There's a reason that the flight attendant warns you to stay in your seat with belt fastened.
The Australian Transport Safety Bureau (ATSB) today said an "irregularity'' in one of the plane's computers caused the dramatic altitude change yesterday that hurled passengers around the cabin.
I would have been all right, because I rarely get up during a flight. I probably would have had to change my undies, though.
But that's also a reason that I'm always a little nervous on Airbuses. When you have a fly-by-wire system, you're essentially putting control of the airplane in the hands (so to speak) of a machine.
Robophobia on Transterrestrial Musings? I am dismayed ... ;^)
Quibble: Boeing also have Fly by Wire (777s) - although there is a significant difference in operation between the Boeing Fly by Wire system and the Airbus "Full Envelope" control system.
I'm usually alright on Airbus aircraft(*), although I'll admit to the same qualms back in the early 90s when I worked in the business and Airbus were suffering a lot of CFTs due to a combination of bad Full Envelope control systems and inadequate pilot experience.
I'm much more nervous on older MD-8x derivatives and older 737s. The only emergency landing I've been in was jammed flaps on an old 737-400 which seems to be a perenial problem for those aircraft(**).
(*) I had a bad experience last year on a 320 leaving Heathrow for Copenhagen in a Thunderstorm which was pretty unpleasant.
(**) At least based on Alaska Airlines statistics from the first half of the year.
I'm not a robophobe. Some of my best friends are robots. I just don't want them flying my airplane. ;-)
Machines are fine. Software developers are what you should fear.
Years back my brother-in-law was a mechanic / inspector on the Airbus A320. I heard lots of horror stories. Good thing they have three flight computers ...
If it aint Boeing, I aint going! Too many problems with scarebuses
How many Boeing aircraft had the tail fall off in flight?
QED no scarebus for me.
If it aint Boeing, I aint going! Too many problems with scarebuses
The reality is Airbuses are pretty safe and, frankly, quieter and more comfortable than a lot of the Boeing stuff out there.
If you want scary aircraft, how about them rear engined Boeing/MD-8X... they scare the hell out of me. 2 down in the last 12 months alone.
How many Boeing aircraft had the tail fall off in flight?
None. Yet. Interested to see how Boeing get on with composite tails myself actually.
How many Airbus have crashed due to jack screw failures or other steering system flaws?
Apart from all the CFTs in the early days Airbus have a pretty good record.
On this subject, you guys aren't curious about flying the A380? I know I am.
More than I'm keen to get on a 787, at least until that thing has spent a lot of time in the air.
you guys aren't curious about flying the A380? I know I am.
Well, me too, but I don't think they'd let me, even if it was empty.
Oh wait...you mean ride in one? Only if it's one of the Emirates Air flying whorehouses upholstered in sea otter fur, with the complimentary in-seat full-body massage and the billiard tables, swimming pool, pistol range, and duty-free shopping on the second deck.
If it's one of the 800-passenger resurrected PeoplExpress cattle cars, I could more easily simulate the experience by going down to the mall megamovieplex to see Batman Flips Out (or whatever) on opening night, standing in line for four hours to get in, buying some soggy popcorn at $1 per gram, and then putting the paper bag over my head and tearing a small hole through which to watch the show, and to get the proper claustrophobic feeling of breathing the fug of my teeming fellow travelers.
On this subject, you guys aren't curious about flying the A380? I know I am.
I have zero, no make that negative interest. I hate jumbos.
Lovely display of rational analysis by the engineers and scientists contributing to the blog! Newspace will go far with these people.
Only if it's one of the Emirates Air flying whorehouses
That does go without saying. Although to be fair, most of the early airlines have some sweet sounding 4 class configurations. I don't think any of them are currently going for the 850 seat variation. BA have certainly found that the margins are in the passengers who sit in front of the wings.
I have zero, no make that negative interest. I hate jumbos.
If I'm spending 8-9 hours plus stuck inside something, that thing, out of preference has to be a Jumbo. I can't stand 777s.
mz wrote:
Lovely display of rational analysis by the engineers and scientists contributing to the blog! Newspace will go far with these people.
Jeff Greason and I are both recovering Electrical Engineers, and we are the two strongest proponants of mechanical, pneumatic, and meat-servo systems. One of the baseline design goals for Lynx is to be able to tolerate a total electrical failure at rotation- the engines should not abruptly die and leave the pilot low on altitude and airspeed. This can be a bit of a pain during design, but pays great dividends during flight test.
Both the EZ-Rocket and the X-racer have fail-consistent engines- whatever they are doing, they'll keep doing. This was tested in the real world on EZ-Rocket flight 11.
Lynx is being designed to be stable at all mach numbers without need for a stability augmentation system, although we may accept rate damping inputs to the RCS. Building a suborbital ship is hard enough, debugging a fly-by-wire system is too much extra work.
Even for orbital systems, it's possible to fly a successful mission manually, as long as the navigation data is presented to the pilot in a useful fashion. The primary mode for an orbiter might be closed loop, but the pilot can and probably will fly the occasional flight manually.
"How many Boeing aircraft had the tail fall off in flight?"
"None. Yet."
Er, really? 1985, Japan Airlines, B747. Lost the vertical stab and wallowed around for half an hour losing hydraulic pressure and control to the remaining surfaces before crashing into Mt Fuji. At the time it was the 2nd worst air disaster ever, after the Canary Islands.
