aviation mythbuster

[ArcticHeliPilot]

what's this about not using a cellphone when flying... rotors or stuck-winged. i have not yet heard a single report of airplanes loosing control due to cell phones in the cabin/cockpit.

what i have heard is that airborne cell phones can pick up too many base stations on ground and thus occupying bandwidth (or slots).

any comments or experiences?

[SASless]

Jetrangers and Huey's being such advanced designs with all the modern FBW, FMS, GPS, HUD's and things seem to tolerate the use of cellphones just fine. Pop a cellset adapter into the headset lead and yer off to the races.

In the USA, that is a mortal sin to the FCC however. One must not break the rules, eh!

[Tokunbo]

There were extensive replies on a thread about this just a few weeks ago. There have been instances in the S76 for example of cell phones bringing on false engine fire warnings. Have a look at the recent thread by using 'search' and you'll see all that was said by opponents and proponents.

[johned0]

There was an interesting article in last month's IEEE (US Institue of Electrical and Electronic Engineers) Spectrum magazine that summarized this whole issue. There have been numerous documented cases of auto pilots etc steering planes in completely the wrong direction. In several of these cases, the captain has managed to locate a specific mobile phone that was the cause of the error. Laptops with 802.11 and Bluetooth have also been seen to cause problems.

As part of the research they put some monitoring equipment on domestic US flights and the number of instances of people deliberately using phones was very high and IIRC the summary of the article was that it was only a matter of time . . . .

[Whirlygig]

Try putting a mobile phone next to a radio and/or a computer monitor. Every time the phone does a little search for a cell, your radio will crackle (assuming it's on of course) and your monitor will flicker. It gets worse if there's an incoming call or text.

So interference is real enough. They way it can affect different systems though can be an unknown quantity; it some cases it may, in others it may not. But it's not entirely a myth.

Cheers

Whirls

[Bladecrack]

Have been told by an experienced EC135 HEMS pilot that one day while doing his A check his fone rang while he was bent over an engine, suddenly the igniters went off, even with the aircraft battery switched OFF. Luckily there was no fuel in the engine or he could have got an unexpected sun-tan. It's now company policy to ensure all fones must be switched off in the helicopter at all times.

Regards,

BC.

[Greaney]

Does the Discovery Channel travel beyond the States?

On Episode 49: Cell Phones on Planes of the Mythbusters
they examined this problem.
(http://dsc.discovery.com/fansites/mythbusters/episode/00to49/episode.html)

If I remember correctly, they had a very difficult time
getting any measurable impact on the avionics of both
a mock-up GA and a fairly modern small jet. Since it's
impossible to exhaustively test all possible combinations
of aircraft and cell phones, it appears to be a case of the
FAA being very conservative.

If you are having problems with engine control in an
EC135, why don't you have problems in your BMW?
(Automotive technology more robust than aviation
technology? :))

--Shaun

[wg13_dummy]

If in doubt, there is no doubt surely?

The case for saying 'it's not happened yet' is frankly ludicrous. I thought the aviation business worked along the lines of prevention as opposed to cure. The cure is usually the result of something going very wrong.

Do you really need to use your phone that badly? I thought thats what answer phones and text messaging was for?

Because of the vast array of different avionic systems out there, you can be sure that one of them will get affected by a rogue signal. It just aint worth the risk. Certainly not taking the 'well its never caused a crash before' stance. I'd rather not be the one to make the precedence that proves the point.

[Teefor Gage]

Mobile phones vary the amount of power used to transmit, based on the signal strength in the area in which they are operating. Generally this means the further you are away from the nearest mobile phone mast, the higher the power output of the cellphone in order to keep the contact going.
In the case of a cellphone in an aircraft, the higher you climb the higher the power output of the cellphone until when you have no useful signal from land based aerials the cellphone is blasting away at maximum output and does so frequently as it tries to locate a new connection. It is at this time that the cellphone is the most dangerous when in an aircraft with loads of electronically controlled critical equipment such as FADEC etc.

Recent ideas are to place a mobile phone "mast" inside the aircraft which is connected to a rebroadcaster outside the aircraft. The interior "mast" only needs to transmit a fairly weak signal to facilitate connection with the passengers cellphones which should also only need to transmit a fairly weak signal to maintain communication. Not sure if this has already been put into practise, but it is certainly being thought of. It also means that those annoying ringtones will invade your sleep on long haul flights together with the familiar conversations like "hello mate. I'm on a plane over Paris"

T4

[wg13_dummy]

Trolley dolly's (we can still call them that, right?) should include in the pax brief, 'if you have your mobile phone switched on during the flight, there is a chance you will kill us all, turn the fcukers off, relax and enjoy the peace. The emergency exits are here.......'.

