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Well, I think that without engines and without APU, there is one more important thing that the RAT will provide on top a pneumatic start. How about hydro power to control the plane? I can be wrong, but don't think that the electric battery that provides emergency electric backup is able to provide hydro power. So without engines, without APU and without RAT you are basically a balsa glider that hopefully is not trimmed for some nasty mode.
APU supplies electrical power and pneumatic power but no hydraulics. RAT supplies blue system (essential) hydraulics and electrical power but no pneumatics. Battery supplies only electrical power. Lose both engines, the APU and the RAT and you are officially having the worst day ever in the history of automated flight.
This is why future aircraft should move to EHA or EMA flight control and away from centralized hydraulic systems. Any fully-automated transport aircraft I could even begin to consider would have to have redundancy involving autonomous flight control actuators.
No, that's nonsense. APU start is standard procedure for a dual-engine failure below FL250 if both fail to relight. There is also a 45-second delay from the time the IDG's go offline until the APU can be started. For both reasons, you wouldn't do this within a few seconds after losing both engines. But you wouldn't need to for flight control anyway. The ram air turbine deploys automatically and provides electrical power and there is also a back-up battery in case the RAT fails for some reason. The main benefit of the APU in this situation is pneumatic power to attempt powered engine restarts, but in Sully's case, they were too damaged for this to help.
Well, I think that without engines and without APU, there is one more important thing that the RAT will provide on top a pneumatic start. How about hydro power to control the plane? I can be wrong, but don't think that the electric battery that provides emergency electric backup is able to provide hydro power. So without engines, without APU and without RAT you are basically a balsa glider that hopefully is not trimmed for some nasty mode.
First of all, Flight Captain Sullenberger switched on the apu, during the next few seconds inflight (!) after he knew that he had lost all his engines.
Who, as a LH-B744 Flight Captain, would have the idea to switch on the apu, inflight?!
Sullenberger knows his A320, in perfection. Without the apu, he would very soon lose the wireless aileron and wireless elevator system of his A320.
No, that's nonsense. APU start is standard procedure for a dual-engine failure below FL250 if both fail to relight. There is also a 45-second delay from the time the IDG's go offline until the APU can be started. For both reasons, you wouldn't do this within a few seconds after losing both engines. But you wouldn't need to for flight control anyway. The ram air turbine deploys automatically and provides electrical power and there is also a back-up battery in case the RAT fails for some reason. The main benefit of the APU in this situation is pneumatic power to attempt powered engine restarts, but in Sully's case, they were too damaged for this to help.
In my simple mind, the cause was simply that “jet engines take several seconds to spool up from low power settings”. (That and that they let the plane get lower and slower than what was planned).
Maybe, somehow, the plane made the pilot “FEEL disconnected” (what’s it doing now?), but I didn’t read anywhere where the plane did something wrong, or fought the pilot, except for final, ‘relentless’ pull ups as they settled into trees.
One of the most interesting automation issues is Bobby and ATLcrew’s seeming disdain for takeoff performance monitoring. Perhaps Kent Olson will give his view.
Bobby once indicated that he saw it as an additional distraction- possibly CAUSING crashes, instead of preventing them. (And that does happen sometimes when we add great new safety systems like DCAS).
ATL has a secret, manual method (which, of course sucks as he is both a fallible human and a cowboy pilot /blue font).
3BS ass-hat opinion sees something extremely simple, on track (Green), off-track, but still FDNH (yellow) and bad-off-track (Red).
I think Gabe has either a more grand system, or something the pilot downloads from the App Store.
And I’m old school modern that the we let the computer monitor “EVERYTHING” and be a nanny…but the cowboy monkey pilots remain in charge.
the rather cute Dassault Falcon 10X business jet with less than 34 meters in length,
is that rather Gabriels and mine type of a rather analogue type of aircraft, which, e.g. the LH-B744, you can also fly
when ALL computers in the cockpit are switched off. In German we say 'popometer' for this analoge kind of flying, and I really really love it.
Or is such a Falcon 10X rather a flying computer, cp the A320. Where your task as an A320 Flight Captain could be,
to manually override the Alpha protection system,
because that system simply does not know how high or how low you fly (!!).
One case where that incompatibility between an A320 Flight Captain and his flying computer ended with dead humans is this one:
With his two seeing eyes, that Flight Captain steered his A320 into a forest. 3 passengers died, among them
"a girl in seat 8C, who was unable to remove her seatbelt"
A dead child as a passenger.
Only because that Flight Captain did not know that an A320 when in alpha protection mode also and especially also raises the nose of the a/c,
when you are slow and low!!
Which immediately leads to a catastrophe: stall. But an A320 Flight Captain who does not know the alpha protection mode is not worth a dime.
So in my eyes, Air France back then in 1988 has done the best which they could do, they fired that unexperienced risky A320 Flight Captain.
Hm. Someone has warned me, that between Gabriel and Evan most of the time a very hefty discussion takes place. Was that you with that warning, 3WE?
A computer is always only as intelligent as the human being who uses it.
That's not higher philosophy, that's a sentence which you can quote me for. Or my father, who said something like that back then in 1985.
Only after Evans #32 here in this topic, I'd say,
Gabriel is rather the analogue type of pilot, cp 737 and 747,
and
Evan likes his bots, he likes it when robots do what he told them to do.
