An
on board secondary propulsion
system for an aircraft provides the capability of taxiing the aircraft on the ground without using the main aircraft engine(s). The power
system includes a small driver mounted on the aircraft. In one embodiment of the invention, the driver may be mounted at any desirable location on the aircraft and is designed to provide sufficient thrust to taxi the aircraft. Such a suitable
system may be provided as original equipment to an aircraft or retrofitted to existing aircraft. In a further embodiment of the invention, the
on board secondary propulsion system, in addition to the taxiing function, may be incorporated with an
alternator to provide electrical power, an environmental
control unit, and an emergency
power unit as desired. The system may also be used to supplement the main aircraft engines as necessary during
takeoff and
climb to further reduce fuel consumption,
noise, engine emissions, maintenance costs and extend the life of the main aircraft engines. Additionally the thrust provided by the secondary propulsion system could essentially reduce the required
takeoff distance of an aircraft, thus allowing the use of shorter runways.