'Snoop'

AKA the 'u-boat'
An RC-135u making a rare visit to RAF Mildenhall.
One of the US Air Forces covert spy planes, hence the 'snoop' call sign they use.
The lumps 'n' bumps all over it house all manner of top secret scanners and radar, to keep a close eye on the hotspots of the world.

The guys from RAF 51 squadron are currently doing intensive training on this type of aircraft, as we have 3 on order from the U.S.

Some years ago i saw some nose art of one of these that said,
"In god we trust- everyone else we monitor"

Says it all really!