auxiliary power unit table of contents - · pdf fileauxiliary power unit table of contents ......

AUXILIARY POWER UNIT

Table of Contents

May 06/2005 Flight Crew Operating Manual Volume 2REV 2 CSP 100-6 05-00-01

Introduction ......................................................................................................................... 05-01-01Compartment....................................................................................................................... 05-01-01

APU Access Panel Locations .................................................................................... 05-01-02APU Schematic.......................................................................................................... 05-01-03

Power Section and Gearbox ............................................................................................... 05-01-04Description ................................................................................................................. 05-01-04Components and Operation....................................................................................... 05-01-04Power Section............................................................................................................ 05-01-04Gas Generator ........................................................................................................... 05-01-04Gearbox Assembly..................................................................................................... 05-01-04

Air Intake and Exhaust ........................................................................................................ 05-01-05Description ................................................................................................................. 05-01-05Components and Operation....................................................................................... 05-01-05Exhaust ......................................................................................................................05-01-05Exhaust Gas Temperature ......................................................................................... 05-01-05

Lubrication System.............................................................................................................. 05-01-05Description ................................................................................................................. 05-01-05Components and Operation....................................................................................... 05-01-05

Fuel Distribution .................................................................................................................. 05-01-06Description ................................................................................................................. 05-01-06Components and Operation....................................................................................... 05-01-06APU Fuel Supply........................................................................................................ 05-01-06Fuel Control Unit and Fuel Shutoff Solenoid.............................................................. 05-01-06APU Shutdown Mode................................................................................................. 05-01-06

Start and Ignition ................................................................................................................. 05-01-07Description ................................................................................................................. 05-01-07Components and Operation....................................................................................... 05-01-07Starter ........................................................................................................................ 05-01-07Ignition System .......................................................................................................... 05-01-07System Operation ...................................................................................................... 05-01-07

Pneumatic Supply ............................................................................................................... 05-01-08Description ................................................................................................................. 05-01-08Components and Operation....................................................................................... 05-01-08Bleed Valve Modulation/Bleed Air Loads ................................................................... 05-01-08Bleed Valve ................................................................................................................05-01-08Surge Control Valve ...................................................................................................05-01-08Bleed Air Availability .................................................................................................. 05-01-08Bleed Air Limitations .................................................................................................. 05-01-08

Control and Indications........................................................................................................ 05-01-09Description ................................................................................................................. 05-01-09External Power Control Panel.................................................................................... 05-01-09Air Cond/Bleed Control Panel .................................................................................... 05-01-10Electrical Control Panel.............................................................................................. 05-01-11Electrical Synoptic Page ............................................................................................05-01-12ECS Synoptic Page ...................................................................................................05-01-13Fuel Synoptic Page.................................................................................................... 05-01-14

EICAS Messages ................................................................................................................05-01-15

REV 2


Sep 13/2004 Flight Crew Operating Manual Volume 2REV 1 CSP 100-6 05-01-01

REV 1

INTRODUCTION

The Honeywell 36-150BD constant-speed gas turbine auxiliary power unit (APU) is installed in a fire-proof compartmentin the tailcone of the airplane. The APU is a fully automated gas turbine powerplant with automatic fault detection, auto-matic and remote shutdown, and in the event of an APU fire on the ground, automatic fire extinguishing.

The APU compartment is accessed by a single panel aft of the aft equipment bay door. The panel must be unscrewed fromthe fuselage underside. The APU is a self-contained unit.

The primary purpose of the APU is to provide power for the gearbox-mounted 400-amp DC generator. Secondary functionsof the APU are bleed-air supply for the environmental control system (ECS) and main engine starting. Under high demand,the APU electrical loads take priority over pneumatic loads.

For APU maximum operating altitudes for ground and flight, and also for continuous starter attempts, refer to the ApprovedAirplane Flight Manual.

The APU should not be started above speed limits stated in the Approved Airplane Flight Manual, as the APU may reversewindmill.

