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Airbus takes pilots back to basics with the A350

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Airbus takes pilots back to basics with the A350

Old 7th Oct 2012, 21:51
  #141 (permalink)  
 
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Nope. It is not faster, it is different. Throttle position is demand, power indication is delivery. You might get away with the misconception it's the same as long as everything is running fine but even just a slight slippage of throttle control cable on Cessna 150 can bite severely if you just shove throttle to forward stop at take-off and don't check the RPM.
Except offcourse that modern jets don't have cables running between the thrust levers and the engines, so we are really talking sensors and thrustlever angle here.

And as for tactile feedback...
- Thrustlevers that are moving even when autothrust/throttle is on.
- Stickshaker
- control yoke / stick that moves in relation to autopilot commands/ follows on what is happening on the other side of the flightdeck

So I guess you could bid on any boeing aircraft...

Last edited by 737Jock; 7th Oct 2012 at 22:01.
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Old 7th Oct 2012, 22:33
  #142 (permalink)  
 
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Originally Posted by 737jock
Except offcourse that modern jets don't have cables running between the thrust levers and the engines, so we are really talking sensors and thrustlever angle here.
Even more complicated with more failure modes but principle is the same: something can go wrong and one won't get the same power for the same lever position.

Originally Posted by 737jock
And as for tactile feedback...
- Thrustlevers that are moving even when autothrust/throttle is on.
- Stickshaker
- control yoke / stick that moves in relation to autopilot commands/ follows on what is happening on the other side of the flightdeck
This is not tactile feedback. Tactile feedback means physically moving the flight control and feeling its resistance. Synthetic pitch feel is its replacement for aeroplanes with power operated controls. It feels similar but is very different beast, heavily reliant on ADC data. Guess what happens when pitots get shot up.

Well, not much, it reverts to low speed position and controls get waaay too light for high speed dashes. Slow down, maneuver gently and you won't rip your wings off.

This notion about "tactile feedback" is just as bad as "children of magenta". No, it is worse, child of magenta at least looks at the screens to see what happens even if he doesn't understand, this is probing by feel what autopilot/autothrust command and not even checking what result they get.

Stickshakers are only required to be fitted to aeroplanes that have insufficient pre-stall buffet. They are not basic stall warning devices.

So much for the Boeings. They are very fine aeroplanes but considering them to have "tactile feedback" is simply misinformed.
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Old 8th Oct 2012, 00:13
  #143 (permalink)  
 
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So much for the Boeings. They are very fine aeroplanes but considering them to have "tactile feedback" is simply misinformed.
Those who want "tactile" at any price will certainly be happy in a few years ..
I am almost certain that " touch screens" (tactile ? lol) will be introduced in the next generations of flight deck and even the remove of any parts as we know today (yoke .. sticks .. levers .. etc..)
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Old 8th Oct 2012, 07:44
  #144 (permalink)  
 
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Whatever Clandestino... Thank god you know it better than the dictionary.

Tactile: tactile - definition of tactile by the Free Online Dictionary, Thesaurus and Encyclopedia.
a. Perceptible to the sense of touch; tangible.
Feedback:
feedback - definition of feedback by the Free Online Dictionary, Thesaurus and Encyclopedia.

If I put my hand on moving thrust levers, I am getting tactile feedback on what the autothrottle is doing.
If I put my hand on a yoke/stick that moves, I am getting tactile feedback om what the autopilot/my colleague is doing.

I feel the action, before I see the result on a PFD. It is faster!

Stickshakers simulate the buffet which you cannot feel, again tactile, it helps as sensory input through feel is much stronger than visual or auditory input.

Did the other pilot on AF447 know that his buddy in the RHS was pulling on the stick? I doubt it.

I never said it is absolute tactile feedback, but those things listed are giving tactile feedback. None of these features exist on an airbus. It relies 100% on visual and auditory senses.

