Basically Tom & Jerry.
They were usually intercepted going through the Faeros gap NW of Scotland. By the time they got there, the Norwegian Air Force would have intercepted them already.
If they went really long range and then to the Icelandic gap, then tha USAF would have a go at them too.
Never armed, and the remote-laid 23mm cannons in the tail were always parked at zero azimuth and maximum elevation.
Friendly crews usually - we even caught one where a rear crew member in the tail blister waved a bottle of Coca Cola!