A couple of years ago, I witnessed one of our MX guys use his ordinary Nextel phone to repeatedly trigger a BSCU fault from the nosewheel area of an A320. It was discovered by accident during troubleshooting an unrelated system fault and was believed to be the result of the mobiles EMF entering VIA a position sensor connection where poor lead dress had existed.
Try this at home:
Have your FO take a walk outside (preferably while the AC is on the ground) and use his/her mobile below the port-side wingtip (flux valve) while watching the Compass SYN light on a 737 Classic - works every time with the Honeywell-gate equipped AC.
I have also seen an Omega Nav CDU go wacky from an o-l-d Motorola brick phone. (ok, I'm dating myself).
Aside from the correctable BSCU system defect, all my examples are from pre-1990s aircraft. Newer systems are supposed to have more robust spurious signal rejection. None of the above resulted from passenger cabin phone use.
I think the most dangerous issue with mobile use while aboard must surely be the cacophony of passenger’s blah-blah-blah during a flight.
