MD-3 Ground Power Unit This unit was designed to provide 28-volt DC 1500 amp, 115/220-volt AC three-phase electrical power for B-47 aircraft for ground operation and start. It also can be used with other aircraft (such as the T-33) that have power requirements compatible with its output. It uses a Continental 180-hp six-cylinder reciprocating engine to drive its electrical generators. The unit was restored for the museum by the 4950th Field Maintenance Squadron, Wright-Patterson Air Force Base, Ohio, in 1979-1980. Click here to return to the Cold War Gallery.