Qantas jet's plunge

[glenc (Glen)]

'Cosmic rays' may have caused Qantas jet's plunge.
http://www.smh.com.au/travel/travel-...1118-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 (Vaclav)]

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

[erick (Eric)]

Drive by wire cannot be too far away now

[leinad (Dan)]

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

[Jen]

[michaellxv (Michael)]

Originally Posted by erick

Drive by wire cannot be too far away now

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 (Vaclav)]

Originally Posted by erick

Drive by wire cannot be too far away now

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

[koputai (Jason)]

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 (Vaclav)]

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]

Originally Posted by 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

Why do you say that?

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

[multiweb (Marc)]

Originally Posted by 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.

Russians have always been very resourceful in any field, mainly due to recent budgeting issues I reckon. 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?

[Baron von Richthofen (Vaclav)]

Originally Posted by Peter Ward

Why do you say that?

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

The ones I am talking about never got of the ground

[stephenb (Stephen)]

Originally Posted by 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.

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 (Mark)]

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]

Originally Posted by Nesti

...

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

Cheers
Mark

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 (Phil)]

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 (Andrew)]

Personally I think that cosmic rays are a plausible diagnosis.

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

[seanliddelow (Sean)]

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.