[bfisk]

If I remember correctly, they had a very difficult time
getting any measurable impact on the avionics of both
a mock-up GA and a fairly modern small jet.

AFAIR they did indeed get a huge impact on the VOR reciever on the GSM 900 band?

[Greaney]

bfisk,

Was that with the older VOR they used in the mock-up? Wish I had
recorded that episode. Didn't they have to go to a sig gen with higher
power to get the response?

--Shaun

[ArcticHeliPilot]

i guess i have flown vfr too long to worry about the output burst of a cell phone. i've jumpseated in turboprop aircrafts where the crew sent text messages (and mms messages with pictures of their sleeping captain) to friends on the ground.

but as some of you have mentioned the transmitting power of a laptop's 802.11 is by far not enough to disturb the electronics in an aircraft flying. i can relate to a cell phone might interfer with relays when being very close or next to it. i don't think it would affect high tech electronics. arguing that you can hear static noise or see disturbance on a monitor when the cell phone is sending is not enough to conclude that it will affect systems in the helicopter. cell phones can't be transmitting with many watts, because if so we would get a lead pouch to protect our jewels from radiomagnetic waves when buying one. :ouch:

maybe we should conduct a poll to see how many of you rotorheads turn off your cell phone when flying. :}

/ahp

[B Sousa]

"while doing his A check his fone rang while he was bent over an engine, suddenly the igniters went off, even with the aircraft battery switched OFF."

That one really sounds like a Myth.........

[Thridle Op Des]

The nices story I heard, I know the people involved so it's not apocrophyl (?) is one of my previous airlines A321 coming in to Heathrow with a CAA Flight Ops Inspector on the jumpseat. As the aircraft comes below 6000', Captains mobile aquires a cell and LOUDLY receives a text message.

I am sure many have heard airport transmissions being made where the log-on chirp of a mobile phone can be clearly heard over the broadcast.

There were several alleged incidents of navigation/autopilot degredation, but so far I have not heard of any accident or fatality directly to the presence on an active mobile phone. I stand ready to be corrected.

TOD

[corncrasher]

What about the thousands of people useing cell phones in modern cars that have way more electronic equipment than a lot of aircraft?

[B Sousa]

"What about the thousands of people useing cell phones in modern cars that have way more electronic equipment than a lot of aircraft? "

Just watch them, they are all over the road......Its sort of like sober people making it hard for Drunk Drivers, they screw up the weave pattern.l

[419]

On the 29th April 2004, a Super Puma L2 (helicopter) was returning from offshore. As it was on the approach to it’s destination airport, a passenger used his mobile ‘phone. This resulted in the loss of all flight and navigation information on both pilot’s Integrated Flight Display System screens lasting one second during this critical phase of flight.
The UK Civil Aviation Authority carried out tests on two parked aircraft to find out the potential dangers of mobile ‘phone use. It found evidence that they produced interference levels which could disrupt aircraft systems. Faults attributed to mobile ‘phones include false cockpit warnings, malfunctioning of aircraft systems, interference in pilot’s headsets – all distracting the crew from their primary task.

Copied from a CAA circular sent to helicopter operators based in the UK.

[Whirlygig]

maybe we should conduct a poll to see how many of you rotorheads turn off your cell phone when flying.
Not wishing to sound sanctimonious (although I probably will), I do. It's about the only time my phone gets switched off :}

Cheers

Whirls

[SASless]

Hovering AND talking


Errrrrr....Whirls....are you really switched off while flying?:E

[Grainger]

What about the thousands of people useing cell phones in modern cars that have way more electronic equipment than a lot of aircraft?They're not having to send and receive information vital to the safety of 300 passengers over the RT are they ?

As Whirls has already pointed out, we've all heard the "bup-bup-bup" sound through the radio or computer speakers caused by the mobile phone. Imagine having that going through your ears while you're trying to receive your departure clearance. "Say again ? " :mad:

[Bladecrack]

"while doing his A check his fone rang while he was bent over an engine, suddenly the igniters went off, even with the aircraft battery switched OFF."
That one really sounds like a Myth.........

That was told to me by a senior line pilot at a large UK HEMS company 2 weeks ago, and as I say, based on that incident the Chief Pilot and Chief Engineer changed company policy to all phones OFF onboard!

BTW, its still illegal to have them switched on onboard an aircraft in the UK anyway.

Regards,
BC.

[ec135driver]

Hello again ppruners, once again I find myself the horses mouth re: the mobile phone setting off the igniters.

This is not a crewroom myth "It was me!"

Aircraft concerned was actually an AS355F1, and happened exactly as Bladecrack described. Made me jump to be sure and was repeatable i.e got someone to ring the phone while I stood on the skid step alongside the engine bay - sure enough each time it went off, so did the igniters.

