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jackr

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Maybe not kill but maim or seriously injure for sure.

Edited by boestar

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33 minutes ago, conehead said:

Maim...

my bad.   corrected

Edited by boestar
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Boeing will survive but their stock has taken a big hit and the trickle down will be felt world wide..

Soon the clown in "la Maison-Blanche"  will do something only he could conjure up and Boeing will be off the front page.......

Just wait for it. 

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21 minutes ago, jackr said:

thebadthingiswhatdoyoudowithabrandnewmaxthatpeoplewillnotwant toflyon?

 

Excellent question. I think free flights or some other unusual PR is  the only way to get passengers boarding a MAX. 

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1 hour ago, blues deville said:

Excellent question. I think free flights or some other unusual PR is  the only way to get passengers boarding a MAX. 

In my case, I would have no hesitation to fly on a MAX with Air Canada or WestJet or other airlines of a similar caliber  because I know the crews would not be flying the aircraft unless they were absolutely certain that the problems had been fixed. 

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30 minutes ago, Marshall said:

In my case, I would have no hesitation to fly on a MAX with Air Canada or WestJet or other airlines of a similar caliber  because I know the crews would not be flying the aircraft unless they were absolutely certain that the problems had been fixed. 

If you have no hesitation your list should really include Sunwing and all other Max operators. When the fault is corrected by Boeing and re-certified by the FAA as well as all other global regulators, there should technically be no issues about flying on anyone’s Max aircraft. The problem will be those people who have a real fear of flying which is a surprisingly high percentage of the traveling public. Two severe crashes with a lot of media coverage has done irreversible damage to the future of this plane. Canceled orders and others now buying 320 Neo’s are not a good sign of things to come for Boeing. 

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1 minute ago, blues deville said:

If you have no hesitation your list should really include Sunwing and all other Max operators.

I thought this did so. 

Quote

or other airlines of a similar caliber  

 

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1 hour ago, j.k. said:

offer the flight on the max for $10 less and people will fill the thing up.

So true.

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Personally I think this will leave a DC-10 like legacy. A safe aircraft that will be successful but will probably always have a stigma attached to it.

I deal with Max all the time, they're great to work on but I've also worked on the A320 as well and I sometimes wistfully think, if only Boeing had...

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Boeing Expands MCAS Demos To Speed Lifting Of 737 MAX Grounding

Apr 9, 2019 Guy Norris | Aviation Week & Space Technology

Pilot feedback to the proposed software changes to the Boeing 737 MAX Maneuvering Characteristics Augmentation System (MCAS) flight-control law is positive, says Boeing. After demonstrations, pilots believe the potential for further flight-control problems from the system are a “nonissue,” the airframer says.

However, despite the positive response from pilots to the upgraded control system and associated training package, Boeing is gearing up for a prolonged international effort to reinstate the grounded MAX fleet. The embattled company, which first unveiled the proposed MCAS changes to a group of certification authorities and airline pilots in Seattle on March 27, is embarking on a global campaign to convince regulators that the updates will be sufficient to enable the aircraft to return to service.

The campaign encompasses a series of simulator demonstrations and briefings at multiple training sites throughout Europe, Asia and Australia and comes as Boeing attempts to handle a situation unprecedented in its history. Because the MAX was grounded first by China and other authorities around the world days before the FAA followed suit, the company says it is imperative to build support for an international caucus of regulators willing to reauthorize the MAX to return to flight.

The FAA, which in past years would have taken a lead role in such an effort, is similarly shifting gears and is now working alongside a broader group of international regulators to adjudicate the case. The agency says it expects to receive Boeing’s final package of its software enhancement over the coming weeks. Meanwhile the FAA has set up a Joint Authorities Technical Review (JATR) to conduct a comprehensive review of the certification of the aircraft’s automated flight-control system. Chaired by former NTSB Chairman Christopher Hart, the JATR is comprised of a team from the FAA, NASA and international aviation authorities.

Boeing, which on April 5 signaled a 19% production slowdown of its 737 line to ease the growing logjam of undelivered aircraft, is also providing more details about the changes to the MCAS functionality contained in the new P12.1 flight-control computer (FCC) software load that will replace the existing P11.1 software. Based on pilot reaction to date, the company says it is confident its software upgrade is certifiable.

