MODEL 172 SERIES SERVICE MANUAL

3-4 . . . . . . . . . . . . . . . . . . . . . . . . . 1 * 5 -24 . . . . . . . . . . . . . . . . . . . . . . . 3 3-4A ........................ 1 5-25 thru 5-38 ................. 0 3-4B Blank ............. 1 5-39 ........................ 1 3-5 thru 3-7 . . .................. 1 *5-40 ....................... 3 3-8 thru 3-12 .................. 0 5-41 ........................ 0 3-12A thru 3-12F ............... 0 *5-42 ....................... 3 3-13 thru 3-14 . ........... 1 5-43 ........................ 0 3-15 thru 3-17 ................. 0 5-44 Blank ................... 0 3-18 . . . . . . . . . . . . . . . . . . . . . . . 1 6-1 . . . . . . . . . . . . . . . . . . . . . . . . . 2 3-19 thru 3-20 . ........... 0 A Revision 3 MODEL 172 SERIES SERVICE MANUAL LIST OF EFFECTIVE PAGES Page Revision Page Revision No. No. No. No. 6-2 thru 6-7 . .................. 0 *12-17 ..................... 3 6-8 ......... ......... ...... 2 12-18 thru 12-22 .............. 0 6-9 thru 6-12 .......... ........ 0 12-23 ..................... 3 7-1 ... ............ ....... .. 1 12-24 thru 12-33 .............. 0 7-2 thru 7-7 ................... 0 12-34 Blank ................. 0 *7-8 ................... . ... . 3 13-1 1 7-9 thru 7-12 .................. 0 13-2 .......... ... 3 8-1 .. 1.................. .. 8-5 . ...................... . 8- ..................... 0 14-1 ....................... 3 *8-7 ........................ 3 14-2 thru 14-6 ................ 0 8-8 ......................... 0 *15-1 ...................... 3 9-1 ........................ 1 15-2 thru 15-20 ............... 0 9-2 thru 9-10 .................. 0 15-20A thru 15-20C ............ 0 10-1 ......................... 1 15-20D ..................... 1 10-2 thru 10-10 ................ 0 15-21 ......... 0 11-1 thru 11-2 ................. 15-22 ....... 3 11-2A . .1 15-23 thru 15-26 .............. 0 11-2B Blank ................... 1* 15-2 thru 51-2 .................... *11-15 3 15-29 thru 15-31 .............. 0 11-36 ................... .... 16-1 thru ................ 1 11-37 thru 11-38 .............. 0-thru 16-6 ................. 0 11-1 thru 11A-2...................... 1- . . .... 0 11-13 thru 11-15 ............... 0 1- Blank ................. 0 *11-16 ....................... 16-7 thru 16-40 ............... 11-18 thru 11-31 .............. 01-3 ................ 11A-20thru 11A-2 ............... 1 16-B6A tak ................ 0 11-3 thru 11A- 1 .............. 0 16-41 thru 16-50.............. 0 11A-1 ...................... 3. 12-2 ............. .. 0 *16-51 ............... 3 *12-3 . .3 16-52 thru 16-54 .. 0 11A-41 ....................... 016 12-4A 0 .............................. 0 16-55 thru 16-60 ................ 11A-18 thru 11A-19 ............. 0. ... . . ... 12-4B Blank.0 16-60A ................ 0 11A-20 Blank .................. 016-0 ..................... 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C Revision 3 MODEL 172 SERIES SERVICE MANUAL TABLE OF CONTENTS SECTION PAGE NO. AEROFICHE/MANUAL 1. GENERAL DESCRIPTION ..................... ......... 1A9/1-1 2. GROUND HANDLING, SERVICING, CLEANING, LUBRICATION AND INSPECTION ...................... 1B11/2-1 3. FUSELAGE ............................................ 1F9/3-1 4. WINGS AND EMPENNAGE ............................. 1H5/4-1 5. LANDING GEAR AND BRAKES ......................... 111/5-1 5. AILERON CONTROL SYSTEM .......................... 1K5/6-1 7. WING FLAP CONTROL SYSTEM ........................ 1K21/7-1 8. ELEVATOR CONTROL SYSTEM ........................ 1L13/8-1 9. ELEVATOR TRIM TAB CONTROL SYSTEM ............. 2A3/9-1 10. RUDDER CONTROL SYSTEM .......................... 2A17/10-1 11. ENGINE (MODEL O-320-H2AD) ......................... 2B7/11-1 11A. ENGINE (MODEL O-320-D2J AND MODEL O-360-A4N) .................................... 2D3/11A-1 12. FUEL SYSTEM ......................................... 2E3/12-1 13. PROPELLERS AND PROPELLER GOVERNORS .......... 2F19/13-1 14. SYSTEMS .............................................. 2G3/14-1 15. INSTRUMENTS AND INSTRUMENT SYSTEMS .......... 2G13/15-1 16. ELECTRICAL SYSTEMS ...................... ......... 217/16-1 17. ELECTRICAL SYSTEMS (DELETED) 18. STRUCTURAL REPAIR ................................. 3A3/18-1 19. PAINTING ............................................. 3C3/19-1 20. WIRING DIAGRAMS ................................... 3C171/20-1 WARNING When performing any inspection or maintenance that requires turning on the master switch, installing a battery, or pulling the propeller through by hand, treat the propeller as if the ignition switch were ON. Do not stand, nor allow anyone else to stand, within the arc of the propeller, since a loose or broken wire, or a component malfunction, could cause the propeller to rotate. Revision3 i MODEL 172 SERIES SERVICE MANUAL CROSS REFERENCE LISTING OF POPULAR NAME VS. MODEL NUMBERS AND SERIALS All aircraft, regardless of manufacturer, are certified under model number designations. However, popular names are often used for marketing purposes. To provide a consistent method of referring to these aircraft, the model number will be used in this publication unless the popular name is necessary to differentiate between versions of the same basic model. The following table provides a listing of popular name, model number and serial number. MODEL SERIAL POPULAR NAME YEAR MODEL BEGINNING ENDING SKYHAWK,SKYHAWK II 1977 172N 17261445,17267585 17069309 1978 172N 17261578,17269310 17271034 (except 17270050) 1979 172N 17271035 17272884 1980 172N 17270050,17272885 17274009 1981 172P 17274010 17275034 1982 172P 17275035 17275759 1983 172P 17275760 17276079 1984 172P 17276080 17276259 1985 172P 17276260 17276516 1986 172P 17276517 17276654 REIMS/CESSNA F172 1977 F172N F17201515 F17201639 SKYHAWK, SKYHAWK II 1978 F172N F17201640 F17201749 1979 F172N F17201750 F17201909 1980 F172N F17201910 F17202039 1981 F172P F17202040 F17202134 1982 F172P F17202135 F17202194 1983 F172P F17202195 F17202216 1984 F172P F17202217 F17202233 1985 F172P F17202234 F17202238 1986 F172P F17202239 F17202254 CUTLASS, CUTLASS II 1983 172Q 17275869 17276054 1984 172Q 17276101 17276211 1985 172Q NONE ii Revision 3 MODEL 172 SERIES SERVICE MANUAL INTRODUCTION This manual contains factory-recommended procedures and instructions for ground handling, servicing, and maintaining Cessna 172 Series airplanes. Besides serving as a reference for the experienced mechanic, this manual also covers step-by-step procedures for the less experienced. If properly used, it will better enable the mechanic to maintain Cessna 172 Series airplanes and thereby establish a reputation for reliable service. This service manual is designed for aerofiche presentation. To facilitate the use of the aerofiche, refer to the aerofiche header for basic information. KEEPING CESSNA PUBLICATIONS CURRENT The information in this publication is based on data available at the time of publication and is updated, supple- mented, and automatically amended by all information issued in Service News Letters, Service Bulletins, Sup- plier Service Notices, Publication Changes, Revisions, Reissues and Temporary Revisions. All such amendments become part of and are specifically incorporated within this publication. Users are urged to keep abreast of the latest amendments to this publication through information available at Cessna Authorized Service Stations or through the Cessna Product Support subscription services. Cessna Service Stations have also been supplied with a group of supplier publications which provide disassembly, overhaul, and parts breakdowns for some of the var- ious supplier equipment items. Suppliers publications are updated, supplemented, and specifically amended by supplier issued revisions and service information which may be reissued by Cessna; thereby automatically amending this publication and is communicated to the field through Cessna's Authorized Service Stations and/or through Cessna's subscription services. WARNING: ALL INSPECTION INTERVALS, REPLACEMENT TIME LIMITS, OVERHAUL TIME LIMITS, THE METHOD OF INSPECTION, LIFE LIMITS, CYCLE LIMITS, ETC., REC- OMMENDED BY CESSNA ARE SOLELY BASED ON THE USE OF NEW, REMANU- FACTURED, OR OVERHAULED CESSNA APPROVED PARTS. IF PARTS ARE DE- SIGNED, MANUFACTURED, REMANUFACTURED, OVERHAULED, PURCHASED, AND/OR APPROVED BY ENTITIES OTHER THAN CESSNA, THEN THE DATA IN CESSNA'S MAINTENANCE/SERVICE MANUALS AND PARTS CATALOGS ARE NO LONGER APPLICABLE AND THE PURCHASER IS WARNED NOT TO RELY ON SUCH DATA FOR NON-CESSNA PARTS. ALL INSPECTION INTERVALS, RE- PLACEMENT TIME LIMITS, OVERHAUL TIME LIMITS, THE METHOD OF INSPEC- TION, LIFE LIMITS, CYCLE LIMITS, ETC., FOR SUCH NON-CESSNA PARTS MUST BE OBTAINED FROM THE MANUFACTURER AND/OR SELLER OF SUCH NON- CESSNA PARTS. 1. REVISIONS/CHANGES. These are issued to the dealers by Cessna Aircraft Company for this publi- cation as required, and include only pages that require updating. 