Our company policy has not been shaped by that incident, but by a report (I will find it and post it)

I try never to anger the Gods of aviation by doing anything that MIGHT just be a problem - so it's phones off in my helicopter.

[Grainger]

[rant = on] What I'm still struggling to understand is how anyone can be so addicted to their phone that they can't manage without it for an hour or two ?

What the f*ck is going to happen that can't wait until you're back on the ground ?

All mobile phones have voicemail anyway so switch the bloody thing off, enjoy the flight and pick up any messages when you get back. [rant = off]

[Teefor Gage]

Couldn't agree with you more. How ever did anybody ever survive before mobile phones were invented.
Switch the bloody things off before you start the engines and concentrate on the flight instead..........................

[Whirlygig]

Errrrrr....Whirls....are you really switched off while flying?:E
Absolutely! Prolix im posterio, mens in neutro!!

Cheers

Whirls







Thumb up bum, brain in neutral!

[Grainger]

Whirls, that brings a whole new meaning to "flying by the seat of your pants" !!!

:eek: :eek: :eek:

[John Eacott]

An oft missed, but important, issue is: what type of mobile phone? We all know how irritating a GSM phone can be with the interference it creates on other electrical equipment, but what about CDMA? Little or no interference caused by CDMA handsets, and generically lumped in with GSM as a Bad Thing to have on aircraft, but is it?

We have CDMA car kits in all our helicopters, as do many other operators in Victoria, fed in through the ICS as another radio. Our Department of Sustainability and Environment, who control the fire fighting helicopters here, require CDMA phones to be installed along with HF, trunking radios, et al. Along with superior range and data handling, CDMA (to the best of my knowledge) has no problem interfacing with aircraft, and causes no interference. Maybe the different types of phone systems should be a consideration, and only GSM banned?

[ShyTorque]

John,

I can imagine what an average passenger would say if asked if his phone was GSM or CDMA. He would probably say "I think it's a Nokia, mate!"

A live phone in the baggage bay of our heli puts on the "Aft Bag Smoke" warning caption. It's no myth.

As there is no fire extinguisher system fitted in there, the drill is to land asap, not nice if IMC. We always get pax to turn phones off and explain why.

[ArcticHeliPilot]

Hello again ppruners, once again I find myself the horses mouth re: the mobile phone setting off the igniters.

This is not a crewroom myth "It was me!"

Aircraft concerned was actually an AS355F1, and happened exactly as Bladecrack described. Made me jump to be sure and was repeatable i.e got someone to ring the phone while I stood on the skid step alongside the engine bay - sure enough each time it went off, so did the igniters.

Our company policy has not been shaped by that incident, but by a report (I will find it and post it)

I try never to anger the Gods of aviation by doing anything that MIGHT just be a problem - so it's phones off in my helicopter.

i don't question what happened to you, but i doubt that it had a seriously affect on aviation safety in your company or for that sake in any other company.

i believe this "turn off your equipment containing radio transmitters" is a fashion issue that started a long time ago. the rumour makes you believe that the aircraft will fall from the sky if you text somebody from 30k feet. just as passengers believe the sky is filled with holes which makes the aircraft bounce and turning some stomachs up and down. i guess the most dangerous situation is that the captain insists on answering a phone call when being on short final during bad weather... :oh:

[Staticdroop]

Just out of interest i have flown a HEMS a/c with a fitted mobile phone for the rear seat medic to make and receive calls, all approved by the feds and caused no problems at all. The aircraft in question was a BO 105 so no glass cockpit ot anything fancy.

[B Sousa]

Based on the Pilots statement it did happen. To me that means I would have the factory boys all over that aircraft until my cell phone didnt fire off the engine.....Something not right.

[Phone Wind]

ahp,

The evidence has been presented here that cellphones have caused interference with aircraft electrical equipment, including the post from 419 about the CAA investigation, aircraft igniters and there have been several reports of baggage compartment fire warnings being brought on by them.

So here's a scenario: you're flying VFR in your S76 on an offshore flight, you're 60 miles from the rig and 60 miles from land when suddenly, horror of horrors, the AFT BAG SMOK[COLOR="Black"] warning comes up on the IIDS. Our company emergency checklist says that if the fire is not confirmed we are to land as soon as possible.

We get the passengers to hand over their mobile phones, make sure they're switched off, and they get them back when they arrive at their destination. Why take the chance? As has been said by many posters, are we so pathetic in our desire to stay connected at all times that we can't turn our phones off for a couple of hours? Soon we won't need brains - we'll just hook up our mobiles to what remains of our fried brain cells and someone else will do the thinking for us..............but what about when the network goes down? :E

[Phot]

A mate of mine is a 767 fo and always has his mobile on. I also know that a mobile phone will set of the fire warning system in the back of a J-Model Herc.

