**GLOSSARY**

The abbreviations and terms listed below are not intended to be an
exhaustive sample of what is or should be used in the preparation of
descriptions of events pertaining to aeronautical products. The list was
compiled from Service Difficulty Report (SDR) data submitted to the FAA.
The duplication of abbreviations is deliberate to allow users to see the
variations and difficulties that are encountered by the FAA and industry
in collecting and analyzing the text of maintenance related data. This
document may help lay the foundation for the development of standard
terminology for the text.

**ABBREVIATION/TERMS CODE ABBREVIATION/TERMS CODE**

**A**

AAP (AUTOFLT ANNUNCIATOR PANEL) 2210

ABS (ANTI-SKID BRAKE SYSTEM) 3241

ACARS (PULSE CODED TRANS SYS) 2320

ACM (AIR CYCLE MACHINE) 2150

ACW (AIR CREW WARNING) 3150

ADC (AIR DATA COMPUTER) 3417

ADF SYSTEM (AUTO DIRECTION FINDER) 3455

ADI (ATTITUDE DIRECTION INDICATOR) 3425

ADU (ATTITUDE DIRECTION UNIT) 3421

AFCS (AUTOFLT CONTROL SYSTEM) 2210

AHC (AUTO HEADING COMARATOR) 3425

AHRS (ATTITUDE HEADING REFERENCE SYS) 3425

AIRSTAIR DOOR 5260

AIRSTAIRS-INDEPENDENT 5260

AIRPHONE 2300

ALTITUDE ALERTER 3444

AOA (ANGLE OF ATTACK SENSOR) 3418

APP (AUTO-PILOT PANEL) 2210

APU GENERAL REPORTS 4900

ARP (AIR DATA REFERENCE PANEL) 3410

ARTS (FLT MANAGEMENT SYSTEM) 3460

ASDAR (ACFT TO SATELLITE DATA RELAY) 3170

ATC (TRANSPONDER SYSTEM) 3452

ATM (AIR TURBINE MOTOR) (HYD PUMP) 2923

ATM (AIR TURBINE MOTOR-STC APJC) 2420

ATM (COOLING TURBINE) 2150

ATTACH (TRUNNION) 3211

AUA (WASTE WATER HEATER) 3070

AUTO ALTITUDE SYSTEM 2220

AUTO COURSEN 6120

AVIONIC FLOW LIGHT 2120

AVM SYSTEM (VIBRATION ANALYZE SYS) 7732

**B**

BATT CHARGER (BATTERY CHARGER) 2432

BETA SWITCH 6140

BIRD STRIKE-ENGINE COWL/INJESTION 7200

BPCU (BUS POWER CONTROL UNIT) 2450

BRAKE DE-ICE 3240

BREATHER TUBE 7261

BULLET 7220

BLEED AIR FAILURE-DUAL (BEECH 1900) 3610

**C**

CADC (CENTRAL AIR DATA COMP) 3417

CAWS (CENTRAL AURAL WARNING SYS) 3150

CCAS (COCKPIT CREW ALERTING SYSTEM) 3150

CDU (CENTRAL DATA UNIT) 3460

CGCC (CENTER OF GRAV CONT COMPUTER) 2820

CHIP DETECTOR 7260

CISW HDS LIGHTS 3150

COALESCER SOCK (HUMIDITY CONTROL) 2170

COMPASS SYSTEM 3420