An engine control unit (ECU) controls and monitors all facets of APU operation, including the recording of operating hoursand start cycles. The DC-powered ECU sets up the appropriate fuel acceleration and EGT temperature schedules. It relaysappropriate operating data to the pilots through the EICAS displays.

APU start is initiated by one switch on the APU control panel in the flight compartment. Operational control of the APUelectric and bleed-air systems is performed at the ELECTRICAL and AIR COND/BLEED control panels.

COMPARTMENT

The APU is mounted in the airplane tailcone and is accessed via the access panel located on the fuselage underside. TheAPU compartment has a NACA inlet for ventilation. The air is pulled through the NACA inlet and routed through the com-partment to cool the APU and its mounted components. This air is then exhausted overboard via the APU exhaust eductor.

The APU-driven air-cooled DC generator also has a NACA inlet for cooling air flow. The air is pulled through the generatorand dumped in the APU compartment. This air is then exhausted overboard via the APU exhaust eductor.

CF

O05

0100

2_00

2

APULOCATION


Volume 2 Flight Crew Operating Manual Sep 13/200405-01-02 CSP 100-6 REV 1

APU ACCESS PANEL LOCATIONS

CFO

0501

002_

007

SIDE ACCESSPANEL

BOTTOM ACCESSPANEL



APU SCHEMATIC

SURGE

DUCT

BLEED AIR

DUCT

TO

AIRCRAFT

BLEED AIR

SYSTEM

AIRCRAFT

SKIN

AMBIENT SENSING

TEST PORT

TORQUE

MORTOR

CONTROL

PRESSURE

REGULATOR

OIL

PUMP

BLEED

DIFFUSER

CF

O0501002_005

INLET AIR

BLEED AIR

ELECTRICAL CIRCUITS

ECU

FROM/TO

APU

SYSTEMS

FROM/TO

AIRCRAFT

SYSTEMS

AIR INLET

STARTER

MOTOR

LOW OIL-PRESSURE

SWITCH

FUEL CONTROL

UNIT

APU

GENERATOR

APU BLEEDVALVE SURGE VALVE

REV 2



POWER SECTION AND GEARBOX

DESCRIPTION

The power section of the Honeywell 36-150BD APU consists of a gas turbine engine with integrated oil, ignition and startsystems. The power section drives a gearbox that reduces the rotational speed of the APU for operation of the gearbox-mounted accessories.

The APU contains the following components:

- Single-stage centrifugal compressor- Single-stage radial turbine- Accessory gearbox with an integral oil reservoir- Annular reverse flow combustor

COMPONENTS AND OPERATION

POWER SECTION

Engine power is developed through compression of ambient air by a centrifugal compressor. The compressed air, whenmixed with fuel and ignited in the annular reverse flow combustor, drives a single-stage radial turbine. The rotating shaftof the turbine rotor drives the compressor, output drive shaft, and accessories.

GAS GENERATOR

The gas generator contains the following components:

- Compressor- Annular reverse flow combustion chamber- Turbine

GEARBOX ASSEMBLY

The gearbox assembly provides power transfer from the starter motor to the accessories and power section during APUstarting as well as to all gearbox-mounted accessories during on-speed operation.

The APU accessories include:

- Starter- DC Generator- Oil pump- Speed sensor- Fuel control unit and high-pressure pump

The APU gearbox also serves as a sump for the lubrication system and incorporates the oil gravity fill cap and quantitysightglass.

V 1



AIR INTAKE AND EXHAUST

DESCRIPTION

The APU air intake is located above the APU compartment on the right side of the fuselage, below the vertical stabilizer.

The APU exhaust gases are discharged by an exhaust duct and eductor through the tailcone of the aircraft.


EXHAUST

The exhaust duct is covered by an insulated exhaust muffler.

EXHAUST GAS TEMPERATURE

The APU exhaust gas temperature (EGT) is displayed as a digital readout on the EICAS.

