MAX’s Return Delayed by FAA Reevaluation of 737 Safety Procedures
Join Date: Mar 2019
Location: On the Ground
Posts: 155
Likes: 0
Received 0 Likes
on
0 Posts
Great example. I was trying to keep mine simple, but apparently it was too simple.
David P. Davies' solution to a slight pitch up into a stall in the 707 used only the elevator, not the much larger horizontal stab, and the solution was safe, effective, and benign. The MAX uses the stab, and trims forward for up to 10 seconds at a shot. That's at least an order of magnitude, maybe two, larger trim input than Davies'. I refuse to believe that a correction that large is "only feel."
The accident aircraft problem was the AoA system failed and provided ridiculously large values and the pilots were unknowingly provoking it further. Had the AoA system been accurate, none of this would be happening today.
Which leaves the question - is the greater blame for an instrument that generates false information or for a user of that data, like the stick-shaker and MCAS and airspeed and the pilots, which believes it? Unfortunately the aviation industry has long accepted that some planes will generate false AoA data and pilots will be forced to go through checklists to realize it's a false alarm.
Thread Starter
Join Date: Apr 2015
Location: Under the radar, over the rainbow
Posts: 788
Likes: 0
Received 0 Likes
on
0 Posts
The 10 second time limit is for when a pilot ignores the increasing angle of attack and increasing control force and continues to pull the wheel farther back, It's not a full-shot on every excursion. A pilot should take the hint and stop pulling all the way to stall unless they are really dedicated to it because that mountain isn't budging or a plane has ignored the Tower and started to taxi across the active runway.
The accident aircraft problem was the AoA system failed and provided ridiculously large values and the pilots were unknowingly provoking it further. Had the AoA system been accurate, none of this would be happening today.
Which leaves the question - is the greater blame for an instrument that generates false information or for a user of that data, like the stick-shaker and MCAS and airspeed and the pilots, which believes it? Unfortunately the aviation industry has long accepted that some planes will generate false AoA data and pilots will be forced to go through checklists to realize it's a false alarm.
The accident aircraft problem was the AoA system failed and provided ridiculously large values and the pilots were unknowingly provoking it further. Had the AoA system been accurate, none of this would be happening today.
Which leaves the question - is the greater blame for an instrument that generates false information or for a user of that data, like the stick-shaker and MCAS and airspeed and the pilots, which believes it? Unfortunately the aviation industry has long accepted that some planes will generate false AoA data and pilots will be forced to go through checklists to realize it's a false alarm.
Join Date: Aug 2007
Location: Alabama
Age: 58
Posts: 366
Likes: 0
Received 0 Likes
on
0 Posts
The 10 second time limit is for when a pilot ignores the increasing angle of attack and increasing control force and continues to pull the wheel farther back, It's not a full-shot on every excursion. A pilot should take the hint and stop pulling all the way to stall unless they are really dedicated to it because that mountain isn't budging or a plane has ignored the Tower and started to taxi across the active runway.
The accident aircraft problem was the AoA system failed and provided ridiculously large values and the pilots were unknowingly provoking it further. Had the AoA system been accurate, none of this would be happening today.
Which leaves the question - is the greater blame for an instrument that generates false information or for a user of that data, like the stick-shaker and MCAS and airspeed and the pilots, which believes it? Unfortunately the aviation industry has long accepted that some planes will generate false AoA data and pilots will be forced to go through checklists to realize it's a false alarm.
The accident aircraft problem was the AoA system failed and provided ridiculously large values and the pilots were unknowingly provoking it further. Had the AoA system been accurate, none of this would be happening today.
Which leaves the question - is the greater blame for an instrument that generates false information or for a user of that data, like the stick-shaker and MCAS and airspeed and the pilots, which believes it? Unfortunately the aviation industry has long accepted that some planes will generate false AoA data and pilots will be forced to go through checklists to realize it's a false alarm.
Join Date: Mar 2019
Location: On the Ground
Posts: 155
Likes: 0
Received 0 Likes
on
0 Posts
MechEngr The 10 second time limit is for when a pilot ignores the increasing angle of attack and increasing control force and continues to pull the wheel farther back,
MechEngr A pilot should take the hint and stop pulling all the way to stall unless they are really dedicated to it because that mountain isn't budging...
Strike two.
Thread Starter
Join Date: Apr 2015
Location: Under the radar, over the rainbow
Posts: 788
Likes: 0
Received 0 Likes
on
0 Posts
I have not seen anything stating that the MCAS paid any attention to pilot input.
Thread Starter
Join Date: Apr 2015
Location: Under the radar, over the rainbow
Posts: 788
Likes: 0
Received 0 Likes
on
0 Posts
Psychophysiological entity
And also, Grebe #4453
Electrical trim beats MCAS until stopped + 5 seconds.
just a guess from this SLF- after turning them( cutout switches PRI and B/U off, they could not move trim wheel, and pulling on yoke did not work asit used to on the NG. But with switches on, at least the electric switches worked- not knowing that HAL ( MCAS ) would overrule them.
Join Date: Sep 2019
Location: leftcoast
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
MCAS 1.0 doesn't cease trimming on MET input. It merely pauses.
Join Date: Sep 2018
Location: Laredo, TX
Posts: 133
Likes: 0
Received 0 Likes
on
0 Posts
Which is the whole point. MCAS DOES respond to pilot input. That is why the Lionair aircraft was able to continue flying, it was only with the change of PF and the lack of required "back" trim that the issue escalated. Ten seconds of back trim then turn off the trim and climb to a safe altitude.
