The primary purpose of an aircraft apu is to start the aircrafts main engines, but it is not limited to this function. Data collection for some of the extremely numerous events, such as flammable. Much of this information is common across all series of 737. Electrical generation for moreelectric aircraft using.
The following information applies mainly to the operation of the apus installed on the 737300 to max. As with any mechanical system, an apu introduces noise into the aircraft, and lord corporations apu mounting system helps ensure passenger comfort by greatly reducing the noise and vibration. Any area where the apu is operated should be checked to prevent damage to overhead infrastructure. Aircraft components and subsystems princeton university. It supplies bleed air for starting the engines and for the air conditioning system. The aircraft residual value engine, major components, lrus, airframe influenced by the market. Apu technology and secondary aircraft systems are also responsible for 50% of the aircraft maintenance cost and some 12% of the delays 2. Airesearch, the same manufacturer that provided the gtc for previous hercules, also supplies the new apu. Hydraulics is the science of liquid pressure and flow. With more than 95,000 apus produced and more than 36,000 in service today, honeywell has a large apu installed base and is poised for further growth.
This engine drives an electric generator, as well as pneumatic and hydrauli. September 2015 content introduction apu description apu history apu operation apu stakeholder views apu characteristics potential savings without an apu apu alternatives. Operating manual aircraft systems equipment flight deck general rja a318a319a320a321 fleet dsc251010 p 14 fcom a to b 07 apr 11 general ident dsc2510000982. We use cookies to improve website performance, facilitate information sharing on social media and offer advertising tailored to your interests. Accounting system budget the following financial aging parameters can be measured over time. Auxiliary power unit federal aviation administration. The offline diagnostics algorithms described in the paper work with historical data of a flight cycle. The united states air force relies up on jets such as the f16 fighting falcon shown in fig. The overall system is divided into 3 redundant systems to allow the turbine apu to be eliminated. If saving money would be so easy, the aircraft without apu would have been. Recognize the procedures for safe operation of aircraft starting equipment.
Aircraft systems apu the auxiliary power unit apu is a selfcontained unit that makes the aircraft independent of external pneumatic and electrical power supplies. Aircraft apu starter health monitoring and failure. Jun 25, 2014 aviation equipment holding has come up with the apu 120 auxiliary power unit, unparalleled in russia, which is designed for the more electric aircraft concept. In its application to aircraft, hydraulics is the action of liquids under pressure used to operate various mechanisms. Since the ecs is supplied with air from the auxiliary power unit apu, engine bleed system or ground power units gpu, there is also a possibility of contamination from these. Scd the apu is normally started prior to engine start, shut down before takeoff and started again during taxiing in. All the aircraft and system controls, required for piloting the aircraft, are arranged in such a way that the. Design of auxiliary power unit apu for cooperation with turboshaft engine p. It supplies electrical power to the electrical system. These standards do not apply to gas turbines intended for aircraft propulsion, nor do they address the integration of the apu into the design of the airplane. A first dry filter element is disposed within the first air inlet conduit, and has a substantially uniform pore size. The pressure vessel is proposed to consist of an inner inconel frame with outer titanium pressure shell with insulation between. Ep3181458a1 suspension system for an aircraft auxiliary. The apu may now supply bleed air and electrical power to the aircraft systems.
The obj ective of this study is to ev aluate the feasibility of such a hybrid system for airc raft applications. With regard to new system architectures, more emphasize will be addressed to interoperable and crossfertilizing aspects between the fuel cell and aircraft systems to fully exploit the. The advantages offered by this hybrid system are that very highcapacity lowweight generators can directly power large loads such as landing gears, swingwings, tilttails, deicing systems, spaceheating, lighting, utility loads, and in commercial aircraft galley loads. This may impose limits to flight altitude and duration. For notes about 200 series apu operation, see notes by jordaan or ferreira.
