Breaking MSNBC TV: Don't fly on an Airbus until retrofit is done

[itsrobert]

French Pilot Union urged their members not to fly planes until external speed sensors are replaced. Your life may depend on it.

[no limit]

1. Just a little paranoid with that headline no?

We always freak out when its too late.

[Renew Deal]

2. Blame game

:shrug:

[Occam Bandage]

7. I agree, this looks like a preemptive effort to shift blame for an accident of unknown cause.

Blaming the external speed sensor doesn't make much sense. The only way that could cause a crash is if the pilots accidentally stalled the plane out, but:

1. That's pretty hard to do on a commercial jet that's already achieved cruising speed; they can glide with no power at all for a long time. There's been plenty of instances of widebodied jets gliding for twenty minutes to half an hour before landing safely. You'll lose thirty thousand feet of altitude long before you'll drop below stall speed.

2. The plane was reporting wildly divergent speeds, so the pilots knew there was a problem. Were that the only problem, they could easily make a landing at any airport, or could even continue to their destination without significant problems.

[MicaelS]

13. Makes perfect sense and here is how:

(1) Aircraft is on autopilot at cruising speed, (470 knots at 35,000 ft cruise altitude) http://en.wikipedia.org/wiki/Airbus_A330
(2) Pitot tube ices over
(3) Computer sees a very low speed reading from pitot tube, "thinks" aircraft is stalling.
(4) Computer reacts by applying maximum engine thrust.
(5) Aircraft exceeds VNE (velocity never exceed).
(6) Aircraft suffers structural failure and disintegrates at altitude.

Maximum Cruise Speed is 493 knots at 35,000 ft cruise altitude, only 23 knots delta from cruising speed. I can't find the VNE but at that attitude Mach 1.0 is 573 knots (660 mph), and no current commercial airliner I'm aware of is rated for Mach 1.0+. The Airbus' VNE is probably Mach .95-.97, which means 544-556 knots.

[sharp_stick]

3. Perhaps we could wait and

see what caused the crash first? Thousands of these planes fly daily and this is the first incident in years, and some folks are supposed to toss travel plans based on a union statement?

"Your life may depend on it" is some of the most overblown rhetoric I've seen in.... ah hell I see this crap almost daily now, typical stuff from a cable "news" network, but I did expect it to be up on Faux first.

Meanwhile, lots of these same people rush around in a panic and then drive to the store without a seatbelt, cross a road against the light, yammer mindlessly on a cellphone while eating and driving with their knees and perhaps even step out of the shower onto tile with no bathmat.

Your chances of dying, or even being involved in a serious flight incident are so much lower than thousands of other causes of death that lurk right around every corner you take.

[zipplewrath]

4. NTSB

Probabaly the most telling indication of the hyperbole here is that NTSB or some similar agency isn't the one making the call. You can be sure they already know about these sensors, and if they were worried enough to want to cover their butts, they would. A faulty air speed sensor in and of itself shouldn't be a fatal event. Yes, it can lead to confused pilots, especially distracted by other events. But all indications are that the plane knew there was a data problem on this flight so the pilots should have been aware as well.

[Baby Snooks]

9. NTSB?

They don't have authority over foreign airlines last time I checked.

[zipplewrath]

10. Actually they do

First of all, those aircraft have to be configured to our standards to come here. Second, many foreign countries basically use our regulations as a basis for theirs, some even allowing our certifications to be used. Third, they are aware of the situation and have made decisions about this problem with respect to aircraft that have come here and if they felt there was a problem, they'd announce they weren't allowed to come here until the planes have been modified. The fact that they haven't speaks volumes.

[stray cat]

5. anyone who has tickets concerned enough to lose their money and trip?

[Occam Bandage]

6. This is the first and only hull-loss incident with an A330 that might be blamed on the plane.

We have no idea what went wrong. Maybe the external speed sensor was involved, maybe it wasn't; either way there's no reason that a malfunctioning speed sensor should cause the loss of the plane and everyone on board. Shouldn't we wait for the investigation to figure out what actually happened?

[brendan120678]

8. The only thing that I don't like about the A330...

is that they are now almost exclusively Fly-by-Wire, correct?

I have no problem with F-b-W in general, but there's something comforting about good old-fashioned hydraulics.

[zipplewrath]

11. You made me laugh.

Only because hydraulics are considering is some circles as uncomfortable as you express with FBW. Rutan's place used to refer to them as "hydrastics" and preferred cables and pulleys. That was some time ago, dunno if they still do. IIRC there was a time that hydraulics had cable "backups" for when the hydraulics failed. Once planes got too big to fly that way, it became sorta pointless.

[cboy4]

12. And we all know what happens when you lose your hydraulics.

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

[cherokeeprogressive]

14. They still use hydraulics.

All flight control surfaces such as the ailerons, elevators, and rudder are still hydraulically actuated. The difference today is that the input from the pilot's yoke and rudder pedals is now in the form of electrical impulse, rather than the old style of push-pull where the stick and pedals had a hard connection with the actuators via cables or hollow tubes.

If I could compare today's fly-by-wire system with anything it would be the dimmer switch for the overhead lights in my living room. The harder I press on a rudder pedal, the higher the electrical impulse to the hydraulic rudder actuator. Same as when I turn the dimmer switch to the right, the lights get brighter.