SAE ARP 906B pdf download

SAE ARP 906B pdf download.Glossary,Aircraft Engine Starting and Auxiliary Power Systems.
The Aircraft Engine Starting and Auxiliary Power System Glossary presents definitions of terms commonly encountered and associated with aircraft engine starting and auxiliary power systems. Terms have been arranged alphabetically.
1.1 Purpose:
The purpose of the Aircraft Engine Starting and Auxiliary Power System Glossary is to promote the consistent usage of terms commonly encountered and associated with aircraft engine starting and auxiliary power systems. The usage of terms presented herein will serve to promote clarity and avoid many misunderstandings throughout the aerospace industry.
2. REFERENCES:
2.1 Applicable Documents:
The following publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence, Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.
2.3 (Continued):
AIRSTART ENVELOPE: Portion of the flight envelope (attitude and airspeed) in which airstarts may be successfully initiated, generally divided into assisted and unassisted (windmilling) subenvelopes.
AIR STARTING: Process of starting a main propulsion engine while inflight by either windmilling, or with starter-assist.
AIR TURBINE STARTER: Air turbine device that provides shaft power to start an engine, generally includes an inlet scroll, turbine, reduction gears, an engagement mechanism or clutch and may include a speed switch or speed signal to signal cutoff speed, a machine that converts the kinetic energy of moving air to mechanical power by the Impulse of the fluid upon blades arrayed about the circumference of the shaft, sometimes referred to as “Pneumatic Starter”.
ANTI-DRIVE END: End of the starter or accessory opposite the end which mates with the engine, or driver device.
ASSISTED WET CAVITY: Oil lubrication arrangement used in some starters that denotes partial shared oil lubrication with the propulsion engine gearbox. arrangement eliminates shaft seals and assures a supply of oil.
AUTO-SHUTDOWN: Uncommanded shut down of the APU, usually caused by the activation of one or more built-in self-protection features to limit the rotor speed, oil temperature, exhaust gas temperature or other APU engine parameter.
AUTOSTART: Associated with digital engine controls such as FADEC, sequence steps in starting a power plant engine programmed into the control and initiated by pushing a button in the cockpit, typically, if the engine does not successfully complete the first attempt, the control will lean the fuel schedule for two additional start attempts before shutting off, also utilize in an APU.
AUXILIARY POWER: Non-propulsive power generated on board the aircraft for the purpose of providing pneumatic and/or shaft power and/or electric power.
AUXILIARY POWER UNIT (APU): Internal combustion engine (usually a gas turbine) used to generate shaft power andor bleed air to power the aircraft’s accessory components. applications of power generated by APU:
a. Providing air for the environmental control system and starter.
b. Driving the AMAD or starling the main propulsion engine.
c. Driving electrical generators and hydraulic pumps, sometime emergency power components.
BACKLASH: Limited rotational motion of shafting in a component or power drive train, when shaft torsion applied in clockwise then, counterclockwise direction.
23 (Continued):
BACK PRESSURE: Static differential pressure level measured between the starter exhaust pressure (P2) and altitude ambient pressure usually due to nacelle venting restrictions and/or overboard ducting.
BATTERY POWER – Imp RATING: Maximum power discharge current, declared as a minimum by the manufacturer and expressed in amperes. which the fully charged, 23 °C cell or battery shall be capable of delivering immediately prior to the condusion of a 15 s maximum power discharge. controlled so as to maintain a constant terminal voltage at 1/2 of the rated value. See AS8033.
BLEED AND BURN: Describes a process whereby air (extracted from a compressor or air bottle) is combined with fuel and burned to release the potential energy of the mixture.