View Full Version : Mobile Phone ringing on Take Off

18th Oct 2001, 16:38
I am flying a PA32-300 in Saipan.
Everyflight we have to make a briefing to passenger such as Seat belt,No smoking, emergemcy exit and "No Electronic Device".

But funny things here they seems to be never understand English or can't hear.

Few days ago :
1 passenger on my flight and I am taxi out and receive TO Clearance from ATC. On the tak-off roll that passenger phone is ringing. So I idle my engine and stop my aircraft and wait for her on the runway. An ask her to turn off the bloody phone. But my flight towards to dest. After touch down not more than 30 sec, that pax take the phone out and make a call.

Any good idea that I can deal with those passenger???????????????????

Please give me an idea :mad: :mad:

18th Oct 2001, 16:50

When the phone rings on the ground, do as you did, stop.

In the air, when it rings (a PA32 I assume!) just roll on 90 degrees of bank and pull the power back - nose falls, recover from the dive.

Then turn around and say - "please turn your phones off - it interferes with the electrical systems - as I told you prior to take off".

That'll do it. Peaceful flying from then on!

DHC Twin
18th Oct 2001, 17:05
Or..Shoot them.

EI - E I - O
18th Oct 2001, 17:41
I like the roll and dive option!

Tell them it costs $20 a minute to use a phone in the air, as the signal they are picking up is been transmitted via your airframe, which the Airline charges to the telephone company and they in return charge the mobile user. If it doesnt stop them, it will certainly reduce their usage!

19th Oct 2001, 01:26
BIK, early cellular phones did have a tendency to cause electro magnetic interference with AM radio signals, but nowadays with the digital networks and closer monitoring of radio telephone frequencies it isn't much of a problem.
I suppose if the Pilot in question were navigating with his ADF and the pax were to be using an early analog phone there may be troubles. I think the regulations haven't changed because nobody has seen fit to do the research necessary to determine how much interference handheld electronic devices can cause with basic VHF/UHF equipment. Not to mention the fly by wire, and auto pilot/throttle systems on so many aircraft in use these days ( I see you mentioned that at the end of your post ). :)

19th Oct 2001, 02:52
The real restrictions on the use of mobile phones while flying has to do with the interference to the mobile phone network by transmissions from altitude. Some antennas are directional and would not receive the signal correctly. Signals can be received by two or more stations at once and that also confuses the system. In the worst case it can close down the entire cellphone network, although that is unlikely now. In the US it was made illegal to use a cellphone on an airplane only to protect the network.
It is incidental that some airplane systems are affected, although to an airplane driver it might be more important.

controller friendly
19th Oct 2001, 02:59
I know someone who crossed the Atlantic 2 days after America reopened their airspace.
At check-in,when everyone was being very cautious,they were not allowed to take their original hand luggage on board.In the rush to pack everything away into the hold luggage, the mobile phone was quite simply forgotten about.It therefore remained on for the entire 10 hours 45 minutes of the flight. As the peson made it back to the U.K. to recount the story,what is the problem? :rolleyes:

19th Oct 2001, 03:07
I figure that if the CAA and the FAA can conduct studies into this (and they do) and from those make it a requirement that mobiles are switched off during the flight then that is a good enough reason in my book!

And anyway, flying is the only time when you can get away from the bloody things! "HI. I'M IN THE PLANE. HOLD ON WE'RE JUST GOING THROUGH A THUNDERSTORM! I SA.. W..'RE.. J.S. GOI.. TH..UG. A.. brrrrrrrrrrrrrr"

Bad news is that BAe Systems are developing a system whereby an airliner will have an aerial system in the cabin and you'll all be able to use your own mobiles on a "roaming" agreement with the provider. I can't think of anything worse than sitting next to someone on the phone for the entire flight - it's bad enough you have to share one armrest and (well, practically) one seat - never mind a conversation too!

19th Oct 2001, 03:28
Grab it and drop in the nearest Vodka-Tonic or beer...that should do it! Oooops, sorry old chap, it slipped.. :rolleyes:

19th Oct 2001, 10:16
Wouldn't it just be simpler to fit a jamming system like they now do in some restaurants so that the bloody things don't work. ;)

Mind you, The unfortunate pax on board the ac on Sept 11th did manage to furnish some usefull info with them. And possibly helped to stop the fourth one from crashing into a building :(

19th Oct 2001, 10:42
One of the problems with the use of mobile phones within aircraft occurs when the handset is first switched on. The phone sends a ident message on maximum power. Agreed, maximum power does not amount to more than about 2 watts but the potential for interference to aircraft systems is always there. Particularly if the handset is not functioning correctly.

