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Vancouver Off-Topic / Current EventsThe off-topic forum for Vancouver, funnies, non-auto centered discussions, WORK SAFE. While the rules are more relaxed here, there are still rules. Please refer to sticky thread in this forum.
Bombardier is sort of cool, because they sort of make a DeHavilland, but not really. And DeHavilland's being the best plane of all time; makes Bombardier sort of cool.
Quote:
Originally Posted by hud 91gt
I was just about to post a similar article. If that is true, now we are into some serious Boeing doo doo, and I will be the first to say I could be wrong.
Never thought about physically being unable to manually trim out a plane... That's a new one.
Quote:
Originally Posted by 68style
I don't see how the plane can get re-certified with this type of actual design fault.
They'll find a way i'm sure. I mean, there's a float plane that's certified for passengers where it's near impossible to open the back/passenger doors from the inside haha.
But Embreaer is Brazillion. That says enough. Lol. I think the 190/175 was a good plane. Have a few hours in that bird too. But it’s no Boeing, but the 190 being the largest Embraer is substantially smaller (fuselage diameter) then any Boeing. Different class. But Bombardier makes good planes and I’m excited to get my hands on the new one. Err Airbus. Yuck. I hate airbus. Lol
Just have to say, I really enjoy your input here, and I hope you keep posting!
Lol well thanks Skinny. Don’t think I add that much. Certainly don’t take my word as gospel. I just realized I lied about Boeing/Embraer comparison. The Boeing 717 is probably considered a competitor to the Emb 190. Not my fault though, no one bought those things except for that Hawaian airline.
There is lots of good knowledgeable people in this thread. Gabby up there is all over it too.
... but besides that. Do we really need a reason to like Bombardier? Show some Canadian pride! Playing with the big boys from our own home.
The goods from the preliminary report. The fact the crew did everything possible gave me goosebumps. The fact the MCAS was able to overpower any manual trim input is scary. I am truely amazed this aircraft was not grounded immediately (by Boeing, knowing the power of the system). The “Stabilizer cutout” system is basically disconnect the power cable from the power trim system from what was taught. A “manual trim” system is taught to always be there just in case. I suppose that is what happens when we get further away from cables and rods, and more into electronics. RIP, and I’m sorry for having any doubt in the crews actions.
I am going to have to review the Lion air preliminary report. I was 90% sure the crew did not take appropriate action. This is a whole other level. I’ve encountered an uncontrollable stickshaker just after takeoff. It was incredibly distracting, nevermind any other issues.
“2 INITIAL FINDINGS
On the basis of the initial information gathered during the course of the investigation, the following facts have been determined:
3
The Aircraft possessed a valid certificate of airworthiness;
The crew obtained the license and qualifications to conduct the flight;
The takeoff roll appeared normal, including normal values of left and right angle-of-attack
(AOA).
Shortly after liftoff, the value of the left angle of attack sensor deviated from the right one
and reached 74.5 degrees while the right angle of attack sensor value was 15.3 degrees;
then after; the stick shaker activated and remained active until near the end of the flight.
After autopilot engagement, there were small amplitude roll oscillations accompanied by lateral acceleration, rudder oscillations and slight heading changes; these oscillations also
continued after the autopilot disengaged.
After the autopilot disengaged, the DFDR recorded an automatic aircraft nose down (AND)
trim command four times without pilot’s input. As a result, three motions of the stabilizer trim were recorded. The FDR data also indicated that the crew utilized the electric manual trim to counter the automatic AND input.
The crew performed runaway stabilizer checklist and put the stab trim cutout switch to cutout position and confirmed that the manual trim operation was not working.”
So even some of the people who have worked on Boeing’s new 737 MAX airplane were baffled to learn that the company had designed an automated safety system that abandoned the principles of component redundancy, ultimately entrusting the automated decision-making to just one sensor — a type of sensor that was known to fail.
