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Automation vs Seat-of-the-pants-flying talking as devil's advocate - so no abuse plea

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Automation vs Seat-of-the-pants-flying talking as devil's advocate - so no abuse plea

Old 26th Jul 2013, 16:45
  #41 (permalink)  
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from the OP

By seat-of-the-pants-flying I meant flying using the feel of the controls to tell you what the aircraft is doing - the force feedback from the stick and pedals and the noise of the engine and airflow and the little clues that the early pilots used; the guys and gals who flew with no instruments. I have only flown little Cessnas but I do have a license! I've done a few cross-wind landings and a spin recovery so I think I know a little about the basics. Of course, as I admit, I know nothing compared to the professionals on here but quite a lot compared to some wannabe's.

"the intent of the OP is pretty obvious " not sure what you mean Capn Bloggs
- I only intended to debate aviation, I did not intend to rile anybody and apologise if I have offended anyone. I did say, 'as devil's advocate' meaning that I take a position with the purpose of debating.
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Old 26th Jul 2013, 17:07
  #42 (permalink)  
 
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Originally Posted by mross View Post
By seat-of-the-pants-flying I meant flying using the feel of the controls to tell you what the aircraft is doing - the force feedback from the stick and pedals and the noise of the engine and airflow and the little clues that the early pilots used; the guys and gals who flew with no instruments. I have only flown little Cessnas but I do have a license!
Right, but one thing to be clear on is that light aircraft like your Cessna will have direct cable control to the flight surfaces. Jet airliners are a little different in that older short-haul types like the B737 and DC9/MD-80 will have hydraulic assist with cable backup and larger widebodies such as the B747, DC-10 and A300 as well as newer narrowbodies like the B757 are all-hydraulic. Nevertheless all of them have an "artificial feel" system which approximates and translates the forces on the flight surfaces to the flight controls.

Boeing's FBW system uses computerised force-feedback algorithms to provide artificial feel on the B777 and B787, and Airbus's FBW system uses passive spring feedback which is not linked to the surfaces in any way.

Therefore in a technical sense, control feedback on airliners is usually at one remove from what the flight surfaces are actually doing. Which is why a holistic approach using all the information available to a pilot, with an integrated scan paramount, is likely to get the best results.

I may be a wannabe, but I'm savvy enough to know that your pants (or more precisely your inner ear and nervous system) are more likely to lie to you about your situation than your instruments are.
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Old 26th Jul 2013, 17:47
  #43 (permalink)  
 
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Hi DozyWannabe,
control feedback on airliners is usually at one remove from what the flight surfaces are actually doing
Only true for Airbus FBW.

On Airbus you select a rate (as you remind me from time to time).
On Boeing you select a flight surface displacement.
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Old 26th Jul 2013, 18:16
  #44 (permalink)  
 
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Hi rrr,

I meant in a physical or mechanical sense - which applies to all the types I listed. Whether electro-mechanical or digital, artificial feel is just that - artificial.

[EDIT : Which is to say that on most jetliners with "conventional" controls, flight surface feedback is mitigated by the artificial feel system and therefore at one remove. Airbus's FBW system, as I said, uses passive spring feel and dispenses with flight surface feedback entirely. ]

Last edited by DozyWannabe; 26th Jul 2013 at 18:33.
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Old 26th Jul 2013, 20:36
  #45 (permalink)  
 
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Ref: seat of the pants. I take this to mean being sensitive to the g sensation of flying. I'm still amazed by pilots who can't sense this. You're looking out of the window on finals and you hit a thermal and feel the a/c ballooning. By instinct you correct the attitude to stop the balloon and adjust thrust to maintain speed, just a tad. Now one thing is pretty certain is that if you fly into a thermal, and it's not too close to TDZ, i.e. you are at some height on finals, then you are going to fly out of it and the a/c will sink there after. Not only are you fore-warned, but you should feel the world falling out of your a/c and 'adjust' attitude and thrust just a tad to resist mother nature.
It doesn't happen that good. If the automatics are in it is masked, if they are disconnected their bum is not connected to the a/c not their brain. They follow the speed loss/gain rather than pre-empt it.
Solution: Change the selection criteria for todays pilots, perhaps? Are the correct senses and skills being assessed?
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Old 26th Jul 2013, 21:36
  #46 (permalink)  
 
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The Irony

How ironic is it that Hollywood generally would have you believe that no matter how advanced technology gets, nothing beats the seat of the pants ability of a crusty old dinosaur or hot shot ala Star Wars/Space Cowboys/Flight etc

So why automate to such a degree? Its an industry driven by accountants and engineers.

