Variable pneumatic output with constant electrical output driven by a single engine

An integrated ground support system for an aircraft, the system comprising:

• a frame on which the system is arranged as a singular assembly;
• an engine mounted on the frame and configured to power the system;
• a drive train, an alternator, and a bleed air unit mounted on the frame, the drive train disposed between and interconnected to the engine and each of the alternator and the bleed air unit;
• an rectifier and a power converter mounted on the frame, the rectifier disposed between and electrically connected to the alternator and the power converter, wherein the power converter is configured to produce electrical power for use by the aircraft;
• a first control loop connected to the power converter and configured to monitor and maintain the electrical power at a level required by the aircraft;
• an air cycle machine mounted on the frame and connected to the bleed air unit, wherein the bleed air unit is configured to produce bleed air for use by the aircraft and the air cycle machine is configured to produce conditioned air for use by the aircraft;
• and
• a second control loop connected to the bleed air unit and the air cycle machine and configured to monitor and maintain the bleed air or conditioned air at a level required by the aircraft,
• wherein the engine operates at a first operational state associated with a first rotational speed that is independent of a frequency associated with the electrical power, if only the electrical power is to be used by the aircraft, and the engine operates at a second operational state associated with a second rotational speed, different from the first rotational speed, that is a function of a pressure associated with the bleed air or the conditioned air, if the electrical power and one of the bleed air or the conditioned air are to be used simultaneously by the aircraft.