Hopefully I’m not the only one who doesn’t know, but what does “trim” mean in this airplane context?
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The only way I can somehow relate it to a vehicle (easier said with a boat)... but....
A trim system uses an aerodynamic advantage to ease the control forces of a control surface. In simple terms...
Let’s say you are driving down the road and you want to put on your make up, and eat your Big Mac but your steering wheel keeps going left. A trim system would be an “on the fly” knob (manual trim) or some buttons (electric power trim) which could adjust your alignment so your car is now straight as an arrow down the road. The MCAS would be like a lane departure system. If it senses things it doesn’t like, it will use the power trim system (powered on the fly alignment) to put the car back in the lane. So if there is a failure in the lane departure system (MCAS), a driver has been taught to shut off the electric alignment system (power trim) so they can use a manual system to get the car straight again. Once it is straight you can use the steering wheel to make your inputs. The thing is with this preliminary report, is that manual knob appears to have been disabled when the lane departure system was doing its job(whether in error or not).You now put down your mascara, and even drop the Big Mac to use your man strength to hold the car in the lane. The thing is, the faster your going the harder and more severe those inputs are. You don’t have much time to correct, and or are not physically able to do so. Due to how an aircraft literally flies, a trim system is required even on the smallest of aircraft. There are huge forces on the control surfaces and we little humans can’t physically control the plane with out this “trim”.
Hope that helps. I had to edit it about a million times.
The goods from the preliminary report. The fact the crew did everything possible gave me goosebumps. The fact the MCAS was able to overpower any manual trim input is scary. I am truely amazed this aircraft was not grounded immediately (by Boeing, knowing the power of the system). The “Stabilizer cutout” system is basically disconnect the power cable from the power trim system from what was taught. A “manual trim” system is taught to always be there just in case. I suppose that is what happens when we get further away from cables and rods, and more into electronics. RIP, and I’m sorry for having any doubt in the crews actions.
I am going to have to review the Lion air preliminary report. I was 90% sure the crew did not take appropriate action. This is a whole other level. I’ve encountered an uncontrollable stickshaker just after takeoff. It was incredibly distracting, nevermind any other issues.
“2 INITIAL FINDINGS
On the basis of the initial information gathered during the course of the investigation, the following facts have been determined:
3
The Aircraft possessed a valid certificate of airworthiness;
The crew obtained the license and qualifications to conduct the flight;
The takeoff roll appeared normal, including normal values of left and right angle-of-attack
(AOA).
Shortly after liftoff, the value of the left angle of attack sensor deviated from the right one
and reached 74.5 degrees while the right angle of attack sensor value was 15.3 degrees;
then after; the stick shaker activated and remained active until near the end of the flight.
After autopilot engagement, there were small amplitude roll oscillations accompanied by lateral acceleration, rudder oscillations and slight heading changes; these oscillations also
continued after the autopilot disengaged.
After the autopilot disengaged, the DFDR recorded an automatic aircraft nose down (AND)
trim command four times without pilot’s input. As a result, three motions of the stabilizer trim were recorded. The FDR data also indicated that the crew utilized the electric manual trim to counter the automatic AND input.
The crew performed runaway stabilizer checklist and put the stab trim cutout switch to cutout position and confirmed that the manual trim operation was not working.”
Scary. Very scary.
Gumby - in addition to hud's explanation, in aviation terms:
An aircraft at a specific speed, in order to remain in level flight, will have a tab or stabilizer on the elevator (up and down control) that will keep the aerodynamic forces where they need to be to maintain that attitude (straight and level). As you speed up or slow down the trim helps alleviate forces on the pilots controls as a result of the aerodynamic forces of the airflow over the flight controls. This video shows how it works:
In these crashes the MCAS (automatic trim) was pushing the nose forward excessively and the pilots could not reverse it. They were pulling back on the controls that were fighting them with more than 100lbs of force. It was so much force, and the aircraft was at such a speed and accelerating in a dive, that they could not manually re-trim the aircraft to regain control. They were being aerodynamically overpowered. They actually turned the MCAS system back on in hopes of that allowing their manual nose-up trim inputs through the system to work. MCAS reacted to its bad sensor input and pushed the nose forward even more. The pilots had no way of regaining control of the aircraft despite going above and beyond the recommended emergency procedures for the situation. Hope this helps your understanding.