Under normal circumstances (for example on the ground) the local cells which are in range will then send acknowledgements. Handshaking takes place to establish the nearest cell and the minimum amount of power necessary for communication.

If a jamming system is installed in an aircraft it would have to not only jam signals, but also prevent the handset from sending these high powered data pulses.

19th Oct 2001, 10:49
By providing a pseudo-cell inside an aircraft, a digital mobile phone would recognise the presence of a strong local signal and would, as a consequence, turn down its RF power to a minimum thus reducing the chance of RF interference with poorly protected aircraft electronic systems. The 'aircraft cell' could be set to allow phones to be used on the ground, but block them prior to engine start. That would require the airtime service providers to enable 'roaming' on an 'aircraft cell'; such cells should have a sufficiently high calling tarriff to dissuade on-aircraft usage. But although this might be suitable for GSM, the chaotic 'Tower of Babel' system in the USA with its multiplicity of systems and operating modes would be more difficult to cater for.

19th Oct 2001, 13:36
BEagle makes a good point...

But does it not occur to anyone that these 'poorly protected' aircraft systems OUGHT to be protected anyway.....??

Suppose the Terrorists got hold of a Jammer and used it near an airport....... :eek: :eek:

Red Snake
19th Oct 2001, 15:20
The possibility of one or two phones interfering with anything on the plane is very small, but if it were to be allowed, the prospect of tens or hundreds of phones all with their 2 watts in use on one aircraft really could create havoc. And who hasen't heard that bip-diddy-bip diddy-bip over the com or nav at some time or other by some GSM phone left on, inadvertently or otherwise? It even interferes with my car radio if leave the phone on the dashboard.

19th Oct 2001, 15:23
I have to agree that it is extremely annoying when a mobile goes off on Rotate - I just never know whether it's mine or a pax's....

19th Oct 2001, 15:40
Let he who is without sin etc.Who hasn't forgotten to switch off their own or the company phone at some time?.My safety brief often includes"Up to 80kts we will stop for any warning,caution or phone call.After 80kts we will only stop for fire,failure or a phone call from the DFO "

19th Oct 2001, 15:43
According to the article some time back in the IEEE Spectrum magazine, one problem is that although the cabling and so on is adequate for protection of aircraft systems when new, it doesn't always maintain that integrity.

Because of the large number of different designs of 'phone, it's also hard to tell whether or not the spurious emissions will cause trouble - even though they are low eneough to meet the specifciations, they could still cause trouble if they were on certain frequencies.

You don't need to think about jammers causing trouble. How about airfield radars - like that big one at LHR? That's more than 2 watts - nearer 2 gigawatts effective radiated power.

19th Oct 2001, 16:15
A couple of weeks back while on a training exercise in my 2-seat thing with a fan on the front, my instructor had his cellphone sat on top of the instrument housing.

While practicing tracking a course I heard a loud buzzing through the I/C and saw a deflection on the magnetic compass or 6 or 7 degrees and the GPS display became distorted. Not two or three seconds later the phone beeped with the tell tale sign of a text message then everything returned to normal. I believe the phone was polled by the ground station and in response belted out a high power Tx that caused the problems.

Of course I can't speak on behalf of you parrafin powered boys, but my cellphone is going to stay switched off as soon as I walk out onto the apron. It's not worth risking anything else as far as I'm concerned.


19th Oct 2001, 16:29
How did everyone communicate 10 years ago before the widespread use of these cell phones?

19th Oct 2001, 18:41
Right now the safest place to stand with you guys is on the bomb target at the bombing range! You’re missing the point arguing about the finer points of whether a cell phone will interfere with the aircraft navigation system or electrical system. The point is the CAPTAIN INSTRUCTED THE PASSENGER TO TURN OFF THE CELL PHONE! PERIOD! Who are you going to allow to be in charge of YOUR aircraft? You the Captain or the passengers? An airplane moving across the ground at 3 to 8 miles a minute is no place to have a IEEE committee meeting!

20th Oct 2001, 11:22
AAL, go back and check the fourth post in this string and you'll understand why we are discussing the effects mobile phones may have on an aircraft, yes we may have steered the string in a little different direction than it was going but I don't think any of us are saying it's ok to ignore the crew or their briefing. :)

20th Oct 2001, 12:08
An interesting discusion, chaps, but I'm a little concerned that most people appear to have missed the humour behind the "roll and dive" posting. Particularly those who wanted to know which systems in a Pa32 would be effected.
As to the origional question:
Roll and dive might be very satisfying, but would probably get you fired.
There seems to be a language problem with your pax. You might try collecting all the mobiles before they board, and return them as they get off, but run that one past your Chief Pilot first. :cool:

