I've flown LS-4, 6 and 7 with a GPS-NAV 10 or 20 in the baggage area.
Wasn't a problem. Might be if you pile too much gear on top, or if
it's right next to a metal battery box like the Dittel.
The original model 10 antenna tends to flop over. Either use a flat
external antenna or put a rubber O-ring inside the BNC connector.
Jim