Qantas jet's plunge

[glenc]

'Cosmic rays' may have caused Qantas jet's plunge.
http://www.smh.com.au/travel/travel-news/cosmic-rays-may-have-caused-qantas-jets-plunge-20091118-ilei.html

"One explanation being considered for the October 7 incident is that cosmic or solar rays interfered with the system, noting that a single particle can cause problems with integrated circuits such as the one used in the data equipment."

[Baron von Richthofen]

That's one reason why I don't like fly by wire, doesn't matter how many backup systems you have its prone to failure:wink2:

[erick]

Drive by wire cannot be too far away now :eyepop:

[leinad]

Hahaha, well they're not exactly gonna say it was a computer/software glitch and ground the entire fleet are they ?

[Jen]

:eyepop::eyepop:

[michaellxv]

Not for me, i've never had a new car in my life.
I wonder if they would ever make it to the 2nd hand market?

[Baron von Richthofen]

They have come and gone, some 4 wheal steering cars were drive by wire, they failed, thank god

[koputai]

I worked down at the convention centre in Darling Harbour for a number of years, and in the underground car park, there's a section where Audi's die. The NRMA would be there a couple of times a week getting Audi's started because their engine management konked out in this particular part of the car park.
Steering cars by 'puter, not a good idea.

Cheers,
Jason.

[Peter Ward]

Fly by wire has been around for a very long time, early analog systems notably by Dassault, were introduced over 50 years ago. NASA first tested digital fly by wire in the early 1970's.

Tens of millions of hours have been logged with no evidence of any systemic problems....and you are kidding yourself if you think contol cable/hydraulic systems don't fail....they can, and do, but thankfully not regularly.

All aspects of travel have some risk..but with aviation it's probably the drive to the airport that will kill you rather than some oddball systems failure.

As for cars...many modern automobile sub systems have similar technology. Notably Mercedes S and E class models. They work superbly.

[Baron von Richthofen]

I do believe the space shuttle has 4 or 5 independent backup computers and they fail and it does not go up, reliable, I don't think so

[gary]

When a MiG 25 Foxbat defected from the Soviet Union to Japan in September
1976, a person I knew had chaired a NATO conference on the electronics
that were found within the avionics. Apparently there was some chuckling by
the attendees when it was revealed the Soviets were still using valves.
However, the chuckling suddenly stopped when this person I knew, who was a
semiconductor physicist, then told the audience that such technology would be
inherently radiation hardened.

[Peter Ward]

Why do you say that?

Shuttle hull losses were due to *totally* different failures that had nothing to do with FCU redundancies.

[multiweb]

Russians have always been very resourceful in any field, mainly due to recent budgeting issues I reckon. :lol: and they had the most reliable ejection seat systems for a very long period of time too because it was simple and it just worked.

One of my mates used to work for MATRA in France as an army contractor and was told me a story. One day during a lunch break he walked in a room with 10 blokes around a table and a russian missile in pieces on the bench. These guys were reverse engineering it trying to figure out what does what. He noticed the top handle of a coke can incorporated in a part of the missile. It was a standard coca cola can bit. Those guys said it was part of the navigation/altimeter system and it worked really well. Just turned out it was cheaper for them to get it off a coke can rather than manufacturing it? :lol:

[Baron von Richthofen]

:rofl:The ones I am talking about never got of the ground:rofl:

[stephenb]

I agree Peter.

In my opinion, the attention on Qantas everytime there is an incident like this occurs is magnified in the mind of the public and in the media because of Australia's small flying population and number of airline companies, compared to other countries. Whilst this does not make these incidents any less important, it does put the impression in the mind of the public that when we go so long without an incident, that airline flying is 100% safe, and we all know it is not. Sometime things occur, whether it be pilot error, mechanical error or external elements. (Yes, I do have a vested interest in Qantas).

[Nesti]

I feel the REAL issue here is fear. In that throughout history there have always been aviation accidents. The issue with fly by wire is that we are effectively handing over our lives to something we have little direct experience with.

We all steer our vehicles using direct mechanical devices which more often than not, employ hydraulic assistance. This provides us with two things, 1. That we can have direct feedback to the road surface and, 2. That we subconsciously think of metal parts as a REAL physical material.

With fly by wire, our psyche is affected, in that we replace our direct feedback with the aircraft with simulated feedback, and when presented with the concept that it is electrical power and signals which are relaying pilot output to control device input (Hydraulic actuator etc), then we have essentially taken the directness out of the system and placed it in the hands of James Clerk Maxwell...people instinctively don't like this...I'm one of them.

I do realise that we have had force gradients, stick shakers and other artificial feedback mechanisms in aircraft for years (particularly with heavy hydraulic reliant aircraft), but in some measure the pilot can always derive a lot of information and orientation from the FEEL of the controls...a side-stick, to me, is something for a PS2 or at best, something that you can use while sitting in a Martin Baker panic chair, not a commercial airliner.

Call me old fashioned, but I've worked and conducted post-maintenance test flying (engine, airframes and electrics) for years, and there's no way a fly by wire system is as forgiving as a properly maintained mechanical system. And that's the REAL problem with fly by wire; when it's running well, it's great, but when it bites, it really bites...it isn't as forgiving as classical systems.

The last real difference is that when the proverbial hits the fan, a pilot flying an aircraft with a predominately classical system reverts automatically to flying the aircraft hands-on as a priority; he becomes the flyer of the plane. With fly by wire, it seems that pilots attention gets diverted toward fault finding; he becomes the Certified Microsoft Systems Engineer. He does this because when a classical system fails, the pilot automatically knows that-that system, be it a cable, hydraulic system, electric worm thread etc, is cactus, whereas the pilot of the fly by wire aircraft has to determine if it is mechanical, or fly by wire related...and are other systems being affected???

I say put Sir Isaac Newton back in the driver's seat.

Cheers
Mark

[Peter Ward]

Sir Issac couldn't fly for Sh*t. He'd never even seen an aeroplane
AND also predicted refractors would have chromatic abberations :)

After 20 years on Boeing (non-FBW) types , I have to say I moved to Airbus with some reservations.

But, I must admit I am a convert.

The A380 has six levels of redundancy in the flight control system....

Even with a *total hydraulic system loss* the aircraft is very flyable.

You'd die in a B747 with the same failures.

[acropolite]

Cosmic rays sounds to me like a lame excuse, (no pun intended) given the number of scary incidents and losses they should be engineering commonsense changes to the flight control systems.