FYI something can always go wrong... Not a single man-made system is foolproof. There are always better fools, including those who program the damn computers.
To make sure that you catch these errors, it is preferable to have an array of inputs. So whats better in terms of the chance of spotting errors: Visual and auditory OR visual, auditory and tactile?

Last edited by 737Jock; 8th Oct 2012 at 08:03.
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Old 8th Oct 2012, 07:56
  #145 (permalink)  
 
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@ Clandestino

This is not tactile feedback. Tactile feedback means physically moving the flight control and feeling its resistance.
You have just proven why I can't take your lengthy essays seriously.
Airbus is wasting their money.

Tactile feedback is anything coming back in a sensory mode through feel.
It has nothing to do with physically moving anything.
It is using a sensory input to a human being other than visual or aural.
Absence of it reduces the possibilities to communicate in the man - machine interaction, thus making it less efficient.
You should get more human interaction on all levels, especially with a partner, maybe you will get it one day ......


@jcjeant

Those who want "tactile" at any price will certainly be happy in a few years ..
I am almost certain that " touch screens" (tactile ? lol) will be introduced in the next generations of flight deck and even the remove of any parts as we know today (yoke .. sticks .. levers .. etc..)
The future is here already. Just take over a cockpit from a new generation "pilot". First thing you have to do is clean the screens from hundreds of fingerprints!
The magenta line generation starts with what it lacks most: Tactile sensations.
I wonder if Sigmund would have diagnosed a certain lack of something .....

Last edited by Gretchenfrage; 8th Oct 2012 at 07:57.
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Old 8th Oct 2012, 08:15
  #146 (permalink)  
 
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737Jock,
I had an FO, ex B52, who always said he had moderate turbulence on short final for the last several hundred feet of his flights with me. I could feel his PIO's on my yoke but said nothing. Once even the tower commented on our unstable approach. I call this tactile feedback in a Boeing 757.

An AB wouldn't give you this feedback. I wouldn't care to fly any airplane that didn't have this feedback to both control yokes.
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Old 8th Oct 2012, 08:30
  #147 (permalink)  
 
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Yes??? but I'm not the on that needs convincing... Maybe you aimed at someone else?

Or am I in complete misunderstanding of your post?
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Old 8th Oct 2012, 11:55
  #148 (permalink)  
 
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bubbers44


Early on, I once heard the tower keep repeating to a pilot on short final, "Wind is CALM..." The a/c was bobbing and rolling just as if in rough air. The a/c was mine. I worked it out, and thankfully left it behind as nothing useful.

I ended up calling it 'Pilot Induced Turbulence.' PIT....

I think that it is a species of "Mayonnaise". A phantom. Some unconscious wish to sense movement, of being in "control".

I don't know about Freud, but having had the experience was important, and I forgave myself. My excuse was I was arriving from the mountains where I lived, where our local strip was one of those "if you you can fly there, you can fly anywhere" places....as if..?
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Old 8th Oct 2012, 12:02
  #149 (permalink)  
 
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had an FO, ex B52, who always said he had moderate turbulence on short final for the last several hundred feet of his flights with me. I could feel his PIO's on my yoke but said nothing. Once even the tower commented on our unstable approach. I call this tactile feedback in a Boeing 757.
Bubbers, with all due respect to your F/O, that's merely poor piloting technique on the 757...a beast renowned for having sensitivities in the roll direction

Last edited by Monarch Man; 8th Oct 2012 at 12:02.
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Old 8th Oct 2012, 12:04
  #150 (permalink)  
 
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I was backing up your discussion with C. I also wouldn't want to be without the tactile feedback Boeing gives. Yes, people fly without it as you could use a steering wheel on a car that had no self centering capability if the wheel is released in a turn but I would prefer not to.
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Old 8th Oct 2012, 15:48
  #151 (permalink)  
 
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Ok cheers

It happens that I'm currently flying airbus, so I know what it is like not to have the feedback. Miss it every day!

Ideal flightdeck: boeing with a sidestick that is driven and a table.

