A relative of mine who used to work for the company that made the antennas for planes said the whole mobile phone thing on a plane is nothing to do with safety rather one of cost.

Basically he explained that if you made a call from a plane your call goes through the plane's antenna and your cellphone service provider bills the airline for the call - this is obviously not a problem if you use a skyphone on the plane since you have to swipe your credit card before making the call. Therefore when you have landed you are free to make calls since your phone will pick up your normal service provider and you will be billed accordingly. He says the safety reason is a red herring.

Is this utter horsesh**t or a commercial explanation as to why we are told we can't use our mobile phones on planes?

If not why can we use the credit card skyphones or equivil;ent on planes but not our mobile phones?