I still remember seeing footage of an aircraft autolanding in to a forest at an airshow when the pilot had intended to simply do a low pass. Pilot error, yes if he had fully understood the flight control system it wouldn't have happened, but the pilot didn't deliberately crash the plane, the flight computer did.

[Kal]

Personally I think that cosmic rays are a plausible diagnosis (http://www.iceinspace.com.au/forum/showthread.php?t=51949).

Hopefully they do make changes so that erratic actions can be removed from the systems if an anomoly like this occurs again.

[seanliddelow]

My dad is a Qantas aircraft engineer and he thinks the Learmonth airbase in North west WA is to blame. All the incidents happened near the area.

[multiweb]

That was a pilot error on an A320 years ago in Northern France. He disabled the computer that was telling him he was too low as he was doing a "fly by" demo for the media. He did get too low and didn't get enough thrust to clear the trees but he was in manual flying mode (not!). Whether people like it or not fly by wire is the safest alternative. A good example is the space shuttle. No one could land this brick. Or the stealth bombers.

[mac]

I don't fly Qantas on long haul flights anymore. They seem to have too many maintenance problems on their big planes. Haven't had any troubles flying them domestically in NZ though.

[avandonk]

Ultimately it is the job of the flight crew to control things regardless of systems failures. The flight envelope at cruise at high altitudes does not allow much room for any error. Autopilots are not as smart as the blokes in the front seats. Even a Pitot tube icing up can kill you unless you have smart pilots.

As for cosmic rays affecting three computers simultaneously. I find that hard to believe.

Why the Qantas flight did not end in disaster was due to very competent pilots.

Bert

[Nesti]

Careful - There was nothing that Newton couldn't understand...the technology of the day was his only limitation. :)

You're speaking from an operators point of view, I'm speaking from a maintainers point of view, we're bound to have a difference of opinion. You talk in terms of, 'what would happen and how would I react if'. I talk in terms of, 'how do I prevent if from occurring and what else is if associated with'.

"You'd die in a B747 with the same failures", so why are fly by wire aircraft falling out of the sky if they're so good???

How often do you fly (simulator time does not count) with a "total hydraulic system loss"??? Is this part of post maintenance test flight procedure?

[GrahamL]

thanks guys :thumbsup:.. my irrational view on flying is once again reinforced
in that I'll sit up the back thanks if I ever have to fly .. I'm sure its safer as no matter how much you guys up front or on the ground stuff up these suckers just never seem to reverse into mouintains or the
ground :thumbsup:

[TrevorW]

It's not the flying that kills you

[multiweb]

Damn right! It's the food they serve you in the plane! :lol: ;)

[gary]

Hi Bert,

When you read the Australian Transport Safety Bureau first and second
Interim Factuals, the current working hypothesis does not suggest that
the redundant computers all took a hit at the same time. Rather than the
computers, one of the primary focuses of investigators has been on instrumentation
upstream from the computers, in particular with a unit known as the
air data inertial reference unit (ADIRU). In the most recent report, they state that
one of the ADIRU units "provided erroneous data that was not
detected by the ADIRU itself" and that "the flight control computers did not
filter spikes in angle of attack data in a specific situation".

My understanding from the reports is that they are investigating the software
and have issued patches to the flight control primary computers so that they
don't respond the way they did to the erroneous data.

What apparently still is a mystery is how and why the ADIRU malfunctioned
and a reading of the reports, which are available from the ATSB web site,
gives some small insight into the extraordinary effort investigators and
engineers have been putting into trying to understand what went wrong.
There are other subtleties and puzzles including a similar malfunction
on another flight but which had a different model of ADIRU manufactured by
a totally different manufacturer.

The interim reports don't make it clear as the investigation is ongoing, but
despite complex redundancies with the ADIRU's and primary computers,
there might have been some unforeseen scenario where a single point of
failure still led to the event. Hopefully time will tell.

What is also compelling reading in the reports for those of us who sit rear of the cockpit
is the part of the story to do with keeping your seat belt fastened whilst
seated and cruising. As the report states, it can be a real mistake to have
the seat belt loose, as it is designed to be worn snug to avoid abdominal
damage and in a worse case scenario where you apparently give it 20cm
of slack, the buckle can get caught on the arm rest, un-clip and you undergo
a negative G maneuver with your head into the luggage racks.

So next time Peter or one of his good colleagues recommend over the PA to keep
your seat belt on at all times when seated, it sounds like advice to be heeded. :)

[DJDD]

From the article:

"
But changing seatbelts would be a massive undertaking for Qantas — and all airlines.
With about 220 planes in the Qantas fleet, carrying up to 300 people per plane, the airline would need to replace more than 60,000 buckles.

"


so, this might cost QANTAS, what, $600,000 maybe $1million?
perhaps another instance of an airline crying poor early to avoid costs. :mad2:





as for the cosmic ray...interesting...maybe I can use that excuse when our servers go down at work...sorry, boss, it was the cosmic rays... :lol:

[Nesti]

You're damn right!!!

I've been strapped in by a 4 point harness and it's been near impossible to do my job properly when you're being bounced around rough enough. Being rattled around like dice inside a cup is not a good way to be.

[pgc hunter]

Cosmic Rays...sound ridiculous. Every single airliner the planet should be equally "affected" by "Cosmic Rays" at high altitude going by this theory, so for this to be a plausable explanation, every airliner on Earth would be suffering the same consequences.

[Nesti]

These are the pitfalls of deregulating the market and allowing TOO MUCH competition - what suffers?? Maintenance then training suffer.

I believe the greatest hazard to aviation in general is actually healthy competition. You need time and money to be able to put up your hand and say "I'm not happy with...or no, let's do this by the book...or no, let's just replace the unit". Alaska Airlines 261 was the sadest case of cutbacks...a handful of grease per plane and nothing would have happened.

[avandonk]

So what you are saying is the aircraft systems had an erroneous angle of attack which was fed back into the aircraft autopilot and then caused a stall with a very high rate of initial decent say 20,000 ft per min.

Interesting!

Bert

[multiweb]

:lol: I have a feeling your air-conditioning is not working properly. :lol:

[avandonk]

Have you ever stalled a jet airliner from cruise altitude? My brother has and 20k feet/min is conservative.

Bert

[Nesti]

LOL...not everyone has a requirement to pipe 6000 BDU of frozen ram-air into their rooms to keep their PS2/XBox/Gaming super computers at optimum temperature ya know.

:D:P

Good thing you do tho, coz you'll need it as a Morgue when I'm done with you on MW2! :rofl:


Back to Henny Penny planes...

[Nesti]

Hang-on, that's only 101m/sec vertical speed...363kph...you're right, that's quite small.