Last edited by 737Jock; 8th Oct 2012 at 15:50.
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Old 8th Oct 2012, 17:08
  #152 (permalink)  
 
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Ideal flightdeck: boeing with a sidestick that is driven and a table.

Amen to that!

Plus the feature to override pitch/bank limit prot with increased force, when necessary.
(To enable the LHR stunt)

Plus auto-trim aft inhibit when reaching stall speed.
(To avoid the AF447 trim situation)

Last edited by Gretchenfrage; 8th Oct 2012 at 17:11.
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Old 8th Oct 2012, 20:08
  #153 (permalink)  
 
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Clandestino
Good catch! Thank you for pointing to me being far less than pedantic. It was not mere stick release, right stick went forward of neutral between approximately 2:12:35 and 2:13:50. Elevator is out of full-up between 2:12:40 and 2:13:15. Pitch goes from +10 to 0, back to 7 then down to -10.

Left stick goes forward of neutral at 13:40, pitch drops from +10 to -3 as right stick input counters the left.

Annex 3 of the final report. Pages 2 and 3.
Thatīs the point. A stick release would have changed nothing, as the trajectory would have been maintained by the C* law. We discussed that to the end already.

And your conclusion, that the reduction in pitch was caused due to the SS nosedown inputs lacks the necessary proof. See the page 6 of the Annex 3 linked below:

http://www.bea.aero/docspa/2009/f-cp...nexe.03.en.pdf

Check the timeframe 2:11:50 until 2:12:15, a time period where the nose was lowest during the whole event with -10°, although the stick was held full back, and the elevators where full nose up. Your word "plunged" seems fully appropriate for this time period, as there was no controlled action causing this nosedrop. That happened at an altitude between 35.000 feet and 28000 feet.

The following nose down event was between 02:12:45 and 02:13:10 with max 7° nosedown, the SS at the beginning of the event some nose down, then most nose up, the elevators from -15° to -30° and beginning at 20.000 feet, ending at 15.000 feet.

Next nose down event took place between 2:13:50 and 2:14:00 with -5° while PF and PNF where srtruggling with the stick, the dual inputs resulting in about zero input. The elevators between -15° and -30° , altitude between 7.000 and 5000 feet.

Last nose drop to -4° at 2:14:20 with overall NU input, at the end dual NU input. Altitude around 4.000 feet.

The nose most probably plunged down in all those events because speed was getting so slow, that gravity took over. And when the speed increased and the airframe produced lift again, the wings, THS and elevators with itīs NU setting became effective again. This could have been prevented by maintaining SS ND until the AOA decreases to unstalled condition, but thats not what you were saying.

The conclusion that a "release of SS caused a plunge" canīt be derived from the available information, and thatīs most probably the reason that BEA didnīt state something like that. They actually saw a lost case early in the event.

Last edited by RetiredF4; 9th Oct 2012 at 19:19.
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Old 8th Oct 2012, 21:43
  #154 (permalink)  
 
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Also between FL350 and FL280 the power was reduced to about 60% N1, if I have read the graph correctly. Would this have had the effect of lowering the nose - at least until the power was restored ? (As it was.)
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Old 8th Oct 2012, 22:39
  #155 (permalink)  
 
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- "David, will I get interconnected side sticks and SS feed-back on the future A30X? And what about moving auto-throttles? (That's what "intuitive" flight is all about...the rest is "gadget technology").

Yes, people fly without it as you could use a steering wheel on a car that had no self centering capability if the wheel is released in a turn but I would prefer not to.
(Yes, I'm with you bubbers44, but I'm just another "old driver")
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Old 9th Oct 2012, 06:18
  #156 (permalink)  
 
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Interesting presentation. However nothing new. Nothing.

The same things presented in a new dress.
What was that at the end? Like: People today no longer want to be pilots, doctors, bankers but celebrities? Todays celebrities are mostly casted, set-up, artificial and are covering what other have done long age. Like this Airbus presentation, a disappointment.