So twenty seconds of "back" trim may have been required before turning off the trim.
How MCAS mk 2 will move (as in motor speed) has not been released.
Psychophysiological entity
Brazilian Certifying Authority
It's very odd about that page. I think I saw the picture of it on Quora, but possibly another PPRuNer a while before. I can't remember. But whatever, it is such a few words in a tiny column given it's such a huge subject. A 47 feet, 1 inch subject. With what we know now, it should have had a page to itself, and been in bold red in every similar publication worldwide.
Thread Starter
Join Date: Apr 2015
Location: Under the radar, over the rainbow
Posts: 788
Likes: 0
Received 0 Likes
on
0 Posts
Almost everyone. This is really not a matter of question or dispute.
That's right, as we know from digging around for documentation. Maybe some of the pilots at Gol or whichever other companies bought it knew about it, too, but I've never seen any evidence of that.
Yup, might be. Again, no evidence. But lots of evidence from companies and air crews who had no bloody idea.
Well, that's alright then . . . Wait. Actually, no, it's not. That fact is at the center of the firestorm over this massive screwup by Boeing and the FAA that is well on its way to resulting in a year-long worldwide grounding -- in the wake of two hull losses and 346 splattered human beings. A screwup which, just by the way, has resulted in major damage to US leadership and prestige in civil aviation.
Seriously, folks, we are far beyond the point where it is even marginally-credible to blame the pilots for these crashes or to defend Boeing and the design and implementation of MCAS 1.0. Nobody is buying that narrative, certainly nobody who has conducted an investigation or is responsible for civil aviation safety, pretty much anywhere around the world.
The Brazilian Certifying Authority knew about it and had it as a Cat B training item.
Might be other countries also.
It appears the FAA knew about it and bought off on not including it as a training item.
Seriously, folks, we are far beyond the point where it is even marginally-credible to blame the pilots for these crashes or to defend Boeing and the design and implementation of MCAS 1.0. Nobody is buying that narrative, certainly nobody who has conducted an investigation or is responsible for civil aviation safety, pretty much anywhere around the world.
Thread Starter
Join Date: Apr 2015
Location: Under the radar, over the rainbow
Posts: 788
Likes: 0
Received 0 Likes
on
0 Posts
It's very odd about that page. I think I saw the picture of it on Quora, but possibly another PPRuNer a while before. I can't remember. But whatever, it is such a few words in a tiny column given it's such a huge subject. A 47 feet one inch subject. With what we know now, it should have had a page to itself, and been in bold red, and in every similar publication worldwide.
Join Date: Sep 2018
Location: Laredo, TX
Posts: 133
Likes: 0
Received 0 Likes
on
0 Posts
Almost everyone. This is really not a matter of question or dispute.
That's right, as we know from digging around for documentation. Maybe some of the pilots at Gol or whichever other companies bought it knew about it, too, but I've never seen any evidence of that.
Yup, might be. Again, no evidence. But lots of evidence from companies and air crews who had no bloody idea.
Well, that's alright then . . . Wait. Actually, no, it's not. That fact is at the center of the firestorm over this massive screwup by Boeing and the FAA that is well on its way to resulting in a year-long worldwide grounding -- in the wake of two hull losses and 346 splattered human beings. A screwup which, just by the way, has resulted in major damage to US leadership and prestige in civil aviation.
Seriously, folks, we are far beyond the point where it is even marginally-credible to blame the pilots for these crashes or to defend Boeing and the design and implementation of MCAS 1.0. Nobody is buying that narrative, certainly nobody who has conducted an investigation or is responsible for civil aviation safety, pretty much anywhere around the world.
That's right, as we know from digging around for documentation. Maybe some of the pilots at Gol or whichever other companies bought it knew about it, too, but I've never seen any evidence of that.
Yup, might be. Again, no evidence. But lots of evidence from companies and air crews who had no bloody idea.
Well, that's alright then . . . Wait. Actually, no, it's not. That fact is at the center of the firestorm over this massive screwup by Boeing and the FAA that is well on its way to resulting in a year-long worldwide grounding -- in the wake of two hull losses and 346 splattered human beings. A screwup which, just by the way, has resulted in major damage to US leadership and prestige in civil aviation.
Seriously, folks, we are far beyond the point where it is even marginally-credible to blame the pilots for these crashes or to defend Boeing and the design and implementation of MCAS 1.0. Nobody is buying that narrative, certainly nobody who has conducted an investigation or is responsible for civil aviation safety, pretty much anywhere around the world.
Join Date: Mar 2019
Location: On the Ground
Posts: 155
Likes: 0
Received 0 Likes
on
0 Posts
There is no dispute. Boeing Technical pilot Mark Forkner asked and got the FAA to agree that MCAS wouldn't be included in the pilot's manuals. He succeeded, and, in his own words, used "Jedi mind tricks" to convince other regulators to do the same. Apparently the Brazilians are more resistant to Jedi mind tricks. Later, MCAS was modified to work at low speed and altitude, giving it more trimming authority, surprising even Forkner, who complained about not being given that information, but the FAA was not informed about the changes. These are all well documented events.
Join Date: Sep 2019
Location: leftcoast
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
It is a question of dispute. Who do you allege was trying to keep it a "secret"? What is a fact is that Boeing did not realize who they were selling airplanes to.
The most egrious issue was allowing a single sensor to take control from the pilot. And no mention, no flags, and no change relating to that issue in the paperwork. All else flows- follows from that choice. AS to pilots- ' average' doesn't cut it - west half of the bell curve always applies.
