This paper describes the design of a new Ingersoll-Rand mobile diesel powered air compressor and electrical generator for aircraft ground support. Compressed air at a maximum gage pressure of 310 kPa (45 psig) and up to 62,000 L/min (2200 CFM) and 77 kg/min (170 lbm/min) is provided for aircraft engine starting and air conditioning. Three phase 400 Hz electrical power is generated at 115 volts and 30 kW.The centrifugal compressor has microprocessor controlled inlet guide vanes and variable outlet geometry to operate at maximum efficiency over a wide demand range. The microprocessor also controls the diesel engine to maintain precise engine speed and electrical frequency control. Both on-board and off-board microprocessor aided diagnostics and performance monitoring are used. The equipment is designed to be extremely fuel efficient, light weight, reliable, and to operate in severe ambient conditions from -46°C to 54°C.