2. REISSUE. Manual is reissued to dealers as required, and is a complete manual incorporating all the latest information and outstanding revisions/changes. It supersedes and replaces previous issue(s). REVISIONS/CHANGES and REISSUES can be purchased from your Cessna Dealer or directly from the Cessna Parts Distribution, (CPD 2) Dept. 701, Cessna Aircraft Company, 5800 East Pawnee, Wichita, Kansas 67201. All supplemental service information concerning this manual is supplied to all appropriate Cessna Dealers so that they have the latest authoritative recommendations for servicing these Cessna aircraft. Therefore, it is rec- ommended that Cessna owners utilize the knowledge and experience of the factory-trained Dealer Service Or- ganization. Revision 3 iii MODEL 172 SERIES SERVICE MANUAL CUSTOMER CARE SUPPLIES AND PUBLICATIONS CATALOG A Customer Care Supplies and Publications Catalog is available from your Cessna Dealer or directly from the Cessna Parts Distribution, (CPD 2), Dept. 701, Cessna Aircraft Company, 5800 East Pawnee, Wichita, Kansas 67201. The Supplies and Publications catalog lists all publications and Customer Care Supplies available from Cessna for prior year models as well as new products. SUPPLEMENTAL TYPE CERTIFICATE INSTALLATIONS Inspection, maintenance and parts requirements for supplemental type certificate (STC) installations are not in- cluded in this manual. When an STC installation is incorporated on the airplane, those portions of the airplane affected by the installation must be inspected in accordance with the inspection program published by the owner of the STC. Since STC installations may change systems interface, operating characteristics and component loads or stresses on adjacent structures, Cessna provided inspection criteria may not be valid for airplanes with STC installations. CUSTOMER COMMENTS ON MANUAL Cessna Aircraft Company has endeavored to furnish you with an accurate, useful, up-to-date manual. This man- ual can be improved with your help. Please use the return card, provided with your manual, to report any errors, discrepancies, and omissions in this manual as well as any comments you wish to make. iv Revision 3 MODEL 172 SERIES SERVICE MANUAL SECTION 1 GENERAL DESCRIPTION Page No Page No TABLE OF CONTENTS Aerofiche/Manual Aerofiche/Manual GENERAL DESCRIPTION ..... 1A9/1-1 Safetying Procedures ........ 1A18/1-10 Model 172 Series ............... 1A9/1-1 Safety Wire Procedures ...... LA19/1-11 Description ................. 1A9/1-1 Use of Cotter Pins ........... 1A23/1-15 Aircraft Specifications ....... 1A9/1-1 Use of Locking Cips .......... 1B1/1-17 Stations .................... 1A9/1-1 Use of Lockwashers .......... 1B3/1-19 General Airframe Practices ..... 1A14/1-6 Use of Self-Locking Nuts ..... 1B3/1-19 Torqueing Procedures ........... 1A14/1-6 Control Cable Wire Breakage Calculating Torque .......... 1A14/1-6 and Corrosion Limitations .. 1B411-20 Torque Values - Bolts ........ 1A14/1-6 Adhesives Cements and Sealants- Torque Values - Fittings ..... 1A17/1-9 Shelf Life and Storage ...... 1B6/1-22 1-1. GENERAL DESCRIPTION. 1-2. MODEL 172 SERIES. 1-3. DESCRIPTION. Cessna Model 172 aircraft, described in this manual, are high-wing mono- planes of all-metal, semimonocoque construction. These aircraft are equipped with a fixed tricycle landing gear with tubular spring-steel main gear struts. The steerable nose gear is equipped with an air/hydraulic fluid shock strut. Four-place seating is standard, and a double-width, fold-up auxiliary rear seat may be installed as optional equipment. All are powered by four-cylinder, horizontally-opposed, air-cooled Lycoming "Blue Streak" en- gines. The engines drive an all-metal, fixed-pitch propeller. Model 172 Series aircraft fea- ture rear side windows, a "wrap-around" rear window and a swept-back fin and rudder. 1-4. AIRCRAFT SPECIFICATIONS. Leading particulars of these aircraft, with dimensions based an gross weight, are given in figure 1-1. If these dimensions are used for constructing a hangar or computing clearances, remember that such factors as nose gear strut inflation, tire pressure, tire sizes and load distribution may result in some dimensions that are con- siderably different from those listed. 1-5. STATIONS. Station diagrams are shown in figure 1-2 to assist in locating equipment when a written description is inadequate or impractical. Revision 3 1-1 MODEL 172 SERIES SERVICE MANUAL NOTE These specifications are applicable to Model 172 and F172 Series airplanes and Model 172Q airplanes, except as in- dicated. GROSS WEIGHT (Takeoff and Landing) 172 and F172 Landplane (1977 thru 1980) .................... 2300 Lbs. 172 and F172 Landplane (1981 & On) ...................... 2400 Lbs. 172 and F172 Floatplane ................................ 2200 Lbs. 172Q Model Only ...................................... 2550 Lbs. FUEL CAPACITY Standard Wing (Total) ................................... 43 Gal. Standard Wing (Usable) ................................. 40 Gal. Long-Range Wing (Total) ............................... . 54 Gal. Long-Range Wing (Usable) ............................... 50 Gal. Wet Wing (Total) BEGINNING 1981 MODEL YEAR ............. 68 Gal. Wet Wing (Usable) BEGINNING 1981 MODEL YEAR ............ 62 Gal. OIL CAPACITY (Without External Filter) THRU 1980 MODEL YEAR ............ 6 Quarts (With External Filter) THRU 1980 MODEL YEAR ............. 7 Quarts (Without External Filter) BEGINNING 1981 MODEL YEAR ....... 7 Quarts (With External Filter) BEGINNING 1981 MODEL YEAR .......... 8 Quarts ENGINE MODEL 172 and F172 Series (Refer to Section 11 for Engine Data) ........ LYCOMING 0-320 Series 172Q Model Only (Refer to Section 11A for Engine Data) ......... LYCOMING 0-360 Series PROPELLER (Fixed Pitch) (172 and F172 Series) ................ 75" McCAULEY PROPELLER (Fixed Pitch) (Model 172Q Only) .................. 76" McCAULEY MAIN WHEEL TIRES (172 and F172 Series) .................... 6.00 x 6, 4-Ply Pressure THRU 1980 MODEL YEAR ........................ 29 Psi Pressure BEGINNING 1981 MODEL YEAR ................... 28 Psi MAIN WHEEL TIRES (Model 172Q Only) ...................... 6.00 x 6,6-Ply Pressure ............................................. 38 Psi NOSE WHEEL TIRE (172 and F172 Series) TIRE THRU 1980 MODEL YEAR ........................... 5.00 x 5, 4-Ply Pressure ............................................ 31 Psi BEGINNING 1981 MODEL YEAR .......................... 5.00 x 5, 6-Ply Pressure ........................................... 34 Psi NOSE WHEEL TIRE (Model 172Q Only) ....................... 5.00 x 5, 6-Ply Pressure ........................................... 45 Psi NOSE GEAR STRUT PRESSURE (Strut Extended) ................ 45 Psi WHEEL ALIGNMENT (Tubular Spring Struts) Cam ber .............................................. 2° to 4 ° Toe-in ............................................... 0" to .18" (Tubular Gear is non-adjustable) AILERON TRAVEL Up .. .............................................. 20 °± 1° Down ...................................... ...... 15 ° ±1° No provisions are made for aligning wheels on tubular gear aircraft. The tolerances provided are to be used only for checking existing wheel alignment. Figure 1-1. Aircraft Specifications (Sheet 1 of 2) 1-2 Revision 1 MODEL 172 SERIES SERVICE MANUAL WING FLAP TRAVEL (172 and F172 Series) Landplane THRU 1980 MODEL YEAR ....................... 0° to 40 ° , +0 °- 2 ° BEGINNING 1981 MODEL YEAR .......................... 0 ° to 30 °, + 0 ° - 2 ° WING FLAP TRAVEL (Model 172Q Only) ...................... 0 ° to 30 ° , +0°- 2 ° RUDDER TRAVEL (Measured Parallel to Water Line) Right ............................................... 16 ° 10' 1° Left ................................................. 16 ° 10' ± 1° RUDDER TRAVEL (Measured Perpendicular to Hinge Line) Right ............................................... 17° 44' ±1 ° Left ................................................. 17 ° 44' ± 1° ELEVATOR TRAVEL Up ......... . ................................. 28 ° + 1° - 0° Down ............................................... 23° +1 °- 0 ° ELEVATOR TRIM TAB TRAVEL Up THRU 1980 MODEL YEAR .............................. 28 ° + 1°- 0° Down THRU 1980 MODEL YEAR ........................... 13 ° + 1°- 0 ° Up BEGINNING 1981 MODEL YEAR (Landplane) .............. 22 ° + 1°- 0 ° Down BEGINNING 1981 MODEL YEAR (Landplane) ............ 19 ° + 1°- 0° Up BEGINNING 1981 MODEL YEAR (Floatplane) .............. 28 ° + 1°- 0° Down BEGNNING 1981 MODEL YEAR (Floatplane) ............ 13 ° + 1°- 0° PRINCIPAL DIMENSIONS Wing Span (Conical-Camber With Strobe Lights) (172 and F172 Series) .................................. 433.00" Wing Span (With Strobe Lights) (Model 172Q Only) ............. 432.00" Tail Span (172 and F172 Series) ............................ 135.14" Length THRU 1980 MODEL YEAR ......................... 