The first lawsuit against Boeing and the FAA was filed in the US today. I expect many more to follow, they are going to win.
RIP to all the victims, those pilots fought hard.
Last edited by JDął; 04-04-2019 at 10:44 PM.
Reason: Clarification
Exactly, that's why I mentioned how I appreciate Hud's posts. He only really talks about what he knows, explains it well (and a lot of the time the topic is fascinating) along with some informed opinions which may or may not be correct but are still more valuable than a layperson's. At the very least, the perspective is valuable and appreciated.
The findings are sad and scary. I only ever wanted to err on the side of caution until we knew more. I didn't assume the worst, I just thought it might be possible and wanted to see. And it looks like grounding the craft was the right move.
I also didn't like the comments from that guy's pilot friend about supposed low quality of inexperienced, non Canadian pilots. I don't care if they came from a pilot or anyone else - I hated the idea of blaming people without knowing more, and now that we do, you can see why. That's a perfect example of two people who can both provide valuable insight, but one chose rumors, speculation, and bad faith assumptions instead.
I didn't even want to bring up all the people talking about how much money they planned to make buying Boeing stock... I hate stock trading and this is an example why. It seems that you have to lose your humanity in order to make money on crises like these, and I don't see how that doesn't just make your skin crawl when doing so. BTW I am NOT hoping for Boeing to die so all the greedy investors lose money (because a ton of people who don't care about stock prices would suffer even more), but come on.
In these crashes the MCAS (automatic trim) was pushing the nose forward excessively and the pilots could not reverse it. They were pulling back on the controls that were fighting them with more than 100lbs of force. It was so much force, and the aircraft was at such a speed and accelerating in a dive, that they could not manually re-trim the aircraft to regain control. They were being aerodynamically overpowered. They actually turned the MCAS system back on in hopes of that allowing their manual nose-up trim inputs through the system to work. MCAS reacted to its bad sensor input and pushed the nose forward even more. The pilots had no way of regaining control of the aircraft despite going above and beyond the recommended emergency procedures for the situation. Hope this helps your understanding.
The first lawsuit against Boeing and the FAA was filed in the US today. I expect many more to follow, they are going to win.
RIP to all the victims, those pilots fought hard.
From your understanding, it sounds like the manual trim was still operational, just not successful in correcting the situation. I haven’t actually read the whole report yet, but “confirmed that the manual trim was not working” makes me believe it was innopriative. There is obviously a huge difference between the two.
For those who don’t quite understand.
1) the manual trim still works, but the aircraft is in such a state it cannot be recovered quickly enough. This could have been remedied by quicker action of the cutout switches, stopping the erratic trim operation earlier on, hoping the aircraft is in a decent state.
2) the manual trim is no longer operative. The aircraft lost that control input completely.
Big difference. If you look at the data analysis of the “trim indiciation”, there is a huge flat spot where it is stated the manual trim is not working. You would think, even a little turn of the manual trim would be indicated. It also does not state the cutoff switches were returned to normal, but the data shows electric manual and the MCAS were used after. Not a lot of info in the report.
From your understanding, it sounds like the manual trim was still operational, just not successful in correcting the situation. I haven’t actually read the whole report yet, but “confirmed that the manual trim was not working” makes me believe it was innopriative. There is obviously a huge difference between the two.
For those who don’t quite understand.
1) the manual trim still works, but the aircraft is in such a state it cannot be recovered quickly enough. This could have been remedied by quicker action of the cutout switches, stopping the erratic trim operation earlier on, hoping the aircraft is in a decent state.
