[@Ladislaz]

@Ladislaz asked the Naked Scientists:
   
Does an aeroplane with frequent flyers aboard have a higher probability of crashing than one with no frequent flyers?

What do you think?

[CliffordK]

It certainly would not make a difference whether the person sitting next to you has a frequent flyer ticket.

However, it does make a difference from one airline to another.

Does Cubana Airlines or Air Zimbabwe have frequent flyer miles?
http://www.airdisaster.com/statistics/

Some of the airlines in the USA like Southwest & Jet Blue have had extremely good crash statistics. 

http://www.planecrashinfo.com/noaccident.htm

It is possible that the budget airlines concentrate on filling seats and providing a good product rather than shaving quality.

One of the disturbing things that has been happening recently is the drive to export maintenance.  So far I don't think there have been any major repercussions, but perhaps that is a disaster waiting to happen.

[Geezer]

Ah! I see your logic, but it doesn't really work that way. Unless frequent flyers were in the habit of doing The Conga up and down the aisles in aeroplanes, it's hard to see how they might have any effect on an aircraft's ability to stay in the air.

Mind you, I suppose if they all started using their laptops and Blackberries, although it's highly unlikely, they might produce enough electromagnetic interference to upset some part of the avionics. 

[SeanB]

More a function of airline policy towards maintenance, and to pilot training and pressure to be "dead on time" than to passenger makeup.

[Geezer]

On the other hand .........

http://news.yahoo.com/s/time/20110611/us_time/httpnewsfeedtimecom20110610reportevidencemountsthatelectronicinterferencemayaffectairplanesafetyxidrssfullnationyahoo

[CliffordK]

Quite some unique comments on that instrument interference article.

I am just surprised that the planes aren't better insulated against interference.  I suppose any wire, and perhaps even the airplane fuselage can act as an antenna and generate tiny amounts of electrical current.  But, in the case that it is part of a sensitive critical instrument, then they should use shielded wires.  A fuel gauge should use a range of inputs so that any minor perturbations would be lost in the noise.

There are some 30+ yr old planes still in the air.  But, cell phones have been around for over 20 years, and the potential problems should have long since been fixed on the majority of the planes in the air.

The new planes should be built to endure modern technology.  If you happen to get a flight on a 30 yr old plane that has issues with interference, then shut off the electronics for only those flights.

Why not add a cell phone relay and WIFI into the airline systems and a 12V or 110V outlet (except then they wouldn't be able to charge $10 per minute to use the sky phones which I have never seen anybody actually use).

[Geezer]

It's really quite difficult to make electronic devices totally immune to interference across the entire spectrum of frequencies, and combinations of frequencies. It can be a lot more complicated than just adding a bit of shielding.

[Geezer]

On reflection, considering how dependent modern aircraft are on electronic systems to make them as safe as possible, I think the FAA should allow airlines to use RF sniffers to weed out any unauthorized radio transmissions.

The guy in the seat next to me might think he's being really clever because he is keeping his Blackberry on. What he may not realize is that he is rolling the dice with the lives of everyone on the aircraft.

The airline industry has an incredibly good safety record, but let's not take any of it for granted. It depends on an incredibly large number of things working just right. When you introduce an unknown into a system of this complexity, you better believe that very bad things can happen. 

[Geezer]

My inital reaction to the original question was "no", but I'm beginning to think it should have been a "yes", so I thought it might be more appropriate for the Technology forum.

[Madidus_Scientia]

No, I think that's a variation on the gamblers fallacy en.m.wikipedia.org/wiki/Gambler's_fallacy

[Geezer]

No, I think that's a variation on the gamblers fallacy en.m.wikipedia.org/wiki/Gambler's_fallacy

It's not. Unless they are cheating, gamblers can't influence an outcome. Those who turn on a cell phone in an aircraft, whether they like it or not, are absolutely influencing an outcome.