CONE BOLTS (ENGINE MOUNTING SYSTEM) 7120

COOLING FAN-EQUIP.RACK.GEN.DISTRI.) 2121

COOLING TUBE (JT8D ENGINE) 7520

COWLING (ENGINE) 7110

CPU (CONTROL PROTECTION UNIT) 2430

CROSS TIE LIGHT \"ON\" 2425

CROWN INSP. (TOP OF FUSELAGE STRUCT) 5310

CRT (CATHODE RAY TUBE) 3442

CRUISE TRIM (HORIZ. STAB. CONT. SYS) 2740

CSD (CONSTANT SPEED DRIVE) 2410

CSEU CONTROL SYSTEM ELECTRONIC UNIT 3140

CTA CURRENT TRANSFORMER ASSY 2433

CTOT (CONSTANT TORQUE ON TAKEOFF) 7712

CTC (CABIN TURBO COMPRESSOR) 2110

CUD (COURSE UNIT DISPLAY) 3425

CV (CONVERTER/REGULATOR) 2436

CVR (COCKPIT VOICE RECORDER) 2370

CW LIGHTS (CENTRAL WARNING SYS) 3150

CWP (COCKPIT WARNING PANEL) 3150

CWS (CENTRAL WARNING SYSTEM) 3150

**D**

DADC DIGITAL AIR DATA COMPUTER 3417

DBU DATABASE UNIT 3140

DCAS (DIGITAL CORE AVIONIC SYSTEM) 3140

DECU (DIGITAL ELECT CONTROL UNIT) 7321

DFDR (DIGITAL FLIGHT DATA RECORDER) 3130

DFGC (DIRECT FLIGHT GUIDANCE CONP) 3460

DFGS (DIRECT FLIGHT GUIDANCE SYSTEM) 3460

DME SYSTEM (DISTANCE MEASURE EQUIP) 3451

DRAIN MAST HEATER (PITOT ANTI-ICE) 3030

DRIP STICK (FUEL QTY.IND.TANK.MNT) 2840

DUAL BLEED AIR FAILURE (BEECH 1900) 3610

**E**

EADI (ELECTRONIC ATTITUDE DIR.IND) 3421

ECU (ENGINE CONTROL UNIT) 7321

ECU ELECTRONIC CONTROL UNIT 2750

EDC (ENGINE DRIVEN COMPRESSOR) 3610

EDP (ENG.FUEL PUMP-RECIP ENGINE) 7314

EDP (ENG.FUEL PUMP-TURBINE ENGINE) 7314

EDP (ENGINE HYDRAULIC PUMP) 2913

EEC (ELECTRONIC ENGINE COMPUTER) 7321

EEL (EMERGENCY EXIT LIGHTS) 3350

EFIS (ELECT.FLITE INDICATION SYSTEM) 3425

EICAS (ENG IND CENTRAL ALERT SYS) 7200

EICAS (PANEL MOUNT-ENG IND/ALERT) 3150

EMERGENCY LANDING GEAR EXTENSION 3230

ENG SCREENS (TURBINE ENG. OIL SYSTEM) 7261

ENG SLOW ACCESS (FUEL CONTROL SYS) 7320

ENGINE CHANGE \-- ROUTINE 7200

ENGINE COMPRESSOR FAN-NO ROTATE 7230

ENGINE STALL/COMPRESSOR STALL 7230

ENGINE VIBRATION 7200

EPA (ENVIRONMENTAL PROTECT.AGENCY) 7170

EPC (EXTERNAL POWER CONTAINER) 2440

EPR (ENGINE PRESSURE RATIO SYSTEM) 7711

EPR BRACKET (ENG.PRESSURE RATIO) 7711

EVBC (ENGINE VARIABLE BLEED CONTROL) 7530

EVC (ENGINE VANE CONTROL) 7530

**F**

FDAU (FLITE DATA ACQUISITION UNIT) 3460

FDI (INTEGRATED FLIGHT INDICATOR) 3425

FEEL SENSOR (STICK SHAKE TEST FAIL) 3418

FETM (FUEL ENRICHMENT TQ MOTOR) 7320