20th Oct 2001, 13:44
Up to now, everything in the avion industry has to be certified free from interference with other onboard systems : it includes avionics from the flight decks, flight controls systems, engine control systems, also in the military all the warheads with various internal seekers and propellors (which are not only for jet fighters but also for big stuff like Nimrod, Orions, Atlantic..) Believe me, it's a long process, very expensive but also quite reliable (what do you think people do for years in the various government or industry test centers?)
So after certification things are rather safe (or one could contempt certification, to replace it with what?)
And even with that, given the life-span of the aircraft of systems, funny things could occur, which are/could be explained (but once again, in aerospace science, you need to be sure that the same causes will entail the same effects, so who is going to pay for the test program?)
Some funny things I heard about in my little career:
Old Jaguar fighters in the 80 shivering when flying close to VLF antennas (the one wich are 1000 ft high, to communicate with submarines)
A safety bolt from the rescue winch of a Lynx helicopter being (allegedly?)triggered (oops..) by a powerful radar system of a new frigate
So coming back to onboard cell phones, with all their different and changing characteristics, to obtain certification with somebody (a/c manufacturer? phone company?)signing (and paying for it) for it... good luck !!

20th Oct 2001, 13:56
Indeed. Poor HF feeder insulation caused RF breakthrough which was picked up by the yaw damper wiring, fed to the rudders and consequently fed back to the rudder pedals of a VC10 I once flew. Weird to find your feet being shqken in direct proprtion to SSB modulation depth!!

And as for the Tornados that could only take-off from one end of a runway as otherwise they'd get too close to the Radio Free Europe propaganda aerial in Germany.....

I'm sure that an antique 'Prinztronic Micro' (cost 49 guineas in 1972) electronic calculator of mine would have far greater effects on aircraft electronics than my cellphone - it uses 0.5W of power and totally jams MF/LF signals if switched on near a normal domestic radio receiver!

3rd Nov 2001, 16:55
That Pax again on my plane last week.
This time she did not use on Take off and use after landing.

I will call Airport Police next time to Kick her....... :mad: :mad: :mad:

3rd Nov 2001, 22:41
[Lack of] electronic interference notwithstanding, it appears that ACTUAL interference with the Captain's duties is a REAL issue in PA-32's airplane (and any other small airplane where the pax are not separated from the Captain). The noise distracted him from his duties at a critical time -- during the takeoff roll. It was enough of a distraction to cause him to take action. It could have distracted him from a warning light or other sign of malfunction, or caused him to miss an ATC transmission.

If I were PA-32, I would have taxied back to the ramp and unloaded that passenger. She IN FACT caused a significant distraction that had an adverse safety impact. That may be the ONLY way to get the message through her thick skull! :mad:

Epsom Hold 2
5th Nov 2001, 00:14
If a pax is using the batphone before departure, can it be confiscated permanently? That would be great fun.

Know a BA captain (734) who sometimes calls his wife on the batphone from the taxiway to tell her to look out for him if he's taking off in a certain direction and will be over their house in a few minutes. Class!

cosmo kramer
5th Nov 2001, 00:22
PA32-300, if it distract you that much that a phone rings, perhaps you should consider staying on the ground. Perhaps you should just be happy that anyone cares to fly in your PA32.

Anyway what is the rumours or news in this topic? :rolleyes:

Di - Hedral
5th Nov 2001, 05:23
Cosmo perhaps the news is: raising the awareness of pax (& poss pilots) to the potential problems caused by cellphones and other electronic equipment. Maybe some people will start to realise that the briefing is not just given because the pilot likes to exert their authority and has nothing better to do.
:mad: :rolleyes:

BIK it looks like you have ample explanations as to why PA32 is entitled to brief this, even though it 'aint no airbus'. It isn't just the old analogue phones that interfere, but the digital ones too. OK, maybe the interference is only a noise over the radio, but as already pointed out this could lead to the potential problem of missing an important R/T instruction. :eek:

PA32, as for this annoying pax. It sounds like the only solution is to confiscate the phone until the end of the flight. I sympathise with your problem. I usually find that most people turn their phones off whilst I tell them to do it and at the same time, show them that I am turning my phone off too. This also stops me from forgetting to do just that! Yes, we all make mistakes :o
Unfortunately one pax had the same idea as her and decided, in their infinite wisdom, to turn the phone back on as we landed. This resulted in R/T interference, a missed taxi instruction at a fairly major/busy airport and caused a delay of approx 7mins, while I was forced to hold my position :mad:
On disembarkation I apologised about the delay, giving a full explanation as to why.
I can assure you, this pax was suitably embarrassed and did not do it again. Good, lesson learned then ;)