As an aside, the need for a human operator within the cockpit will probably exist until all processes of air travel becomes fully automated.

Last edited by Chronic Snoozer; 26th Jul 2013 at 21:40.
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Old 27th Jul 2013, 09:34
  #47 (permalink)  
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To DozyWannabe

"Envelope protection and the like is a different matter entirely, and only enters into the equation extremely rarely."

How can you sure of this? Meaning how do you (DozyWannabe) know when the protection has limited the effect of the pilots input?

I agree with all you said in post 43. And thank you for not rising to my little jibe

Last edited by mross; 27th Jul 2013 at 13:53. Reason: emphasis added
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Old 27th Jul 2013, 10:44
  #48 (permalink)  
 
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How can you sure of this? Meaning how do you know when the protection has limited the effect of the pilots input?
It's pretty obvious: if you're pulling like and the thing doesn't stall, you try to bank to 60 and the thing won't do it, you end up in the 30 dive with the speed rocketing towards the barber pole the power comes off and the nose comes up by itself...
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Old 27th Jul 2013, 10:49
  #49 (permalink)  
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to Capn Bloggs

Sir, I'm sure YOU know! I was asking how DozyWannabe claims to know that the automation/envelope protection rarely cuts in.
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Old 27th Jul 2013, 12:17
  #50 (permalink)  
 
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There are already 'planes without pilots. Care to have a look at the loss statistics for military drones? Put simply, there is a hell of a long way to go before such technology is implemented in commercial aviation. It is very much disputable that there will be airliners withouts pilots within 20 years. In fact, I'd say it's almost a nailed on certainty that there won't be.
There are reasons for this though. Modern UAVs by and large are single engine and are not certified with the levels of redundancy exhibited by transport category aircraft. UAVs don't bother with systems such as anti-icing and de-icing and by and large still have a human operator to land them (Predator is landed on site and is not autoland) and its for these reasons the loss rate is higher.

Do I see completely autonomous transport cat aircraft in the mid-term? No. I can imagine a single pilot operator though, sat in first, on some pretty hideous crew duty days who can step in if there is multiple system failure. We wont see the step straight over to no pilots, but there will be an intermediate step whilst the concept is proven and issues shaken out imho.
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Old 27th Jul 2013, 16:40
  #51 (permalink)  
 
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Wouldn't surprise to see freight flown as UAVS in the future. Whatever the case, any pilot who pretends that the boxes won't break, hoping he will never have to hand fly or mentally navigate is beyond contempt in my book and is part of that special crowd of pilot who 'networks' for a seat in a plane, in the hopes that sitting in a plane, with a title of 'pilot' suffices to all his friends that he actually is one.
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Old 27th Jul 2013, 17:04
  #52 (permalink)  
 
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FedEx-founder Fred Smith posted this in 2009:

Unmanned cargo freighters have lots of advantages for FedEx: safer, cheaper, and much larger capacity. The ideal form is the 'blended wing.' That design doesn't make a clear a distinction between wings and body, so almost all the interior of both can be used for cargo. The result is that the price premium for air over sea would fall from 10x to 2X (with all the speed advantages of air).
and

the key thing is having NO people on board, not even as backup. A single person in the craft requires a completely different design, along with radically different economics and logistics. The efficiencies come with 100% robotic operation.
What he says mostly makes sense to me (my biggest doubt at this point is that he claims it will be "safer", that remains to be proven, but no human pilots on board may well be safer in terms of loss of human lives, if the things can manage to avoid crashing into humans on the ground and in other airplanes). It's also interesting to note that the unmanned X-47B which just completed first carrier landings is a blended wing design.