LUBRICATION SYSTEM

DESCRIPTION

The APU has a self-contained lubrication system. Major components include a gearbox mounted oil pump and an integralgearbox oil sump. Intake air cools oil and ventilates of the APU enclosure. A magnetic chip collector provides visual indi-cation of metal particles in the lubrication system.


The oil pump directs filtered oil under pressure to the APU bearings, gearbox, and generator bearings.



FUEL DISTRIBUTION

DESCRIPTION

The Honeywell 36-150BD APU fuel system is a full-authority digital electronic engine (FADEC) controlled system. Dur-ing start, the fuel system provides the correct amount of fuel to support combustion and smooth acceleration of the engineto full power. When full power is reached, fuel flow is modulated to meet electrical and pneumatic load while maintaininga constant engine speed.

Protection from overtemperature during APU acceleration is provided by protective features incorporated in the ECU.

The APU receives fuel from the right collector tank. The APU fuel system incorporates the right DC-powered fuel pump,fuel feed shutoff valve (SOV), fuel shutoff solenoid, fuel system filters, a high-pressure fuel pump (mounted on the APU),fuel control unit (FCU), and the fuel manifold assembly.


APU FUEL SUPPLY

The right DC-powered fuel pump delivers fuel under pressure to the APU fuel control unit. When the right engine is run-ning, the fuel pump ceases operation and fuel is delivered by the main engine ejector pump.

FUEL CONTROL UNIT AND FUEL SHUTOFF SOLENOID

The APU fuel control unit (FCU) meters fuel under command of the electronic control unit (ECU). During the start se-quence, the fuel shutoff solenoid, located between the FCU and the fuel nozzles is opened by the ECU at 5% rpm. Fuel issupplied in accordance with a schedule that accelerates the APU throughout the start sequence. When the APU is stabilized,fuel scheduling is influenced by the rpm and EGT as well as generator and bleed air demands.

During normal or automatic APU shutdown, an overspeed signal closes the fuel solenoid valve and torque motor at theAPU and causes the APU to shutdown.

APU SHUTDOWN MODE

Engagement of the APU master switch to OFF, remote stop, emergency/fire, or in the event of an exceeded limit, the ECUinitiates the APU shutdown sequence by commanding the fuel off. When the shutdown sequence is complete, the ECU tran-sitions to idle mode and then powers down if the APU master switch is in the OFF position. The following is a list of allthe APU protective shutdowns showing the ones that are inhibited in-flight (essential mode):

* - An asterik indicates these shutdowns are inhibited in the essential mode.

28 VDC Power Loss Fire Indication*Reverse Flow* No Acceleration (during start)*Loss of EGT Signal* Overspeed

Low Oil Pressure* Emergency FireHigh Oil Temperature* Internal ECU FailureOvertemperature* Loss of Overspeed Protection Circuit

No Flame (during start)*

1



START AND IGNITION

DESCRIPTION

The starting and ignition systems operate automatically during the APU start sequence.


STARTER

The APU start system consists of a DC starter and a series of relays controlled by the electronic control unit (ECU). Theelectrical power source is:

- ECU — battery bus- Starter — APU battery direct bus

To start the APU, the APU start contactor is closed and the right battery is connected to the APU starter.

The right battery contactor is opened to isolate the right battery from the right essential bus during APU start to prevent avoltage drop on the essential busses. The left battery maintains power to the left and right essential busses during APU start

It is important to delay starting the APU for five minutes after application of anti-icing fluid near the APU area. This allowsany anti-icing fluid inadvertently directed into the APU inlet to drain out.

Three consecutive APU start attempts may be made at 1 minute intervals, followed by a 20 minute wait. Two more startattempts may be made. No further attempts may be made for a period of at least 40 minutes.

Six consecutive and successful APU starts may be made at 10 minute intervals with a one-hour waiting period priorto additional start attempts.