I would think 35,000 to 40,000 would be getting extreme.

Heck, a toy can do 2/3rds of that no sweat...at 1min mark is boom flexing at around 250kph.

http://www.youtube.com/watch?v=w7q9Pk7kH9c

[multiweb]

Bring it on! Women! :lol: Nah I've got a ceiling fan, like a chopper. You gotta be "in the zone" man ;)

[multiweb]

I rest my case. Chill up. Couple of beers, blood pressure check.. :lol: :thumbsup:

[stephenb]

Just a thought? How many of the passengers who were injured/claiming compensation, did not have their seatbelts fastened?

I do not believe any major commerical passenger airline is more risky than the other. There is a risk to all flight travel, and in the end, it is humans who design, build, test and fly the aircraft and its components. And as a passenger you accept that small risk when you board.

[Nesti]

In actuality, although I am against fly by wire, I do realise that they are showing themselves to be more reliable, statistically speaking, and far more economical. This is why airlines are so attracted to them. Also, they should be less labor intensive for the flight crew (maybe there is a trade-off here tho). My only gripe is that when something does go wrong, that fly by wire is not as intuitively friendly as classical systems.

Also, until a pilot or flight engineer actually gets into the position of being a true test pilot, he/she must obey specific flight envelopes and procedures which best satisfy the safest possible mode of flight in a commercial environment. Test flight operations for post maintenance must obey specific flight envelopes and procedures too, but differ in that the envelope must be tested to ensure that the vehicle does actually meet the requirements. This means pushing a systems, one by one, to their required parameters and in some circumstances, further so as to determine its adherence to the manufacturer's specifications. Therefore a pilot who is carrying passengers is safe in the knowledge that if everything has been done correctly, he/she is at the controls of a vehicle that can operate within operational envelopes without risk of failure/catastrophy. (an example of "further" can be seen in a 'Topping Check', where altitude is gained in order to ensure that an engine compressor air is bleed to prevent compressor surge or stall...this is a common helicopter test...I've done this a hundred times, a few times with the loss of an engine. No big deal if you're prepared for it. Although we did have to autorotate onto a dirt car park of a hill-top look-out once...that was pretty cool).

Now a test pilot who is conducting true 'test flying', is something completely different. Usually these pilots and engineers test manufacurer accuracies in the aircraft type and/or modifications. I call these pilots and flight engineers the 'Scientists of the Air', because they are. The aircraft is essentially an apparatus which must be measured in all its capacities and how one parameter defines another parameter. Mostly this is only to confirm earlier static testing or engineering calculations. And still, they must obey specific flight envelopes and procedures while doing so...everything is thought about and calculated in advance...now-a-days, it is simulated time and time again before confirming in an operational aircraft, but most general aviation aircraft out there don't have simulators, so they must be tested the old way; fly it.

Until air crew can say that they have done test flight operations, then they are essentially flying a 'known' and 'tested' vehicle. There's nothing magical about it, its just a different way of operating the same machine...and fly by wire does add to the complexity, not the contrary, in that it places a wall between the operator and what is physically happening to the machine.

Cheers
Mark

[Peter Ward]

So even though you admit it's safer/cheaper you are "against FBW"

:doh: !?

BTW Airline operators get *really* upset with pilots who shut down perfectly serviceable systems ..like hydraulics...with fare paying passengers on board...just to see how the airplane compares to the simulator.

I don't glibly make these things up....Multiple hydraulic systems inoperative in a Boeing is a really bad scenario (the RAAF tried a similar stunt in flight with a B707 some years ago. All on board were killed)

Total loss of Hydraulics in the A380 is not great, but still very flyable.

Trying this in anything other than a simulator, would be asinine as best.

Sure a bit of canvas and cables has some aviation romance about it, but things have moved on since the Wright flier.

[Matt Wastell]

Great time to see this post - I am about to get on a plane to fly to Brisbane!

[TheCrazedLog]

To add fuel to the FBW thing:

Between the Boeings and the Airbuses there are two different systems with very important differences.

Boeing:
Pilot flying -> Computer helping -> Control surfaces.

Airbus:
Computer flying -> Pilot helping -> Control surfaces.

In an airbus, the computer is flying. The computer has complete control authority and cannot be overridden, unless the three flight computers are turned off and the plane thus reverts into Direct Law (this is quite simple to do, but is a huge step to take. You'd lose so much by doing this). Incidentally, in a landing configuration and close to the ground, the computer reverts to Direct Law.

In a boeing, the pilot is flying with computer oversight. The computer can be overridden.

Now. Which is better? Well... it depends. Lets first describe the airbus computer system. Three seperate computers. Three seperate types of chips. Three seperate computer languages, done by three seperate groups of people (I think anyway). It is virtually impossible to put an airbus in an unsafe configuration: The computer will not let you. Haul all you like on the sidestick, it will not let you stall. Also, a computer will compensate and react far faster than a human can ever hope to, and within set parameter it will react the same way every time: Perfectly. It does not get flustered or distracted.

Despite all these very good advantages, the flight computers have one major flaw: When they are fed incorrect information or they hit an unknown situation, they cannot react to it. A human can.

Take a very simplistic example: All three pitot tubes freeze. The airspeed indicator will read zero. A pilot will look out the window, realise his controls still have authority and he is still flying and react accordingly.
A computer will assume falling airspeed and will react by increasing thrust and possibly commanding a down angle.
Now this is a very simple example and is probably catered for, but it serves to demonstrate the point: A computer can only react to what it is programmed to, a human has the capibility to react to the unknown. He may have difficulty, he may make the wrong decisions and contribute to the demise of the aircraft, but he still has the inbuilt capibility to react correctly.

Now on the Boeings now I understand they have computer input whereby the computer assists. Lost and engine and got differential thrust? No problem, the computer compensates and its almost as if you were flying normally.

Getting back to the airbuses and their computers, I said that they cannot be overridden. This does not mean to say that they do not give up themselves. There are circumstances where the computers say "we've had enough, we can't handle this, here you do whatever the %()#%R$# you want, just get us out of here".

(Edit: Epic wall of text!)

