Turboprop-powered aircraft with thermal system

A method of thermally managing a turboprop-powered medium altitude long endurance aircraft, the method comprising:

• providing a heat exchanger having an air flow channel interlaced with a heat-storage material;
• using external air input from ground-based cooling air and/or a ram air scoop directly into the heat exchanger from an air inlet via the air flow channel to cool the heat-storage material;
• and
• cooling, after using the external air input from ground-based air and/or the ram air scoop to cool the heat-storage material of the heat exchanger, the turboprop-powered medium altitude long endurance aircraft with recirculated air passed via the air flow channel.

A system for thermally managing a turboprop-powered medium altitude long endurance aircraft, the system comprising:

• a heat exchanger;
• a heat-storage material;
• an air inlet;
• an air flow channel;
• an air recirculation path;
• external air from ground-based cooling air and a ram air scoop;
• wherein the air flow channel is interlaced with the heat-storage material;
• wherein the air inlet is arranged to input the external air into the heat exchanger so as to cool the heat-storage material within the heat exchanger;
• wherein the heat exchanger is configured to cool recirculating air around the air recirculation path;
• wherein the air recirculation path is arranged to allow the recirculating air to provide aircraft cooling air;
• and
• a thermal control system configured to
• provide cooling of the heat-storage material in the heat exchanger using the external air from the air inlet into the air flow channel;
• and
• after the cooling of the heat-storage material, provide cooling, with the recirculated air cooled via the air flow channel, the turboprop-powered medium altitude long endurance aircraft.