IGNITION SYSTEM

The APU ignition system consists of an ignition unit, igniter plug lead and a single igniter plug. The ignition system isenergized during the APU start cycle and is de-energized when the APU start sequence is complete. To engage the APU,pull up on the switch, position the switch to RUN for approximately 3 seconds until the APU indications are displayed onthe left MFD. Then move the switch to START and hold until the START icon is displayed on the left MFD, the APU willthen begin the start sequence.

The APU ignition system consists of a single output ignition unit. Should a flameout occur during operation, the ignitionunit automatically fires the igniter through the auto relight function of the ECU. An immediate restart (APU starter re en-gagement) can be initiated upon APU rolldown below 10% rpm.

SYSTEM OPERATION

The ECU uses 28 vdc power from the right aircraft battery bus to energize the ignition system during the ignition/start se-quence. During the start sequence, the R BATT switch is illuminated OFF on the ELECTRICAL panel and the flow linefrom R BATT to the R ESS BUS on the Electrical synoptic page is depicted in white. The ignition system is energized at5% APU rpm and stays energized until 95% rpm.

REV 2



PNEUMATIC SUPPLY

DESCRIPTION

APU compressor bleed air is used to pressurize the right side of the bleed air manifold to provide pneumatics for enginestarting and air conditioning. Reverse airflow protection is provided by a one way check valve.


The APU pneumatic control system consists of a bleed valve and a surge control valve.

BLEED VALVE MODULATION/BLEED AIR LOADS

The pneumatic load on the APU is controlled by the ECU as a function of demands sent from the APU bleed valve. Whenthe bleed valve is opened, a portion of the compressor discharge air is diverted from the plenum chamber to the right sideof the bleed air manifold. The bleed valve opens when the flight deck APU bleed load switch is placed in the open position.

The APU engine reaction to bleed loads is different from shaft loading. Bleed air extraction from the APU diverts pneu-matic energy from the turbine and some of the cooling air from the combustion system. As with the shaft load, the rpmdrops, and with the corresponding ECU command fuel flow increase, recovers to full governed speed.

Air diverted into the aircraft bleed manifold is no longer available to drive the turbine or cool the combustion system. Theloss of pneumatic energy is replaced with thermal energy (fuel) with significant temperature increase.

The following variables influence exhaust gas temperature (EGT) under bleed air load conditions:

- Aircraft demand for bleed air- Ambient air temperature and density

Should EGT reach the limit, the ECU will reduce bleed air flow by modulating the bleed valve toward the closed positionto prevent over temperature.

BLEED VALVE

The APU bleed valve controls airflow to the aircraft bleed system and protects the APU from an overtemperature condition.The valve is controlled electrically and the valve mechanism operates a butterfly valve pneumatically. When the bleedVALVE is open, the ECU adjusts the butterfly plate position to supply the correct quantity of bleed air. These adjustmentsare related to the required quantity of bleed air and APU EGT.

SURGE CONTROL VALVE

The surge control valve is automatically controlled by the ECU. The surge valve is commanded open when the APU issupplying electrical loads at flight altitudes above 15 000 ft. This function reduces APU surge potential when operating inan unloaded condition.

BLEED AIR AVAILABILITY

For the ECU to energize the bleed-air supply system, the APU must be more than 95% of its maximum speed.

BLEED AIR LIMITATIONS

Refer to the Approved Airplane Flight Manual for bleed air limitations.



CONTROL AND INDICATIONS

DESCRIPTION

The APU control panel contains a single three position switch with OFF, RUN and START positions.

For ground operations, a remote cutoff switch is located on the right side of the aircraft, aft of the wing and behind theelectrical connection assess door.

DC electrical power provided by the APU generator is controlled from the ELECTRICAL control panel. Bleed-air servicesare controlled from the AIR COND/BLEED control panel.

APU system operation and fault presentation is provided on the EICAS pages. The FUEL, ECS, ELECTRICAL synopticpages monitor the APU system and services.