[Exfso]

I wasnt going to buy into this conversation as it appears to have been pretty well done to death. Having worked in the Aviation Environment for 30 years as a Flight Service Officer, (similar to ATC), I know of one airline I would never fly with end of story, they are downright dangerous, they operate out of Indonesia, so you can probably guess. I distinctly remember a jet arriving from Indonesia into Darwin with hydraulic issues. At that time, it was TAA that were doing the servicing for that particular airline in Aust, and they had to replace a fairly minor hydraulic line somewhere in the aircraft. They did not have exactly the same part required and used what I was told by a LAME to be a very high quality piece of replacement hose, but not as recommended by the aircraft manufacturer concerned. It was meant to get the aircraft back to Indonesia where the part could be replaced properly. Apparently that aircraft came back into Darwin some weeks later with the same part still attached. This was something I got 2nd hand from a friend who worked with TAA at the time, so there may be a degree of license involved. However having said that, I had numerous experiences when communicating with that airline where they broke ATC rules drastically and in one instance departed Jakarta for Sydney and climbed to FL390 without a single airways clearance, at the same time that numerous other long haul jets were on the same route inbound to Australia. The fact that they were not in Australian airspace was probably a contributing factor, but they were approaching the boundary and we as Flight Service used to use HF radio to communicate with aircraft on international routes once they were out of VHF range, and as such we could hear all the chatter going on in neighboring airspace. IMHO, Indonesia is one very dodgy place to be flying, or it used to be, things may well have changed, and they would have needed to.
I know this is somewhat off topic but seeing it was mentioned that all airlines are basically the same is IMO quite wrong.

[Nesti]

OMG, I have tried to articulate my reasons for preferring classical systems over fly by wire, and you have responded in slap-stick. Thanks!

Did you not read the entire passage I wrote, or do you have selective literacy? You have conveniently left out this passage from the same para "My only gripe is that when something does go wrong, that fly by wire is not as intuitively friendly as classical systems." Then you have based your response upon my introduction...how convenient Peter!

So if I'm not mistaken, you originally said that "Total loss of Hydraulics in the A380 is not great, but still very flyable", to which I have asked you when have you ever flown, not just an A380, but any airliner without hydraulics...but you have avoided replying to this question, merely stating that "BTW Airline operators get *really* upset with pilots who shut down perfectly serviceable systems ..like hydraulics...with fare paying passengers on board...just to see how the airplane compares to the simulator."...you'll need to answer that question properly if I'm to believe your original statement. This is why I introduced passages about the differences between pilot under charter, post maintenance test pilots, and manufacturer test pilots, because I'm pretty sure nobody outside of Airbus (or under tuition of Airbus) has ever tried it before. In fact, I reckon only Jacques Rosay and his flight crew have ever performed the operation (If it's even possible).

"Sure a bit of canvas and cables has some aviation romance about it, but things have moved on since the Wright flier" Why have you spoken in extremes to fob-off my opinions about fly by wire versus classical systems? That's exactly how pilots at parties behave funnily enough.

[Peter Ward]

I have spent the last 20 years on B747 and B767 types and, and ,sorry they have no "computer assist" as you describe. It simply doesn't happen.

[Peter Ward]

OK Mark, we can take it a point at at time



I disagree. With degraded systems, rather than struggling to keep in control as in non-FBW, FBW makes the push-pull bit easier, giving you more brain power to manage the failure and come up with a solution.



No aviator in their right mind would want a total (flight control) hydraulic loss. I have never had one in a non-FBW type, simulated or real. Wouldn't want one either.

United Flight 232 (Soux City) had one and despite some very remarkable flying by the crew, the aircraft still crashed and burned.

Yet the A380, (a FBW type) can have this type of failure and remain very flyable....which was my point in the first place.

Most heavy (non-FBW) types have hydraulic systems with artificial feel making them no more friendly than FBW systems, hence I do not understand why you would be "against FBW" , as in both cases it is not possible (to downright dangerous) to develop/test their systems for real at high levels of degradation without serious risk of a hull loss.

[Nesti]

The "push-pull" may well be easier, but you've substituted it with complex flight computer issues and as we have recently seen in that case of Airbus (Air France) pitot data input issues as well...which may be beyond a pilots capability to diagnose in the heat of the moment and in time sensitive scenarios. Being able to fly 'hands-on' and forget diagnosing a computer's hissy-fit is THE primary objective during a flight issue. Let me know what airline disagrees with that I promise you I'll stay clear of them. I bet this exact issue is being addressed at Airbus right now (just remember they're French and I've worked on Mirage; they're never wrong...NOT!). Aeroflot 593 was a classic case of trying to recover an aircraft (A330) in a classical manner but what resulted was an inevitable fight between the pilot, the flight computer. I would not be surprised if the pilots of AF447 had done the right thing and let the computer do the flying when the issues occurred, the aircraft became unrecoverable for the computer, the computer then handed the controls back to the pilots during the unrecoverable state.

I don't really want a pilot to be flying with his brains, I would much prefer his flying skills, gut instinct and a good eye...as for grey matter, that's highly overrated in an emergency...just a cool head and an automatic (trained) response within a classical system is the best. Don't work the problem, work a solution to your current situation. Worry about bugs in Microsoft when it asks you to send a failure massage...coz that means that you're alive still.




Totally besides the point.




As the Hstab was shredded, the only way United 232 could have survived was if the ailerons were on a separate system and that they could be run as AilerVons.

There are two issues here;
1. Total Hyd failure
2. FBW failure

In case 1, the A380 should be usable IF the failure is limited to just the main Hyd systems and the EHAs are not affected, reverting to local hyd circuit. If an aileron becomes locked (stuck valve or flight computer), and ports fluid then you'll have max throw or a fight between EBHA and EHA (EHA will win). EBHA shifts from main hyd to local hyd under electric power under main hyd failure. Both EHA and EBHA circuits seem entirely dependent upon flight computer input. If you have both Hyd and electrical failure (not likely), better pray there's a good battery and ram air generator somewhere.

In case 2, you're dead. And this brings us right back to the original FBW discussion.




But they still have mechanical feedback. For instance, a push-pull tube which is hyd assist (99%) will still give good flight control feed back as there is only so much a hyd system can dampen strain and vibrations. Go Hyd off and everything weights a tonne and with near 100% feedback. Of course they introduce stick shakers and force gradients, but these can be disables during hyd off operations.

What manufacturers could look for is more hyd assist in larger A380 size aircraft, and in hyd off (failure of prim and sec), offer 70% hyd assist via accumulator/local elect-hyd systems. FBW merely looks for pilot (strain) input and provides assistance, knowing what inputs are being done by the crew, and porting hyd power BEHIND the pilots [force] input, rather than IN FRONT of the pilots input as in the case of current FBW.

Think of a CNC milling machine. If it has an image and just cuts away according to a program it will simply break the tooling. But if the mill is able to sense the dimensions of the material to be cut, rate of rotation etc, then it is able to apply the milling process in an intelligent manner. This is where FBW fails, it looks at side stick (& pedal) input. I'm saying it should look for strain within the physical linkages and get behind the pilots' actions at the actuator end AND mid stream too!

