AC 43.13-1B

Historical

Advisory circular · Acceptable Methods, Techniques, and Practices—Aircraft Inspection and Repair

A newer version is currentThis is a historical version. AC 43.13-1B CHG 1 Ed Update is the version in force, approved September 27, 2001.
Approved
September 8, 1998
Last reviewed
June 11, 2024
Cancelled by
AC43.13-1B CHG 1
Family
AC 43.13-1 · 7 versions
Revision
B
14 CFR parts
43, 65, 145, 21, 105, 23, 91, 121, 25
Cited by
95 ADs

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 21, 2025.

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Appendix 1

624 resin—vast profusion of natural and increasingly, synthetic materials used as adhesives, fillers, binders and for insulation.

resistancethe opposition a device or material offers to the flow or current.

resonance method (ringing) of ultrasonic inspection—a method of detecting material thickness or indications of internal damage by injecting variable frequency ultrasonic energy into a material. A specific frequency of energy will produce the clearest indication of damage in a given thickness of material. When the equipment is calibrated for a specific thickness, and this thickness changes, an aural or visual alert is given.

resonant frequency— the frequency of a source of vibration that is exactl y the same as the natural vibration frequency of the structure.

resonate—a mechanical system is said to resonate when its natural vibration frequency is exactly the same as the frequency of the force applied. When an object resonates at a particular frequency, the amplitude in its vibration will increase immensely as that frequency is reached and will be less on either side of that frequency.

rib—part of primary structure, whose purpose is to maintain profile of airfoil and support fabric or thin wood covering.

sacrificial corrosion— a method of corrosion protection in which a surface is plated with a metal less noble than itself. Any corrosion will attack the plating rather than the base metal.

sandwich construction a structural panel concept consisting in its simplest form of two relatively thin, parallel sheets (face sheets) of structural material bonded to and separated by a relatively thick, lightweight core. High strength-toweight ratios are obtained with sandwiched materials.

scarf joint —a joint made by cutting away similar angular segments of two adherents and bonding the adherents with cut areas fitted together.

score—a surface tear or break on a surface that has a depth and length ranging between a scratch and a gouge.

scratch—a superficial small cut on a surface.

semiconductor device any device based on either preferred conduction through a solid in one direction, as in rectifiers; or on a variation in conduction characteristics through a partially conductive material, as in a transistor.

severe wind and moisture problem (SWAMP) areasareas such as wheel wells, wing folds, and near wing flaps, and areas directly exposed to extended weather conditions are considered SWAMP areas on aircraft.

silicone rubber a high temperature (200 °C) plastic insulation that has a substantial silicone content.

soldering—a group of welding processes that produces coalescence of materials by heating them to the soldering temperature and by using a filler metal having a liquidus not exceeding 450 °C (840 °F) and below the solidus of the base metals.

The filler metal is distributed between the closelyfitted surfaces of the joint by capillary action.

solenoida tubular coil for the production of a magnetic field; electromagnet with a core which is able to move in and out.

spar—main spanwise structural member(s) of an aircraft wing or rotorcraft rotor. A wing may have one or two made into a single strong box to which secondary leading and trailing structures are added.

spiral grain—a type of growth in wood which the fibers take a spiral course about the bole of a tree instead of the normal vertical course. The spiral may extend right-handed or left-handed around the tree trunk.

statorthe part of an AC generator or motor which contains the stationary winding.

stress corrosion— corrosion of the intergranular type that forms within metals subject to tensile stresses which tend to separate the grain boundaries.

surface tape—pinked-edge strips of fabric doped over all seams, rib stit ching, and edges of fabric covering (also called finishing tape).

switcha device for opening or closing an electrical circuit.

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Appendix 1

625 tape—a tape or a “narrow fabric” is loosely defined as a material that ranges in width from 1/4 inch to 12 inches.

TCAStraffic alert and collision avoidance system. An airborne sy stem that interrogates mode A, C, and S transponders in nearby aircraft and uses the replies to identify and display potential and predicted collision threats.

thermocoupledevice to convert heat energy into electrical energy.

thermoplastic material a material that can be repeatedly softened by an increase in the temperature and hardened by a decrease in the temperature with no accompanying chemical change. For example, a puddle of tar on the road in the summer during the heat of day:

the tar is soft and fluid; however, when cooler in the evening, it becomes solid again.

thermoset material a material which becomes substantially infusible and insoluble when cured by the application of heat or by chemical means. A material that will undergo, or has undergone, a chemical reaction (different from a thermoplastics physical reaction) by the action of heat, catalysts, ultr aviolet light, etc. Once the plastic becomes hard, additional heat will not change it back into a liquid as would be the case with a thermoplastic.

tip—part of the torch at the end where the gas burns, producing the high-temperature flame.

