This is (I think) an NC-135A ‘Rivet Digger’ a quick-response airborne diagnostic airplane at kirtland Air Force Base. (if anyone knows for sure what this is let us know in the comments.
Here is an EC-18B Advanced Range Instrumentation Aircraft with a 10 foot radome in its nose.
The F/A-22 Flying Test Bed (FTB) is a modified Boeing 767 with a simulated F/A-22 wingspan on top of its fuselage and an F/A-22 radar mounted on its nose. It is used to test avionics in the same configuration as the F/A-22.
Right next to the FTB at Beoing Field in Seattle is a Royal Australian Air Force Boeing 737-7ES Wedgetail AEW&C, similar to the E-3C AWACs in the US Air Force.
This US Customs Service P-3 AEW at NAS Cecil Field has a radome on top used to track drug smuggling aircraft.
And finally, we’ve seen the E-2C Hawkeye twice before. Here is another one but this time in the air near Virginia Beach Naval Air Station.
Contributed by Parabellum and Kevin.