You're actually a pilot, you should agree with the pilot being in control, but as it stands, you really aren't. And you can come up with whatever computer to pilot algorithm model you like, the fact is-is that you aren't. Your inputs aren't being inputted at all, they're being analysed (assessed actually) and then inputted. I'm not saying pilots are redundant, since FBW looks for your input, but you are being handed your hat and coat on the flight deck.

[Peter Ward]

Better steer clear of QF then. During complex emergencies we are trained to use the auto-flight system as much as possible..."unload" yourself so you can tend to the problem.

We can all fly engine out approaches etc. if we couldn't we'd be shown the door.

Managing a scenario well, is often critical to a successful outcome...hence your comment



...has me gobsmacked. Would you like a surgeon to have "a good pair of hands" but have no idea what he's cutting??!!

A professional aviator needs excellent systems knowledge, without which he/she is nothing more than a professional passenger. It really does help to know how the fuel system works (saves gliding to the Canary islands), what inputs the ADC's are getting (767 lost in South America), what happens when you depressurise the Yellow (or 1-2-3-4) hydraulics or de-power a #3 electrical bus. etc. etc.




I'm trying to think of a case where this could happen. Failure of six independent systems while not impossible is *extremely* unlikely.

Control cables/hydraulic lines can also be severed/freeze/rupture on non-FBW types. (I've personally had a runaway trim on
a Metroliner)

Again unlikely, but I'll still go to work tomorrow with this knowledge and that Engineering (at least in Oz) do a splendid job in maintaining the airframe and systems so that none of the above happen.

As for "not being in control"....

It is true in FBW pilot inputs are filtered but in doing so, the A380 FBW system provides high speed, low speed, bank & pitch, g-loading and many other flight protections...making it *really hard* to stall or stress the airframe in any way at all.

In many dynamically unstable military types they have to be FBW, otherwise you'd simply loose control.

As to whether this is preferable in a public transport aircraft to a non FBW system.... that will literally allow you to tear the wings off....I'd be happy to let the fare paying punters decide.

[Nesti]

Will do.




What's wrong with gliders, I like gliders!




You've misinterpreted what I've written. I'm talking about in an emergency situation I would prefer pilots to run through exactly how they are trained to respond (prior to FBW and on non FBW types). This means focusing on the flying an not on the damn computer...but as you said, you don't have a choice anymore, because it's now doing the flying for you and you've been retrained to spend your time figuring out what version and build it is that's playing-up, and if you can download a patch...or whatever the scenario happens to be that's taking you away from flying.




I wasn't talking about normal operations, haven't yet, I was talking about in an emergency situation where time is critical. "overrated in an emergency", I believe I wrote that in plain english.

There is an investigation going on right now which is looking at this exact relationship; the issue of distracting pilots from hands-on flying in an emergency instead of diverting their attention to systems trouble shooting which might not even be rectifiable. They are investigating the likelihood of avoidable accident because of this change in doctrine and, glass cockpit issues also. And they're not conspiracy theorists or crack-pots, they're seasoned aviation technology specialists and wait for it...aviation lawyers. They're looking to reverse the trend.




No, not likely, but possible. In the last minutes, Swiss Air 111s fire may have done just that.




Of course, but we're talking about failures on FBW and how pilots respond versus failures and responses on classical types.




That's true however, I also know first hand that maintenance is currently walking a fine line between serviceability and budget. That was one of the reasons I quite aviation 15 years ago. Now money's even tighter.





Again, you are trading-off flying for ease of flying...do you even feel like a pilot anymore?




But they have ejection seats.

I know what unstable is, I fly RC aerobatic planes and competition gliders on the neutral point...it's demanding, controls are sensitive and pitch s very unstable. These days it is possible to mix all manner of flight controls together for assistance against balance points. Although expensive and crashes occur, you can play around with setups that you cannot with real aircraft...you get a feel for what can and what cannot be achieved.




That's just it, they don't get to decide, and what's worse, they only hear how wonderful new technology is...until of course we see what comes out of the recent spate of Airbus issues...and the concern is growing.

[Jen]

:rofl::rofl::rofl:

[Kal]

So Mark, would you prefer to drive a car with Electronic Stability Program switched off or on, because if it is switched on, a computer will be making critical decisions overriding driver input in an emergency situation. Would you prefer to have it off so that the driver is 100% in control, even though statistics will prove that the driver with ESP on has a much higher chance of not wiping out in an accident?

[AstroJunk]

If we can change this to a poll, I'm flying with Peter.

Interesting discussion...

[multiweb]

Yeah. That's a no brainer. :) :thumbsup: Sorry Mark. I'll still snipe you in the back though ;) :poke:

[Nesti]

Ask an F1 driver what he would prefer? My answer would be the same.

Putting a computer in charge is insanity and Airbus have proceeded along an incorrect pathway in order to rake-in inherent economies associated with electrical/electronic systems to take leading share in the aerospace market. The truth is-is that when electronics/computers work fine until they screw-up , and when they do, they fail 'big-time'.

[kinetic]

With all due respect Mark, that is a mighty big statement to make without
maybe being fully informed about the complexities of the aircraft.
I think a quote from Oscar Wilde fits in perfectly....see my signature.

Steve

[Nesti]

I'm not fussed that you prefer Peter's argument, remember, this is a complex issue that runs deeper than what words have been written in this thread so far. But in time, you will see this issue come to the surface in the media, you will see documentaries on TV about this exact discussion and many pilots speaking up about their concerns, and believe me many pilots do have concerns. Many pilots who have been involved with a computer/pilot conflict.

The thing is-is that I have worked on classical systems for many years and conducted post maintenance test flight operations for 6 years. I have seen failures in flight and NOTHING, and I really do mean NOTHING, can replace a gifted pilot at the controls and someone competent reading to him all of the data that he needs on the way down, so he may straighten it out. You take that pilot out of the loop and replace it with machine code, and get the pilot to go look for the popped fuse (or whatever), then good luck to you!

Myself, I just wish I had a choice when I travel, as every carrier is out to save buck and is opting for FBW.

[Nesti]

Steve, that statement is absolutely true. Airbus themselves have said that it's all about economies...the other part, proceeding down the wrong path, will become more obvious over time.

Well in Oscar's statement, I guess my ignorance must come from many years of ignorant training, ignorant maintenance and ignorant flying. Must have been wasting my time then.