FFG (FUEL FLOW GOVERNOR) 7320

FFR (FUEL FLOW REG) 7320

FGC (FLIGHT GUIDANCE COMPUTER) 3460

FIREWALL 5412

FIRST AID KIT 2560

FLAP CONTROL UNIT 2750

FLIGHT DIRECTOR 3425

FLIGHT RECORDER 3130

FLUX DECTECTOR 3422

FMC (FLT.MANAGEMENT COMPUTER) 3460

FMCS (FLT MNGMNT COMPUTER SYS) 3460

FMS (FLIGHT MANAGEMENT SYSTEM) 3460

FOD (FOREIGN OBJ DAMAGE-ENG) 7200

FOD (FOREIGN OBJ DAMAGE AIRFRAME 5101

FOD (FOREIGN OBJ DAMAGE FUSELAGE 5300

FOD (FOREIGN OBJ DAMAGE WING 5700

FOD (FOREIGN OBJ DAMAGE EMPENNAGE) 5500

FSEU (FLAP/SLAT ELECTRONIC UNIT) 2750

FUEL FLOW INDICATION 7331

FUEL HEATER/SYSTEM 7312

FUEL LEAK-ENGINE/PYLON/COWL AREA 7310

FUEL LEAK-WING AREA 2810

FUEL LINE FROM VSV-MEC 7310

FUEL NOZZLE 7313

FUEL PRESSURE WARNING SWITCH 2840

FUEL TEMP (TANK PROBE) 2843

FUEL TOTALIZER (FUEL QUANTITY IND) 2841

**G**

GALLEY EQUIPMENT LIFT 2530

GARLOCK SEAL (STARTER SEAL) 7261

GASPER FAN 2121

GCU (GENERATOR CONTROL UNIT) 2424

GIRT BAR (ESCAPE SLIDE SYSTEM) 2560

GPWS (GROUND PROXIMITY WARNING SYS) 3444

GROUND RANGE LIGHT (PROP INDICATING) 6140

**H**

H.P. BLEED AIR VALVE-JET ENGINE 7532

HASOV (HOT AIR SHUT-OFF VALVE) 2120

HMU (HYDROMECHANICAL UNIT) 7320

HOC (HIGH OIL CONSUMPTION-JET ENGINE) 7261

HOT SECTION (ENGINE COMBUSTION SECT) 7240

HOT/HUNG START/LOW ENGINE POWER 7320

HPT BORESCOPE-HIGH PRESSURE TURBINE 7250

HSI (INTEGRATED FLIGHT INDICATOR) 3425

HSTCU (HORIZ STAB TRIM CONTROL UNIT) 2740

HYD ISO VALVE (HYDRAULIC ISOLATION) 2910

**I**

IDG (INTEGRATED DRIVE GENERATOR) 2421

IFS (INTEGRATED FLIGHT SYSTEM) 3425

IGV (INLET GUIDE VANE) 7230

ILS SYSTEM (INSTRUMENT LANDING SYS) 3431

INLET BULLET/CONE 7220

INU (INERTIAL NAVIGATION UNIT) 3441

IRS (INERTIAL REFERENCE SYSTEM) 3420

IRU (INERTIAL REFERENCE UNIT) 3441

ISOLATION VALVE 3610

ISOV (ISOLATION SHUTOFF VALVE) 3610

ISU (INTERTIAL SENSING UNIT-FLT IN) 3441

ITT (INLET TURBINE TEMP) 7722

IVSI (INSTANT VERTICAL SPEED IND.) 3413

IEC (INTEGRAL ELECTRONIC CONTROL 7600

**J**

JFC (ENGINE FUEL CONTROL) 7321

**L**

LAV LEAK - NOT SPECIFIC 3800

LBA LOW BLADE ANGLE 6120

LDG PROXIMITY BOX 3260

LIGHT/LAMP/SWITCH-OIL FILTER BYPASS 7931

LIGHTNING STRIKE-ENGINE COWLING 7200

LOC (LOCALIZER - VOR SYSTEM) 3454

