Boeing
03-12-2019, 05:22 AM
#11
There is an interesting article in Slate regarding the decisions that were made when the 800Max was being developed. It appears to be a decision to save money couple with an inability to correct the problem that they created.
https://slate.com/technology/2019/03...e-737-max.html
Interesting read. Profitability over safety, IMHO.
I predict that this will get worse before it gets better, with many countries around the world grounding this model. Might be a good time to buy Airbus stock. or maybe bail out of Boeing (stock) for the time being.
https://slate.com/technology/2019/03...e-737-max.html
Interesting read. Profitability over safety, IMHO.
I predict that this will get worse before it gets better, with many countries around the world grounding this model. Might be a good time to buy Airbus stock. or maybe bail out of Boeing (stock) for the time being.
03-12-2019, 06:38 AM
#12
Join Date: Aug 2012
Location: Foothills East of Sacramento
Posts: 5,605
Received 1,563 Likes
on
929 Posts
This can be a tough and complicated issue to address. I have not received the "inside" scoop on the Lion Air incident so I am hesitant to chime in on this without a solid foundation to work with. I might add that aviation history, safety, procedures, construction techniques, training, and all the rest have been written in blood. Engineers do their best to design and build safety into this industry but the permutations and combinations of real life, weather, materials, training, and human factors, will come together in disaster. By human factors I refer to how humans interact with the actual aircraft. It is a big deal. Switches have a certain location, even a "feel" how they are shaped, lights have specific meanings, etc, etc. All of these things have a bloody history. Even the design of aircraft has a "philosophy" if you will. There is quite a difference between Boeing and Airbus in the approach of how the plane interacts with pilots. I have flown both.
Pilots are the last in the chain of events and have the bird's eye view of how the operation is coming together and what they need to do to make the best decisions. Experience and training serve as the bedrock of good aviation. In the case of Air France's A330 (my current aircraft) going down, the poor judgement and flying skills of the pilot, in particular the very inexperienced first officer's understanding of the plane, directly lead to the crash. Northwest Airlines (absorbed by Delta) had 7 incidents of the same unreliable airspeed events prior to the Air France. Nothing noteworthy occurred. Why? Better training. Better hiring. The FAA put a a dozen NWA/DL pilots (almost all former military) in the simulator, recreated the AF situation and then let them go to see what would happen. All the NWA/DL pilots recovered the aircraft.
In the latest case, the Captain was experienced but the first officer was not. However, as I am somewhat familiar in the cockpit of the 737 (jumpseating and flying the similar 727) the trim wheel for the horizontal stabilizer (unlike Airbus) is mechanical, prominent, and noisy as it operates. If the trim were to runaway you would notice it. There are trim cutoff switches right below the throttles to kill it if it does malfunction. If you let the trim move full nose down, it would become impossible to maintain level flight. If you used the kill switches and needed nose up trim, you can extend a handle on the wheels (there is a wheel on either side of the center throttle quadrant for each pilot) and crank it to the desired position. A bit of a pain but doable. I do not know if the auto trim function on the new Max aircraft makes trim wheel move and if it can operate even with the trim switches in the off position. If it does, and it runs away, you are pretty much doomed.You cannot pull back on the yoke enough to overcome it. The problem stems from erroneous information from the sensors but sensors can and do fail. I find it concerning that this latest incident happened in good weather. Usually sensors fail in inclement weather. However, other things can cause problems. A German 757 went down after a night takeoff from Central American years ago when tape was left on the plane covering the static ports. It was waxed in the hanger and the tape was missed during the night preflight. We had a problem with an A330 taking off from Amsterdam (perfect daytime weather) when some polishing compound was inadvertently deposited in one of the pitot tubes causing failures once airborne.
Airbus can have a similar issue with uncontrolled nose down and we have to "kill" 2 of the 3 operating inertial references units to bring the plane back under control. We practice it in the simulator. That being said, I know it can become quite stressful in the cockpit when unanticipated events occur. We work hard to identify errors and prevent or correct them. Unfortunately, sometimes events can overcome the best of aircrews. We shall see.
Update from the WSJ:
Boeing is making an extensive change to the flight-control system in the 737 MAX aircraft implicated in October’s Lion Air crash in Indonesia, going beyond what many industry officials familiar with the discussions had anticipated.
The change was in the works before a second plane of the same make crashed in Africa last weekend—and comes as world-wide unease about the 737 MAX’s safety grows.
The change would mark a major shift from how Boeing originally designed a stall-prevention feature in the aircraft, which were first delivered to airlines in 2017.
U.S. aviation regulators are expected to mandate the change by the end of April.