EXTERNAL POWER CONTROL PANEL

CF

O05

0300

2_00

3

APU

OFF START RUN

CF

O05

0100

2_00

6

EXTERNAL POWERCONTROL PANEL

ON

GndService EXT DC

AVAIL

IN USE

APU ShutdownLampTest



CONTROLS AND INDICATIONS (Cont)

AIR COND/BLEED CONTROL PANEL

The APU bleed selection can be controlled from the AIR COND/BLEED panel. and the bleed valve position is displayedon the ECS synoptic page.

AIR SOURCENORM

PACK ONLYOFF

AIR COND / BLEED

TRIM AIRONLY

COCKPIT

COLD HOT

RAM AIR

ON

XBLEED R BLEED

OFF

MAN TEMP

ON

CABIN

COLD HOT

APU

ON

L BLEED

OFF

CF

O02

0200

2_00

3

REV 1



CONTROL AND INDICATIONS (Cont)

ELECTRICAL CONTROL PANEL

The APU generator can be controlled by switches located on the ELECTRICAL control panel.

Shown with optional Hydraulic Motor Generator (HMDG) system.

EXT PWRL BATT R BATT

OFF

AVAIL

ON

ELECTRICAL

OFF OFF

OFF

ON

BUS TIE

L GEN APU GEN R GEN

R ESS

R MAIN R AUX

L ESS

L AUX L MAIN

STBYINST

EXT PWRL BATT R BATT

OFF

AVAIL

ON

ELECTRICAL

OFF OFF

OFF

ON

BUS TIE

L GEN APU GEN R GEN

R ESS

R MAIN R AUX

L ESS

L AUX L MAIN

STBYINST

OFF

ON

HYD GEN

REV 2



CONTROLS AND INDICATIONS (Cont)

ELECTRICAL SYNOPTIC PAGE

CF

O07

0100

2_00

7

CAS

CKLST SKIP

FRMT TFC TR/WX ENTER SUMRY

A/ICE FLT FUEL HYD

L R

ECS

600 600

93.0 61.0NI

MACHHOLD

ITT

N2OIL PRESSOIL TEMPFF PPH

84.7461157300

84.7461157300

APU RPM250APU EGT

FUEL QTY LBSTOTAL 12000

6000 6000

START

START

STAB AIL

LWD RWDRUD

L R

NU

ND

6.6

SPOILERS

CAB ALTCAB RATE

73001000

MFD CONTROL

O85.0 MCT 85.0 MCT TRIMV

T

600 600

93.0 61.0NI

MACHHOLD

ITT


84.7461157300

84.7461157300

APU RPM 100250APU EGT

FUEL QTY LBSTOTAL 12000

6000 6000

START

START

STAB AIL

LWD RWDRUD

L R

NU

ND

6.6

SPOILERS

CAB ALTCAB RATE

73001000

MFD CONTROL

COM1 NAV1 ATC1/TCAS ADF1 HF1 COM3 COM2

118.000 108.00 1799.5 118.000 118.000118.000 118.0002.0000190.0108.00118.000 STBY

ABV

TX

O

2.0000 AM

85.0 MCT 85.0 MCT TRIMVT

25

ELECTRICAL° C35 ° C26

24.0 V

L BATT

24.5 V

R BATT0.0 V

GENHYD

L ESS BUS

L MAIN BUS

R ESS BUS

R MAIN BUS

BUS TIE

20 A 30 A0 A

28.5 V 28.0 V

GEN GENGEN

0.0 V

APU

R AUX BUSL AUX BUS

ELEC

1200

AUTO PLAN

SHLDR SIDE

PWREXT

24.1V

DN

GEARFLAPS 0

DN DN




ECS SYNOPTIC PAGE

The ECS synoptic page is used to monitor the APU load control valve.