Gunner B12
5th Nov 2001, 09:14
First post but this topic is right up my street. The national telephone company is Australia wont allow mobiles to be switched on in their call centres as headset users have actually lost eardrums and had permanent damage to their sense of balance due to high pitched tones from the network. These tones are possibly generated by interference from mobiles and if you are in an industry which wears headphones (as you are) you should be very wary of people using mobiles in your vicinity. Imagine spending all the money and time achieving your enviable career only to have it destroyed by someones mobile phone screwing up your sense of balance. It can happen one of my colleagues has to walk up six flights of steps every day because she can't even stand riding in a lift and actually has to be sedated to go on holiday in a plane. :(

Edited for spelling mistakes

[ 05 November 2001: Message edited by: gunner b 1 2 ]

5th Nov 2001, 14:24
Recceguy, you've got it spot on! Same problem regaridng approval exists incidentally with mobile radios and vehicles under the EU Automotive Directive. Interesting problem for emergency services......

However, there's a two year old CAA report on the subject:

FWIW, my opinion is that right now, the only electronics that are useable by passengers at all times are pacemakers and hearing aids.
Anything else should be only used at the Captain's discretion. In the longer term, all the aircraft equipment should be suitably hardened - especially with stories like BEagles!

5th Nov 2001, 15:00
Isn't the PA32 one of the more popular aircraft for parachute dropping?
If it happens again, merely push the passenger out of the big door at the back..... :D :D :D

Elliot Moose
5th Nov 2001, 22:30
An interesting one is that certain cell phones can (and do)set off the cargo smoke detectors in RJ's. Apparently an incoming call to a phone in the last several rows of an RJ will do this. I have heard of more than one instance of the bottles being blown (sorry about your puppy in the cargo hold there Johnny) and the aircraft being evacuated after cargo smoke indications for this very reason.

7th Nov 2001, 04:08
An electronics engineer I am not. A B767 Captain I am. Despite the passengers being briefed in the terminal before boarding the aircraft and then again on the aircraft before takeoff, we still have the problem of passengers using their mobile phones when in the aircraft.


Why ?

Some of you may have been using a 'normal' (landline) phone when someone close by has switched on their mobile. You will have heard the "click click click click" through your landline phone earpiece.

I have had several occasions now when this "click click....." has blocked out R/T comms.
The last time was in Dubai a few weeks ago. We had just landed and had switched to Ground 118.35 Our taxi instructions were;
"XXX123 turn right onto click click click click click"
Fortunately we were on the ground that time.

Now lets change the time and place to (say) London Heathrow, early morning (busy time), Low Vis (Cat 3B) proceedures, you are on short finals, cleared to land.
Surface Movement Radar now detects a ground vehicle entering the runway (it is heavy fog after all). The A.T.C. immediately transmits a Go Around instruction.

What you hear is;
"XX 123 click click click click click"

RVR is 75m. Touchdown speed is 135 Kts.

Maybe you will be lucky.
Maybe you will be dead.

Small single engine piston, or multi engine wide body jet. What's the difference ? Dead is dead.

You can now go into the realm of a passenger deliberately and willfully disobeying an aircraft commanders lawful instruction regarding safety of flight if you want to. I remember earlier this year a Saudi Arabian newspaper reporting a major in the Saudi Armed Forces being sentenced to a flogging of 70 lashes for refusing to switch off his mobile during an internal flight in Saudi. I think a video of such a flogging should be played in all transit lounges. I'm sure a good flogging along with a message like "You too can have your back mutilated, just use your mobile in flight" would have a remarkable effect on those people who absolutely must use their mobiles on board.

P.S. I'm not really a miserable grouch, I just don't like people trying to kill me.

7th Nov 2001, 04:24
Always on flights around the gulf you see people using mobiles on take off and landing.
cabin crews requests to switch off are usually ignored. You see the look of arrogance on the man's face when being told this by a young woman.
If mobiles are this dangerous why are they not put in the same class as knives and taken away prior to boarding and collected after landing. Surely flight safety is paramount.

7th Nov 2001, 14:01
For all of You who think that mobile phones won't do any harm:

I had a flight on an A320 from Moscow to Vienna a few years ago enrouete at FL 350 when suddenly the Primary Flight Display got weird, switching from Flight to "Specific Ground Indications" showing max sidestick deflections and back every second; after half a minute or so we got an additional ECAM warning about an EIU fault, with maybe Reverser deployment inflight.
At this time I made an immediate announcment requesting ALL electronic equipment to be turned off immediately. After 10 seconds all was fine again.

Even if Mr. Niki Lauda publicly announced that there can't be any influence by phones becaues he left two of them on in the cockpit (during landing !!!!), he doesn't convince me. Especially if You know that he has a contract with a mobile phone network that pays him US$ 290,000.- per year for ads.