[CliffordK]

When I look at the Yahoo Article above:

autopilot, autothrust and landing gear were disturbed, while 13 of the incidents produced electronic warnings, including "engine indications."
[...]
"Auto pilot was engaged." At about 4500 ft, the autopilot disengaged by itself and the associated warnings/indications came on.
[...]
Other descriptions detail how "a clock spun backwards and a GPS in the cabin read incorrectly while two laptops were being used nearby." And another flight altitude control readings increased rapidly.

I certainly am aware that if you sit a cell phone next to a radio, it may disrupt the reception.  Likewise, sitting it on top of a CRT can disrupt the CRT. 

However, if I went out and bought a $50,000 car, and the radio skipped every time my cell phone synched with a new cell tower, I'd be upset.  If the "check engine" light came on with every call, I'd be upset.  And if the GPS jumped to Timbuktu every time a someone activated their ipod...  I'd throw it away.

If I bought a new $300,000,000 airplane, and the check engine light came on every time a cell phone call was made, I'd be worried.

There is nothing in the landing gear that should be sensitive enough to the minuscule currents generated by a cell phone. 

If the antennas are a problem, mount the primary antennas in the winglets, and a secondary antenna near the cockpit.  Likewise, primary altimeters or other sensors reading subtle atmospheric difference should be able to be isolated from the passenger compartment, and likely from the crew too.

In the comments to the Yahoo article, it mentioned that if a cell phone is so disruptive to our aircraft, wouldn't one expect the next terror attacks to be simple cell phones/radio transmitters smuggled into a dozen airplanes scheduled to land at JFK at the same time?

[Geezer]

Clifford,

You might be quite right to get upset if your car conked out due to RFI. If the aeroplane in which you were flying conked out due to RFI, your upset might only be temporary.

Under what circumstances is it acceptable for one passenger to deliberately do anything that increases the risk of a catastrophic failure that might kill all of his, or her, fellow passengers?

[graham.d]

The chances of a mobile phone disrupting a modern aircraft systems is very small but I would not like to guarantee that and I certainly would not like to say that many mobile phones being operated would not cause problems so I completely agree with Geezer. The design of aircraft systems takes quite a while and all these systems are quite thoroughly checked during the design and approval phase. New mobile phones with different designed wireless sections (even if to the same spec) are produced rather regularly. They have quite sufficient power output to disrupt electronic equipment, as has been mentioned, and some systems will output on full power if the received signal is weak (which it probably would be on an aircraft). Some aircraft are now approved for use of mobile phones but airlines have been slow to permit use just the same. I don't blame them because the place they would all get used is on final approach and landing which is probably the riskiest time to have any problem with an aircraft system. As this is probably not a wholly black and white issue, I would err on the safe side.

[Madidus_Scientia]

No, I think that's a variation on the gamblers fallacy en.m.wikipedia.org/wiki/Gambler's_fallacy

It's not. Unless they are cheating, gamblers can't influence an outcome. Those who turn on a cell phone in an aircraft, whether they like it or not, are absolutely influencing an outcome.

I meant all other things equal, without making the assumptions that frequent flyers are more likely to use electronic devices, and that electronic devices could cause the plane to crash.

Maybe we should turn off all the electronic devices in the cockpit so that they don't interfere with themselves, especially the radio.

It must be hard for people with pacemakers to get around avoiding everyone who has a mobile phone so that it doesn't kill them.

I wonder how many terrorists have tried and failed to crash a plane by leaving their phone on.

Clifford,

You might be quite right to get upset if your car conked out due to RFI. If the aeroplane in which you were flying conked out due to RFI, your upset might only be temporary.

Under what circumstances is it acceptable for one passenger to deliberately do anything that increases the risk of a catastrophic failure that might kill all of his, or her, fellow passengers?

Yeah, we should ask passengers if they've seen a black cat or walked under a ladder recently before they board as well.

