TSCP700 Auxiliary Power Unit for the DC-10 Aircraft

The Model TSCP700 discussed in this paper is a new advanced-technology auxiliary power unit currently under development at AiResearch. The design provides the most favorable fuel consumption characteristics possible with the current state-of-the-art and the excellent maintainability characteristics required for airline auxiliary power unit operation. This optimization is accomplished by a twinspool, coaxial, high-pressure-ratio cycle with interstage bleed from the low-pressure spool and shaft power extraction from the constant-speed high-pressure spool. Variable turbine nozzles, at the first-stage of the low-pressure spool, control pneumatic output to satisfy the environmental control system requirements (on a demand basis) and, thus, minimize the fuel consumption.