For the past two nights, in the evening around 10:00 or so on the US
east coast
on 5.065 (or was it 5.056) mHz sideband, I have heard a broadcast that I
cannot identify. I cannot tell if it's lower or upper sideband as my
reciever has an adjustable BFO,
not a LSB/USB switch.

It is definately aviation. It's a two way conversation of which I can
only
make out the ground based side. I cannot make out the aircraft side.
It sounds like instrutions of some sort but not the type you would hear from
an approach or ground controller and anyway, it's not on standard
(civilian) tower freqs.
It's a two way conversation so it's not ATIS.
Most of the side of the conversation that I can hear seems to consist of
LAT/LON quordinates.

That's as best as I can describe it. If you need more info, I'll try to
listen better
so as to supply better details.

Any idea what this might be?

Thanks,