[Peter Ward]

Sorry Mark, this is alarmist rubbish. Boeing also have moved to FBW
(B777, B787) as they are also aware of significant advantages these systems offer. There is no Airbus conspiracy here.

Your suggestion that SwissAir Flight 111's demise was due to a FBW failure totally ignores the fact the aircraft was on fire, with the cockpit overhead panel melting, just seconds prior to impact. (the cockpit transcript is very sad and depressing).

(I can't help but think that's like chipping someone for lighting up a cigarette as a major bushfire is approaching)

As a pilot, there are very few things you need to do in a hurry in an emergency. Securing the flight path is a given. I have no problem with letting an automated system do that while I then figure out what to do
as a result of any failure, be it systems or software.

[Nesti]

My alarmist point of view comes from ferrying three mates down from High Range to Townsville hospital in body bags instead of conducting night flying as was originally intended. That particular accident was pilot error, but out of the 67 contributing factors, the main contributor was that the pilot in control became confused and was distracted from flying the aircraft. He preferred to keep an eye on his Ts and Ps. When he entered into a situation where he should have reacted, he did, but opposite to what would have saved them. He was fully trained and had conducted many night flying operations. We had actually warned aircrews to be mindful of certain issues that occur during such operation, but were ignored...but the RAAF accident investigation team we're all ears.

If you think that you've got a good grip on the situation, fair enough, but I've seen that know-it-all attitude in pilots before. And it only goes so far.

The problem with aviation, is that there's a political issues between pilots, carriers and manufacturers. Pilots either tow-the-line or they are ousted from the airline, and it's difficult to get flying jobs, especially if you have ever rocked the boat. So pilots tend to shut up just to keep their jobs. This presents as a perpetuating moral hazzard to which the general public is not aware. The main perpetuator of this philosophy on the pilots side is usually the chief instructor/pilot. That's the same issues in the two Black Hawk incident, pilots which were vocal on what we had suggested were told to shut up. This isn't BS, this is rife in civil aviation.

Do you think that I would believe that if you did have a an issue with FBW that you would speak out on an open forum??? I pretty much knew the line you would have to take. That is the only rubbish in this thread Peter, not my "alarmist" point of view.

Tow-the-line Peter, tow-the-line! :P

[Kal]

The fact is I didn’t have any experience without traction control and I was rubbish. It’s interesting. The throttle used to be like a button, you’d lift or floor it with no half measures. Now you need to be as smooth as possible. The laptimes have been good immediately, that’s a sign that we’ve started on the right footing.
But from a safety point of view, these limitations in the use of electronics look like a step backwards to me: in the event of wet races we’ll have a lot more accidents.
Felipe Massa
Without traction control it is much more difficult to accelerate – you have to apply your foot on the throttle much more carefully.
It is more fun to drive but also more difficult. We are going to see more mistakes because it is easier to lose control when you are pushing, but there will be the same winners.
Personally I prefer cars with full electronics. In terms of technology and safety, I think it is a backwards step.
Pedro de la Rosa


F1 removed traction control, not full ESP, which is what I was referring to anyway. To use your argument against Peter, I'm not interested in computer assistance during normal control, only emergency situations. I am only interested in when the computer takes over when the driver has for all intents and purposes 'lost control' of the vehicle, such as in an emergency maneuver, or when road conditions cause a sudden loss of control.

[Nesti]

I would not hesitate to driver a car with traction control, ABS, computer fuel management, semi-automatic electronic shifting, no problem, I love that type of technology. But these are all secondary systems. I will never drive a car that turns the steering wheel or feeds the brake hydraulics for me, not while my family is on-board at least, as these are primary systems. Traction control doesn't steer the vehicle or conduct braking, it balances the torque between wheels to best ASSIST the drivers input. The driver steers and controls throttle response, Traction Control then senses and balances the output torque so as to maximise acceleration and control the pneumatic trail (understeer and oversteer). FBW is primary and secondary controls.

Would you sit in an F1 car and drive it using a PS2 gaming controller? Because that's what FBW does.

[TheCrazedLog]

I understand the 777's have them do they not? I should have clarified that. The 747 and 767 certainly don't, but I seem to recall that the 777 has this feature.

http://en.wikipedia.org/wiki/Boeing_777#Fly-by-wire doesn't prove this, but seems to support its presence.

[Nesti]

Article on fly by wire philosophy;
http://www.seattlepi.com/business/boe202.shtml


This is where the investigation into AF447 is headed. Even the Air France pilots union is annoyed.
http://www.youtube.com/watch?v=2ei-qss0sPQ


Just ignore the typical American hype, but it does point out what I was saying. Do you build aircraft where the pilot has final say, or aircraft where the computer has final say. Does the pilot fly, or is the pilot now a babysitter for a computer...it's embarracing how far Airbus's philosophy has taken aviation. Again, the clip is loaded with pro American rhetoric so just ignore it. They are correct that Boeing's philosophy on flight computer assistance is correct. This is what I was saying earlier, let the pilot fly and the computer should only assist. Airbus seem to want to cut the pilot out of the loop, and won't admit they are wrong.
http://www.youtube.com/watch?v=v2poqIcGb_I


If a pilot flies for an airline which operates Airbus types, then the pilot will support full FBW primarily to keep employment. If another pilot flies for an airline which operates Boeing types, then the pilot will not support full FBW, again, primarily to keep employment. The only way to know which direction is best/safest, is through the investigation currently be conducted into outstanding accident investigations. This will show aviation the path.

Keep in mind what is at stake here. If Airbus's philosophy is wrong, they may fold, and aviation is big business. Don't expect them to admit it, ever.

General background.
http://www.youtube.com/watch?v=sjFmNERebcU&feature=related

[Peter Ward]

OMG what a lot of hogwash.

QF has both types, pilots are free (seniority permitting) to choose either way which type they wish to fly, and I can assure you, some are critical of either type when things don't work as advertised.

I have around 11,000 hours on Boeings and just under 1000 on Airbus. To argue either is inherently "unsafe" is nonsense IMHO.

Another *big* fallacy I really need to clear up is: you "can't turn off the computer" (on an Airbus)

Fact of the matter is *you can*

Doing so removes all protections, throws you into a back-up mode with fewer moving surfaces (makes flying the aircraft quite a bit more of a challenge), but you can have a good old one-on-one if the situation warrants it.

The machines haven't taken over....yet :)

[Kal]

I've spent countless hours driving F1 cars with PS2 type controllers on my PC, so why not :lol:

I may have misinterpreted you, I thought that the premise of your FBW dissaproval was that ultimately the computer can override the pilot (or driver), but it seems that your dislike of it also includes the control implementation mechanism (electrical Vs hydraulic).