323.00" Length BEGINNING 1981 MODEL YEAR ..................... 323.04" Tail Span (Model 172Q Only) .............................. 136.00". Fin Height (Maximum With Nose Gear Depressed and Flashing Beacon Installed on Fin) (172 and F172 Series) ......... 104.00" Fin Height (Maximum With Nose Gear Depressed and Flashing Beacon Installed on Fin) (Model 172Q Only) ........... 107.00" Track Width (172 and F172 Series) ......................... 100.36" Track Width (Model 172Q Only) ........................... 100.50" BATTERY LOCATION .................................... Firewall * Neutral position measured with the bottom of the balance area flush with the bottom of the stabilizer. Figure 1-1. Aircraft Specifications (Sheet 2 of 2) Revision 1 1-3 MODEL 172 SERIES SERVICE MANUAL 23. 62 NOTE 172. 00 190. 00 208. 00 56.70 Figure 1-2. Reference Stations (Sheet 1of 2) 1-4 Revision 1 MODEL 172 SERIES SERVICE MANUAL NOTE Wet wing option beginning with 1981 model year 22. 875 39.00 85.875 100.50 23.65 Figure 1-2. Reference Stations (Sheet 2 of 2) Revision 1 1-5 Revision 1 1- 5 MODEL 172 SERIES SERVICE MANUAL 1-6. GENERAL AIRFRAME PRACTICES. the following paragraphs deal with general torque and safetying practices used to ensure security of installation and prevent overstressing of com- ponents. Special torque values, when required, are specified with the specific component maintenance and installation instructions. 1-7. TORQUEING PROCEDURES. The importance of correct application cannot be overem- phasized. Undertorque can result in unnecessary wear of nuts and bolts as well as parts they are holding together. When insufficient pressures are applied, uneven loads will be transmitted throughout assembly, which may result in excessive wear or premature failure due to fatigue. Overtorque can be equally damaging because of failure of a bolt or nut from overstressing threaded areas. a. Calculating Torque. There are a few simple, but very important, procedures that should be followed to assure that correct torque-is applied: 1. Calibrate torque wrench periodically to assure accuracy; and recheck frequently. 2. When using a torque wrench adapter which changes distance from torque wrench drive to adapter drive, the indicated reading must be adjusted for desired torque reading. (See Figure 20-1.) 3. Be sure that bolt and nut threads are clean and dry unless otherwise specified. 4. Determine friction drag torque and add to specified dry torque value to ensure proper bolt utilization. (a) Hand-turn nut onto bolt until it stops. (b) Using a torque wrench, measure running torque (torque required to turn nut on bolt). (c) This running torque must be added to specified dry torque value to ensure proper bolt utilization. EXAMPLE Average running torque for a nut = 15 in.-lbs. Dry torque required = 125 ±5 in.-lbs. Final torque wrench reading = 140 ±5 in.-lbs. (d) Since running torque will become less due to nut/bolt re-use (in accepted ap- plications), this procedure must be repeated each time. (e) When necessary to tighten from bolt head, increase torque value by an amount equal to shank torque (torque required to turn bolt when installed). Measure with a torque wrench. EXAMPLE Average running torque for a nut = 15 in.-lbs. Average running shank torque for installed bolt = 10 in.-lbs. Dry torque required = 125 ±5 in.-lbs. Final torque wrench reading = 150 ±5 in.-lbs. b. Torque Values - Bolts and Nuts. (See Table 1-1.) 1. Tables included in this section do not apply to the following exceptions: (a) Sheet metal screws should be tightened firmly, but with no specific torque value. (b) Screws attached to nutplates should be tightened firmly, but with no specific torque value. (c) Bolts, nuts, and screws used in control systems and installations where re- quired torque would cause binding or interfere with proper operation of parts. (d) Screws used with dimpled washers should not be drawn tight enough to elim- inate washer crown. (e) Fasteners that have a specified torque in a specific installation. 1-6 Revision 1 MODEL 172 SERIES SERVICE MANUAL NOTE When using a torque wrench adapter which changes the distance from torque wrench drive to adapter drive, apply following formula to obtain corrected torque reading. SHORT OPEN END FORMULA LEGEND ADAPTER T = Desired Torque T x L = Y Y = Indicated Torque L = Effective Length Lever L + E E = Effective Length of Extension WRENCH HANDGRIP SETSCREW DRIVE CENTERLINE ADAPTER CENTERLINE (PREDETERMINED) ADAPTER TORQUE DRIVE WRENCH CENTERLINE HOSE CLAMP ADAPTER EXAMPLE T = 135 In.-Lbs y = 135 x 10 = 1350 = 117.39 Y = Unknown L = 10.0 In.-Lbs 10 + 1.5 11.5 L = 10.0 In.-Lbs E = 1.5 In. Y = 117 In.-Lbs OPEN-END WRENCH ADAPTER HANDGRIP ADAPTER DRIVE CENTERLINE CENTERLINE (PREDETERMINED) WRENCH TORQUE DRIVE WRENCH CENTERLINE FLARE NUT WRENCH ADAPTER EXAMPLE T = 135 In.-Lbs = 135 x 10 1350 158.82 SPANNER WRENCH Y = Unknown ADAPTER L = 10.0 In.-Lbs 10 - 1.5 8.5 E = -1.5 In. Y = 159 In.-Lbs Figure 1-3. Torque Wrench Adapter Adjustment Revision 1 1-7 MODEL 172 SERIES SERVICE MANUAL BOLT TORQUE VALUES Tension Shear Tension I Shear BOLTS BOLTS AN3 thru AN20 MS20004 thru MS20024 NAS464 AN42 thru AN49 NOTE: Bolts in tension NAS144 thru NAS148 AN73 thru AN81 column may be used NAS172 AN173 thru AN186 with shear nuts. Bolts NAS174 AN509NK9 in shear column NAS333 thru NAS340 AN525NK525 should not be used un- NAS585 thru NAS590 MS20033 thru MS20046 less a minimum of two NAS624 thru NAS644 MS20073 threads extend beyond NAS1303 thru NAS1320 MS20074 nut after installation. NAS517 MS24694 MS27039 NUTS NUTS AN310 AN320 AN310 AN320 AN315 AN364 AN315 AN364 AN363 MS20364 NA363 NAS1022 AN365 NAS1022 AN365 MS20364 MS20365 MS20365 MS20500 MS21045 MS21045 NAS679 NAS679 NAS1021 NAS1021 291 FINE THREAD SERIES FINE THREAD SERIES Nut-bolt Nut-bolt size Torque Limits Torque Limits Torque Limits Torqu Limits size in.-lbs. in.-lbs. in.-bs. in.-lbs. MIN. MAX. MIN. MAX. MIN. I MAX. MIN. I MAX. 8-36 12 15 7 9 10-32 25 30 15 20 10 32 20 25 12 15 14-28 80 00 50 60 14-28 50 70 30 40 5 16-24 120 145 70 90 5 16-24 100 140 60 85 38-24 200 250 120 150 38-24 160 190 95 110 716-20 520 630 300 400 716-20 450 500 270 300 1 2-20 770 950 450 550 1 2-20 480 690 290 410 916-18 1100 1300 650 800 916-18 800 1000 480 600 58-18 1250 1550 750 950 58-18 1100 1300 660 780 34-16 2650 3200 1600 1900 34-16 2300 2500 1300 1500 78-14 3550 4350 2100 2600 78-14 2500 3000 1500 1800 1-14 4500 5500 2700 3300 1-14 3700 4500 2200 3300 1-1 8-12 6000 7300 3600 4400 1-1 8-12 5000 7000 3000 4200 1-1 4-12 11000 13400 6600 8000 1-1 4-12 9000 11000 5400 6600 COURSE THREAD SERIES MS17825 MS17826 Nut-bolt Nut-bolt Torque Limits Torque Limits Torque Limits Torque Limits in.-lbs. in.-lbs. in.-bs. in.-lbs. MIN. MAMINM . I MAX. MIN. I MAX. MIN. MAX. 8-32 12 15 7 9 10-32 28 35 16 20 10-24 20 25 12 15 14-28 65 80 35 45 14-20 40 50 25 30 5 16-24 180 225 70 90 5 16-18 80 90 48 55 3,8-24 260 325 100 125 38-16 160 185 95 110 716-20 460 575 180 225 716-14 235 255 140 155 12-20 720 900 240 300 12-13 400 480 240 290 9.16-18 880 1100 320 400 9 16-12 500 700 300 420 5.8-18 1300 1600 480 600 58-11 700 900 420 540 3/4-16 2200 2800 880 1100 3.4-10 1150 1600 700 950 78-14 3700 4600 1500 1900 78-9 2200 3000 1300 1800 1-14 5400 6800 2400 3000 1-8 3700 5000 2200 3000 1-1 8-12 8000 10000 4000 5000 1-1 8-8 5500 6500 3300 4000 1-1 4-12 11000 14000 5600 7000 1-1 4-8 6500 8000 4000 5000 Table 1-1. Torque Values - Bolts and Nuts 1-8 Revision 1 MODEL 172 SERIES SERVICE MANUAL 2. The values shown in Table 1-1 are based on parts being clean and dry with no lu- bricants added. 3. Castellated nuts requiring cotter pins should be tightened to low torque value. Torque can be increased to install cotter pin, but should never exceed maximum torque value. NOTE Self-locking castellated nuts, MS17825 and MS17826, re- quire a separate torque range. These values are shown separately in torque value tables. c. Torque Value - Threaded Straight Fittings. NOTE Tables in this section are for general applications. Refer to specific installations for special torque values and pro- cedures. 1. Connectors installed in bosses with no required orientation should be installed using torque values given in Table 1-2. 2. Connectors installed in bosses requiring a specific orientation do not use a torque value, but use the following steps: (a) Place jam-nut on fitting along with retainer and packing. (b) Turn nut down until packing is firmly against lower threaded section of fit- ting. (c) Install fitting into boss and tighten until there is a sudden increase in torque. (d) Tighten fitting 1-1/2 turns. (e) Orientation is accomplished by tightening fitting, but not exceeding one turn. (f) Tighten jam-nut to torque values in Table 1-2. THREADED CONNECTOR TORQUE VALUE - HOSE ASSEMBLIES TUBE JAM-NUT CONNECTOR Nipple or Nut OUTSIDE THREAD w/ PACKING HOSE ALUMINUM STEEL INSIDE DIAMETER w/o JAM-NUT DIAMETER Torque-Limits Torque-Limits (Inches) Torque-Limits Torque-Limits in.