Hybrid engine accessory power system

A method for generating accessory power from a gas turbine engine comprising the steps of:

• monitoring at least one parameter which provides information about an incipient change in power demand;
• bleeding air from said engine during a transient state in response to said at least one monitored parameter;
• supplying said bleed air to a pneumatically operated means for generating power to operate equipment onboard an aircraft;
• and
• said monitoring step comprising inputting a signal representative of a power demand of at least one electrical generator to a full authority digital engine control device.

A method for generating accessory power from a gas turbine engine comprising the steps of:

• monitoring at least one parameter which provides information about an incipient change in power demand;
• bleeding air from said engine during a transient state in response to said at least one monitored parameter;
• and
• supplying said bleed air to a pneumatically operated means for generating power to operate equipment onboard an aircraft,
• said supplying step comprising supplying said bleed air to an air turbine and delivering power from said air turbine to a generator for supplying power to at least one aircraft system.