In response to VinRouge: following Smith's line of thinking, I'm not sure if we will see single pilot operated transport category cargo aircraft first. It's not a necessary intermediate step to what he wants. A more likely evolution, as I see it, would be to let Boeing gather experience with the Phantom Ray, maybe they'll even win the contract for the US Navy UCLASS and then, much later, when the military technology matures, start to work with them to look at the feasibility of larger civil cargo UAVs.

You also mentioned that
UAVs [...] by and large still have a human operator to land them (Predator is landed on site and is not autoland)
This may be true right now, but it will change. Carrier-based UAVs use task based automation, including autoland, mainly because there is no current datalink technology which is fast and powerful enough to allow something as precise as a carrier landing to be remote controlled, and autoland on the other hand is known technology.

But for civil aviation this is not even at the stage of long term strategic planning, but merely a visionary concept. Four years later, we're not really much closer to Fred Smith's aspirational idea. It will no doubt happen, that's not the question. The question is when? There I agree with previous posters, it will take at least two decades, most likely longer, with a caveat that it's hard to predict anything, particularly the future.

Just applying military experience to design civil UAVs won't be enough, there's many civil aviation specific issues that will need to be addressed. Military UAVs mostly operate in a very different kind of airspace (think of separation and control). Civilian (partly) autonomous/automated UAV would need much better sense-and-avoid technology, eg the ability to interpret video images, radar, as well as transponder/ADS-B data, to maintain separation. Also, the military owns and operates satellites and has huge network bandwidth at it's fingertips which can relay images to the ground with short latency. Civilian/Commercial UAV operators would have to buy bandwidth, and even compete for the spectrum with other uses if they want to t/x huge amounts of data to allow for remote control. And finally you also need FAA to certify all this new technology which could easily add 20 years alone...

Last edited by deptrai; 28th Jul 2013 at 11:32. Reason: damn tpyos
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Old 28th Jul 2013, 20:09
  #53 (permalink)  
 
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Originally Posted by mross View Post
How can you sure of this? Meaning how do you (DozyWannabe) know when the protection has limited the effect of the pilots input?
Don't take it from me - let Bruce Dickinson show you:

Now, this being recorded for a mainstream tv programme, Bruce does leave out a few key points - chief among which is that the Normal Law hard protections are not just there to guard against mistakes, but also allow the pilot to execute evasive manoeuvres at the full extent of the control movement without overstressing the airframe.

The reason I said the hard protections rarely come into play is also illustrated in the video. Bruce (at the time an Astraeus B757 Captain - in fact he was F/O on a flight out to Barcelona that I took with the missus) demonstrates that in normal circumstances he would not execute a bank manoeuvre much past 25 degrees. Bank protection only kicks in at 67 degrees, so if we take his own limit as a reasonable one for a line pilot then you're not going to see that part of the protection come into play very often.

Alpha Prot and Alpha Floor are likewise only designed to come into play when at risk of stalling, and again - on a day-to-day basis we're talking about very rare occurrences, are we not?
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Old 29th Jul 2013, 06:45
  #54 (permalink)  
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You have misunderstood my question. I know what the envelope protection does. I was asking, if a pilot somewhere in the world asks the aircraft to go outside the envelope and the protection becomes active, how would you or I ever know? We likely would not read about it. I suppose the airline would know - from the flight data recorders.
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Old 29th Jul 2013, 07:03
  #55 (permalink)  
 
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mross,

There's something called FDM in the aviation industry: Flight Data Monitoring!

Pilots in most companies will get invited to "Tea and biscuits" with the "Chief pilot" when he/she significantly exceeds normal flight parameters, without even getting close to flight envelope protection!

When a pilot messes up so badly that flight envelope protection has to kick in, it will be known! And yes, this will happen only very rarely!

Of course, not all of these very rare occurrences will make it to the press, and you and I might not hear of it. The simple fact that reaching the flight envelope protection is very unlikely, is, by logic, enough to say that these events occur only very rarely. Back to topic now, please.

Last edited by sabenaboy; 29th Jul 2013 at 07:24. Reason: added paragraph
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Old 29th Jul 2013, 08:04
  #56 (permalink)  
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to Sabenaboy

There's something called FDM in the aviation industry: Flight Data Monitoring!
Yes, we know, it's called many other things too.....

