Aircraft with disengageable auxiliary power unit components

Abstract

Several improvements to an aircraft turbine engine and Auxiliary Power Unit (APU) are disclosed, as well as methods of using these improvements in routine and emergency aircraft operations. The improvements comprise the addition of cockpit-controllable clutches that can be used to independently disconnect the engine's integrated drive generator (IDG), engine driven pump (EDP), fuel pump, and oil pump from the engine gearbox. These engine components may then be connected to air turbines by the use of additional clutches and then powered by the turbines. Similar arrangements are provided for the APU components. Cranking pads, attached to various engine and APU components, are disclosed to provide a means for externally powering the components for testing purposes and to assist with engine and APU start. Detailed methods are disclosed to use the new components for routine ground-testing and maintenance and for the enhancement of flight safety, minimization of engine component damage, and extension of engine-out flying range in the case of an emergency in-flight engine shutdown.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application is a division of prior U.S. application Ser. No. 11 / 419,192 filed May 18, 2006, entitled “AIRCRAFT WITH DISENGAGEABLE ENGINE AND AUXILIARY POWER UNIT COMPONENTS”, currently pending and incorporated by reference herein in its entirety. The prior U.S. application claims the benefit of U.S. Provisional Application No. 60 / 594,929, filed May 19, 2005, which is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The invention relates to methods and devices for improving the safety of flight operations of turbine-powered aircraft and the efficient maintenance of aircraft engines and auxiliary power units (APU's).[0004]2. Description of the Related Art[0005]Aircraft gas turbine engines particularly turbofan and APU comprise many components that require an adequate and proper maintenance to operate reliably and efficiently. In order to test or troubleshoot engine and APU componen...

AI Technical Summary

Benefits of technology

[0008]Certain aircraft's engine (turbofan) and Auxiliary Power Unit (APU) gearbox components are fitted with certain accessories: clutches, cranking pads, air turbines, air valves, and air compressors. These engine and APU gearbox components are disconnected from their respective gearboxes and are connected to air turbines using clutches. On the ground, these gearbox components are driven by the turbines, which are supplied by air through an outlet air compressor, or driven by cranking pads using a motor. Each engine and APU gearbox component may therefore be driven separately without running the entire engine or APU. This will allow personnel to test and troubleshoot the engine / APU gearbox components and related systems when the aircraft is inside a hangar and / or lifted on jacks, or at an airport gate (apron) without towing the aircraft away from the hangar or the gate, without running the engine and APU, and without being exposed to hazard areas around the engine, APU, and aircraft. According to this invention, leak check, test, and troubleshooting of the engine / APU components and systems are performed easily and efficiently with engine fan and reverser cowls open.

[0009]When the engine and APU gearbox components are connected to their respective gearbox and driven by the related turbine or the cranking pad, they can also be utilized as a starter for the engine or APU: According to this invention there is no dedicated starter as in the current engines, because many of these gearbox components can be used as starters. They can also provide higher engine motor speed on the ground. Certain engine and APU components (IDG, EDP, APU generator, engine compressor, APU compressors, and APU hydraulic pump) can provide electric, hydraulic, and pneumatic power on ground when they are disconnected from their respective gearbox and driven by an air compressor outlet or motor (no need to run the entire APU, to use the ground power unit, ground pneumatic cart, or the ground hydraulic power). The compressor of the APU starter-generator, the hydraulic pump, or installed on engine gearbox can provide pneumatic power for the test and troubleshooting of air conditioning system on the ground (even inside hangar) and during the aircraft turn-around time to supply conditioned air to the aircraft. Other applications listed below in other paragraphs, ensue from installing these new accessories (clutches, cranking pads, turbines, compressors, valves).

Problems solved by technology

To improve APU start in the flight, it is possible to connect an APU starter-generator and hydraulic pump, the related turbine, and the APU gearbox all together to provide the adequate torque; this technique would be employed mainly at high altitude, where normal APU start is not always successful especially when the APU is cold-soaked after long flight during cruise.

Images