To assess the effectiveness of EW equipment, the 412th Test Wing at Edwards AFB operate a specially modified KC-135 Stratotanker as the NKC-135E, known as 'Big Crow', as a flying EW laboratory. The aircraft provides electronic countermeasures (ECM) testing and training support for all elements of the US armed services, using various jammers housed in the two large radomes above and below the fuselage. The aircraft generally operates within US airspace and provides high power, stand-off jamming to test the effectiveness of current US radars and any other equipment vunerable to jamming.
A recent Big Crow EW Enhancement Package (BCEP) used predominantly commercial off-the-shelf equipment to modernise the aircraft and enhance its capabilities. The updated equipment included new antennas, amplifiers, VCRs, data analyzers and other items of electronic equipment. A significant inprovement has also been made to the aircrafts communications equipment by updating the SATCOM, telemetry and secure encryption systems. In Dec 2000 is was reported that a $3 classified programme would use 'Big Crow' to investigate whether it could be used to impede the satellite operations of an adversary.
During the recent military operations in Iraq the only NKC-135E ‘Big Crow’ was sighted as it routed through RAF Mildenhall. After some difficulties in transiting through French airspace, the aircraft departed for Soudha Bay in Crete on 18 Mar.It is very unusual for ‘Big Crow’ to leave the USA and, as the aircraft is not normally used to conduct operational missions, there was some speculation about the aircraft's mission. On 26 Apr 03 ‘Big Crow’ routed back through Mildenhall on its way to Edwards, displaying 19 newly acquired ‘mission marks’ on the side of the fuselage. Whether the aircraft was used to conduct EW sorties during Gulf War II is unknown, but I suspect the missions were actually flown in the Mediterranean against ships of the Sixth Fleet.