You may have to retire from purchasing new cars after 2011 Mark if the government passes (or has passed) some new regulations (http://www.themotorreport.com.au/35060/federal-government-to-make-electronic-stability-control-mandatory-from-2011/). ESP units have a hydraulic component to actively control braking on individual wheels in an emergency situation, meaning that a computer will override complete driver control of the vehicle and take steps to point the car in the direction that it thinks it should be pointing.

[Nesti]

First of all Peter, believe it or not I actually support you, as a pilot [doing what you should doing] 100%. Now Airbus (and Boeing too), have made your job a little cushier by reducing work-load, and that may sit well with you, but there's more to this arguement than what a pilot gets exposed to in his/her career. I feel that you should not be utilized in the manner in which modern flying has proceeded, for my reasons, you believe it's fine, for your own reasons. No problem!

You are still communicating inputs to actuators through electrical wires and electronic devices. I prefer torque tubes, cables (wires), butterfly cams, push-pull tubes, REAL PHYSICAL DEVICES WHICH CAN BE MEASURED FOR WEAR AND DETERIATION, ELECTRICAL AND ELECTRONIC DEVICES TEND TO FAIL WITHOUT WARNING. And if you have to have FBW, better that the pilot gets full authority. If you prefer being baby-sat, that's fine by me, but I'd feel a little insulted myself.

There is a reason why pilots are not allowed to write-up what a failure is; it's because pilots really have no way of knowing for sure from the flight deck...that's what maintenance must determine, it's their job, not yours. All you need to do is simply write-up what has fallen outside serviceable parameters and by how much; that is all that you do. It is the engineering cell which determines the unserviceability and the rectification to be taken, not the flight crew. You are talking as if you were reading notes from your classes, but they do not and will not teach you the underlying principles involved in maintenance for good reason. And as an ex engineer I am telling you that there is more to systems than what you see on the flight deck, or the colorful schematics in your manuals or checklist procedures.

I feel like I'm talking to a pilot...you just don't get it do you?? Lift your head out of the manuals, which you are TOLD to believe, for just 5 seconds.

I've spent over 30,000 hours swinging spanners on aircraft, so don't bother throwing that pilot log book rubbish at me (as every pilot does when they want to win an agruement) as if it's a get out of jail free card...coz it ain't. I'm happy to trust my knowledge and experience in how and why aircraft systems and components fail over your log hours any day.

There are literally thousands of things I don't know about flying/piloting aircraft, what you need to recognise is the reciprocal.

[wasyoungonce]

I used to dream of the day/place when pilots & engineers get along reasonably amicably. Dreaming of Nirvana I was.

This only happened at one place I worked...ARDU.

The rest of the time...butt heads!

[multiweb]

Tough call. On one side of the ring an experienced hands on pilot and on the other side someone who knows and has been working on the internals and maintenance of the planes. Not having any in depth knowledge on the subject my understanding is that FBW makes the pilot's job easier and safer by restricting him in doing manoeuvers so he doesn't put the plane in a critical situation. On the other hand the computer can have glitches from being fed bad data and override the pilots commands. It's a bit of a catch 22 isin't it? Can't you have the best of both worlds and have the computer drive the plane but leave the ultimate choice to the bloke in the seat? Isn't that what Boeing Phylosophy is? :shrug:

[Wavytone]

Mmm... from the perspective of a realtime control systems engineer - one who works with safety-related systems - attributing the cause to a cosmic ray is about as meaningful as claiming "the Aliens did it".

Just another way of saying they have no idea.

[Peter Ward]

I mentioned earlier "Wright fliers" and that technlogy moves on. While you may not like it, an aircraft like the A380 simply would not be flying due to the weight limitations these ancient systems impose.

FBW systems don't hang off a single wire. Wire looms can be and are tested.

There are numerous pathways to the flight controls which is not the case (particularly in light aircraft) in conventional systems where failure of a single pulley means you are not going home. Ever.



All Pilots would like to think we're Chuck Yeager, seat of the pants test flying is not warranted or encouraged in regular public transport operations!

Pilot error is still the single biggest cause of hull losses, so having an aircraft that looks after you (and everyone else) works for me.



Are you suggesting our manuals are wrong? ( I could see some serious legal issues there) or that (pilot) systems knowlege is a waste of time? Sure we don't have to know how to fix a hydraulic line/EBHA but it would be remiss not knowing what it's connected to.




Maybe. But Enginners always get to go home after a bad day at the office. Pilot's don't have the same luxury and are faced problems extending far beyond the nuts and bolts of the airframe.

FBW systems offer multiple levels of redundancy, excellent protection of the flight envelope and airframe. Yet despite exhaustive testing and very safe flight histories we have a retired LAME who says they are not safe.

This is not true of non FBW systems. Sorry, I'll happily put my butt into a system that looks after me.

And if I think some rouge computer is trying to kill me, I can still switch it off.

[Peter Ward]

Getting back to the original post..."cosmic rays" possibly causing the FCC spike that upset the QF flight. I find that to be almost laughable.

There have been several flight "excursions" in the same area (2 or 3 with QF and one with MAS) .

The area? As young Sean's Dad mentioned, the same area. Right above the Learmonth VLF tower. Humm...

[Nesti]

Your education is FBW is a little misguided. Go an ask you head of maintenance, in a properly maintained modern aircraft if it is possible to predict the failure of ANY electronic/electrical system, this includes FBW systems which you seem to be somewhat trustworthy of. Than ask the same person if it is possible to predict failures in mechanical systems.

Outcomes; in electrical/electronic/FBW, other than the components being 'Lifed', there is no way known to predict failure - Fact!
In mechanical systems we have oil spectrum analysis which can tell you [exactly] which bearing is wearing and when we should expect it to be out of wear limits. We have the same type of analysis for hydraulic systems, so we know pump wear rates. We can measure creep in control surfaces which indicate seal wear rates in hydraulically actuated controls. We have cable tensiometers which can tell us how much a cable has stretched and when it required to be replaced. We have push-pull force meters and indicaters for 'slop' which tells us how the bearings are wearing within the flight control system. The list is almost endless.

You seem to like referring to my aircraft philosophy as some fly by the seat on ones pants stick and rudder old-school upbringing...you're absolutely clueless and seem to know nothing about what really goes on.

Mechanical systems are almost totally measurable, electrical/electronic systems can and do fail without warning. End of story.