[NorthSeaTiger]

Re offshore flights, I always thought that mobiles were prohibited on rigs anyway ? so why not ban them from the flights all together, it's not as if they need them.

[HELOFAN]

Where the hell does all the faith come from?

I am a mechanic & a pilot, and see some things as a mechanic that really makes you wonder some times about how things, there is always a theory about it but when you see something that just shouldnt happen but does .... and does repeatedly & you start to question how much we really know bout simple things like electrickery & magnetism.

Its funny all of a sudden folks are kings of maintenance & know that their ride is electrically impervious to receiving signals from a powerful little radio reciever & transmitter( thats all a cell phone is, though it doesnt really run on numbers, more like radio frequencies ... the phone numbers are just for us silly humans instead of us having to remember these bigger frequency numbers. A cell is not a house phone)

I degress.......

Imagine that, an electrical system is perfect( ho hum righto then ) and cannot be affected by a powerful litte radio tranmitter reciever.
It can give us cancer but not affect a delicate system of electronics.

So what we need is a test pilot that is prepared to fly about whilst a cell phone is placed in his A/C in various locations & whilst he performs his daily duties... unless that is sitting on his butt, the cell(s) transmit & recieve all day.

I bet that may take a few pilots back a step & think it.
Although can you imagine what his stories of affermation would be like if it did bring his ride to an early ending.... " no really my helo did just stop & as the cell rang .....no really then the gyro's went all funny and...... No really"

even if it may not happen, who is seriously going to risk that ?? !!

:}

HF

[kissmysquirrel]

iPods are great aren't they? Well not if you are using one and have your mobile phone near you.
Try this on for size. Pick a nice loud AC/DC track (or similar) on your iPod, and then place the mobile phone near it. Get someone to ring you or move suffuciently for the phone to search out another cell. When the volume jumps to full on your iPod, it doesn't half make you jump. :oh:
I tried this a few times just to see if that was the cause and yes, I can assure all, the phone interferes with the iPod!:eek:



So they must interfere with other stuff.

[ArcticHeliPilot]

phone wind,
i see your point. our 212's have "baggage fire" warnings for smoke warnings and the checklist do say land as soon as possible. good example! :)

/ahp

[212man]

KMS,
don't you find that that listening to the ipod distracts you from the RT?;)

[pants on fire...]

I was recently refuelling my car when my cell phone rang and the car blew up!:eek:

When I worked offshore, I accidently dropped my bic lighter and the rig blew up!:ouch:

The other day when I was flying my Mini 500, the phone rang and the engine quit!:D

etc, etc.....:)

[ArcticHeliPilot]

no wonder, you're from the gutter... :E

[Nipper]

On a particular aircraft that I flew the cellphone would cause a "ghost" aircraft return on the TCAS. Ask the pax to check their phones and the "ghost" aircraft would soon disappear.:=

[gli77]

There is a big difference between an A320 and a 212. The compelxity of the avionics is vastly different. What everyone has neglected to look at is not the avionics but the wiring that connects the avionics. Manufacturers are currently obsessed with HIRF(high intensity radiated field) With the exception of DC power and ground wires pretty much everything else is run through a shielded wire. That means that the odds of a rogue signal being radiated onto the line are low, but still possible. Consider that in an A320 a run may be a 100 feet or so. That is a long way and will have many disconnects. That is a lot of chances for the shield line to break or be in poor condition. A perfect opportunity for someone in seat 13F to radiate his cell's signal into an AFCS line.

The other thing no one has mentioned is that the signals travelling down wires in a modern aircraft are not analog or high voltage. In terms of voltage some signals can be in the millivolts. Sensors can be looking for a slight miliohm change to trigger a caution. Things are sensitive. This is quite advantageous as wire size can now be decreased significantly. Of course it also means that a cell phone signal may wreak havoc under the right circumstances. For those skeptics consider how many times a simple connector removal and cleaning will solve a problem. Why? Simple low level signals - a dirty connection adds resistance where there should be none. The result is erroneous data or no signal at all.

In my career I have seen, heard and experimented with radiated interference. It is quite interesting. I am interested to see how Boeing is going to offer cell and wireless service in the 787. As they say where there is a will there is a way. Unfortunately there is a will which means there will be no where that will be cell phone free.

For the poster who had the igniters go off that sounds like a very interested experience. I have never heard of something that serious. I am guessing the aircraft was FADEC or EEC equipped?

For the poster who thinks there is more electronics in his BMW than an aircraft....Stop posting, unless of course you fly a cub. Even the databus architecture on a regional airliner is amazing, let alone a 777. Your post shows your ignorance of the industry.