This Aerospace Information Report (AIR) reviews the factors to be considered in determining the location and arrangement for auxiliary power unit (APU) installations for airborne applications and reviews requirements for flight suitability. As treated in this discussion, the APU normally includes a power section (or engine), a starting system, an electronic control unit (ECU), a gearbox with accessory mounting pads, and an oil cooling system. The accessories that are driven by the APU, such as CSD's (constant speed drives), alternating current (AC) generators, hydraulic pumps, or air compressors, are not covered here except insofar as they make demands on the APU. The various installation components and systems that are covered here are outlined by the table of contents. Turbine-type APU's are by far the most highly developed and universally used airborne units, so their installation will dominate the discussion in this document.
This document provides a brief description of the auxiliary power equipment that is available with enough description and pertinent comments to enable an engineer to make logical preliminary selection of the appropriate equipment for advanced military aircraft programs. The information has been kept as brief as possible to include the maximum amount of equipment in a relatively short document. It is not intended to replace textbook design analysis or detailed information available from the equipment suppliers. The document describes auxiliary power equipment. Auxiliary power is defined as follows: "Those elements of secondary power [defined as all aircraft nonpropulsive power generation and transmission] related to main engine bleed air and shaft power extraction or power generation separate from the main engines. Included are engine bleed air systems, remote engine driven gearboxes, engine starting systems, auxiliary power units, and emergency power systems."
This SAE Aerospace Information Report (AIR) covers basic aircraft engine start systems fundamentals. It presents various ground power sources and aircraft “on board” starting units. Also included are descriptions of start system components and interconnections which together comprise an engine starting system.
The purpose of this SAE Aerospace Information Report (AIR) is to present a brief discussion of pneumatic starters for reciprocating engines. This AIR also provides a general analysis guide for preliminary sizing of pneumatic starter systems for reciprocating engines.
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 starters covered by this specification shall be designed to operate on compressed air from ground support equipment, engine interbleed or on board air supply, for the purpose of starting aircraft jet engines.
This report lists military and industry specifications and standards which are used in aerospace engine starting systems. Only those hardware standards which have been specifically designed for engine starting systems are listed. Revisions and amendments which are current for these specifications and standards are not listed.
This report lists military and industry specifications and standards which are used in aerospace engine starting and auxiliary power systems. Only those hardware standards which have been specifically designed for engine starting systems are listed. Revisions and amendments which are current for these specifications and standards are not listed.
This SAE Aerospace Information Report (AIR) presents a discussion of drag torques of engine accessories operating at cold temperature. Various conditions of temperature, speed, and acceleration rates are reviewed showing the merits of each method and recommending a standard test method.
This SAE Aerospace Information Report (AIR) presents safety criteria for pneumatic type engine starting system design and component hardware. Included are safety criteria in design of both starter control valves and starters as well as in design of airframe control systems. Safety topics concern starter valve operation and material application, airframe controls and instrumentation installations and starter rotor integrity and containment.
This SAE Aerospace Information Report includes procedures for the analysis of a gas turbine engine start. It utilizes a standard form for the essential starting characteristics of the gas turbine engine and for the starting power capability of the aircraft battery. This report illustrates the format of the characteristic which is provided by the electric starter to transform the battery electric power (voltage and current) to the mechanical power (torque and speed) required to successfully start the engine. An aircraft engine start battery typically also serves as a backup source for emergency electrical energy. Guidelines are therefore provided for the determination of battery capacity to fulfill the emergency energy requirements of the aircraft.