How to hook handheld up to external antenna?

My club wants to equip all our planes with jacks so people can plug
their handhelds into an external antenna in case the panel radios fail.

In the past, what we've done is had a length of coax run into the
cockpit with a BNC connector crimped onto it. The problem there is it
tends to get kicked around, the connector gets smashed, etc. When you
need it, it's not usable.

One alternative I've thought of is to have the antenna cable run to a
BNC jack on the panel. The problem with that idea is then you need a
length of cable to go from the jack to your radio, which will in turn
get lost, smashed up, etc.

Has anybody come up with a good solution to this problem?