Steve Silverwood wrote:

That's usually the case here in the US, as with any radio: if
you can show them that it is a real, working radio, they're
okay with it, but they will usually admonish you not to operate
it while on board the aircraft. They've been doing the
operational-test thing ever since the Lockerbie bombing.

I usually travel with a small digital radio (about half the size of a
deck of cards). I will listen to FM stations if I'm sufficiently
bored (no AM reception even when you press the radio against a
window). I will also usually fly with my GPS turned on (Gecko). It's
about the same size as the radio. I like to record the track of
approaches and landings, as well as to record the exact positions of
runway take-offs and landings.

The whole issue of not allowing the use of radio's on planes is
bogus. Sure, once upon a time radio's emitted a measurable amount of
IF RF, but anything made in the last few years, especially if it
operates on a couple of AAA's isin't going to screw up the plane's
comm or NAV systems.

The real reason is to ban any form of real-time communication that
passengers have with the outside world while in flight. It's a "human
factors" reason. I guess the argument goes that if passengers learn
while in flight that, say, World-War-3 has started, or if there is a
coordinated hijacking combined with suicidal crashing into buildings,
that it may unnerve the passengers enough to cause caos on board that
the FA's couldn't handle. They'd rather have a cabin full of sheep
insulated from the happenings of the outside world for the duration of
the flight.

It's the age-old balance between what's good for the individual vs
what's good for the group (or society). Similar to the wide-spread
use of antibiotics from a public health point of view (it may, or
will, benefit the individual, but if enough do it it will harm society
in general).

Have you ever wondered why the airlines don't pipe in real-time video
or audio into their entertainment systems? I garantee you it's not
for technical or cost reasons.