The absence of a pneumatic system simplifies the design, but high demand for electricity requires heavier generators. The features of sofcs make them suitable for hybrid systems,,,, because they work at a high operating temperature and when combined with conventional turbine power plants, offer high cycle efficiencies. Auxiliary power units are usually found on large aircraft and naval ships as well as some large land vehicles. Some apu designs use a combination startergenerator for apu starting and electrical power generation to reduce complexity. This material is covered in detail in many textbooks see anderson 1998, 2000, asselin 1997, eshelby 2000, layton 1988, lowry 1999. A first air inlet conduit directs air to a first component disposed in the compartment. Aircraft structure zoning system zoning of large aircraft is specified by the air transport association of america in the ata100 specification. Technical report on propulsion system and apurelated. This group originally developed minimum performance standards and test methodologies for nonhalon aircraft fire suppression agentssystems in cargo compartments, engine nacelles, hand held extinguishers. An auxiliary power unit apu is a device on a vehicle that provides energy for functions other than propulsion. If an apu is to be used inside of a facility, considerations should be made for ventilation of the exhaust gases. Design of auxiliary power unit apu for cooperation with. The design and construction of the apu must be shown to meet the mps of appendix 1. Most passenger aircraft do not need an auxiliary power unit apu to provide them.
Aircraft engine connected with the orc heat recuperation system 31. An engine compressor bleed system is connected to the airplane pneumatic system. The panel has all the status information and control elements for the apu complete if fault flags and status indicator lights. Scope the data collection for level 3 and higher events covered the time period 19922000 inclusive. Fuel cell apus in commercial aircraft an assessment of.
Feb 08, 2011 aircraft structure zoning system zoning of large aircraft is specified by the air transport association of america in the ata100 specification. Airlines are also experiencing increased operating costs associated with. Suspension system for an aircraft auxiliary power unit 1 located in a fuselage structure 2, the system comprising. An optiomal apu for passenger aircraft haw hamburg. Can also charge the battery through the plug at a 10 amp rate. Some aircraft utilize an auxiliary power unit apu for engine start.
Auxiliary power unit control panel the apu control panel is located on the lower panel section of the flight engineer station of the lockheed l1011. System task categories are detailed below, and figure 4 illustrates anexampleof asystem. Before landing usually after passing 0 feet, the apu is started and before the final checks, the cabin pressurization system is switched to the apu. Root cause determined to be low input voltage provided by the aircraft redesign ignition unit to operate at a lower voltage status we38762957 ignition unit service bulletin 498071 released in. The system consists of the extinguishingagent bottle, distribution tubing, discharge nozzle, and necessary flightdeck controls and displays.
Apu operation is allowed during aircraft refueling. An auxiliary power unit, also known as apu, is a device on a vehicle that provides energy for functions other than propulsion. Auxiliary power units everything you need to know aerotest. The electrical power system may be categorized into three main divisions. The apu consists of a gas turbine engine, an ac electrical generator driven by a turbine through an accessory drive, and controls for safe and continuous operation. Aircraft apus generally produce 115 v alternating current ac at 400 hz rather than 5060 hz in mains supply, to run the electrical systems of the aircraft. Aircraft structure zoning system aircraft maintenance. The apu fireextinguishing system located in the aft fuselage is a singleshot system provided to extinguish a fire in the apu compartment. The aircraft electrical system is powered from a 400hz threephase ac system. The apu system itself represents the third highest aircraft system cost in terms of repair and replacement. They are commonly found on large aircraft and naval ships as well as some large land vehicles. Apu bleed should be switched off during aircraft deicing.
The primary purpose of an aircraft apu is to start the aircraft s main engines, but it is not limited to this function. Aviation equipment holding has come up with the apu120 auxiliary power unit, unparalleled in russia, which is designed for the more electric aircraft concept. The efficiency of the sofc apu system is further enhanced by connecting a compressorturbine couple to the system and using the exhaust heat to rotate the turbine. Up to 25 or 50 amp is available for operating avionics and flight control systems when the master switch is activated. The expression apu stems from aircraft auxiliary power. What is the difference between apu and epu in aircraft. Pdf comparison of auxiliary power unit apu and ground power. The pneumatic system supplies compressed air for airconditioning and pressurization, engine starting and ice and rain protection.