-lbs. in.-lbs (in.-lbs.) (in.-lbs.) (in.-lbs.) MAX. MIN. MAX. MIN. MAX. MIN. MAX. 18 20 30 75 85 1/8 516-24 35 50 50 55 3.16 25 35 95 105 3'16 3/8-24 65 80 65 75 14 50 65 135 150 1/4 7/16-20 85 105 95 105 516 70 90 170 200 5'16 1/2-20 105 125 125 135 38 110 130 270 300 38 916-18 120 150 155 165 12 230 260 450 500 12 34-16 240 280 280 305 58 330 360 650 700 58 77-14 320 380 380 405 34 460 500 900 1000 34 116-12 500 600 550 600 1 500 700 1200 1400 1 1-516-12 720 880 800 900 1-14 800 900 1520 1680 1-14 1-5 8-12 960 1200 900 1000 1-1 2 800 900 1900 2100 1-12 1-7 8-12 1200 1440 900 1000 1-3 4 - - - 2 2-1 2-12 1400 1500 900 1000 2 1800 2000 2660 2940 Table 1-2. Torque Values Table 1-3. Torque Values Jam-Nuts and Threaded Connector Hose Assemblies Revision 1 1-9 MODEL 172 SERIES SERVICE MANUAL THREADED STRAIGHT FITTING TORQUE VALUE (RIGID TUBE) FLARED END STRAIGHT END TUBE ALUMINUM ALUMINUM STEEL 6061-0 ALUMINUM STEEL 6061-T(X) ALUMINUM OUTSIDE On Oxygen Lines 5052-0 ALUMINUM w/ steel sleeve DIAMETER Torque-Limits Torque-Limits Torque-Limits Torque-Limits Torque-Limits Torque-Limits in-lbs. in-lbs. in-lbs. in-lbs. in-lbs. in-lbs. MIN. MAX. MIN. MAX. MIN. MAX. MIN. MAX. MIN. I MAX. TUBE WALL MIN. MAX. 1 8 20 30 45 55 316 90 100 30 40 90 100 0.028 45 55 14 40 65 135 150 40 65 135 150- 0.022 -80 105 0.028 80 105 0.035 80 105 0.049 90 115 516 60 80 100 125 180 200 60 80 180 200 0.028 80 105 0.035 80 105 0.042 125 175 38 75 125 270 300 75 125 270 300 0.028 125 175 0.035 125 175 0.049 125 175 12 150 250 450 500 150 250 450 500 0.028 135 180 0.035 200 300 0.049 400 500 0.058 400 500 0.065 400 500 58 200 350 700 800 200 350 700 800 All 500 600 34 300 500 1100 1150 300 500 1100 1150 All 600 700 1 500 700 1200 1400 500 700 1200 1400 All 1000 1300 1-1 4 600 900 1300 1450 600 900 1300 1450 All 1300 1500 1-1 2 600 900 1350 1500 600 900 1350 1500 All 1400 1700 2 600 900 1500 1700 Table 1-4. Torque Values - Straight Threaded Fittings (Line) 3. Bulkhead fittings are installed with jam-nuts and should be torqued to values in Table 1-2. 4. Torque values for hose end fittings (nipple or nut) are given in Table 1-3. 5. Torque values for straight threaded fittings used with rigid lines are given in Table 1-4. 1-8. SAFETYING PROCEDURES. The use of safety wire, cotter pins, lockwashers, and self-lock- ing nuts is to prevent relative movement of critical components subject to vibration, torque, tension, etc., which could cause attaching parts to be broken, loosened, and/or detached. 1-10 Revision 1 MODEL 172 SERIES SERVICE MANUAL 1-9. SAFETY WIRE PROCEDURES. a. Identification. Lockwire comes in three types which are identified by size and color. The three types are classified by use. 1. Inconel and Monel wire is used for general lockwiring and is identified by a natu- ral wire color. (a) Inconel can withstand temperatures up to 1500°F. (b) Monel can withstand temperatures up to 800°F. 2. Copper that is cadium-plated and dyed yellow is used for shear and seal wiring applications. (a) Shear applications are those where it is necessary to break or shear wire to permit operation or actuation of emergency devices. (b) Seal applications are where wire is used with a lead seal to prevent tampering or use of a device without indication. 3. Aluminum Alloy (Alclad 5056) is dyed blue and is used exclusively for safety-wir- ing magnesium parts. 4. Size of wire is dependent on material and purpose of installation. (a) 0.020-inch diameter copper wire should be used for shear and seal applica- tion. (b) 0.020-inch diameter wire may be used to lockwire parts with tie holes smaller than 0.045 inches; or, on parts with tie hole diameters between 0.045 and 0.062 when spacing between ports is less than two inches; or, when bolts and screws of 0.25-inch diameter or less are closely spaced. (c) 0.032-inch minimum diameter wire is used for general purpose lockwiring. NOTE When using single-wire method of locking, the largest wire that will fit tie holes should be used. b. Lockwire Installation. There are two basic forms of lockwiring. The single-wire method has limited application; the double-twist method is the common method of lockwiring. 1. Use new wire for each application; do not try to re-use old wire. 2. Single-wire method is accomplished by passing a single wire through tie holes and back with ends then twisted together. (See Figure 1-4.) (a) Single-wire method is used for shear and seal wiring applications. (b) Single-wire method can be used in closely spaced, closed geometric patterns. Closely spaced is defined as spacing two inches or less between centers of parts. CAUTION Screws in closely spaced geometric patterns which secure hydraulic or air seals, hold hydraulic pressure, or are used in critical areas should use double-twist method of lockwiring. 3. Lockwiring by the double-twist method is really one wire twisted on itself several times and is accomplished by the following steps (see Figure 1-4). (a) Insert one end of wire through tie holes of bolt head and firmly loop around bolt head. NOTE This does not necessarily apply to castellated nuts when slot is close to top of nut. The wire will be more secure if it is made to pass along side of stud. Revision 1 1-11 MODEL 172 SERIES SERVICE MANUAL FOR LEFT-HAND THREADS. SINGLE FASTENER APPLICATION CASTELLATED NUTS ON DRILLED STUDS DOUBLE-TWIST METHOD DOUBLE-TWIST METHOD Figure 1-4. Lockwire Safetying (Sheet 1 of 2) 1-12 Revision 1 MODEL 172 SERIES SERVICE MANUAL DOUBLE-TWIST METHOD STEP 1. Insert wire through bolt A and bend BOLT A around bolt (if necessary, bend wire across bolt head). Twist wires clockwise until they reach bolt B. STEP 2. Insert one end of wire through bolt B. Bend other end around bolt (if necessary, bend wire across head of bolt). Twist wires counterclockwise 1/2 inch or six twists. Clip ends. Bend pigtail back againt part. BOLT B CLOCKWISE DOUBLE-TWIST METHOD COUNTERCLOCKWISE CLOCKWISE COUNTERCLOCKWISE CLOCKWISE MULTIPLE FASTENER APPLICATION ELECTRICAL CONNECTION DOUBLE-TWIST METHOD Figure 1-4. Lockwire Safetying (Sheet 2 of 2) Revision 1 1-13 MODEL 172 SERIES SERVICE MANUAL (b) While taut, twist strands to within 1/8 inch of next part. The twisting keeps wire taut without overstressing and prevents wire from becoming nicked, kinked, or mutilated. (c) Lockwiring multiple groups by double-twist method is accomplished in a similar manner except twists between parts are alternated between clockwise and counterclockwise. (d) After last tie hole, wire is twisted three to five times to form a pigtail. (e) Cut off any excess wire and bend pigtail towards part. 4. When lockwiring widely spaced multiple groups by double-twist method, three units shall be the maximum number in a series. NOTE Widely spaced multiple groups shall mean those in which fasteners are from four to six inches apart. Lockwiring shall not be used to secure fasteners or fittings which are spaced more than six inches apart, unless tie points are provided on adjacent parts to shorten span of lockwire to less than six inches. 5. When lockwiring closely spaced multiple groups, the number of units that can be lockwired by a 24-inch length of wire shall be the maximum number in a series. 6. Parts should be lockwired so that wire is placed in tension (pulled on) if a part at- tempts to loosen. c. Required Lockwire Installation Applications. 1. Bolts and other fasteners securing critical parts that affect airplane safety and operation. (a) In blind-tapped hole applications or bolts or castellated nuts on studs. lockwiring is installed in same manner as described for bolt heads. (b) Hollow head bolts are safetied in manner prescribed for regular bolts. (c) Drain plugs and cocks may be safetied to a bolt, nut, or other part having a free tie hole in accordance with instructions described. (d) External snap rings may be locked if necessary using general locking princi- ples as described and illustrated. Internal snap rings should not be lockwired. (e) When locking is required on electrical connectors which use threaded cou- pling rings, or on plugs which employ screws or rings to fasten individual parts of plug together, they shall be lockwired with 0.020-inch diameter wire in accordance with locking principles as described and illustrated. It is prefer- able to lockwire all electrical connectors individually. Do not lockwire one connector to another unless it is necessary to do so. (f) Drilled head bolts and screws need not be lockwired if installed into self-lock- ing nuts or installed with lockwashers. Castellated nuts with cotter pins or lockwire are preferred on bolts or studs with drilled shanks, but self-locking nuts are permissible within limitations described in Paragraph 1-13. 