Boeing publicly released details about the planned 737 MAX software update on its website late Monday. A company spokesman confirmed the update would use multiple sensors, or data feeds, in MAX’s stall-prevention system—instead of the current reliance on a single sensor.
The change was prompted by preliminary results from the Indonesian crash investigation indicating that erroneous data from a single sensor, which measures the angle of the plane’s nose, caused the stall-prevention system to misfire. Then, a series of events put the aircraft into a dangerous dive.
Focus on the update has taken on greater urgency as aviation regulators and airlines around the world have grounded their MAX fleets, following the Ethiopian crash over the weekend—despite no links being made between the two crashes by investigators.
The MAX software change is expected to take about an hour for each plane, a Boeing spokesman said Tuesday. He declined to offer other details about how the system would weigh the multiple data inputs.
“For the past several months and in the aftermath of Lion Air Flight 610, Boeing has been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer,” Boeing said late Monday in a statement.
The FAA has decided to allow the 737 MAX to continue flying, a break with counterparts in countries including the U.K., Australia and Singapore, which grounded the model in recent days.
The investigation into the Oct. 29 Lion Air crash is continuing, but has focused on the stall-prevention system, apparent maintenance lapses and potential pilot error. Investigators have revealed little about the circumstances leading up to the Ethiopian crash, but have found cockpit voice and data recorders.
When the plane was first designed, engineers determined that using a single sensor—measuring what is technically known as the angle of attack—would be simpler and was in line with the plane maker’s long-held philosophy to keep pilots at the center of cockpit control, a person familiar with the matter said.
That earlier design of the system, known as MCAS, has puzzled some pilots and safety experts, who wondered why the system didn’t rely on multiple feeds.
Mike Michaelis, chairman of the safety committee at American Airlines Group Inc.’s pilot union, welcomed news of the coming Boeing software fix.
“That’s the way it should have been in the first place,” he said.
Pilots are the last in the chain of events and have the bird's eye view of how the operation is coming together and what they need to do to make the best decisions. Experience and training serve as the bedrock of good aviation. In the case of Air France's A330 (my current aircraft) going down, the poor judgement and flying skills of the pilot, in particular the very inexperienced first officer's understanding of the plane, directly lead to the crash. Northwest Airlines (absorbed by Delta) had 7 incidents of the same unreliable airspeed events prior to the Air France. Nothing noteworthy occurred. Why? Better training. Better hiring. The FAA put a a dozen NWA/DL pilots (almost all former military) in the simulator, recreated the AF situation and then let them go to see what would happen. All the NWA/DL pilots recovered the aircraft.
In the latest case, the Captain was experienced but the first officer was not. However, as I am somewhat familiar in the cockpit of the 737 (jumpseating and flying the similar 727) the trim wheel for the horizontal stabilizer (unlike Airbus) is mechanical, prominent, and noisy as it operates. If the trim were to runaway you would notice it. There are trim cutoff switches right below the throttles to kill it if it does malfunction. If you let the trim move full nose down, it would become impossible to maintain level flight. If you used the kill switches and needed nose up trim, you can extend a handle on the wheels (there is a wheel on either side of the center throttle quadrant for each pilot) and crank it to the desired position. A bit of a pain but doable. I do not know if the auto trim function on the new Max aircraft makes trim wheel move and if it can operate even with the trim switches in the off position. If it does, and it runs away, you are pretty much doomed.You cannot pull back on the yoke enough to overcome it. The problem stems from erroneous information from the sensors but sensors can and do fail. I find it concerning that this latest incident happened in good weather. Usually sensors fail in inclement weather. However, other things can cause problems. A German 757 went down after a night takeoff from Central American years ago when tape was left on the plane covering the static ports. It was waxed in the hanger and the tape was missed during the night preflight. We had a problem with an A330 taking off from Amsterdam (perfect daytime weather) when some polishing compound was inadvertently deposited in one of the pitot tubes causing failures once airborne.
Airbus can have a similar issue with uncontrolled nose down and we have to "kill" 2 of the 3 operating inertial references units to bring the plane back under control. We practice it in the simulator. That being said, I know it can become quite stressful in the cockpit when unanticipated events occur. We work hard to identify errors and prevent or correct them. Unfortunately, sometimes events can overcome the best of aircrews. We shall see.
Update from the WSJ:
Boeing is making an extensive change to the flight-control system in the 737 MAX aircraft implicated in October’s Lion Air crash in Indonesia, going beyond what many industry officials familiar with the discussions had anticipated.
The change was in the works before a second plane of the same make crashed in Africa last weekend—and comes as world-wide unease about the 737 MAX’s safety grows.