2) the manual trim is no longer operative. The aircraft lost that control input completely.
Big difference. If you look at the data analysis of the “trim indiciation”, there is a huge flat spot where it is stated the manual trim is not working. You would think, even a little turn of the manual trim would be indicated. It also does not state the cutoff switches were returned to normal, but the data shows electric manual and the MCAS were used after. Not a lot of info in the report.
It's still a bit gray. From what I saw/read the use of the manual trim was ineffective and they pointed to the aircraft's speed and heavy pilot input on the controls as limiting the ability of the manual trim, so they turned MCAS back on in hopes that it would give more authority to their trim inputs in order to recover. Didn't specifically say 'not operational'. Obviously with MCAS having a single point of failure flaw in its design it just made the situation worse and put them in to a steeper dive. It alluded to Scenario 1 but until ALL data is released the exact chain of events is still speculative.
Last edited by JDął; 04-05-2019 at 01:04 PM.
Reason: Fucking RS keeps logging me out as I type
I'm curious if a full fly by wire system would have allowed them to put in the correct amount of control input. Or if the plane would essentially stop them from over g'ing the plane... I know that fly by wire pushes back on the pilot to give the "sensation" of control forces, I wonder how strong the system is able to push back against the pilot.
Regardless I know I wouldn't be comfortable flying a plane where I couldn't 100% manually control and make it do what I want it to do when shit hits the fan.
Sounds like a question I'm going to ask in ground school one day haha.
You can easily G these things out. I see it all the time recovering from unusual attitudes in the sim. The odd acrobatic maneuver does it too.... when they do it wrong. Not that I’ve never screwed up
After reading the report, there is certainly lots of holes and missing information. Interesting things I’d like to know is if the FDR actually record the action of the cutoff switch. If you notice in the report, it is a verbal confirmation. Whether the FDR records manual trim input. These two things would tell a lot more of the story.
Excellent article, it took me a good 30 minutes to read, but I suggest anyone who was interested in this accident give it a long thorough read. Long story short, it goes back to our initial thoughts on the crews performance and decades of industry cost cutting, industry expansion and lack of due diligence.
Excellent article, it took me a good 30 minutes to read, but I suggest anyone who was interested in this accident give it a long thorough read. Long story short, it goes back to our initial thoughts on the crews performance and decades of industry cost cutting, industry expansion and lack of due diligence.
Not to sound alarmist and I do implore you to take this with a grain of salt, but this is why I avoid on trips to Asia, when possible, certain carriers. Its gotten to the point where you are playing roulette with your life on specific airlines. Pilots for these companies have low levels of airmanship and overly rely on automated systems. When shit hits the fan, these guys are not the types of pilots you want flying the aircraft manually. Look no further than the Asiana crash in SFO.
Not to sound alarmist and I do implore you to take this with a grain of salt, but this is why I avoid on trips to Asia, when possible, certain carriers. Its gotten to the point where you are playing roulette with your life on specific airlines. Pilots for these companies have low levels of airmanship and overly rely on automated systems. When shit hits the fan, these guys are not the types of pilots you want flying the aircraft manually. Look no further than the Asiana crash in SFO.
It's true, you get what you pay for. Air Asia is another low cost airline that has their own training academy. They however do fly A320s that according to this article is more forgiving to lack of pilot skills.
the 30 min $25 flight i flew in africa seemed okay
I think the stat is like 1 in 300 million to die in a plane crash. It's just your chances go up quite a bit to maybe 1 in 50 million with an airline that doesn't have the best safety records.
Excellent article, it took me a good 30 minutes to read, but I suggest anyone who was interested in this accident give it a long thorough read. Long story short, it goes back to our initial thoughts on the crews performance and decades of industry cost cutting, industry expansion and lack of due diligence.
If this is consensus view, why are the 737 Max still grounded? And why delay after delay to get them back up in the air?
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