[Kal]

*cue terminator music* :lol:

[Peter Ward]

I've seen a hot end turbine..not just a blade..the whole assembly...depart the main shaft, skip down the wing, score the flap and end up some farmers paddock (never to be seen again) near Albury.

Forgive me if my faith in crack testing/wear/spectral/creep/tension/fluid anaylsis is a little less than fanatical.

Unforseen major failures can & do occur on the mechanical side of the fence.

But...being clueless, I guess my faith in a highly networked system with dozens of pathways and redundancies is misguided. :shrug:

[avandonk]

In the good old days when I used to regularly get flown to Japan, Europe and the US for work my brother who is a Check Captain for Qantas used to arrange a visit to the cockpit for me.

I can fly a lighty and have aerobatic experience but no way could I even begin to control a light twin safely let alone modern jet airliner without a lot of further training.

The comment all these flight crews made to me was that when a non flyer sat in with them, inevitably the comment 'you don't seem to be doing much' was blurted out by the visitor to the cockpit.

The same ignorance is rife in the media as well as the general public.

Sensationalist ignorant comments in the same way do not add anything to safety.

I would far prefer Peter Ward to be flying the aircraft I am on and the engineers looking after the flight systems. Not the other way around.

Only careful evaluation of scientific evidence by everybody in the industry can improve things.

The mindless claims being made about the LHC are another example of ignorant twits commenting outside their area of expertise.

Bert

[Omaroo]

Along with the billions of dollars and millions of man-hours in development.

"Well.. lets just do it and see if it works then, eh?"

Companies like Airbus don't gamble with figures like these. FBW is here to stay.

[Peter Ward]

:lol: So would I Bert!

[Nesti]

Airbus have been looking at all the data [of the QF flight] for months now, and where are we hey? Cosmic rays! Give me a break.

I can see four major conclusions;
1. It's a bug in the flight computer and they've not been able to replicate it, thus it still exists.
2. They've found something and won't make it public until they have a recitification action tested and ready to roll-out.
3. There's an unknown incompatibility between the input devices and the flight computer, which may take years to determine and rectify.
4. FBW is technologically premature and may carry something from #1-3 (my belief).

In cases 1-3, intermittent issues can occur. I have just seen the end on a data messaging corruption (lock-up) for Australian Fire and Emergency Services and that was a single occurance every 6-9 months of continuous operation. That's once in over 2 million transmissions/receptions of identical messages. So even though the message is exactly the same, and the firmware remains the same, the system didn't lock-up for millions of cycles...hugely frustrating! But when it finally did, it was as dumb as a post, and came without any warning. The system could not be rebooted, it required re-flashing of the firmware first, then a hard start. There was nothing in the data to suggest what was going on, it was determined through searching tens of thousands of lines of script.

This is a similar scenario to what we are seeing with the Qantas flight as well as some other recorded cases. The systems seem fine both before and after, but it was real and the flight data would support that.

I still stand behind FBW being way too premature.

[avandonk]

I had a control cable break due to fraying on my yaw (rudder) control. All cables should be banned until we understand cable fraying?

There are many more failures of mechanical systems that led to many deaths.

Of course I understand that there are far more people that die in larger aircraft in one 'incident'

Only rational assessment of the scientific data is the way to understand what is really happening.

I personally prefer a nice taut uninterrupted cable between my joystick and my control surfaces. When you are pulling a 6G loop and then roll 180 deg level out inverted and then push for a vertical climb and then do a stall turn and then something breaks....

Bert

[kinetic]

Sort of Fred....
It's more along the lines of multiple redundancies Peter mentioned
several times.
Ever heard of the Gimli Glider....
Great happy ending story.
Pretty much all due to both the right pilot being in the seat and
a redundancy contingency working.
A RAT or RAM Air Turbine gave some control back to an almost
dead in the air 767 when it ran out of fuel at cruise alt.
As all of the power systems and hydraulics rely on the engines
running...this was curtains for the crew and passengers.
Except for the R.A.T that did it's job...and the experience and unique
background of the pilot.
Read it up.....great story.

Steve

[Peter Ward]

Sort of Fred. The A330 incident wasn't actually a "failure" of the FBW system.

Several very abnormal "spikes" came from one of the Air Data/Inertial reference units (ADIRU's) ....and the flight envelope computer "protections" pitched the aeroplane when there was no physical reason to do so.

As it turned out the samplng intervals did not help things, in that the perfectly functioning ADIRU outputs were ignored (they supposed to look at each other and discard spurious signals).

I believe this has since been addessed by Honeywell.

And as I mentioned earlier..there is indeed an out...turning off all primary and secondary flight computers.

[Peter Ward]

Bugger

I dare say had it been the elevator you'd not be telling the tale !

[avandonk]

Yes Peter lose the elevator and you are in deep do do's. At least you can ask your 400 odd passengers to run from the back of the aircraft to the front or vice versa to simulate an elevator. I am sure you can also pump fuel to change the balance. I still maintain the tail slide had nothing to do with it. If you lose your elevator control and it is even worse in a large aicraft as the worm can get jammed due to lack of maintenance and overcycling then only thrust can start to control your attitude. Too bad if to maintain some sort of level flight to attempt a landing full thrust is required.

The most important bit of your flight is what you check on the ground. That is all your pre flight checks.

All of us are still safer in an aircraft than even crossing a busy road.

We pilots read everything we can about aircraft crashes as it may give us some ideas to not go down in the same way.

I used to work with a senior scientist who was terrified of flying. He thought that paying pilots heaps of money was a good thing as it gave them a reason for living. So that way in his own irrational logic he sort of felt safer as long as he was flying with an airline with highly overpaid pilots.

Bert

[Nesti]

This is all starting to get pretty interesting now. How we use technology has always been critical, but the decision to place too much technology between the human operator and the machine might prove to be even more critical.

http://www.spiegel.de/international/world/0,1518,679980,00.html

"The controls suddenly feel completely different to the pilot," says flight expert Hüttig. The sheer complexity of the Airbus' systems makes it difficult to control in critical phases of the flight. It would be easier for pilots if they could simply switch the computer off in critical situations, as is possible on Boeing planes

Pitot tubes sometimes also fail on Boeing aircraft. When SPIEGEL contacted the American Federal Aviation Administration, the body which oversees civilian flight in the US, the FAA confirmed that there had been eight such incidents on a Boeing 777, three on a 767, and one each on a 757 and a Jumbo. Boeing is currently conducting a study on the safety effects of "high-altitude pitot icing on all models in its product line," says FAA spokeswoman Alison Duquette. The FAA did not, however, identify "any safety issues arising" during these incidents.