2. For new design, lockwire shall not be used to secure nor shall lockwire be depen- dent upon fracture as basis for operation of emergency devices such as handles, switches, and guard-covering handles that operate emergency mechanisms such as emergency exits, fire extingushers, emergency cabin pressure release, emergency landing gear release, and the like. However, where existing structural equipment or safety of flight emergency devices requires shear wire to secure equipment while not in use, but which are dependent upon shearing or breaking of lockwire for successful emergency operation of equipment, particular care exercised to assure that wiring under these circumstances shall not prevent emergency operations of these devices. 1-14 Revision 1 MODEL 172 SERIES SERVICE MANUAL 1-10. USE OF COTTER PINS. a. Cotter Pin Installation. Castellated nuts and pins may be safetied with cotter pins or lockwire. The preferred method is to use cotter pins. 1. Select cotter pin material in accordance with temperature, atmosphere, and service limitations (see Table 1-5). 2. Cotter pins shall be new upon each application. 3. When nuts are to be secured to fastener with cotter pins, tighten nut to low side (minimum) of applicable specified or selected torque range, unless otherwise specified, and if necessary, continue tightening until slot aligns with hole. In no case shall you exceed high side (maximum) torque range. 4. If more than 50 percent of cotter pin diameter is above nut castellation, a washer should be used under nut or a shorter fastener should be used. A maximum of two washers may be permitted under a nut. 5. The largest diameter cotter pin which hole and slots will accommodate should be used, but in no application to a nut, bolt, or screw shall pin size be less than sizes described in Table 1-6. 6. Install cotter pin with head firmly in slot of nut with axis of eye at right angles to bolt shank. Bend prongs so that head and upper prong are firmly seated against bolt (see figure 1-5). 7. In pin applications, install cotter pin with axis of eye parallel to shank of clevis pin or rod end. Bend prongs around shank of pin or rod end (see Figure 1-5). CAUTION Cadium-plated cotter pins should not be used in applica- tions bringing them in contact with fuel, hydraulic fluid, or synthetic lubricants. COTTER PIN - MINIMUM SIZE THREAD SIZE MINIMUM PIN SIZE COTTER PINS (MS24665) 0.028 MATERIAL TEMPERATURE USE 8 0.044 Carbon Steel Up to 450°F Pins that contact cadmium- 10 0.044 plated surfaces. 14 0.044 516 0.044 General Applications 3 8 0.072 12 0.072 7 16 0.072 Normal Atmospheres 12 0.086 9 16 0.086 Corrosion-Resistant Up to 800°F Pins that contact cor- 58 0.086 rosion-resistant steel. 3 4 0.086 7 8 0.086 Corrosive atmospheres 1 0.086 1-18 0.116 1-1 4 0.116 1-38 0.116 1-12 0.116 Table 1-5. Cotter Pin Table 1-6. Cotter Pin Temperature and Use Minimum Size Revision 1 1-15 MODEL 172 SERIES SERVICE MANUAL TO PROVIDE CLEARANCE PRONG MAY BE CUT HERE PREFERRED METHOD ALTERNATE METHOD CASTELLATED NUT ON BOLT TANGENT TO PIN MAXIMUM MINIMUM COTTER PIN COTTER PIN LENGTH LENGTH PIN APPLICATION Figure 1-5. Installation of Cotter Pins 1-16 Revision 1 MODEL 172 SERIES SERVICE MANUAL 1-11. USE OF LOCKING CLIPS. a. afetying Turnbuckles. (ee Figure 1-6.) 1. Prior to safetying, both threaded terminals shall be screwed an equal distance into turnbuckle body and shall be screwed in at least so far that not more than three threads of any terminal are exposed outside body. 2. After turnbuckle has been adjusted to its locking position, with slot indicator groove on terminals and slot indicator notch on body aligned, insert end of lock- ing clip into terminal and body (refer to Figure 1-6) until U-curved end of locking clip is over hole in center of body. (a) Press locking clip into hold to its full extent. (b) Curved end of locking clip will expand and latch in body slot. (c) To check proper seating of locking clip, attempt to remove pressed "U" end from body hole with fingers only. NOTE Do not use tool as locking clip could be distorted. 3. Locking clips are for one time use only and shall not be re-used. 4. Both locking clips may be inserted in same hole of turnbuckle body or in opposite holes of turnbuckle body. Revision 1 1-17 MODEL 172 SERIES SERVICE MANUAL LOCKING CLIP BARREL Detail A Figure 1-6. Safetying Turnbuckle Assemblies Revision 1 1-12. USE OF LOCKWASHERS. a. Lockwashers can be used only under the following conditions. 1. When self-locking feature cannot be provided in externally or internally threaded part. 2. When a cotter pin cannot be used to prevent rotation of internal threads with re- spect to external threads. 3. When lookwire cannot be used to prevent loosening of threaded parts. 4. When fastening is not used for fabrication of primary structure. 5. When loosening of threaded parts would not endanger safety of airplane or people. 6. When corrosion encouraged by gouging aluminum or magnesium alloys by edges of teeth on tooth-locked washers would not cause malfunctioning of parts being fastened together. 1-13. USE OF SELF-LOCKING NUTS. a. Restrictions. 1. Self-locking nuts cannot be used under certain conditions. (a) Used. reworked, or reprocessed nuts should not be installed for any applica- tion. (b) Do not use if at joints in control systems for singular attach points. (c) Do not use on externally threaded parts that serve as an axle of rotation for another part where tensional (torque) loads can cause nut to loosen and/or be- come separated. Examples are pulleys, levers, linkages, and cam followers. NOTE Self-locking nuts can be used when threaded parts are held by a positive locking device that requires shearing or rupture before torsional loads can act on threaded parts. (d) Do not use where a loose nut, bolt, or screw could fall or be drawn into an area that would impede or damage or otherwise distort operation. (e) Do not use to attach access panels and doors or to assemble components that are routinely disassembled or removed for access and servicing. (f) In general, do not use self-locking nuts where loss of bolt affects safety of flight. 2. Bolts, studs, or screws, excluding Hi-Locks, must extend through self-locking nut for a length equivalent of two threaded pitches. This length includes chamfer. 3. Self-locking nuts which are attached to structure shall be attached in a positive manner to eliminate possibility of their rotation or misalignment when tighten- ing is to be accomplished by rotating bolts to structure, and permit replacement of nuts. Revision 2 1-19 MODEL 172 SERIES SERVICE MANUAL 1-14. CONTROL CABLE WIRE BREAKAGE AND CORROSION LIMITATIONS. a. Inspection of Control Cables. 1. Control cable assemblies are subject to a variety of environmental conditions and forms of deterioration that ultimately may be easy to recognize such as wire/strand breakage, or the not so readily visible types ofdeterioration including corrosion and/or distortion. Thefollowing information will aid in detecting these cable conditions. 2. Broken Wire. (a) Examine cables for broken wires by passing a cloth along length of cable. This will detect broken wires, if cloth snags on cable. Critical areas for wire breakage are those sections of cable which pass through fairleads, across rob blocks, and around pulleys.If no snags are found, then no further inspection is required. If snags are found or broken wires are suspected, then a more detailed inspection is necessary which requires that the cables be bent in a loop to confirm broken wires (refer to figure 1-7). Loosen or remove cable to allow it to be bent in a loop as shown. While rotating cable, inspect bent area for broken wires. (b) Wire breakage criteria for cables in flap, aileron, rudder, and elevator systems are as follows: (1) Individual broken wires are acceptable in primary and secondary control cables at random locations when there are no more than six broken wires in any given ten-inch cable length. 3. Corrosion. (a) Carefully examine any cable for corrosion that has a broken wire in a section not in contact with wear-producing airframe components such as pulleys, fairleads, rub blocks, etc. It may be necessary to remove and bend cable to properly inspect it for internal strand corrosion as this condition is usually not evident on outer surface of cable. Replace cable if internal corrosion is found. If a cable has been wiped clean of its corrosion-preventive lubricant and metal-brightened, the cable shall be examined closely for corrosion. For description of control cable corrosion, refer to Chapter 18, Corrosion and Corrosion Control. 1-20 Revision 2 MODEL 172 SERIES SERVICE MANUAL BROKEN WIRE UNDETECTED BY WIPING CLOTH ALONG CABLE BROKEN WIRE DETECTED VISUALLY WHEN CABLE WAS REMOVED AND BENT NORMAL TECHNIQUE FOR BENDING CABLE AND CHECKING FOR BROKEN WIRES 00 NOT BEND INTO LOOP SMALLER THAN 50 CABLE DIAMETERS 55611119 Figure 1-7. Cable Broken Wire Inspection Revision 2 1-21 MODEL 172 SERIES SERVICE MANUAL 1-15. ADHESIVES, CEMENTS AND SEALANTS - SHELF LIFE AND STORAGE. a. General. 