Pilots?? Quantas says Bluetooth caused plane to dive?

[Z-man]

Originally Posted by Dennis Kalma

The real reason is as stated....too many cell zone changes from fast moving aircraft causes the cell system to go wonky....

Dennis

From what I've heard, it's not the fast moving cell phone, but the fact that up there in the air, a cell phone can connect with so many towers. That's what causes the cell phone systems to flood.

I have an insulin pump - it communicates via RF frequency with my blood glucose meter, as well as my blood glucose sensor I wear on my body. Before getting on a plane, I must disconnect the sensor, but there is no requirement to do anything with my glucose meter. Then again, the radio transmission on all three (meter, pump, sensor) is so little, that I doubt it even has a 10 foot range. Heck, if the sensor is 'around the equator' from my pump (ie: my fat belly is in the way), I get a weak signal reading...

I've seen cell phones accidentally left on, as well as laptop computers with the bluetooth feature left on.

I seriously doubt that any of these devices would cause an electrical glitch on an airplane. You would think that the airplane wireless and RF frequencies are vastly different than those used in consumer goods. Isn't that what the FCC ensures?!?

-Z-man.

[cgarr]

fly-by-wire scares the hell out of me: I want something solid from my hand to the controls.

[competentone]

Originally Posted by cgarr

fly-by-wire scares the hell out of me: I want something solid from my hand to the controls.

Yea, something "solid," like hydraulic fluid!

Why are electrons in a wire some how considered less reliable than molecules in a tube?

[legion]

Originally Posted by onewhippedpuppy

I missed that. I'm an aero engineer, and love new technology. But FBW is a bit scary.

It scares me too.

I'm a computer programmer.

No matter how exhaustive the testing I do, users ALWAYS find a way to get input into a system that I did not anticipate. This is not their fault, and it is not my fault. It's just the nature of the beast that it is impossible to anticipate every single possible thing that can be done.

Guess what? Unexpected inputs result in unexpected results. I've seen everything ranging from a wrong answer, a right answer for the wrong reasons, or a total system crash. Well, all of those things can be very bad when you are in the air and the computer decides to override the pilot.

[cgarr]

Originally Posted by competentone

Yea, something "solid," like hydraulic fluid!

Why are electrons in a wire some how considered less reliable than molecules in a tube?

I was thinking Cables like used in the old B-17's

At least as a backup!

[Hard-Deck]

Originally Posted by competentone

Yea, something "solid," like hydraulic fluid!

Why are electrons in a wire some how considered less reliable than molecules in a tube?

FBW airplanes have redundant hydraulic backup systems.

[jeffgrant]

It appears that the original claim of it being onboard passenger electronics that caused the problem was due to faulty reporting by the "journalist". Qantas said "onboard computer", and the journalist interpreted it as being a passenger computer.

[onewhippedpuppy]

Originally Posted by Snapper33

FBW airplanes have redundant hydraulic backup systems.

Which is not helpful if the computer commands the flight control system incorrectly, only if the primary system fails.

What always worries me, have you ever encountered software that is so well developed that it does not have ANY bugs? Putting total reliance on computers and software with no mechanical link between the pilot and flight controls has never seemed entirely safe to me. Just an opinion of course, we are yet to see an Airbus crash because of the "blue screen of death" popping up on the AFDs.

[dhoward]

Originally Posted by onewhippedpuppy

Which is not helpful if the computer commands the flight control system incorrectly, only if the primary system fails.

What always worries me, have you ever encountered software that is so well developed that it does not have ANY bugs? Putting total reliance on computers and software with no mechanical link between the pilot and flight controls has never seemed entirely safe to me. Just an opinion of course, we are yet to see an Airbus crash because of the "blue screen of death" popping up on the AFDs.

[Z-man]

Originally Posted by onewhippedpuppy

What always worries me, have you ever encountered software that is so well developed that it does not have ANY bugs?

10 PRINT "SEE SPOT RUN"
20 GOTO 10
> run

Anything more complicated than that, and you are bound to have bugs...

I've written quite a bit of code myself (I'm in IT - SAN / Storage admin), and most of the code isn't about interpretting correct data, rather dealing with incorrect data.

Like they say, "Build an idiot proof piece of code, and they'll find a better idiot!"

-Z-man.

[Jim727]

Originally Posted by Snapper33

FBW airplanes have redundant hydraulic backup systems.

Not necessarily.

[Joeaksa]

Our airplanes are hyd controlled but have backup cables "just in case."

I am biased but "if it aint Boeing, I aint going" is what a lot of us feel. That said, I used to fly for Boeing. Boeing never has had a tail fall off of an airplane, yet Airbus states in their flight manual that you cannot use the tail control surfaces to their full limits at times or you might lose part of the tail! This is what happened to the airplane that went down over Long Island right after 9/11.

For me, Airbus is far too electronic and they do not debug their systems enough before putting the plane out into service.