7th Nov 2001, 15:39
maxmobil, i agree there is a good reason to be concerned, it just frustrates me to see these d---heads who still insist on using mobiles on aircraft, surely they can be classed as a dangerous implement and taken off passengers prior to boarding.

7th Nov 2001, 16:41
As stated in previous posts it’s not only the pax who are guilty. I phoned a friends mobile a few months ago to get to hear.. “Err Can I phone you back in a couple of mins, just turning on to the localiser at xxx” Apart from the interference, & legal implications with Single pilot ops (as in this case) the distraction factor has got to be a major issue. When we spoke later he jovially admitted he never turned it off in flight. I shall be forwarding a link of this thread to him and he already now knows my opinion! Whatever type, whatever the conditions & whatever the circumstances MOBILES SHOULD BE SWITCHED OFF PRIOR TO BOARDING and have the battery removed in case the Alarm function, which switches some phones on, is enabled. This should be an internationally agreed legal requirement. Referring to Maxmobil’s post had the offending electronic gizmo been in the hold the implications are horrendous. Is it such a hard ship to be incommunicado for the period of a flight?

Just my opinion!


The regulators
8th Nov 2001, 15:30
An extract from the JAA Guidance Leaflet No. 29 dealing with cellphones. TGL 29 has been published by the JAA on behalf of its 33 member European authorities and sets the policy for airlines operating under JAA regulations.

Cellphones are both non-intentional and intentional transmitting PEDs, operating on spot channel frequencies in the bands of approximately 415 MHz, 900 MHz or 1800 MHz. (Some regions of the world use slightly different bands). Most use digital modulation but analogue types are still in use. Their maximum transmitted power is in the range of typically 1 to 5 watts. The actual power transmitted at a particular time is controlled by the cellular network and may vary from 20mW to maximum rated power of the cellphone depending on quality of the link between the cellphone and the network. Even in standby mode, a cellphone transmits periodically to register and re-register with the cellular network and to maintain contact with a base station.

The transmitted power and precise radio frequency of an operating cellphone is dependent on the traffic on the network, the distance of the cellphone from the nearest base station, and any obstacles or attenuation in the signal path. An aircraft on the ground at an airport is likely to be in close proximity to a base station resulting in a strong link between that station and an onboard cellphone. Under these circumstances, the cellphone would seek a free channel in the assigned communication band and its output power would be set by the network to a low level sufficient to maintain the link. Interference levels would, as a result, be low and probably harmless but this cannot be guaranteed. Closing of the aircraft doors increases attenuation in the signal path, and as the aircraft increases its distance from the base station, the output power setting of the cellphone is increased, eventually to its maximum rating. The risk of interference is then at its greatest. At altitude, the cellphone will transmit periodically attempting to register with the cellular network. The quality of the link is likely to be poor and the cellphone will radiate maximum power in these circumstances. Furthermore, since it is likely to be in line-of-sight range of multiple base stations, some degradation of the network operation may result and actual communication may not be possible.

The effect of this type of functioning is that, when the aircraft is on the ground near a base station, the interference risk can be low but not negligible, and it will increase as the aircraft taxies and then climbs away from the network base stations.

The simultaneous use in an aircraft of several cellphones will result in transmissions at different radio frequencies leading to a more complex interference environment.

Reports of interference are increasing but it has been difficult to positively confirm in all cases that a PED has been the actual cause of a problem. This is due to the difficulty in replicating the conditions that existed at the time of the occurrence due to the multiple factors involved (e.g. geographical location of the aircraft, system operating modes, interference frequency and intensity, source location in the aircraft, and path attenuation). Cellphones have been positively identified as the cause of degraded communications and of false baggage compartment smoke warnings. Cellphones have been strongly implicated in other spurious cockpit warnings, corrupted instrument displays, and pressurisation system malfunctions.

Although the total number of reports is relatively low considering the aircraft flight hours involved, the potential severity of the effects of interference means that the problem cannot be ignored.

JAA documents are available from Information Handling Services (IHS). Information on prices, where and how to order, is available on the JAA web site (http://www.jaa.nl) and on the IHS web sites http://www.global.ihs.com and http://www.avdataworks.com.

End quote

8th Nov 2001, 17:21
What about radio-pagers.

The briefing deals with mobiles, but doesn't mention pagers, presumably they also send and receive signals?