1. This section provides information which defines the proper storage and usable life (shelf life) of adhesives, cements and sealents which are used for maintenance and/or repair of the airplane. Also included in this section is the criteria used for testing these materials after the normal shelf life has expired, to determine if an extension to the shelf life is possible. 2. Shelf life refers to a specified period of time usually from the date of manufacture (normally stamped or printed on the product container ) to the expiration date (which should be determined using limits specified in Table 1-7 or if applicable, the manufacturer's expiration date printed or stamped on the product container). The specified shelf life is dependent on proper storage in accordance with the limits specified in this section and/or the manufacturer's instructions. b. Storage Criteria. 1. Storage of Adhesives and Cements. All adhesives and cements shall be stored under controlled temperature conditions. . If open shop storage becomes necessary, these products shall in no case be stored in an area which will subject them to temperatures in excess of 95°F. Containers shall be tightly closed prior to being placing them into the proper storage environment. For proper storage environment, refer to Table 1-7 and the-following paragraphs. (a) Class I - These adhesives are epoxy base materials and have one year storage at room temperature. 0°F storage will extend the storage life. Refer to the product container instructions for storage temperature and life. (b) Class II, III and IV - These adhesives are rubber and resin base and are good for six months at room temperature storage. 40°F storage will extend the storage life. Refer to the product container instructions for limits of each adhesive. (c) Class V - These are silicone rubber adhesives. If stored in their original containers at a temperature below 80°F, have a shelf life of one year or as indicated on the storage container. (d) Class VI - These are solvent bonding solvents. They should be stored in their original containers and tightly closed, and stored at 40°F temperature. (e) ClassVII - Cyanoacrylate base materials must be stored in the original containers at 40°F or as specified on the container instructions. (f) Class VIII - These are pressure sensitive materials. The shelf life is two years when stored at 75°F and 50 percent relative humidity. (g) Class IX - These are polyurethane products. Store in original container, between 70 and 100°F. Urethanes are moisture sensitive and precautions should be taken to ensure complete protection from moisture contamination. Container must be tightly closed at all times. (h) Class X - These are acrylic base materials. They require storage at 40°F or per instructions on product container. c Storage of Sealants. 1. All sealants shall be stored under controlled temperature conditions. If open shop storage becomes necessary, these products shall in no case be stored in an area which will subject them to temperatures in excess of 95°F or below 40°F. Containers shall be tightly closed prior to placing them in the proper storage environment. For proper storage environment, refer to Table 1-7 and the following paragraphs. (a) Premixed and frozen sealants shall bestored at -40°F or colder and shall not be used more than six weeks after the date of mixing even if all storage is at -40°F or colder. If storage temperatures rise above 40°F, but not warmer than -30°F, the material may be stored for a maximum of two weeks warmer than -40°F plus time at -40°F or colder for a combined total not to exceed five weeks beyond the date of mixing. If storage temperatures rise above -40°F but are not warmer than -20°F, the materials may be stored for a maximum of one week above -30°F plus time at -40°F or colder for a combined total not to exceed four weeks beyond the date of mixing. (b) Unmixed sealants shall be stored at a controlled temperature of between 40 and 80°F and have a shelf life of approximately six months when stored within this temperature range. Unmixed sealants stored at temperatures exceeding 80°F shall be used within five weeks. 2. All materials should be used on a "first in-first out" basis. The adhesives, cements and sealants should be rotated so this requirement can be accomplished. All material containers should be clearly marked with a "use by" date, consisting of the year and month. All materials not used by this date must be tested prior to use. Refer to Testing criteria and Table 1-7. d. Testing Criteria. 1. Any material (adhesive, cement or sealant)not used within its shelf life will be tested and the results reviewed to determine if the material is usable. If there is doubt about the material being usable, it must be properly disposed of. Material that has exceeded its original shelf life may be retested to determine if the material meets its requirements. Materials meeting their requirements will have their shelf life extended as specified in Table 1-7. Materials with shelf life extensions must be retested after a specified period of time. Refer to Table 1-7. 1-22 Revision 2 MODEL 172 SERIES SERVICE MANUAL 2. Testing of Overaged Adhesives and Cements. NOTE Overaged adhesives and cements are those that have exceeded their original shelf life and must be tested prior to use and/or given extended shelf life. (a) Class I Epoxy Adhesive - Examine bothcomponents to ensure that they are still workable. Check for gelling and/or contamination. Stir components and mix a small amount of adhesive. Verify that adhesive sets up and hardens. (b) Class II, III and IV Rubber and Resin Base Adhesives - Open containers and check for gelling and/or contamination. Check for spreading and drying. (c) Class V Silicone Rubber Adhesives - Examine adhesive for hardness. If adhesive is still soft and can be spread, it is acceptable. Verify that adhesive will harden. (d) Class VI Solvent Bonding Solvents - Check for signs of apparent contamination. Solvents should be clean and clear with no signs of cloudiness. (e) Class VII Cyanoacrylic Base Adhesives - Verify that product is still liquid with no visible signs of contamination. (f) Class VII Pressure Sensitive Materials - Open containers and inspect for hardening, gelling and contamination. Stir components and mix a small amount of adhesive. Verify that adhesive sets up properly. (g) Class X Acrylic Adhesives - Inspect base material to ensure that it is still liquid. Mix a small amount of the components and verify that it sets up properly. 3. In general, if these materials exhibit normal physical properties, with no signs of hardening, gelling or contamination and set up and/or harden properly as applicable, the shelf life may be extended as specified in Table 1-7. e. Testing of Overaged Sealants. NOTE Overaged sealants are those that have exceeded their original shelf life and must be tested prior to use and/or given extended shelf life. 1. For identification of sealants Classification, refer to Fuel, Weather, Pressure and High- Temperature Sealing - Maintenance Practices. 2. Overaged sealants to be tested for possible shelf life extension shall be properly mixed using the correct materials, procedures and equipment. 3. Overaged premixed frozen sealants, along with unmixed sealants should be visually inspected. Sealants whic show conclusive evidence of separation, discoloration and/or gelling prior to the addition of a thinner or curing agent shall be discarded. When in doubt of the sealant quality, the overaged sealant should be compared with the same type of sealant, under six months old, which is known to be satisfactory. 4. The mixed sealants may be tested by placing a small amount of sealant (smaple buttons) on a sheet of paper. After the sample buttons have cured, they should be cut in half and examined. The sealant should show no signs of spots or streaks of unmixed base compound or curing agent. However, sample buttons containing spots, streaks, discoloration and/or variations in uniformity of color are acceptable if these spots, streaks, etc., are tack free upon inspection. All mixed sealant should be as void free as possible. 5. Contaminated sealant, premixed sealant that have been thawed and refrozen shall be discarded. 6. Type I, Class A sealants should be checked for appearance, application time, tack-free time, cure time and adhesion. 7. Type I, Class B sealants should be checked for appearance, applicatiion time, cure time, tack- free time and adhesion. In addition, Class B-2 and B-4 sealants should be checked for initial flow. 8. Type I, Class C sealants should be checked for appearance, application time, cure time and adhesion. In addition, Class C sealants should be tested to determine that they ARE NOT at a tackfree condition at the end of their rated work life (squeeze out life). 