CF

O03

0500

2_01

0

CAS

CKLST SKIP

FRMT TFC ENTER

ELEC FLT HYD

L R

FUEL

TR/WX SUMRY


118.000 108.00 7777 1799.5 118.000 118.000118.000 118.0002.0000190.0108.00118.000 STBY

ABV

TX 2.0000 AM

DN

CAB ALT

CAB RATE

APU RPM

APU EGT

FUEL QTY LBS

TOTAL


I T T

N1 NU

ND

STAB AILTRIM

LWD RWDRUD

GEARFLAPS

73001000

0

61.0

600

84.746

1157300

100250

1200060006000

93.0

84.7461157300

START

START

600

IGN IGN

85.0 MCT

MACHHOLD

VIBVIB

85.0 MCT

REV

L R

6.6

A/ICE

ECS

MFD CONTROL

RAM AIR

COCKPIT22°

24°

16°

24°

28°

25°

CABIN

MANUAL

PACK TRIM AIR

XBLEED

APU

PSIPSI

OXY QTYCAB ALTCAB RATECAB APLNDG ALT

120062001500

9.114000

45 60

C

C

C

C

C

C

ECS

AUTO PLAN

SHLDR SIDE

DN DN

SPOILERS




FUEL SYNOPTIC PAGE

Operation of the APU pump and fuel SOV is monitored on the FUEL synoptic page.

CAS

CKLST SKIP

FRMT TFC TR/WX ENTER SUMRY

A/ICE ELEC FLT HYD

L R

600 600

61.0NI

ITT


84.7461157300

84.7461157300

APU RPM 100250APU EGT

FUEL QTY LBS

STAB AIL

LWD RWDRUD

NU

ND

6.6

GEAR

SPOILERS

CAB ALTCAB RATE

73001000

FUEL


118.000 108.00 1200 1799.5 118.000 118.000118.000 118.0002.0000190.0108.00118.000 STBY

ABV

TX

UP

2.0000 AM

ECS

85.0 MCT 85.0 MCT TRIM

FUEL USED3900 LBS

° C135° C135

° C43

4870 LBS4870 LBS

TOTAL FUEL9740 LBS

25 25

APU

FUEL

CF

O03

0500

2_01

3

PLANAUTO

SIDESHLDR

61.0

UPUP

L R

FLAPS 0

TOTAL 97404870 4870

TOTAL

CONTROLMFD



EICAS MESSAGES

The APU system messages are displayed on the EICAS.

Inhibits, a brief description, and aural warnings (if applicable) are listed in the table below.

MESSAGE INHIBITS MEANINGAURAL

WARNING

APU FIRE

The APU fire detection loop has activated. On the ground the system should automatically shut the APU down and activate the fire extin-guisher. In flight the APU will not automatically shut down or activate the fire extinguisher

“APU FIRE”

APU OVERTEMP TOAn APU EGT over temperature has been detected. On the ground, the APU will auto-matically shutdown

APU BLEED ALT LIMIT TO/LANDAPU bleed air has been commanded above 20 000 ft or the APU bleed modulated due to excessive EGT

APU FUEL SOV FAIL TO/LAND The APU shutoff valve has failed

APU OVERSPEED TO/LAND The APU has shutdown due to an overspeed

APU OIL PRESS LOW TO/LAND The APU oil pressure is low while in flight

APU OIL TEMP HIGH TO/LAND The APU oil temperature is high while in flight

APU STARTER FAIL ON

TO/LANDPower is still being supplied to the APU starter when electronic control unit is not command-ing a start

APU FAULT TO/LAND

A fault is indicated in the APU system. One or more of the following has occurred:- The APU bleed valve has failed- The APU fuel solenoid has failed- A start is prevented- The avionics are not communicating with the

APU electronic control unit- Reverse flow has been detected

APU SHUTDOWN TO/LANDThe auxiliary power unit electronic control unit has shut down the APU for protective reasons

auxiliary power unit table of contents - · pdf fileauxiliary power unit table of contents ......

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