping a dry and dusty windscreen the next morning.
On the gripping hand, when does that ever happen in the UK
with a commercial aircraft there should be no actual reason for not giving it the best possible stability and ease of control
Apparently, the 737 was originally a smallish plane designed for regional airports. It had short landing gear so it was convenient for places without boarding ramps.
After many changes and upgrades, Boeing reached the point where they needed a model with more economical engines. But they couldn't fit new high-bypass engines under the wing. They couldn't make the landing gear taller because of the way it retracts, so the engines had to be moved forward. This pushes the nose up under maximum power. There's a suggestion that when the nose goes up the fat nacelles themselves produce lift, which pushes the nose up even more. This is the instability they were trying to disguise.
"with a commercial aircraft there should be no actual reason for not giving it the best possible stability and ease of control"
When I finished my apprenticeship at BAe in Bristol in 1979 I worked in the Avionics department. There were two research projects active: Relaxed Stability; and Gust Load Alleviation. The former investigated reducing the size of the tail plane, thus reducing stability, but regaining stability via a control system. The latter adjusting control surfaces to reduce thermal gust load on the wings, using a control system, allowing for a thinner wing skin. Both control systems would allow for a lighter, and therefore more efficient aircraft.
The reasons for these changes are obvious. The competitive pressures between aircraft manufacturers is huge, and the flying public expect / have become accustomed to, cheap air travel. I wouldn't say that this kind of design is defective - but the control systems must be expertly scrutinised and employ majority voting.
As others have pointed out, it's possible that where there are multiple sensors if one sensor fails, they might all fail. In this case the failure must be detectable and ... safe. Perhaps for this particular aircraft more effort should have been taken to design a more robust AoA sensor.
I agree. But one thing that will make for even more uncomfortable reading for Boeing Execs, Shareholders and fans, is that all 3 possible warning systems which Boeing had designed to alert of possible malfunction of, or pilot conflict with, said MCAS system were ALL additional extras on the both the Max 8&9 aircraft. Neither of the two aircraft that have crashed had any of these systems installed**. In fact, a recent pilots report from American Airlines suggests they may be the only carrier who has selected them. How such critical alerts could be "optional extras" given the number of stripped back, bare bones carriers out there is a galling commercial decision for any company to have taken. This, more than anything I feel will be highlighted in all the reports written on the causes of these tragic events. [** Source: AvTalk Podcast No53, produced by FlightRadar24. Worth a listen].
If the US courts have been locking up VW engineers for allowing cars to operate contrary to federal regulations, how many Boeing executives and engineers are going to be spending time in the local pententiary for killing a few hundred passengers?
If the US courts have been locking up VW engineers for allowing cars to operate contrary to federal regulations, how many Boeing executives and engineers are going to be spending time in the local pententiary for killing a few hundred passengers? ...... Bonzo_red
I wouldn't like to be held responsibility and liable for the following input/output ...... the last two paragraphs on this page .... Alert ..content is protected
MCAS is more like lane keeping technology and auto braking on newer cars. Lane keeping is weird, its like the steering gets really heavy and feels almost like the car is steering in a rut in the road when actually the car is steering. Lane keeping does allow you to change lane if your positive enough, I guess if you where tired you'd just go with where the car is steering you. Looks like MCAS just kept on ever more forceful overriding the pilots despite their numerous positive control inputs.
I've read 50kg needed to be applied to counter the effect of MCAS. I tell you what - you try pulling back 50kg, just to straighten your dive, and then more to try to pull out.
Even if you can split this load between both yokes, that's still a hell of a load to try to sustain. From the sound of things, this looks like what Boeing is going to address. By limiting MCAS to 1/4 authority that 50kg can be dropped to 12.5kg, plus additional input to raise the nose. That's doable for a while in an emergency.
What it doesn't do, though, is address the one-input issue.
MCAS works on the "Horizontal Stabiliser"
The Yoke works on the Elevators
There is no 50kg of force needed.
https://theaircurrent.com/wp-content/uploads/2019/04/737-mistrim-stab-forces-the-air-current-3.jpg
https://en.wikipedia.org/wiki/Tailplane
https://en.wikipedia.org/wiki/File:Tail_of_a_conventional_aircraft.svg
https://en.wikipedia.org/wiki/Elevator_(aeronautics)
The mainstream media seems to keep misrepresenting the role of MCAS.
It is not a simple anti-still mechanism. There is a stick pusher for that.
I am pasting a very clear explanation of what MCAS does and why it came to be. Credit to FCeng84 (https://www.pprune.org/member.php?u=291487) from PPRune for this post.
"There is a cert requirement that as AOA increases, the nose up pilot command required must not decrease. This is demonstrated at fixed thrust levels so there is no change in thrust pitching moment. The 737MAX issue here that gives rise to the need for MCAS is that as AOA increases the lift provided by the engine cowling that is so large and mounted so far forward of the wing causes a nose up pitching moment that results is a decrease in the column pull needed to maintain a steady positive AOA rate. That characteristic is not compliant with the requirements. MCAS comes active during this maneuver putting in nose down stabilizer that must be countered by the column. The net effect of engine cowling lift and MCAS nose down stabilizer as AOA increases is that the column needed to complete the maneuver does not decrease part way through the range of AOA for which characteristics must be demonstrated. 737MAX without MCAS fails the cert demo. 737MAX with MCAS passes the cert demo."
It exists to make sure that the "feel of the aeroplane" is consistent across increasing Angles of Attack in order to pass certification, not as a protection against stall as such.
That said, that is more or less irrelevant. The engineering of it (one single data feed? Seriously?) and the certification process (the manufacturer self-certifies? Seriously?) are critical issues which, I believe, are rooted in complacency: 2017 was the first year in aviation history where not a single life was lost to commercial aviation.
It's sad to see that this flagship industry is starting to let its guard down.
@Andytug
Yes, absolutely correct. But in Boeing's corporate world, the costs of doing it properly were deemed greater than doing it quickly. Guess which won.
Also note that no model of 737 has more than two AOA sensors, so already the rule-of-three is broken.
A point raised by someone on PPrune is however interesting:
There are literally thousands of conventional 737s of various types still flying around every day, using the same AOA sensors as those fitted to the MAX, so why do we not hear about many failures? It would suggest that in general, the AOA sensors are pretty reliable.
But then that begs the question, what is different about the MAX that caused the AOA sensors on two separate airframes to fail in such quick succession?
I thought it had already been established - at least for LionAir - that the reason that the MCAS kept triggering was that the AOA sensor was providing erroneous data?
Such that even after the plane had pitched nose down below the horizon, the MCAS was still seeing a high AOA and responded by adding more nose-down trim.
> why do we not hear about many failures
Because on the OG 737s, the AOA sensors aren't tied into a system that kills you if they fail, thus making the evening news.
In the OG models, they mainly run a display. The pilot notes it's wrong/disagrees with the copilot's display, and ignores it, logging a maintenance ticket. That does not make the evening news.
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