Development of a Hot Gas Vane Motor for Aircraft Starting Systems

Design, analyses, and tests have been conducted on a double-cavity (pressure-balanced) hot gas vane motor suitable for aircraft APU starting over the temperature range of −65°F to +130°F (−54° to +54°C).

Testing of the motor was accomplished with H-70 (70% hydrazine, 30% water) monopropellant hot gas decomposition products.

Motor development focused on testing minor modifications aimed at eliminating vane breakage. The performance goals (zero to 8,800 rpm in 8 to 10 seconds) were achieved after approximately 40 tests. Hot restarts and starts at the extreme temperatures have also been demonstrated.