But in case of Cactus #1549, I assume that Evan somehow has a misunderstanding. I saw Sully the movie in the cinema, and after that I saw it again at least five to seven times, both, in the German and in the English language version. Mr Tom Hanks with his Original voice. A real happening.
Plus, I was present here in this forum when Cactus #1549 happened.
The misunderstanding is, Cactus #1549 did not end with 'all 155' due to a robot.
It was the sole and alone achievement of
Flight Captain Mr Chesley Sullenberger III.
and his 30 years of experience as a commercial jet pilot until he retired as a Flight Captain on March 3rd, 2010.
You can ask the Lufthansa CEO, Flight Captain Spohr, who is also an A320 pilot. And I assume that he shares my assumption,
that even an experienced A320 pilot can make much more mistakes during Cactus #1549
than Captain Sullenberger.
First of all, Flight Captain Sullenberger switched on the apu, during the next few seconds inflight (!) after he knew that he had lost all his engines.
Who, as a LH-B744 Flight Captain, would have the idea to switch on the apu, inflight?!
Sullenberger knows his A320, in perfection. Without the apu, he would very soon lose the wireless aileron and wireless elevator system of his A320. So, no perfect landing in the Hudson,
but rather one or two miles beyond Teterboro airport, if he hadn't been able to increase the sink rate, in the worst case in one of the neigborhoods there... ......
Fligh Captain Chesley Sullenberger III made his masterpiece on January 15th, 2009.
Why not? The actuation of the control surfaces in a FBW plane is still hydraulic. If the problem is a mechanical / hydraulic malfunction that when you open the "go left" valve the rudder goes right (ref 737), it will be very hard for the automation (or for the human) to recognize it. Or take the LAMIA Embraer incident in Portugal for another example.
I can understand a misrig on cable controls and a hydraulic issue on an old 737 design but show me an example on a 21st century FBW aircraft. And really, the future airframes should be EMA or at least EHA actuated. Again, this is the future we are talking about.
I don't dispute that an autoflight can be programmed to deal with a whole lot of things that the engineers think in advance. The problem is the things that the engineers don't think in advance.
And then you have Sully and TACA where the engineers think in advance and say "let's leave that to the pilots", because, seriously, we are decades away of having the technology that can moderately reliably deal with these situations like spotting the levee and deciding that that plane is better to put the plane down than the river.
Ok, that's one. Maybe. Take the case of Cactus 1549. It had the range to make a runway. An intelligent system would know that, would fly at green dot, would extend the proper flaps and would keep airspeed sufficient to prevent a hard touchdown. With an internal terrain database and GPS it could, if no runway was in range, select a river as the next best option. It could even be programmed to avoid populated areas if no option existed. But it couldn't know if there was traffic on a river or freeway. So I'll give you that... very... very... very... unlikely scenario.
Why not? The actuation of the control surfaces in a FBW plane is still hydraulic. If the problem is a mechanical / hydraulic malfunction that when you open the "go left" valve the rudder goes right (ref 737), it will be very hard for the automation (or for the human) to recognize it. Or take the LAMIA Embraer incident in Portugal for another example.
This hasn't occurred since hydraulics were redesigned to be more redundant. However, an autoflight system could be programmed to degrade to power-levels-only control.
I don't dispute that an autoflight can be programmed to deal with a whole lot of things that the engineers think in advance. The problem is the things that the engineers don't think in advance.
And then you have Sully and TACA where the engineers think in advance and say "let's leave that to the pilots", because, seriously, we are decades away of having the technology that can moderately reliably deal with these situations like spotting the levee and deciding that that plane is better to put the plane down than the river.
*A aircraft malfunction resulting in control reversal.
On FBW? No.
*Slats retracted on one wing with no indication during a critical, minimum-speed engine-out climb out.
On a proper FBW system, there would be indication and compensation.
*An engine shreds your hydraulic lines, giving you only the power levers for control.
This hasn't occurred since hydraulics were redesigned to be more redundant. However, an autoflight system could be programmed to degrade to power-levels-only control.
Just curious, can anyone think of an exception to this "absolute" statement when an autoflight system has redundant internal attitude reference and power level data as well as redundant static air data and radar altitude data, and GPS and an internal terrain database and full control surface authority from the very moment the upset begins?
*A aircraft malfunction resulting in control reversal.
*Slats retracted on one wing with no indication during a critical, minimum-speed engine-out climb out.
*An engine shreds your hydraulic lines, giving you only the power levers for control.
But really, autoflight alone should be able to handle any upset situation.
Just curious, can anyone think of an exception to this "absolute" statement when an autoflight system has redundant internal attitude reference and power level data as well as redundant static air data and radar altitude data, and GPS and an internal terrain database and full control surface authority from the very moment the upset begins?
Not sure... The one about absolute statements, about riding a bicycle, or about squids? (oops, wrong forum)
Expeletive-laden, ban-worthy, personal flame attack! Squids are not_my favorite topic (by a long shot) and bike riding is very narrow (Evan has never done it).
What’s my favorite phrase, Gabriel? (That is favorite AFTER aggressive pull ups should be carefully measured and monitored and it’s hard to stall at healthy attitudes and air speeds)
Not sure... The one about absolute statements, about riding a bicycle, or about squids? (oops, wrong forum)
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