9. Type II sealants should be checked for appearance, application time, tack-free time and cure time. 10. Type III sealants should be easily thinned with MEK, when difficulty is encountered in thinning the sealant, it should be discarded. Revision 2 1-23 MODEL 172 SERIES SERVICE MANUAL 11. Type IV sealants should be checked for appearance, application time, tack-free time and cure time. 12. Type V and VI sealants should be checked for appearance, tack-free time and cure time. 13. Type VII sealants should be checked for appearance, application time, tack-free time and cure time. 14. Type VIII sealants should be checked for appearance, application time, tack-free time, cure time and adhesion. Adhesion to aluminum should be (peel) less than two-pounds, per inch of width. 1-24 Revision 2 MODEL 172 SERIES SERVICE MANUAL STORAGE CONDITION EXTEND PRODUCT (TEMPERATURE SHELF LIFE IN DEGREES IN MONTHS IN MONTHS MONTHS FAHENHEIT) ADHESIVES AND CEMENTS EA9309.3NA 40 TO 80°F 12 Months 6 Months 6 Months EA9339 40 TO 80°F 12 Months 6 Months 6 Months EA9314 40 TO 80°F 12 Months 6 Months 6 Months EA9330 40 TO 80°F 12 Months 6 Months 6 Months EA907 40 TO 80°F 12 Months 6 Months 6 Months Devcon F 40 TO 80°F 12 Months 6 Months 6 Months EA934NA 40 TO 80°F 12 Months 6 Months 6 Months 380/6 40 TO 80°F 12 Months 6 Months 6 Months A1186B 40 TO 80°F 12 Months 6 Months 6 Months EC2216 40 TO 80°F 12 Months 6 Months 6 Months #10 Fastset 40 TO 80°F 12 Months 6 Months 6 Months 608 Quickset 40 TO 80°F 12 Months 6 Months 6 Months EC880 40 TO 80°F 8 Months 3 Months 3 Months EC847 40 TO 80°F 8 Months 3 Months 3 Months EC1300L 40 TO 80°F *6 Months *3 Months *3 Months 5452 40 TO 80°F 12 Months 6 Months 6 Months 56431 40 TO 80°F 12 Months 6 Months 6 Months 1636 40 TO 80°F 12 Months 6 Months 6 Months RTV - 157 40TO 80°F 12 Months 6 Months 6 Months RTV - 158 40 TO 80°F 12 Months 6 Months 6 Months RTV - 159 40 TO 80°F 12 Months 6 Months 6 Months RTV732 40 TO 80°F 12 Months 6 Months 6 Months RTV102 40 TO 80°F 12 Months 6 Months 6 Months RTV103 40 TO 80°F 12 Months 6 Months 6 Months RTV106 40 TO 80°F 12 Months 6 Months 6 Months RTV108 40 TO 80°F 12 Months 6 Months 6 Months RTV109 40 TO 80°F 12 Months 6 Months 6 Months RTV94034 40 TO 80°F 12 Months 6 Months 6 Months Loctite 222 40 TO 80°F 12 Months 6 Months 6 Months Loctite 242 40 TO 80°F 12 Months 6 Months 6 Months Loctite 271 40 TO 80 ° F 12 Months 6 Months 6 Months Loctite 277 40 TO 80°F 12 Months 6 Months 6 Months Loctite 290 40 TO 80°F 12 Months 6 Months 6 Months Loctite 416 40 TO 80°F 12 Months 6 Months 6 Months Loctite 495 40 TO 80°F 12 Months 6 Months 6 Months Loctite 515 40 TO 80°F 12 Months 6 Months 6 Months Loctite 569 40 TO 80°F 12 Months 6 Months 6 Months Loctite 592 40 TO 80°F 12 Months 6 Months 6 Months Loctite 595 40 TO 80°F 12 Months 6 Months 6 Months * Do not use after three months of storage in the 81 ° F to 90°F range Do not use after five days of storage above 90°F. Table 1-7. (Sheet 1 of 2) Revision 2 1-25 MODEL 172 SERIES SERVICE MANUAL STORAGE CONDITION EXTEND CONDITION SHELF LIFE EXTEND RETEST IN PRODUCT (TEMPERATURE IN MONTHS SHELF LIFE MONTHS IN DEGREES IN MONTHS FAHENHEIT) ADHESIVES AND CEMENTS (CONTINUED) Loctite 601 40 TO 80°F 12 Months 6 Months 6 Months Loctite 620 40 TO 80°F 12 Months 6 Months 6 Months Loctite 680 40 TO 80°F 12 Months 6 Months 6 Months Loctite 1282 40 TO 80°F 12 Months 6 Months 6 Months Loctite 1283 40TO 80°F 12-Months 6Months 6 Months DA-5521 40 TO 80°F 12 Months 6 Months 6 Months PS- 18 40 TO 80°F 12 Months 6 Months 6 Months PS-30 40 TO 80°F 12 Months 6 Months 6 Months XA-3678 40 TO 80°F 12 Months 6 Months 6 Months XF-3585 40 TO 80°F 12 Months 6 Months 6 Months LR-100-226 40TO 80°F 12 Months 6 Months 6 Months EC776 40 TO 80°F * 8 Months * 3 Months *3 Months SB and P2 40 TO 80°F 12 Months 6 Months 6 Months SEALANTS Pro-Seal 890 40 TO 80°F 6 Months 2 Months 2 Months GC-408 40 TO 80°F 6 Months 2 Months 2 Months PR1422 40TO 80°F 6 Months 2 Months 2 Months PR1440 40 TO 80°F 6 Months 2 Months 2 Months GC435 40 TO 80°F 6 Months 2 Months 2 Months Pro-Seal 567 40 TO 80°F 6 Months 2 Months 2 Months PR810 40 TO 80°F 6 Months 2 Months 2 Months Pro-Seal 700 40 TO 80°F 6 Months 2 Months 2 Months GC 1900 40 TO 80°F 6 Months 2 Months 2 Months PR366 40 TO 80°F 6 Months 2 Months 2 Months Pro-Seal 735 40 TO 80°F 6 Months 2 Months 2 Months Pro-Seal 895 40 TO 80°F 6 Months 2 Months 2 Months Pro-Seal 706B 40 TO 80°F 6 Months 2 Months 2 Months PR1321 40 TO 80°F 6 Months 2 Months 2 Months GC200 40 TO 80°F 6 Months 2 Months 2 Months RTV-730 40 TO 80°F 6 Months 2 Months 2 Months Pro-Seal 815 40 TO 80°F 6 Months 2 Months 2 Months GC402 40 TO 80°F 6 Months 2 Months 2 Months PR-1005L 40 TO 80°F *8 Months *3 Months *3 Months GC-3001 40 TO 80°F *8 Months *3 Months *3 Months 444R 40 TO 80°F *8 Months *3Months *3 Months * Do not use after three months of storage in the 81°F to 90°F range Do not use after five days of storage above 90°F. Table 1-7. (Sheet 2 of 2) 1-26 Revision 2 MODEL 172 SERIES SERVICE MANUAL SECTION 2 GROUND HANDLING, SERVICING, CLEANING, LUBRICATION AND INSPECTION WARNING When performing any inspection or maintenance that re- quires turning on the master switch, installing a battery, or pulling the propeller through by hand, treat the prop- eller as if the ignition switch were ON. Do not stand, nor allow anyone else to stand, within the arc of the propel- ler, since a loose or broken wire, or a component mal- function, could cause the propeller to rotate. Page No. TABLE OF CONTENTS Aerofiche/ Manual GROUND HANDLING ......... 1B14/2-4 Engine Induction Air Filter Towing .................. 1B14/2-4 (172 & F172 Series Only) .... 1C1 2-15 Hoisting ................. 1B14/2-4 Engine Induction Air Filter Jacking ............... 1B14/2-4 (172Q Only) ............. 1C2 2-16 Leveling ................. 1B14/2-4 Vacuum System Filter ....... 1C2 2-16 Weighing ................ B14/2-4 Battery .................. C2 2-16 Parking ................. 1B14/2-4 Tires ................. 1C3 2-17 Tie-Down ............... 1B14/2-4 Nose Gear Shock Strut ....... 1C3 2-17 Flyable Storage ............ 1B15/2-5 Nose Gear Shimmy Damper .. 1C3 2-17 Returning Aircraft to Service .. 1B16.2-6 Hydraulic Brake System . . . 1C4 2-18 Temporary Storage ......... 1B16/2-6 CLEANING ......... .... .C4 2-18 Inspection During Storage .. 1B18/2-8 Cleaning and Care Returning Aircraft to of Windshield and Windows . 1C4 2-18 Service ................ 1B18/2-8 Plastic Trim .... 1C6 2-20 Indefinite Storage .......... 1B18/2-8 Painted Surfaces ...... . . 1C6 2-20 Inspection During Storage .... 1B20/2-10 Aluminum Surfaces ......... 1C7 2-21 Returning Aircraft to Service .. 1B20/2-10 Engine Engine Compartment .. 1C7 2-21 SERVICING ................ 1B21/2-11 Upholstery and Interior ...... 1C9 2-23 Fuel .................... 1B21/2-11 Propeller ......... .... . 1C10 2-24 Use of Fuel Additives for Wheels ......... ....... 1C10 2-24 Cold Weather Operation ..... 1B21/2-11 LUBRICATION ............ C10 2-24 Fuel Drains ............... 1B22/2-12 Wheel Bearings ............ 1C10 2-24 Carburetor Drain Plug Nose Gear Torque Links ..... 1C10 2-24 Inspection ............... 1B22/2-13 Wing Flap Acuator ......... 1C11 2-24 Engine Oil ............... B23/2-13 Fuel Selector Valve ......... 1C11 2-25 Engine Oil Additive ......... 1C1/2-15 Rod End Bearings .......... 1C11 2-25 INSPECTION ............... 1C21 2-35 Revision 1 2-1 MODEL 172 SERIES SERVICE MANUAL NOTE Use tow bar carefully to avoid scarring finish on speed fairing. Figure 2-1. Tow Bar REFER TO SHEET 2 FOR JACKING - INFOR MATION NOTE Corresponding points on both upper door sills may be used to level the aircraft laterally. Reference points for longitudinal leveling of aircraft are two screws on left side of tailcone at zero waterline. These are indicated in illustration by A (Also refer to paragraph 2-5) Figure 2-2. Jacking and Leveling (Sheet 1 of 2) 2-2 MODEL 172 SERIES SERVICE MANUAL JACKING INFORMATION ITEM NUMBER TYPE AND NUMBER REMARKS 1 Block 1x4x4 padded with 1/4" rubber 2 #2-170 Basic jack (includes #2-71 Min. closed height: 34" Slide tube: Liftstroke 22-1/2") Max. extension height: 56-1/2" #2-70 Slide tube: Liftstroke Min. closed height: 57-1/2" 22-1/2" Max. extension height: 80" #2-64 Extension cap Adds 4" #2-109 Leg extension Adds 12" 3 Built-in jack pad Part of step bracket (SEE CAUTION) 4 Cessna #SE2-168 Tail tie-down stand 1. Wing jacks are placed under front spar of wing just outboard of wing strut, and must extend far enough to raise wheels off ground, and must be adequate strength. 2. Attach a Cessna #SE2-168 stand to the tie-down ring. Beure tail stand weighs enough to keep tail down and under all conditions that it is stong engough to sup- port any weight that might be placed on it (place shot bags or sand bags on tail stand). In addition, the base of adjustable tail stand is to be filled with concrete for additional weight as a safety factor. 