A general discussion is presented herein, to outline the starter functions which are necessary for a successful engine start. In addition, sample calculations are included to illustrate an accepted method of determining the engine starting time from known data. Further consideration is then given to the relationship between starter torque output and engine pad strength and a generalized formula is presented for calculating the theoretical transient torque peaks for a simplified starter-engine system. Sample calculations for actual tests are included, and the results of these calculations are compared with measured values.
This specification covers the general requirements for pneumatic control valves for use with the starters on aircraft gas turbine engines. This specification shall be used in conjunction with AS943, ARP949, and AIR1639.
The information contained in this report has been simplified to facilitate its use. Specific manufacturers should be contacted for more detailed information. Many of the basic power plants are available in numerous configurations to provide shaft power or electrical power in addition to the pneumatic capability. Vehicles for the ground transportation of the power supplies are also varied to fit specific requirements. The state-of-the-art in small gas turbines has advanced to a point where they are competitive with the more conventional ground power supplies in practically all areas.