[Geezer]

No, I think that's a variation on the gamblers fallacy en.m.wikipedia.org/wiki/Gambler's_fallacy

It's not. Unless they are cheating, gamblers can't influence an outcome. Those who turn on a cell phone in an aircraft, whether they like it or not, are absolutely influencing an outcome.

I meant all other things equal, without making the assumptions that frequent flyers are more likely to use electronic devices, and that electronic devices could cause the plane to crash.

Maybe we should turn off all the electronic devices in the cockpit so that they don't interfere with themselves, especially the radio.

It must be hard for people with pacemakers to get around avoiding everyone who has a mobile phone so that it doesn't kill them.

I wonder how many terrorists have tried and failed to crash a plane by leaving their phone on.

Clifford,

You might be quite right to get upset if your car conked out due to RFI. If the aeroplane in which you were flying conked out due to RFI, your upset might only be temporary.

Under what circumstances is it acceptable for one passenger to deliberately do anything that increases the risk of a catastrophic failure that might kill all of his, or her, fellow passengers?

Yeah, we should ask passengers if they've seen a black cat or walked under a ladder recently before they board as well.

Sounds like you must know a lot about avionics Madidus.

[CliffordK]

I think the regulations, at least in the USA are FCC regulations and not individual airline regulations.  A few years ago it was made legal to use the cell phones on the tarmac after the plane has landed.  Personally I do like a little quiet, so I don't really want to be stuck in a middle seat between two people chatting on their cell phones for the whole flight.

I agree.
Better safe than sorry.

But, I would also anticipate more of an effort to incorporate modern technology.  For example making an airplane fully wired for computers, power, phones, and the internet. 

As an aside.
A few years ago when the Centrino processor was released, Dell, HP, and a number of other companies were essentially giving away 802.11 WIFI cards for FREE.
My company absolutely refused to include the cards in new systems.
Within a year, almost every hotel, motel, and coffee shop was offering free WIFI.
You can't imagine the number of WIFI cards I bought and installed at about $100 each.

Airplanes last for a good 20 years...  some of the for over 50 years.

In an ideal world, one would at least strive to keep up with modern technology, if not trying to keep ahead of the curve.

I suppose the risk is that if half the planes are rated for unlimited electronics, and some are not.  And flight crews periodically change planes.  They would have to be aware of what type of plane they are on, where the exits are, and usage restrictions for electronics (which would be stickered all over the plane anyway).

[Geezer]

I used to have to do a lot of business travel, which rapidly became a major pain in the neck, but the one aspect of it that I actually enjoyed was the fact that nobody could communicate with me while I was in the air! It was about the only place on the planet that I could be in where I was not expected to reply to EXPLETIVE e-mails and voice- mails in less than fifteen minutes.

So, I do tend to be slightly biased against anything that might improve "in-flight" communications.

However, I don't suppose I can stand in the way of "progress", so, if people really want to be wired on aircraft, I would like to see the development of a standard IR interface, or a very specific low energy RF interface that can be used for that purpose. For all I know, there may actually be something like that in the works.

If such a thing existed it would give the airlines the opportunity to be much more stringent with people who think the FAA (and similar organizations) doesn't know what it's talking about and it's OK to gamble with other people's lives.

[graham.d]

A few airlines have taken a sensible look at mobile comms for aircraft and provided a fully incorporated satellite comms system. This has the advantage of actually working (try using your cell phone half way across the Atlantic). Of course there is a charge for using this but for those people who really need to be in touch it is a safe and secure system. Anyway the cost is lost in the noise when undertaking air travel.

I agree with Geezer about having a space free from people on cell phones and being out-of-contact for a while. I was on some flights this weekend and found it slightly annoying, allbeit probably irrationally, that there was a cacophony of cellphone noises as soon as the planes touched down; I doubt it would have mattered at all to anyone to have to wait until they had disembarked.

[Don_1]

No, I can't see the logic in this question. The frequency, or otherwise, of the individual travellers will not have any effect on the plane.