The briefings continue to emphasize that the MCAS, which was added to the speed-trim system to standardize handling qualities with those of the 737 Next Generation, is “not a stall-protection function and not a stall-prevention function,” says Mike Sinnett, Boeing Commercial Airplanes vice president of product development and future airplane development. “It is a handling-qualities function. There’s a misconception it is something other than that. “

Added to ensure a linear relationship between stick force per G, “speed trim is a function of airspeed, so if you’re going fast, it’s a low angle-of-attack (AOA), and if you’re going slow, it’s at higher AOA,” he notes. “The thing you are trying to avoid is a situation where you are pulling back and all of a sudden it gets easier, and you wind up overshooting and making the nose higher than you want it to be.”

The updated MCAS is being demonstrated to pilots in MAX simulators around the world. Credit: Boeing

Underscoring the difference between the speed-trim system on the 737 Next Generation (NG) and the MAX, Sinnett says: “Mechanically, on the NG there is a column cutoff switch that stops any automatic trim when the column is back to a certain spot. On the MAX, we still needed automatic trim when you got to that spot. MCAS differs from speed trim at elevated alpha because it bypasses that switch by design. To do that, it activates based on AOA rather than based on speed—which is what speed trim does. Speed trim is a function of airspeed, and MCAS is a function of angle-of-attack and Mach number, but it only triggers off AOA.”

In the initial briefing sessions for pilots on March 27, “we didn’t talk specifically about either of the accidents, but we ran through MCAS scenarios,” says Sinnett. “From the accidents, we now know how MCAS can behave when there is an erroneously high AOA input, so we walked through scenarios where that could occur. We demonstrated those in the simulator.”

In these sessions, pilots and regulators were able to interact via intercom and a big screen with Boeing pilots in the 737 MAX engineering cab. Following the sessions, “we went back to the classroom and said, ‘Here are the things that concern us most when we look at the scenario of the two accidents we just experienced,’” Sinnett says. “Upon reflection on what has occurred, it appeared the system could present a high-workload environment—and that’s not our intention. So we looked at changing the design to compare values from multiple AOA indicators to essentially eliminate the unintended trigger condition that causes MCAS to activate. “

Sinnett says pilots appear satisfied that the three main layers of protection now added to the MCAS will prevent any potential repeat of the circumstances involved in the Lion Air and Ethiopian Airlines accidents. “We answered a lot of questions during the discussion, and then we went back into the simulator and demonstrated a number of different scenarios to run against these changes,” Sinnett says. “And the most compelling thing is that the AOA failure case turns into a run-of-the-mill AOA failure case like you might have on any other airplane. We didn’t get any negative feedback. It was all very positive, and any of the pilots who got into the simulator and saw the before and after, it was like, ‘Yes, OK, this is now a nonissue.’”

The first main layer of protection provided by the update is a cross-channel bus between the aircraft’s two FCCs, which now allows data from the two AOA sensors, or alpha vanes, to be shared and compared. AOA data continues to be fed from left and right vanes into their respective air data inertial reference units before being passed to the flight computers. However, the AOA data in both computers is now continuously compared. The change is made by software only and requires no hardware modification.

“In a situation where there is erroneous AOA information, it will not lead to activation of MCAS,” says Sinnett. He underlines that the entire speed-trim system, including the MCAS, will be inhibited for the remainder of the flight if data from the two vanes varies by more than 5.5 deg. If an AOA disagreement of more than 10 deg. occurs between the sensors for more than 10 sec., it will be flagged to the crew on the primary flight display.

The second layer of protection is a change to the logic in the MCAS algorithm that provides “a fundamental robust check to ensure that before it ever activates a second time, pilots really want it to activate,” says Sinnett. 

The change would have protected the system from continuing to activate in the case of the Lion Air accident, in which the left AOA vane was stuck in the 20-deg.-nose-high position. In that circumstance, the logic rechecked if the MCAS was required and, registering the apparent nose-high position from the errant vane, commanded more nose-down trim. “Now it sees you’re in the same spot, it says you’ve got a stuck vane and says, ‘I’m not going to activate again,’” Sinnett notes.

“That’s assuming it will activate in the first place, which it won’t because one AOA vane with a high value won’t activate,” he adds. “When you do defense in depth, you have to artificially fail one layer to make sure you adequately design and test the next layer—so that’s what we had to do.” 

Explaining the background to the third layer of protection, Sinnett says: “We also made sure if the second layer of protection failed somehow in some weird way and allowed MCAS to activate multiple times, the system now ensures the sum total is command-limited.” The result is that the pilots always have maneuvering authority remaining with the control column. “Pilots will always have the ability to override—although they had that before in other ways, like with the trim switch, for example. But with the software update, the column itself will always provide at least 1.2g of maneuvering capability. So you don’t just have the ability to hold the nose level, you can still pitch up and climb.” 

 

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