Larger windows? Remember the DC10 or MD11? No? I guess so, because they had them.
Intuitive interface, functional approach? They showed a Palm Treo. A thing that is 10 years old. WOW! But these handies have vibra alarms, don't they? Isn't that something like a tactile feedback loop?
Touch interface? They showed an iPad and pointed that this is the way forward: Touch, what a discovery! But their interpretation is only one way. You touch it, but it no longer touches you (no tactile feedback). They should call their discovery "touch singleface and clean it after use please".
"We no longer look at the interface with one individual pilot, no, we look at an interface with the crew". wtf! What with pilot incapacitation? Does the aircraft talk to me then, being alone? How does the crew interface with each other without connected handles? Via the displays in a visual communication triangle only? This is simply a silly title, not explored nor explained. At least I didn't get it.

The only good thing coming out of these 28 minutes was the admission that the industry goes wrong by paying pilot peanuts, considering the dwindling popularity of the pilot job versus demand. But this passage was 10 seconds long and David didn't explore the role of Airbus themselves by belittleing the role of the pilot. Namely blaming exclusively the pilot when something happens, the aircraft, airline and regulator are always protected. Why would someone want to play the eternal scapegoat in an environment that he can barely influence?

If you touch on a subject, you have to explore it and this to a way more profound level.

This was plastic surgery to a 320 system by botoxing up all the controversies with some slides.
Even with a revamped Boeing SST project presented as top secret next generation aircraft .......

Nothing learned here, for both sides.

Last edited by Gretchenfrage; 9th Oct 2012 at 06:21.
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Old 9th Oct 2012, 08:42
  #157 (permalink)  
 
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RetiredF4

Also between FL350 and FL280 the power was reduced to about 60% N1, if I have read the graph correctly. Would this have had the effect of lowering the nose - at least until the power was restored ? (As it was.)
There would be lots of effects influencing the pitch behaviour of any airframe in a stalled situation. Power is one of them, but also bank, yaw, flight control deflections and asociated drag, pressure altitude, to name a few, and the amplitude of those inputs. Another point to consider would be the relevance of measurements by sensors operating outside their specs, like AOA, pitots, maybe gyros, ..... and the outcome of those measurements for the deflection of the flightcontrol surfaces when we talk about FBW aircraft.

All those factors interact together and produce a near random output, therefore, the conclusion of Clandestino imho is far fetched.

BEA should know for sure, but they did not go into any detail.
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Old 9th Oct 2012, 19:10
  #158 (permalink)  
 
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Originally Posted by 737Jock View Post
Ideal flightdeck: boeing with a sidestick that is driven and a table.
What about the positives to non-connected I mentioned a few pages back? Should Airbus just throw that away on your say-so?

The fact is that there have been no hull losses on on Airbii that are attributable to the non-connected sidesticks, and several instances where connected PFCs made no difference.
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Old 9th Oct 2012, 19:35
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Dozywannabe,

Airbus changed the connectors on the sidesticks so that they cannot be reversed, which is what happened in the LH incident.

It was poor design that caused that problem...

The stick can still be wired so that a button on the stick deactivates the sidestick on the other side including the drive mechanism. Which is exactly the same technique as used today in airbii, the pilot flying needs to push the instinctive disconnect button and hold it until the othersidestick is deactivated. The problem of pilot incap can be solved. Remember that interconnectivity and the drive mechanism can be FBW as well...

There have been plenty of hard landing incidents that could have been prevented by interconnected sidesticks. Captains on airbii simply have no idea what control inputs their FO's are making.
And the sidestick logic adds dual inputs algabraically together, so that is a problem as well.

Last edited by 737Jock; 9th Oct 2012 at 19:57.
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Old 9th Oct 2012, 19:55
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What about the EgyptAir990 scenario? With non-linked PFCs, one side can lock out the other - impossible in a connected setup. See also Birgenair 301 and the Stony Creek 727 crash where linked PFCs made no difference.

As far as I'm concerned, to link or not to link is a personal preference - one design is not categorically better than the other.
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