The apu can be started utilizing only the aircraft batterys and, once running, will provide electrical power to aircraft systems as well as bleed air for air conditioning and for. The conventional aircraft apu is a system composed of a small gas turbine designed to supply part of the aircrafts electrical and pneumatic loads. The pneumatic air supply normally comes from the engines inflight, and the apu or a highpressure ground air supply unit on the ground. It will change from blue on to green avail as the apu or engines begin to supply power. Apu auxiliary power unit an aircraft backup power unit. An aircraft auxiliary power unit serves as an additional energy source normally used to start one of the main engines on. An auxiliary power unit apu system comprises an auxiliary power unit apu mounted in a compartment of an aircraft. Design of auxiliary power unit apu for cooperation with a. Aircraft components and subsystems t his chapter deals with the fundamental physical components and properties of conventional. A p u lubrication the a p u lubrication system is a self contained system that provides pressurized and spray lubrication for all gears and bearings within the unit.
System operation general the apu cannot run in flight. The generator provides electrical power for the airplane. Turboshaft engines a turboshaft engine is a gas turbine engine which basically consists of three components. External controls ecam apu page 1 avail displayed in green when apu n is above 99. An aircraft s auxiliary power unit is typically a small jet engine situated in the tail section of the fuselage, such as is in the photo, behind the rear cabin bulkhead. At the request of the faa, the aia pc sanctioned the. Electrical generation for moreelectric aircraft using solid. All modern naval aircraft use hydraulic systems and hydraulic components. A zone is identified by one of three indicators, depending upon whether it is a major zone, major subzone, or simply a zone. Jeta fuel for an aircraft auxiliary power unit apu.
Additionally, the apu and the landing gear are also components that have expensive routine maintenance. Foreword the material presented in this second caam report has been developed by experts from industry and the faa under the auspices of the aerospace industries association aia propulsion committee pc. The former gtc system provides bleed air to power an atm air turbine motor which in turn. Aircraft equipped with dual battery primary electrical power is provided by two engine integrated drive generators idgs which supply threephase, 115 volt, 400 cycle alternating current. An apu is an auxiliary generator that powers aircraft systems when grounded, enabling operators to avoid running the main engines at the gate. The apu is a small turbine engine installed near the rear of the fuselage. The results demonstrate that a condition based maintenance program for the apu starter can be implemented to avoid unnecessary economic losses and to enhance aircraft operating safety. The overall system is divided into 3 redundant systems to. Pdf in this study, the auxiliary power unit apu and the ground.
The apu is a source of bleed air and ac electrics for the aircraft, this gives independence during. One source of inservice contamination events reported on the a320 family fleet is the apu. A generator problem, the apu generator replace the failed generator. When you wish to switch to ships power first ensure that a power source is available, normally the apu. Aircraft power systems an overview sciencedirect topics. An aircrafts auxiliary power unit is typically a small jet engine situated in the tail section of the fuselage, such as is in the photo, behind the rear cabin bulkhead.
The apu is a small jet engine which is normally located in the tail cone of the aircraft but, in some cases, is located in an engine nacelle or in the wheel well. Once the external power has been deselected and the green avail is. In airliners, apus are usually located at the very. The diagnostics algorithms use detailed engine systems models and fault model knowledge available to honeywell as the engine manufacturer. System architectures for solid oxide fuel cellbased. On the boeing 787 moreelectric aircraft, the apu delivers only electricity to the aircraft. The apu sources are independent of all installed airplane systems except for the electrical power source used during starting and fuel supply from the airplane. The international aircraft system fire protection forum was established as the international halon replacement working group in october 1993.