Mobiles and PA38's

[maxdrypower]

Last week whilst preparing to punch some 90kt holes in the cheshire sky I briefed my passenger re loose articles etc etc I then saw him turn off his mobile . Leaving Liverpool and heading toward Chester (still with my wheels) I changed frequency to inform atc I was approaching the VRP ,,,, Nothing , bugger! oh my ! Now I could hear them but could not transmit , I tried on five occasions to contact them with no result. Whilst pondering and preparing to reach for my trust tranceiver I heard that lil ole sound you get when you place a mobile near a speaker , you know the one I mean sounds like the countdown on Independance Day . I asked the Pax if his mobiole was off , it turned out it wasnt , he turned it off , I then tried to transmit again and found it perfectly clear no probs ???
Was this a coincidence or can mobiles really affect the radio ? any one else had similar experiences?

[Henry Hallam]

(electrical engineering student)

I've heard the buzzing noise in headset when pax left her mobile on. I'm pretty sure you will get that with more or less any circuit that uses an audio amplifier and a speaker/headphone. As far as I can tell it didn't actually interfere with the radio but I would not be surprised if it did. In any event the buzzing can be distracting. So... mobiles off please!

[Budd]

Was this a coincidence or can mobiles really affect
the radio ? any one else had similar experiences?

Funny, right now I'm watching an episode of Mythbusters that talk about if it's possible for a cellphone to affect the planes avionics. The consensus was yes, in lab conditions (they couldn't legally do it in a plane) certain cell phones (they found some that run in the 800mhz range to be the worst) can affect the airplanes avionics.

[Kanu]

I've heard of a mobile phone producing a 30 degree error on a HSI. Once switched off the HSI swung back round to the correct heading.
strange but I promise its true.

[Chequeredflag]

I was once told by someone who should know, that in commercial airliners, the only thing affected by mobile phones is the auto throttles. I'm sure there are plenty who can correct me if I'm wrong, but it is sort of backed up by the following incident on a BA757 in which I was travelling to Rome. Over Italy, in completely smooth air, the planes engines suddenly revved up dramatically, and the plane started to climb - all with no warning. The crew quickly stabilised the situation, and the Captain came on to ask everyone to ensure their mobiles were switched off. Could have some connection?

[QDMQDMQDM]

Every airliner which takes off probably has at least one phone still switched on in someone's hand luggage. If they really affected things consistently there would be compulsory handing in of phones to the cabin crew to ensure they were switched off.

QDM