transceivera unit serving as both a receiver and a transmitter.

transformera device for raising or lowering AC voltage.

transmitteran electronic system designed to produce modulated RF carrier waves to be radiated by an antenna; also, an electric device used to collect quantitative information at one point and send it to a remote indicator electrically.

transponderan airborne receiver-transmitter designed to aid air traffic control personnel in tracking aircraft during flight.

unbonding—adhesive or cohesive failure between laminates. Compare definitions of adhesive, cohesive debond, and disbond.

very high frequency (VHF) a frequency between 30 and 300 MHz

VHF omnirange (VOR) an electronic air navigation system that provides accurate direction information in relation to a certain ground station.

videoscope—a type of borescope.

visible light—electromagnetic radiation that has a wavelength in the range from about 3,900 to 7,700 angstroms and that may be seen by the unaided human eye.

visual check utilizing acceptable methods, techniques, and practices to determine physical condition and safety item.

voltunit of potential, potential difference, or electrical pressure.

voltage regulator device used in connection with generators to keep the voltage constant as load or speed is changed.

warpthreads in a fabric that run the length of the woven material as it comes from the mill.

wattthe unit of power; equal to a joule per second.

wattmeteran instrument for measuring electrical power.

waveguidea hollow, typically rectangular, metallic tube designed to carry electromagnetic energy at extremely high frequencies.

wavy-grained wood —wood in which the fibers collectively take the form of waves or undulations.

welding—a materials-joining process used in making welds.

welding rod— a form of welding filler metal, normally packaged in straight lengths.

welding torch—the device used in gas welding.

wood decay —disintegration of wood substance through the action of wood-destroying fungi.

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Appendix 1

626 wood decay - incipient—the early stage of decay in which the disintegration has not proceeded far enough to soften or otherwise perceptibly impair the hardness of the wood.

wood decay - typical or advanced —the stage of decay in which the disintegration is readily recognized because the wood has become punky, soft and spongy, stringy, pitted, or crumbly.

x-ray—a radiographic test method used to detect internal defects in a weld.

XL-ETFEA process of radiation cross-linking the polymer chains is used to thermally set the plastic. This prevents the material from softening and melting at elevated temperature.

XL-Polyalkenean insulation material based on the polyolefin family that has its normally thermomelt characteristic altered by the radiation cross-linking process to that of a nonmelt, therm-set material.

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Appendix 2

1 APPENDIX 2. ACRONYMS AND ABBREVIATIONS

The acronyms and abbreviations listed are some of many that are likely to be encountered by the aviation mechanic or technician involved in the maintenance of aircraft.

429ARINC 429 data bus standard 629ARINC 629 data bus standard A/Danalog/digital; analog-to -digital A/D CONVanalog-to -digital converter A/Lautoland ACAdvisory Circular acalternating current ACARSARINC Communication Addressing and Reporting System ACOAircraft Certification Office ADAirworthiness Directive ADCair-data computer ADCPATC dual-control panel ADEDSadvanced electronic display system ADFautomatic direction finder ADIattitude-director indicator; air data instrument AFCautomatic frequency control AFCSautomatic flight control system AFDSautopilot flight detector system AIMAeronautical Information Manual AIRCOMair/ground communications AMamplitude modulation AMP or AMPLamplifier AMPamperes AMSAerospace Material Specification ANArmy/Navy ANDArmy Navy Design ANSIAmerican National Standards Institute ANTantenna APautopilot APBauxiliary power breaker APCUauxiliary power control unit APUauxiliary power unit ARINCAeronautical Radio Incorporated ARNC IOARINC I/O error ARNC STPARINC I/O UART data strip error ASTMAmerican Society for Testing Materials ATAAir Transport Association ATCair traffic control ATCTATC transponder ATCTSATC transponder system AUXauxiliary AVCautomatic volume control AWGAmerican Wire Gauge AWSAir Weather Service B/CUbattery/charger unit BAT or BATTbattery BCDbinary-coded decimal BITbinary digit; built-in test BITEbuilt-in test equipment BITSbus interconnect transfer switch BNRbinary numerical reference; binary BPband-pass BPCUbus power control unit BTbus tie BTBbus tie breaker BTCbefore top center BUSelectrical bus; 429 digital data bus C.G.Center of Gravity CACcaution advisory computer CAGEcommercial and government entity code CAWScentral aural warning system; caution and warning system CB, C/B, or CKT/BKRcircuit breaker CDIcourse-deviation indicator CDUcentral display unit CFCcarbon fiber composite CFDIUcentralized fault display interface unit CFDScentralized fault display system CH or CHANchannel CHGRcharger CKTcircuit CLKclock CLRclear CMCScentral maintenance computer system CMPTRcomputer COcarbon monoxide COAXcoaxial COPcopper CPcontrol panel CRTcathode-ray tube; circuit CSE or CSEU control system electronics unit CSEUPcontrol system electronics unit panel CTcomputed tomography CTcurrent transformer CTNcaution CUcontrol unit; copper CVRcockpit voice recorder CWcontinuous wave D/Adigital-to-analog DACdigital-to analog converter DADCdigital air-data computer DBTdead bus tie dcdirect current