LOP (LOW OIL PRESSURE ACTUAL JET ENG) 7261

LRRA (LOW RANGE RADIO ALTIMETER) 3444

**M**

MACH TRIM & MACH SPEED CONTROL 2220

MAGNA STICK 2840

MASTER WARN ANN PANEL 3150

MAXARET (BRAKE ANTI-SKID SENSOR) 3241

MCDU (MULTIPURP CNTL DISPLAY UNIT) 3150

MEC MAIN ENGINE CONTROL 7321

MEGAPHONE 2560

MFDU (MULTI FUNCTION DISPLAY UNIT) 3140

MFQ (MAIN FUEL QUANTITY) 2841

MH4 (INTEGRATED FLIGHT SYSTEM) 3425

MHDI (HORIZON DIRECTION IND) 3425

MHR4 3425

MICROPHONE/HEADSET/SPEAKER/NOISE 2350

MITP (METAL IN TAIL PIPE) 7200

MUX (MULTIPLEXER) 2330

**N**

N1/N2 (TACHOMETER) 7714

NAV RECEIVER (NAVIGATION) 3454

NAV. NO.1 ILS 3431

NAV/COM REPORTS (CODE TO COMM 23) 2312

NOSE BULLET (ENGINE INLET CENTER) 7220

NOSE CAL VALVE 3020

NTS (NEGATIVE TORQUE SENSOR) 6120

**O**

OAT (OUTSIDE AIR TEMPERATURE) 3412

OIL CAP/LOW OIL LEVEL-TURBINE ENGINE 7261

OIL FILTER\--TURBINE ENGINE 7261

OIL LEAKAGE (TURBINE ENGINE ONLY) 7261

OIL PUMP, TURBINE ENGINE 7261

OIL REPLENISH (TURBINE ENGINE) 7261

OVERTEMP-TURBINE ENGINE (ACTUAL) 7250

**P**

P & D VALVE (ENG FUEL PRESS/DUMP) 7320

P/S (POWER SECTION-RECIP ENGINES) 8520

P2 LINE 7320

P3 LINE 7320

PCU (PROP CONTROL UNIT) 6120

PDC PERFORMANCE DATA COMPUTER 3460

PDU (INDEPENDENT POSITION UNIT) 3440

PERSONNEL LIFT 2530

PFCS (SPOILER SYSTEM) 2760

PFP4 (BLEED AIR SENSE LINE FILTER) 7320

PGB (PROPELLER GEAR BOX) 7210

PMC (POWER MANAGEMENT CONTROL) 7320

PNEUMATIC COMPRESSOR 3600

POWER BUSS 2450

PRBCV (BLEED CONTROL VALVE) 7532

PRE-COOL BLEED AIR (BEFORE CABIN) 3610

PRESS/VENTURI FAN (BAE125) 2130

PROXIMITY SWITCH 3260

PSEU (PROXIMITY SENSE ELECT UNIT) 3260

PSU (PASSENGER SERVICE UNIT) 2520

PT2 PROB (TEMPERATURE PROBE) 7320

PTU POWER TRANSFER UNIT 2910

PYLON BLOWOUT PANEL 5400

**Q**

Q HEAT (PITOT HEAT) 3030

**R**

RADIO ALT (RECEIVER) 3444

RADIO ALT (RADIO ALTIMETER) 3444

RADOME STRUCTURE 5350

RAT (RAM AIR TEMP) 3412

RAT (RAM AIR TURBINE) 2920

RCCB (REMOTE CTRL CIRCUIT BREAKER) 2430

RDI (INTEGRATED FLIGHT INDICATOR) 3425

RMDI (COURSE DIRECTION INDICATOR) 3425

RMI (RADIO MAGNETIC INDICATOR) 3454

ROOTS BLOWER 2121

ROSEMONT HEAT 3030

ROSEMONT PROBE (STALL WARNING) 3418

RTOP (RESERVE TAKEOFF POWER) 7320

RVDT (ROTARY VARIABLE DISPL TRANSD) 3418