[air-cool-me]

Interesting you chose a fly by wire 777 with blue screens for your Pro Boeing anti FBW rant!
I would be really surprise me if the boeings don't include "no full and abrupt alternating rudder inputs" somewhere.. the kind of loads laterally that would put on a tail would be downright astronomical... Unless there is some FBW code that slows or limits the action of the rudder when commanding a "rudder reversal".

I see Fly By Wire as a two edged sword...

On one end: the Envelope limits\ G-limits ext of the airbus can prevent Mr. pilot from bending or breaking something..

The other end: sometimes you would rather have the flexibility to break those limits.

Here is a great example:
"Airbus' fly-by-wire is that as it is computer controlled, an inbuilt flight envelope protection makes it virtually impossible to exceed certain flight parameters such as G limits and the aircraft's maximum and minimum operating speeds and angle of attack limits."

so you have an upset and end up nose low near the ground... it takes 2.5 G pullout to avoid that building.. the computer limits you to 2.0. ouch... i would rather have the option of risking that extra bit and maybe making it.

Then again.. the AOA vs thrust limit could prevent you from slowing enough to reach that limit. The bank angle limit might prevent you from rolling into the problem.

Whats the answer? I think its Soft limits. make the control column really stiff if you approach the limit.. Its another form of feedback telling the pilot he is doing something unusual.. but if the force jumps 80 pounds ... and both pilots are yanking deep into there layover gut.. ...give it too them... even if it could bend something.

[Hard-Deck]

Originally Posted by Jim727

Not necessarily.

Agreed, accepted. Some have no redundancy I suppose, some have hydraulic, some have cables and pulleys. I'll caveat my answer that I'm biased since I've only flown FBW fighter aircraft, not transport aircraft. In a fighter you always have that backup system called an ejection seat; wouldn't be prudent for an airline crew to eject and leave the passengers.

I guess calculated risk has to be taken; a MOTO opinion.

Back to the Bluetooth/cellphone thing. I strongly oppose that it causes airplanes to fly out of whack.

[competentone]

Originally Posted by Snapper33

In a fighter you always have that backup system called an ejection seat; wouldn't be prudent for an airline crew to eject and leave the passengers.

Maybe there is a good idea there.

What about every passenger on a commercial airline sitting in an ejection seat controlled by the Captain?

[Scuba Steve]

I'd like to control certan passengers ejection seats...

[MFAFF]

Originally Posted by Joeaksa

Our airplanes are hyd controlled but have backup cables "just in case."

I am biased but "if it aint Boeing, I aint going" is what a lot of us feel. That said, I used to fly for Boeing. Boeing never has had a tail fall off of an airplane, yet Airbus states in their flight manual that you cannot use the tail control surfaces to their full limits at times or you might lose part of the tail! This is what happened to the airplane that went down over Long Island right after 9/11.

For me, Airbus is far too electronic and they do not debug their systems enough before putting the plane out into service.

Morning Joe,

I know you are biased...but a couple of questions... the 737 rudder issue.....it might be a hydraulic one but its still a 'bug' that should have been sorted at tad sooner... or the failure mode of the admittedly electronic controller of the 767 thrust reverser...again could it be classed as a 'bug' that should have been ironed out prior to fleet wide use?

Both of those failure modes were as much an inherent part of the Boeing design as the full authority FBW of the Airbus.

Airbuses are far from perfect...and your preference for Boeings is understandable.. but I'd argue that Boeings are no more or less perfect than Airbuses... different for sure and to many its approach to piloting that is not acceptable, but that is a different matter.

[jhynesrockmtn]

Cell phones are not powerful enough to reach a tower at altitudes that commercial aircraft reach.

I worked in a subsidiary of McCaw Cellular that put up the old in flight seatback phone system with GTE as a partner. The network was a separate one that used specially engineered towers and electronics based on cellular technology. The ban on cell phones in planes has nothing to do with the cell companies worried about fast moving phones screwing up their networks.

[flashgordon13]

The French can't build a simple reliable car so why should they be able to build a plane capable of staying airborne? I don't distrust fbw but I have concerns over any technology that the french have their hands in. The airbus fleet seems to have too many bizzare events to just write of as freaks. There seems to be a lack of proper testing common to all airbus designs.

[MFAFF]

Originally Posted by flashgordon13

The French can't build a simple reliable car so why should they be able to build a plane capable of staying airborne? I don't distrust fbw but I have concerns over any technology that the french have their hands in. The airbus fleet seems to have too many bizzare events to just write of as freaks. There seems to be a lack of proper testing common to all airbus designs.

And Americans can build a reliable car? Leave such blatant prejudice somewhere else...

As for bizzare events.. did you consider it bizzare when a very similar incident occured on a B777...or was that some how different?

Or perhaps you have overlooked the other nations who contribute somewhere in the region of 50-70% of content by value to the Airbus fleet...depending on which model...at times shock horror its around 40% US content....French plane....