AIR SYSTEM SWITCHING SYSTEM TO ALLOW AERO-ENGINES TO OPERATE IN STANDBY MODE

摘要

A method of operating a multi-engine aircraft (1, Fig. 1a) having two or more gas turbine engines (10, Fig. 1b) includes operating a first engine in a powered mode to provide motive power to the aircraft (1), and, in flight, operating a second engine in either a powered mode to provide motive power to the aircraft (1) or in a standby mode to provide substantially no motive power to the aircraft (1). When operating the second engine in the powered mode, pressurized air is bled from a first bleed location (19) of a compressor (9) of the second engine. When operating the second engine in the standby mode, pressurized air is bled from a second bleed location (21) of the compressor (9) of the second engine and supplying the pressurized air to a bleed air system of the second engine. The second bleed location (21) is downstream of the first bleed location (19) within the compressor (9) of the second engine.