Flight Data Monitoring (FDM), Operational Flight Data Monitoring (OFDM), Flight Operations Management (FOM), Daily Flight Operations Monitoring (DFOM), Flight Operations Quality Assurance (FOQA), Flight Operations Data Assurance (FODA), Maintenance Operations Quality Assurance (MOQA).
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Old 29th Jul 2013, 13:34
  #57 (permalink)  
 
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Originally Posted by mross
I was asking, if a pilot somewhere in the world asks the aircraft to go outside the envelope and the protection becomes active, how would you or I ever know? We likely would not read about it. I suppose the airline would know - from the flight data recorders.
In Perpignan, looking at the elevator trace, the final resource has been limited by something, most probably the vertical acceleration ... But the BEA has never published that data ...
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Old 31st Jul 2013, 16:12
  #58 (permalink)  
 
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Originally Posted by sabenaboy
The Turkish crew still had the excuse that the A/thr did not perform as designed, because of a failure of the radio altimeter system.
Actually, ATHR performed as designed, retarding the throttles on ground. How did it "know" it was on ground? In computer logic; if RA is zero, then one has to be. It was not outright failure of radalt, it kept emitting realistic value, which had no semblance to actual, it's what we call "unreliable".

You can not teach today's computers to deal with unreliables. It takes intelligence to tackle them and success is not guaranteed.

Originally Posted by Capn Bloggs
Immediately reacting when you feel the @rse falling out of the aircraft instead waiting for the sight picture to change always produces a better outcome.
Except in rare cases where those feeling their nether regions falling out are actually victims of somatogravic illusion.

Originally Posted by RAT 5
Ref: seat of the pants. I take this to mean being sensitive to the g sensation of flying. I'm still amazed by pilots who can't sense this.
I'm still amused by PPRuNers seriously suggesting that personal g feel is something that can be used to fly transport aeroplane successfully.


Originally Posted by Chronic Snoozer
How ironic is it that Hollywood generally would have you believe that no matter how advanced technology gets, nothing beats the seat of the pants ability of a crusty old dinosaur or hot shot ala Star Wars/Space Cowboys/Flight etc. So why automate to such a degree?
Discrepancy between Hollywood movies and real world is part of the answer.

Originally Posted by mross
How can you sure of this?
Originally Posted by mross
Yes, we know, it's called many other things too.....

Flight Data Monitoring (FDM), Operational Flight Data Monitoring (OFDM),
You have answered your own question, lest you just know the names for it and are unaware what it means.

Originally Posted by mross
Meaning how do you (DozyWannabe) know when the protection has limited the effect of the pilots input?
He had read and understood them manuals.

Originally Posted by mross
I know what the envelope protection does.
What was the point of previous question, then?

Originally Posted by CONF iture
In Perpignan, looking at the elevator trace, the final resource has been limited by something, most probably the vertical acceleration ... But the BEA has never published that data ...
Parbleu! Scandaleuse! We should self-righteously and indignantly reject the report on shoddily maintained and lousily test flown 320 because there is no G trace in published FDR readouts.
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Old 31st Jul 2013, 18:27
  #59 (permalink)  
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to Clandestino

Did you read post 1?

What I am interested in is how many times FBW automation intervenes and stops the pilot from making errors, and comparing this to the more well known cases where the pilot has had to prevent the automation doing something to hazard the aircraft. I'm not asking how does a skilled ATPL knows when the automation is limiting his input's affect on the a/c. I am asking, how do we, joe public, know how many times the FBW has prevented pilot error?
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Old 31st Jul 2013, 18:27
  #60 (permalink)  
 
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I'm still amused by PPRuNers seriously suggesting that personal g feel is something that can be used to fly transport aeroplane successfully.
Don't know what your experience is but anyone who spent any significant time operating in extreme windy environments such as the Highlands and Islands of Scotland probably has a very refined personal g feel.

It pays off particularly in windshear situations where there have been dramatic power changes and has saved my personal bacon on big aeroplanes on several occasions..

Bet it works just as well on your smarter-than-the-average-pilot Airbus.
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