I'm surprised no one has mentioned the V22 Osprey. Boeing seem to have given up on the idea of placing a large radar on top of the aircraft as it seems there was very little clearance between this and the rotors when in verticle mode. However they are now looking at fitting an inflatable rad dome to the rear ramp. Beedall's site gives this description under a photograph:-
"As an alternative to the Merlin airframe, Boeing is actively promoting a version of the V-22 Osprey fitted with a palletized version of the Thales Cerberus mission system and the Searchwater airborne radar system under the project designation of TOSS".
Third photograph from the top
Navy Matters | Maritime Airborne Surveillance and Control