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Appendix 2

2 DCDRdecoder DDBdigital data bus DEMODdemodulator DEMUXdemultiplexer DFDRdigital flight data recorder DGdirectional gyro DGTLdigital DHdecision height DISC SOLdisconnect solenoid DISCdisconnect DISTRdistribution DMAdirect memory access DMBdead main bus DMCdisplay management computer DMEdistance-measuring equipment DMEAdistance-measuring equipment antenna DNdown DUdisplay unit E/Eor E & E electrical/electronic E1-1first shelf, number 1 equipment rack E2-2second shelf, number 2 equipment rack EADFelectronic automatic direction finder EADIelectronic attitude-director indicator EAROMelectrically alterable read-only memory ECEICAS computer ECAMelectronic centralized aircraft monitoring EDSPEICAS display select panel EDUEICAS display unit EECelectronic engine control EFIelectronic flight instrument EFISelectronic flight instrument system EFISCPEFIS control panel EFISCUEFIS comparator unit EFISG EFISsymbol generator EFISRLS EFISremote light sensor EHSIelectronic horizontal-situation indicator EHSIDelectronic horizontal-situation indicator display EHSVelectrohydraulic servo value EICASengine indicating and crew alerting system ELCUelectrical load control unit ELECelectric; electronic ELECTelectrical ELEXelectronics; electrical ELTEmergency Locator Transmitter EMER GENemergency generator emfelectromotive force EMFIelectromechanical flight instrument EMIElectromagnetic interference EP AVAILexternal power available EPexternal power EPCexternal power contactor EPCSelectronic power control switch EPROMerasable programmable read-only memory eV—electron volt EXCTRexciter EXT PWRexternal power FAAFederal Aviation Administration FAA-PMAFederal Aviation Administration Parts Manufacturer Approval FMfrequency modulation FM/CWfrequency modulation continuous wave FMCflight management computer FMCDflight management computer control display unit FMCSflight management computer system FMSflight management system FODforeign object damage FREQfrequency FSEUflap/slat electronic unit FW or FWDforward G/Sglide slope GAL or GALYgalley GCRgenerator control relay auxiliary contact GCUgenerator control unit GEBgenerator circuit breaker GENgenerator GLRgalley load relay GMAWgas metal arc welding GMTGreenwich mean time; cordinated Universal time GND PWRground power GND RETground return GND SVCEground service GND or GRDground GPCUground power control unit GPSglobal positioning system GPSWgear opposition switch GPUground power unit GPWground proximity warning GPWSground proximity warning system GSRground service relay GSSRground service select relay GSTRground service transfer relay GTAWgas tungsten arc welding GWPCground proximity warning computer H/Lhigh/low HEAhigh-frequency radio antenna HF (hf) high frequency (3 to 30 MHz) HFCPhigh-frequency radio control panel HI Zhigh impedance HZhertz

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Appendix 2

3 I.D.inner diameter I/Oinput/output IAPSintegrated avionics processor system IASindicated airspeed IDGintegrated drive generator IFintermediate frequency IFRinstrument flight rules IGNignition IISintegrated instrument system ILSinstrument landing system INDLindicator light INSTinstrument INSTRinstrument INTCONinterconnect INTECinterface INTERinterrogation INTPHinterphone INVinverter IR ILSreceiver kHzkilohertz KSIthousands of pounds per square inch kVkilovolts kVAkilovoltamperes kVARkilovoltampere reactive L-Bandradio frequency band (390 to 1550 MHz) LCDliquid-crystal display LDload LEDlight-emitting diode LF (lf) low frequency (30 to 300 kHz) LO Zlow impedance LOClocalizer LRUline replaceable unit LSloudspeaker LSBlower sideband LSPTMlimit switch position transmitter module LTlight LTS lights MACmean aerodynamic chord MAN/ELECmanual/electric MBAmarker-beacon antenna MCDPmaintenance control and display panel MCDUmultipurpose control and display unit MDEmodern digital electronics MECmain equipment center; main engine control MEG or MEGAmillion MEKmethylethylketone MEMmemory METOMaximum except-take off MF(mf) medium frequency (300 kHz to 3 MHz) MHzmegahertz MICmicrophone MICRO-Pmicroprocessor MIGmetal inert gas MILLIone one-thousandth (0.001) MKR BCNmarker beacon MSmilitary standard MSDSMaterial Safety Data Sheets MSEC(ms) milliseconds MSGmessage MTBFmean time-between-failure MUXmultiplexer mVmillivolts NASNational Aerospace Standard NAVnavigation NCnormally closed; not connected;

