As part of the Aerospace Defense Command (ADC), the B-57 was the "Friendly Enemy".  These Defense Systems Evaluation Squadrons (DSES) were used to penetrate Air Defense Identification Zones (ADIZ) acting as enemy bombers to test the defense capability of interceptors and ground control radar sites of ADC.  In addition, training for individual intercept squadrons was a continuing responsibility.  The last two active duty units were the 4713  DSES and 4677 DSES which became the  17th DSES when the unit moved to Malmstrom AFB. The aircrews and ground crews  were frequently on duty away from their home station. The 4713th called itself  the "Roving Ravens".

The rotatable bomb bay of the Canberra replaced bombs with electronic black boxes and the fuselage bristled with antennas.  From the wing pods, chaff, used by the British in World War II was still an
 effective radar jammer.

    
Photo Mark Witt
In the back seat of the B-57, the Electronic Warfare Officer (EWO) orchestrated these   electronic countermeasures using his own skills to test and hone those of the interceptor aircraft crew.  At the same time the EWO took pride in developing the skills needed in his assigned wartime mission.

As changes occurred in Air Force structure and the nation's defense needs were updated, the Air National Guard absorbed this mission as it had others.  One of the last units to fly the ECM aircraft was the Vermont Air National Guard from Burlington known as "The Green Mountain Boys".   E model 499 from that unit is on display in the Air Force Museum at Wright-Patterson AFB, Ohio.
Photo:  Westover AFB 4713 DSES: John Harris