8th Nov 2001, 18:55
The regulators, thanks for posting that!
Interesting read for a Wagon Dragon who has to make these announcements in a convincing manner 6 times a day without ever being shown any JAA documents by the company. ;)

PS: I phrase the thing a bit "different" :eek: from the official bland comp version, and as a result a few pax always jump up as if stung by a bee and switch off their darlings as soon as I've finished talking. :D

Gunner B12
9th Nov 2001, 07:53

Pagers are relatively passive as they don't transmit or register with a network. Or so I heard. Mobiles are a much greater danger. I was involved with experiments in Australia on headsets in telephone call centres to try and protect against squeals which mobiles are suspected of causing. The company spent millions trying to protect its staff against these things and you are still outlawed from having a mobile on in one of their call centres. I would be as concerned about my hearing as the interference to the equipment as in the telephone network there is no real amplification but the headsets used on aircraft do have amplifiers yet squeals believed to be caused by mobiles ruptured the eardrums of a number of staff and left others with balance problems due to damage to the inner ear. :(

9th Nov 2001, 12:05
Most pagers are 'passive' i.e. receive only, but some have a 'talk back' facility.

10th Nov 2001, 05:13
How about showing some ****ing curtesy and learn the language in which country you are flying in and brief in their language? Whatever they are speaking there it can't be that difficult to have a note in phonetic text in your lap to give pax a briefing in their own language.
If that doesn't work ask all 5 or 6 of your passengers if they have mobile-phones and put them in the little luggage-compartement you have in the back! I mean how hard can it be?????

11th May 2003, 00:41
I'm very amused by the idea of diving the plane if one is detected... wouldnt do it myself, but its funny to read!

Dont know about the rest of you, but under Australian regs we've got a bone fide way of dealing with mobile users on the plane.. Ive threatened it myself to SLF but never been required to carry through.

CAR 224 states that the PIC is responsible for
"the operation and SAFETY of the aircraft during flight time"

I would suggest that, due to radio interference possibilities at the least, mobile phones present a hazard to the safety of the aircraft.

CAR 309 states that
"A person who, on an aircraft in flight, whether within or outside Australian territory, is found committing, or reasonably suspected of having committed, or having attempted to commit, or of being about to commit, an offence against the Act or these Regulations may be arrested without warrant by a member of the crew of the aircraft in the same manner as a person who is found committing a felony may, at common law, be arrested by a constable and shall be dealt with in the same manner as a person so arrested by a constable."

In other words... remind your SLF that it is under your discretion as PIC whether or not to arrest them and have have them dealt with by police on a charge of 'threatening the safety of an aircraft'.

Or if you are in an unpressurised craft like the PA28, chuck the offending phone out the window!


Rwy in Sight
11th May 2003, 03:21
As a SLF (with limited electronics knowledge) I agree that mobiles could cause bad bad problems. For some reasons I thought that the problem was only serious on Airbuses under IFR conditions and there were little problems to send a sms or make a short call on a VFR take off on a Do228 or from a C-130H. And I thank maxmobil for his story. (NIce name by the way)

On the other hand a lot of people are seek and tired because employees at various industries (including airlines) invent rules and regulation just to make their lifes easier NO sir we can't do that because of regulations.

Maybe we should find a way to make the regulations more belivable..

Rwy in sight

11th May 2003, 07:29
as an engineer on the b777 and b744 for the world's fav. i can honestly say that just about everyone i know at the hangar during anything from a ramp check to a full d check uses their mobiles (secretly!) all over the aircraft, i know the thing isn't flying, but engines can be running and systems are simulated in air mode frequently and i've never seen any emi problems. not to say they don't happen, but just think more is made of this than is necessary. plenty of people leave their mobiles on silent during flights, enabling them to text & recieve calls quite discreetly - i accidentally left mine on on a longhaul flight and received text all the way.

Devils Advocate
11th May 2003, 16:31

You’re about to operate the return leg of a night flight that is right up against the stops on Flight Duty Period limits. You already know that, as a result of various problems earlier in the night, that you're going to go well into ‘discretion’.

You’re currently sitting there, all ready to go, but waiting for an ATC slot - one which will allow you to go in about 10 minutes from now – you must make this slot !

The SCCM walks in to the flight deck and announces “Since we reminded the pax about the use of mobile phones, we’ve just had about eight of them tell us that they have packed their mobile phones in with their luggage and they 'think' that they've left them switched on”. :=

“Oh buggger !”, says you ( or words to that effect ).

You request the handling agent and ask if they have any idea of where these bags are located ?
They reply, after using a few precious minutes consulting the baggage manifest, that ( inevitably ) they were some of the first to be loaded into the hold - and so as such you'll have to drag hundreds of bags out in order to get to them.