no connection NDBnondirectional beacon NDINondestructive Inspection NEGnegative NSEC (ns) nanoseconds NTSBNational Transportation Safety Board NVMnonvolatile memory OAMoriginal aircraft manufacturer OBSomni bearing selection OCovercurrent OEMoriginal equipment manufacturer OFover-frequency OVV or OVovervoltage OVVCO or OVCOovervoltage cutout P-Sparallel to series PApassenger address; power amplifier PARA/SERparallel to serial PCUpassenger control unit; power control unit PFDpermanent-magnet generator PMAParts Manufacturer Approval POSpositive POTpotentiometer; plan of test PRpower relay PRLparallel PROMprogrammable read-only memory PROXproximity PSEUproximity switch electronic unit PSIpounds per square inch PWRpower PWR SPLYpower supply QPLQualified Products List QTYquantity r-treceiver-transmitter RAradio altimeter; radio altitude RADradio RAIND radio altimeter indicator RAMrandom-access memory RARTradio altimeter receiver-transmitter

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Appendix 2

4 RATram air turbine RCCBremote-control circuit breaker RCLrecall RCVRreceiver RCVR/XMTRreceiver/transmitter RDMIradio distance magnetic indicator RF (rf) radio frequency RFIradio-frequency interference RLSremote light sensor RMIradio magnetic indicator rpmrevolution per minute RTVroom temperature vulcanizing SAESociety of Automotive Engineers SATstatic air temperature SATCOMsatellite communication SCRsilicon-controlled rectifier SDIsource destination identifier SELCALselective calling system SER DLserial data link SGsymbol generator SITASociété International de Telecommunications Aeronautiques SMAWshielded metal arc welding SMDsurface mounted device SNRsignal-to-noise ratio SOLsolenoid SOLVsolenoid valve SOMstart of message SOTstart of transmission SPKRspeaker SPRsoftware problem report SQLsquelch SSBsingle sideband SSIDSupplemental Structural Inspection Documents SSMsign status matrix STsynchro transmitter STAT INVstatic inverter STBYstandby STCSupplemental Type Certificate SWswitch SYM GENsymbol generator T-Rtransformer-rectifier TATtrue air temperature TBDPtie bus differential protection TCType Certificate TCAStraffic alert and collision avoidance system TCDSType Certificate Data Sheets TDCtop dead center TFRtransfer TIGtungsten inert gas TMCthrust management computer TMSterminal marking sleeve TMSthrust management system TMSPthrust mode select panel TRUtransformer-rectifier unit TSOTechnical Standard Order TXPDRtransponder µmicro UBRutility bus relay UFunderfrequency UHFultrahigh frequency (300 MHz to 3 GHz) UNDFunderfrequency UNDVundervoltage USunderspeed USB (us)upper sideband USECmicroseconds UVundervoltage UVutraviolet V ac, Vac, or VACvolts alternating current V dc, Vdc, or VDC volts direct current Vvolts; voltage; vertical; valve VAvolt-amperes VARvolt-ampere reactive VFRvisual flight rules VHF (vhf) very high frequency (30 TO 300 MHz) VLSIvery large-scale integration VORVHF omnirange; visual omnirange VORTACVOR tactical air navigation VRvoltage regulator VRMSvolts root means square Wwatts WARNwarning WCPweather radar control panel WEAweather WEUwarning electronics unit power supply WPTwaypoint WX (WXR)weather radar XCVRtransceiver XDCRtransducer XFMRtransformer XFRtransfer XMITtransmit XMTRtransmitter XPDRtransponder

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Appendix 3

APPENDIX 3. METRIC-BASED PREFIXES AND POWERS OF 10

Atto (a) = quintillionth of = 10 -18 times Femto (f) = quadrillionth of = 10 -15 times Pico (p), or µµ = trillionth of = 10 -12 times Nano (n), or mµ = billionth of = 10 -9 times Micro (µ) = millionth of = 10 -6 times Milli (m) = thousandth of = 10 -3 times` Centi (c) = hundredth of = 10 -2 times Deci (d) = tenth of = 10 -1 times unity = 10 0 = 1 Deka (da) = ten times = 10 times Hecto (h) = hundred times = 10 2 times Kilo (k) = thousand times = 10 3 times Mega (M) = million times = 10 6 times Giga (G), or kM = billion times = 10 9 times Tera (T) = trillion times = 10 12 times

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Appendix 3