Abstract: A method and apparatus are provided for de-icing an aircraft of the type having wings and fuel storage in the wings. Hot fuel is provided for fueling the aircraft. The hot fuel is at elevated temperatures which are sufficiently high enough to transfer heat from the fuel, through a fuel tank extending within the wings, and to the exterior of the wings to de-ice the aircraft. A storage tank stores the fuel, and a heater heats the fuel to elevated temperatures. An intermediate thermal transfer system having a secondary thermal fluid transfers heat from a primary power source to the fuel. Further, a substantial volume of the secondary thermal fuel may be maintained at elevated temperatures to provide a sufficient thermal reserve capacity for heating the fuel upon demand.

Abstract: A tungsten electrode (35) is positioned adjacent the root face (15) of a tube (10) with the tube and the electrode being connected to a source of direct current (40) such that the electrode is positive with respect to the tube. The electrode is mounted in an assembly (30), and the assembly is provided with a shielding gas from a source (48). The electrode assembly is mounted for rotation on an orbiting head (60) with the electrode axially spaced from the root face. As the electrode is rotated about the tube, the root face (15) and a portion (20) of the inner surface and a portion (25) of the outer surface are simultaneously cathodically cleaned. Preferably, the electrode (35) cleans the root face from two to four times in preparation for a subsequent welding operation.