You’re well aware that if you have to drag all the bags out of the hold that 1). you won’t make the ATC slot, and 2). it will take so long to drag them out, and then put them back in again, that the flight will then have to be cancelled - as the crew will be out of hours to operate it - as you’ll have maxed-out on the discretion that you have to extend the crew’s duty.

So what you gonna do ?

CarltonBrowne the FO
11th May 2003, 21:42
Devil's Advocate, how about adding mobile phones to the list of dangerous items that are only allowed on board if carried on your person? That would make it easier for the pax to check their phones are off...

11th May 2003, 22:00

You see, I bet you a month's worth of salary that on every, or 99% of your flights, there's at least one mobile on. Most likely alot more than that. On purpose, by accident, in the hold or in the overhead lockers, there's going to be a few on.

Yes, we should minimise the chances, but really, being told there's a few mobiles on on your airplane should be no news at all.

12th May 2003, 02:31
it shouldn't have to be a question of if the phone interferes (sp) with the aircraft's systems or not. who is so bloody important that they can't wait until back inside teh terminal before loading them up. I think all aircraft should be fitted with no-mobile devices. mind you, they'd probably block other important communications. how about getting any pax who's phone that goes off to do the safety briefing?

Few Cloudy
12th May 2003, 03:36
To those posters who quote cases of phones being left on and getting home safely:

- how do you know it was safely - were you in the cockpit?

- even if nothing happened, the logic is akin to saying "I knew a
man who walked across a main road and nothing hit him, so
what's the problem?"

Most of the time there won't be a problem it's true. Not too long ago pilots suspected Gameboys and other devices of causing almost any anomaly - instead of writing problems in the log, crews filed journey reports quoting suspected electronic interference. This goes too far in the other direction and led, on occasion to aircraft with serious problems despatching without repair.

However, these devices Can cause problems - especially when they have had a fall, damaging the internal screening. The peaks of power are actually over 2 watts and a phone on a network makes a regular "squitter", which is the typical sound (see above) you get when your Natel is close to a radio or line telephone.

There is only one safe answer - the thing must be Off.

12th May 2003, 09:30
Bloddy 'Phones,

One of my S/O trainees left his on in his pocket, we were 45 late due to the usual day type stuff,

SO as we rolled out on the runway, his sector, full reverse, the wife rang to see why he was late====


Safety F/O in J/Seat cancells reverse as "we were below 80 Kts Capt", but forgets to pause in idle so we speed up a bit from the redirected thrust.

I manage to keep it all on the runway and stop laughing long enough to taxi in to the bay.

Shall we say that is the danger of 'Phones on board??

Positive debrief to all, big KUA to S/O who is only a small glow in a dark room at best, roll on retirement.

Dan Winterland
12th May 2003, 11:18
Last time I heard a phone go off during the take off roll, it was the Captains!:O

25th May 2003, 21:11
Why This Fuss?

Dear PPruners,
It is a surprise that so much doubt exists regarding usage of cellphone onboard aircraft. As a layperson one can have these doubts but "Moo" as an engineer on latest generation aircraft should have researched little before making a comment like that, no wonder he doesn't fly those he services!! I agree with "Few Cloudy" remark that it is not for the cellphone user to determine whether or not the flight was safe. If any one has any doubt please take a cellphone close to an aircraft compass and see for yourself. I personally had an occasion when an ATC's instruction could not be heard before take off from one airport and after landing in another, on a 737-800. On both occasion same person was using his cellphone.

If there as any further doubt, it can be clarified by going through a report on cellphone by CAA (Effects of Interference from Cellular Telephones on Aircraft Avionic Equipment) under the "Reports Forum" of PPrune.

A few watts of transmission or not, whether it interferes with aircraft system or not, it does seem to be causing lot of brain tumors around the world! (one died recently in London). So why add to that list when you can save your brain a few hours of cell storming!!!

26th May 2003, 07:44
On a flt into LGW yesterday, radios were blocked by mobile seeking and blocking R/T comms. It didnt cause a huge problem but was very innconvienient. No idea where handset was. Should we have reported it???

26th May 2003, 12:11
Crusing along in a very unsophisticated (at least not in the same league as the biggies) Rockwell Commander 114, guy in the back keyed in his numbers to ring for a pickup at the destination airport and pushed the send button...triggering a disconnect in the auto-pilot.

Phone interference is real. I've seen it in action.:eek:

27th May 2003, 09:01
Heavin Forbid!
Last week I DH'ed on a CRJ50. Upon arrival I found my cell phone still in the "ON" position. Thank goodness we made it!!!!

28th May 2003, 01:41
Great you made it. That doesn't mean it wasn't dangerous.

I have flown CRJ 50 & 70 for years now & your right, normally there are no problems when phones are left on but there HAVE been problems.