The change would mark a major shift from how Boeing originally designed a stall-prevention feature in the aircraft, which were first delivered to airlines in 2017.
U.S. aviation regulators are expected to mandate the change by the end of April.
Boeing publicly released details about the planned 737 MAX software update on its website late Monday. A company spokesman confirmed the update would use multiple sensors, or data feeds, in MAX’s stall-prevention system—instead of the current reliance on a single sensor.
The change was prompted by preliminary results from the Indonesian crash investigation indicating that erroneous data from a single sensor, which measures the angle of the plane’s nose, caused the stall-prevention system to misfire. Then, a series of events put the aircraft into a dangerous dive.
Focus on the update has taken on greater urgency as aviation regulators and airlines around the world have grounded their MAX fleets, following the Ethiopian crash over the weekend—despite no links being made between the two crashes by investigators.
The MAX software change is expected to take about an hour for each plane, a Boeing spokesman said Tuesday. He declined to offer other details about how the system would weigh the multiple data inputs.
“For the past several months and in the aftermath of Lion Air Flight 610, Boeing has been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer,” Boeing said late Monday in a statement.
The FAA has decided to allow the 737 MAX to continue flying, a break with counterparts in countries including the U.K., Australia and Singapore, which grounded the model in recent days.
The investigation into the Oct. 29 Lion Air crash is continuing, but has focused on the stall-prevention system, apparent maintenance lapses and potential pilot error. Investigators have revealed little about the circumstances leading up to the Ethiopian crash, but have found cockpit voice and data recorders.
When the plane was first designed, engineers determined that using a single sensor—measuring what is technically known as the angle of attack—would be simpler and was in line with the plane maker’s long-held philosophy to keep pilots at the center of cockpit control, a person familiar with the matter said.
That earlier design of the system, known as MCAS, has puzzled some pilots and safety experts, who wondered why the system didn’t rely on multiple feeds.
Mike Michaelis, chairman of the safety committee at American Airlines Group Inc.’s pilot union, welcomed news of the coming Boeing software fix.
“That’s the way it should have been in the first place,” he said.
03-12-2019, 02:44 PM
#13
Thread Starter
Cos I have great respect for what you and your fellow pilots do. 
03-12-2019, 05:26 PM
#14
Ditto. And thanks for a very lucid and interesting backgrounder, Cos.
03-12-2019, 05:44 PM
#15
Great review of systems. From my pedestrian viewpoint, usually takes several unfortunate conditions, in coincidence to lead to an airplane disaster.
03-12-2019, 05:44 PM
#16
Flew into Antigua last week on a 737-8 Max, supposed to fly back home tomorrow morning, and I am really hoping that our tour airline doesn't send us one of their 737-8 max planes for the trip home. I find this very stressful that much of the world is grounding the aircraft but the US and Canada are not. I don't want to fly on one again, I have no faith in the people who program these fixes, if they screwed up once they can bloody well screw up again. They really need to ground the planes until the fix is delivered to all airlines and tested to be working properly. The profit motive in this situation is sickening, Boeing had plenty of time to get this done after the first crash, and the company should be held completely responsible for this second crash if the evidence indicates a similar cause of events. I don't normally encourage a jump to conclusion, but this certainly merits it and the planes need to be grounded. Here's hoping for an older 737 for my flight home tomorrow.
03-12-2019, 05:53 PM
#17
03-12-2019, 08:20 PM
#18
Cosmo, that was excellent. I read it twice. If I understand what you wrote, there system MAY be configured in such a way the the crew cannot save the plane from crashing if it goes into a sensor related nose dive. That seems like a glaring error that is contrary to their design philosophy, so I'm guessing that isn't the case, i.e. there would be some way for the pilot to take over. Is that your suspicion as well?
03-13-2019, 02:54 AM
#19
One thing I really hate is statistics though, if I have one in a billion chance of winning the lottery it would never happen, but one in a billion chance of falling from the sky and I don't like those odds knowing my luck, lol. I'll post up if I land safely this evening.
03-13-2019, 05:43 AM
#20
very true, particularly with the driving conditions here in Antigua, lol. Thanks for the calming words.
One thing I really hate is statistics though, if I have one in a billion chance of winning the lottery it would never happen, but one in a billion chance of falling from the sky and I don't like those odds knowing my luck, lol. I'll post up if I land safely this evening.
One thing I really hate is statistics though, if I have one in a billion chance of winning the lottery it would never happen, but one in a billion chance of falling from the sky and I don't like those odds knowing my luck, lol. I'll post up if I land safely this evening.