It is interesting though how good Boeings are at keeping flying with major parts missing. As well as the JAL 747 there is the Aloha 737 that lost the entire roof of the cabin and landed safely, and the United 747 that lost a cargo door and a couple of rows of seats en route from Honolulu to Auckland and returned safely. A number of DC10's lost cargo doors and they all went down quickly.
I'm a computer programmer and a pilot (mostly of gliders) and I'm absolutely with Doug Jones and Jeff Greason. I don't want any computer programs between me and the flight surfaces. Or at least not one much longer than twenty lines. In assembler. The computer can give me as much advice as it wants. I'm all in favour of that. The computer is fine -- even better than a pilot -- while you're in the soft middle of the air, but if the meat can't override it and do something completely different then you're going to have periodic problems when you're near the hard edges of the air.
Er, really? 1985, Japan Airlines, B747
To be brutally fair to Boeing that was a botched repair failing rather than a mechanical failure brought on by either a design flaw or poor maintenance. Once they knew what they were looking for it didn't take long to realise that the repair was doomed from the moment they made it.
On the subject of flying with bits ripped off. Did anybody see the footage of the A320 landing at Hamburg in a 100mph cross gust a few months ago (http://www.youtube.com/watch?v=z42fchrzhHY)? The pilot lost it on approach, clipped the wing on the ground, taking a piece out of the wing, but still managed a go around and a safe landing.
Not bad flying and not bad performance from the aircraft in the circumstances. They probably shouldn't have had the airport operating when the winds got up there.
I have a problem with some of this. Anytime an aircraft is flying with the autopilot engaged it is "fly by wire" and autopilot failures have caused upsets.
Disengaging the autopilot is a good solution except that it leaves you with either looking out the windscreen(not good over the middle of the pacific at night in a cirrus layer) or relying on the gyro derived aircraft attitude information which nowadays is likely the same information the autopilot used. It has been a while since mechanical spinning gyros were used in high end civil aircraft. It is all electronics. Having a pilot fly the aircraft really only protects against servo failures. Even there, mechanical/hydraulic systems have had failures(Boeing 737 rudder comes to mind).
I don't want any computer programs between me and the flight surfaces.
Sadly not practical in modern aircraft. I remember going to a talk on the Typhoon fighter where they pointed out that the engines themselves were controlled via negative feedback, essentially they are naturally running at maximum power and the control system powers them back. If there is a flight control system failure there's also a probability of the turbines going with it.
Of course, even without that risk the Typhoon has the flight stability of a brieze block (cinder block for my USian friends).
The kind of fuel economy demanded by airlines leads to the same problem for airliners. I wonder if Boeing will have learned from Airbus's mistakes?
And what does that have to do with the scarebus comments, Doug Jones?
I don't disagree with you. When developing light, cheap or one off planes (long-ez, spaceshipone, lynx) the meat servo systems naturally make most sense.
It's another thing to make five hundred pieces of a hundred million dollar airliner with very high efficiency, operability, ease of use and other demands. Software makes quite a difference there. It's one of the reasons why the airlines buy the planes in the first place. Mojave is full of old airliners.
Boeing has not had many fly by wire planes simply because its designs are older. I guess Paul Breed is not getting on a 777 because it's fly by wire, or a 787 because it's made of composites. Well, it's a free choice.
I'm all for avoiding software where it can be reasonably avoided. For example I'm quite suspicious about electronic voting machines, because a simple good old fashioned alternative exists.
I don't have much bad experiences from flying. Mostly I hate the noise, and your luck with the seat placement affects that the most. Because of that my personal experience from an A330 was more noisy than a B767. I don't much care of the electronic gadgets embedded in the back of the seats.
"If you want scary aircraft, how about them rear engined Boeing/MD-8X... they scare the hell out of me. 2 down in the last 12 months alone.
How many Airbus have crashed due to jack screw failures or other steering system flaws?"
Oh please...those are MD models; Boeing gets blame only through guilt by association.
If you really want to spank Boeing, there's that little issue they had with rudder throw on the 737 "classic" at PIT and DEN.
Daveon:
>> I don't want any computer programs between me and the flight surfaces.
>
> Sadly not practical in modern aircraft. I remember going to a talk on
> the Typhoon fighter
Fighters are a very special case. Not only are they expendable, it is worth making them uncontrollable in the (to be fair quite rare) event of a computer glitch if that gives them an advantage that help prevent them getting shot down the rest of the time.
Mike Borgelt:
> Having a pilot fly the aircraft really only protects against servo failures.
You're thinking about cruising flight in the soft middle of the air. By all means use an autopilot (that you can disconnect) then.
Having a pilot fly the aircraft gives you the option to exceed the normal flight envelope when the alternative is worse -- when someone drives onto the runway, when you suddenly encounter cumulo-granite. Auto-pilots and fly by wire systems also aren't in general very good at learning to fly an aircraft whose flight characteristics have unexpectedly changed because bits have fallen off or stopped working.
It's just really hard to make an automated system that can have sufficient sensors and pattern recognition to see all of the big picture of the situation, and really hard for the programmers to foresee every possible situation that the pilot and aircraft might one day find themselves in, find a workable solution (in a general enough way to be useful), and program and test the appropriate action.