We've had radio comms interference and even a spurious cargo fire indication (with obligatory diversion & evacuation which caused a/c damage & could easily ended up with people being hurt). Officially attributed to mobile phone signals.

You just don't know what might be affected what the consequences may be therefore it makes sense to take the variable out of the loop & ban their use on A/C.

Can't understand why anybody would argue with this, it's a safety issue.

28th May 2003, 01:54
...i admit it beeing a bad thing, a cellular left on in the air, as the continuous search for connection will drop the battery of the phone rapidly...

28th May 2003, 05:08
I wonder why the latest generation of phones aren't designed so that they can be switched off remotely. I’m not talking about jamming. I mean design the phone so that it switches itself off when it receives a specially coded message. You could then put a small “killer” transmitter on every plane or right near the gate. If on the plane it would only need to be on for a second or two before take off and perhaps again briefly when it detected a phone being switched on in the air. You could even design the phone so that it couldn’t be turned on again (for 24 hours?) if it’s deliberately switched on when onboard an aircraft.

28th May 2003, 05:41
did you know.....

That there is a pert of the GSM protocol (available publicly) which shows that all gsm phones can be switched on so that the microphone becomes active, and transmits, and this can be activated by the relevant authourities (SP) even when the phone appears to be switched off. Therefore the only way to make sure that your phone is definately not active is to take the battery out.

If you dont belive this, then you can read the published protocols, but i can promise you that it is exeedingly dull reading


28th May 2003, 06:33
Ninja, that sounds like utter bo!!ocks, so yes do please post a URL to the GSM spec about being able to power up phones etc.

7th Jul 2004, 14:35
Dont forget, ladies and gents,

Large commercial aircraft use FADEC systems to regulate engine controls and fuel flows...


As in, static hardward system telling the engine how to work...

and it HAS been tested and proven that mobile phone ident transmissions can input erranous data into a FADEC system by electromagnetic induction...

strange but true


7th Jul 2004, 15:57
ninja ..... I sure hope you are wrong???

:( :( :(

7th Jul 2004, 17:26
The CAA have a research paper on mobile phones, see this web site.


White Bear
7th Jul 2004, 19:41
I do not wish to argue with you sir, so please look upon my comments as more of a discussion point.

I know a 'jet' engine is not the same as a 'car' engine, but I do know a little about the latter. In as much as the 'jet' engine is an 'internal combustion engine' the control function of it's computer (ECM) cannot be all that different from a cars ECM. Air/fuel ratio's must be controlled, barimetric pressure, throttle position, internal temperatures must all be monitored, adjustments made etc. My point is most cars made today use what is, to all intents and purposes, a FADEC engine control system. Even the throttle is a drive by wire. Yet they remain unaffected by mobile phone use (sadly the same cannot be said of the phone user). Most of the time these phones are in use a very few feet from the engine ECM, and also close to the many other microprocessors used to operate a multitude of other systems installed in modern cars, including GPS navigation systems.

Surely an aero engine, it's ECM, and associated wiring harness are built to a much higher quality standard than a mass produced car? The use of shielded wiring to prevent unwanted R/F incursions from it's own onboard systems, much more powerful than a mobile phone, must be a given. One would expect them to be as unaffected as the above mentioned mass produced car.

One related question I have is this. What happens when a group aircraft are lined up awaiting takeoff clearence? All have their very powerful systems turned on, strong radio transmissions going to and fro, weather radar, and I'm sure many other systems I know nothing about, all up and running. At this point many aircraft are only a few hundered feet apart. Surely if an aircraft's system's are going to be affected, then with so many aircraft, so close together, and so many powerful systems all operating at the same time, in the same place, this might represent a worst case scenario for unwanted R/F input. Is there any evidence to suggest this happens?

If not, and given the mobile phone is a tiny little transmission in this crowded environment of high powered equipment, how could such a weak signal represent such a large threat?

White Bear.

8th Jul 2004, 04:54
If mobile phones really are a safety threat to aircraft (as airlines and many here claim) then allowing them on planes in the first place is quite irresponsible. If they really are dangerous take them off passengers (and crew) at the security check, switch them off and hand them back at the other end.

Of course this would add significant time to loading/unloading, but safety is the first priority isn't it? On the other hand, if profitability is the first priority then carry on.

Beaver Driver
8th Jul 2004, 05:25
The original poster had a problem with a cell phone in a CHEROKEE SIX??. Come on folks this is ridiculous. He obviously knows nothing about his aircraft. What is he afraid of? The miniscule wattage from a cell phone interfering with the coil in the magneto. Maybe he thinks the RF from a cell phone is so furious that it is going to melt his throttle control cable in it's housing.

very very silly thread.