Abstract: A turboprop-powered medium altitude long endurance aircraft, having a gas turbine engine; a heat scavenging device to scavenge heat from the gas turbine engine; and a heating device to use the scavenged heat to provide heating to the aircraft. The heat scavenging device may be placed on an engine casing and/or on or in an engine exhaust duct. The heating device may include a circulation path routed directly to a location in the aircraft where heating is to be performed, for example a leading edge of an engine support pylon or a leading edge of an engine-carrying wing. The heating device can include a heat exchanger.

Abstract: A method and apparatus are disclosed for a turboprop-powered medium altitude long endurance (MALE) aircraft, having: a heat exchanger with a heat-storage material, for example a heat-storage wax; and an air recirculation path. The heat exchanger can be arranged to cool air recirculating around the air recirculation path which is arranged to provide cooling to the MALE aircraft, for example to an equipment bay. The heat-storage material may be cooled by ground-based cooling apparatus when the aircraft is on the ground and/or by ram air when the aircraft is in flight. The heat-storage material may have a melting point selected so as to be rendered solid during ground-based cooling and/or ram air cooling, and/or selected so as to undergo melting while cooling the air recirculating around the air recirculation path.

Abstract: A turboprop-powered medium altitude long endurance aircraft, having a gas turbine engine; a heat scavenging device to scavenge heat from the gas turbine engine; and a heating device to use the scavenged heat to provide heating to the aircraft. The heat scavenging device may be placed on an engine casing and/or on or in an engine exhaust duct. The heating device may include a circulation path routed directly to a location in the aircraft where heating is to be performed, for example a leading edge of an engine support pylon or a leading edge of an engine-carrying wing. The heating device can include a heat exchanger.