**S**

S DUCT 5400

S/G (STARTER-GENERATOR) 2435

SAI (STANDBY ATTITUDE INDICATOR) 3420

SAS (STALL WARNING SYSTEM TEST) 3418

SAT (STATIC AIR TEMPERATURE) 3412

SBC (SURGE BLEED CONT. COMP STALL) 7530

SCAT (INTEGRATED FLIGHT SYSTEM) 3425

SIF (ACFT STALL INDICATOR FAILURE) 3418

SIGN (NO SMOKE/SEAT BELTS SIGN) 3320

SKIN AIR VALVE (RAM AIR VLV) 2150

SLIDE PRESSURE LOW (BOTTLE REPLACE) 2560

SLIDE PRESSURE LOW (SLIDE REPLACE) 2565

SNUBBER.TIRE IN WELL AFTER RETRACT) 3230

SPEED TRIM FAIL LIGHT 2220

SPOOL DOWN-ENGINE 7200

SPR (SINGLE POINT REFUELING) 2810

SQUAT SWITCH (FLT/GROUND SWITCH) 3260

SRL (SINGLE RED LINE COMPUTER) 7722

SSB (SPLIT SYSTEM BREAKER) 2450

STABILON 5510

START VALVE (ENGINE MANUAL START) 8010

STATIC WICKS 2360

STATOR BLADE-VARIABLE 7530

STAUS MESSAGE PRI CONTL.CLEAR.MES 3160

SWIVEL FITTING(LDG.GEAR RETR.SYS) 3230

SWIVEL FLAP (ENG.THRUST REVERSER) 7830

SYMB GEN (ELECTRIC POWER IND.SYS) 2425

**T**

T.O. WARN HORN (TAKEOFF WARN HORN) 3150

T/R (THRUST REVERSER SYSTEM) 7830

TACAN (MILITARY TYPE NAVIGATION) 3451

TAI (TAIL ANTI-ICE) 3010

TAIL CONE 5350

TAS (TRUE AIR SPEED) 3414

TAT (TOTAL AIR TEMPERATURE) 3412

TGT (TURBINE GAS TEMP) 7722

TMS (THRUST MANAGEMENT SYSTEM) 7600

TMS ACTUATOR (THRUST MGMT SYS) 7600

TO (TAKEOFF WARNING) 3150

TORLON INSERT 7210

TORQUE COND UNIT 7712

TORQUE RING 7712

**T**

TPU (TRANSIT PRESSURE UNIT) 7532

TRAP PANEL (TRAPEZOIDAL) 5320

TRI (THRUST RATING INDICATOR) 7711

TRU (TRANSFORMER RECTIFIER UNIT) 2433

TRUNNION-MLG 3211

TRUNNION-NLG 3221

TSCU )TORQUE SENSING CONTROL UNIT) 7712

TSCU (TORQUE SIGNALING COND.UNIT) 7712

TTL (TOTAL TORQUE LIMITER) 7712

TTL VALVE 7712

TURBOCOMPRESSOR (DC8, 880, 707, 720) 2110

**U**

UBR UTILITY BUS RELAY 2450

UER (UNSCHEDULED ENGINE REMOVAL) 7200

**V**

VARIABLE STATOR VANE (VSV) TUBE 7530

VBV (VARIABLE BLADE VANE) 7530

VERNATHERM VLV 7922

VHF (COMM 1 OR COMM 2) 2312

VOICE RECORDER 2370

VOR SYSTEM (VISUAL OMNI RANGE) 3454

VORTILON (AIR DAM ON WINGS) 5720

VOT (VARIABLE OMNI TEST-VOR) 3454

VSI (VERTICAL SPEED INDICATOR) 3413

**W**

WEU WARNING ELECTRONIC UNIT 3150

WOW (WEIGHT ON WHEELS) SQUAT SWITCH 3260

WSW (WIND SHEAR WARNING) 3436

WXR (WEATHER RADAR) 3442

**Y**

YAW DAMPER 2210