3. Operate jacks evenly until desired height is reached. CAUTION When using built-in jack pad, flexibility of the gear strut will cause the main wheel to slide inboard as the wheel is raised, tilting the jack. The jack must be lowered for a second operation jacking both wheels simultaneously at built-in jack pads is not recommended. jack pad may be used to raise only one main wheel. Do not USE brake casting as a jack point. 4. Items 2 and 4 areavailable from the Cessna Supply Division. Figure 2-2. Jacking and Leveling (Sheet 2 of 2) 2-3 MODEL 172 SERIES SERVICE MANUAL 2- . GROUND HANDLING. 2-2. TOWING. Moving the aircraft by hand is accomplished by using the wing struts and landing gear struts as push points. A tow bar attached to the nose gear should be used for steering and maneuvering the aircraft on the ground. When no tow bar is available, press down at the horizontal stabilizer front spar adjacent to the fuselage to raise the nose wheel off the ground. With the nose wheel clear of the ground, the aircraft can be turned by pivoting it about the main wheels. Beginning with serials 17275035 and F1722135 tow bar stowage provisions are provided. In the baggage area a strap located at FS 110.75 and a bracket located at FS 140.10 are used to secure and store the tow bar assembly when not in use. CAUTION When towing the aircraft, never turn the nose wheel more than 30 degrees either side of center or the nose gear will be damaged. Do not push on control surfaces or outboard empennage surfaces. When pushing on the tailcone. always apply pressure at a bulkhead to avoid buckling the skin. 2-3. HOISTING. The aircraft may be lifted with a hoist of two-ton capacity by using hoisting rings, which are optional equipment, or by means of suitable slings. The front sling should be hooked to each upper engine mount at the firewall, and the aft sling should be positioned around the fuselage at the first bulkhead forward of the leading edge of the stabilizer. If the optional hoisting rings are used, a minimum cable length of 60 inches for each cable is required to prevent bending of the eyebolt-type hoisting rings. If desired, a spreader jigmay be fabricated to apply vertical force to the eyebolts. 2-4. JACKING. See figure 2-2 for jacking procedures. 2-5. LEVELING. Corresponding points on both upper door sills may be used to level the aircraft laterally. The reference points for longitudinally leveling the aircraft are the two screws located on the left side of the tailcone. See figure 2-2 for screw locations. 2-5A. WEIGHING AIRCRAFT. Refer to Pilot's Operating Handbook. 2-6. PARKING. Parking precautions depend principally on local conditions. As a general precaution, set parking brake or chock the wheels and install the controls lock. In severe weather and high wind conditions, tie down the aircraft as outlined in paragraph 2-7 if a hangar is not available. 2-7. TIE-DOWN. When mooring the aircraft in the open, head into the wind if possible. Secure control surfaces with the internal control lock and set brakes. CAUTION Do not set parking brakes when they are overheated or during cold weather when accumulated moisture may freeze them. 2-4 MODEL 172 SERIES SERVICE MANUAL After completing the preceding, proceed to moor the aircraft as follows: a. Tie ropes, cables, or chains to the wing tie-down fittings located at the upper end of each wing strut. Secure the opposite ends of ropes, cables, or chains to ground anchors. b. Secure rope (no chains or cables) to forward mooring ring and secure opposite end to ground anchor. c. Secure the middle of a rope to the tail tie-down ring. Pull each end of rope away at a 45 degree angle and secure to ground anchors at each side of tail. d. Secure control lock on pilot control column. If control lock is not available, tie pilot control wheel back with front seat belt. e. These aircraft are equipped with a spring-loaded steering system which affords protection against normal wind gusts. However, if extremely high wind gusts are anticipated, additional external locks may be installed. 2-8. FLYABLE STORAGE. Flyable storage is defined as a maximum of 30 days nonoperational storage and/or the first 25 hours of intermittent engine operation. NOTE O-320-H2AD ENGINES Thru aircraft serial 17274009, these engines are deliv- ered from the factory with SAE 20W-50 Ashless Disper- sant Oil conforming to MIL-L-22851. This oil must be used in these engines for all operations. (See figure 2-4, sheet 2 of 6.) MODEL 172Q ONLY - 0-360-A4N ENGINES 172 AND F172 SERIES -320-D2J ENGINES Beginning with aircraft serial 17274010, these engines are delivered from the factory with MIL-L-6082 Aviation Grade Mineral Oil. This oil is to be used to replenish the oil supply during the first 25 hours of operation, at the first 25-hour oil change, and until a total of 50 hours have accumulated or oil consumption has stabiized. Then use MIL-L22851 Ashless Dispersant Oil conforming to AVCO Lycoming Service Instruction No. 1014 and all re- visions and supplements thereto. (See figure 2-4, sheet 3 of 6). During the 30 day nonoperational storage or the first 25 hours of intermittent engine operation, every seventh day the propeller shall be rotated through five revolutions, without running the engine. If the aircraft is stored outside, tie-down in accordance with paragraph 2-7. In addition, the pitot tube, static air vents, air vents, openings in the engine cowling, and other similar openings shall have protective covers installed to prevent entry of foreign material. After 30 days, aircraft should be flown for 30 minutes or ground run-up until oil has reached operating temperature (lower green arc range). CAUTION Excessive ground operation shall be avoided. Revision 1 2-5 MODEL 172 SERIES SERVICE MANUAL 2-9. RETURNING AIRCRAFT TO SERVICE. After flyable storage, returning the aircraft to service is accomplished by performing a thorough preflight inspection. At the end of the first 25 hours of engine operation, drain engine oil and clean oil screens (or change external oil filter). Service engine with correct grade and quantity of engine oil. See figure 2-4 and paragraph 2-21 for correct grade of engine oil. 2-10. TEMPORARY STORAGE. Temporary storage is defined as aircraft in a nonoperational status for a maximum of 90 days. The aircraft is constructed of corrosion resistant alclad aluminum, which will last indefinitely under normal conditions if kept clean, however, these alloys are subject to oxidation. The first indication of corrosion on unpainted surfaces is in the form of white deposits or spots. On painted surfaces, the paint is discolored or blistered. Storage in a dry hangar is essential to good preservation and should be procured, if possible. Varying conditions will alter the measures of preservation, but under normal conditions in a dry hangar, and for storage periods not to exceed 90 days, the following methods of treatment are suggested: a. Fill fuel tanks or bays with the correct grade of gasoline. WARNING DURING ALL FUELING PROCEDURES, FIRE FIGHTING EQUIPMENT MUST BE AVAILABLE. TWO GROUND WIRES FROM DIFFERENT POINTS ON THE AIRPLANE TO SEPARATE APPROVED GROUND STAKES SHALL BE USED TO PREVENT ACCIDENTAL DISCONNECTION OF ONE GROUND WIRE. ENSURE THAT FUELING NOZZLE IS GROUNDED TO THE AIRPLANE. NOTE Tie-down rings should be used as grounding points for all grounding wires during refueling procedures. b. Clean and wax aircraft thoroughly. c. Clean any oil or grease from tires and coat tires with a tire preservative. Cover tires to protect against grease and oil. d. Either block up fuselage to relieve pressure on tires or rotate wheels every 30 days to change supporting points and prevent flat spotting the tires. e. Lubricate all airframe items and seal or cover all openings which could allow mois- ture and/or dust to enter. NOTE The aircraft battery serial number is recorded in the aircraft equipment list. To assure accurate warranty records, the battery should be reinstalled in the same aircraft from which it was removed. If the battery is returned to service in a different aircraft, appropriate record changes must be made and notification sent to the Cessna Claims Department. f. Remove battery and store in a cool, dry place; service battery periodically and charge as required. 2-6 Revision 1 MODEL 172 SERIES SERVICE MANUAL NOTE An engine treated in accordance with the following may be considered being protected against normal atmos- pheric corrosion for a period not to exceed 90 days. g. Disconnect spark plug leads and remove upper and lower spark plugs from each cylinder. NOTE The preservative oil must be Lubricating Oil-Contact and Volatile, Corrosion Inhibited, MIL-C-6529. Type I heated to 200°F-220°F spray nozzle temperature. h. Using a portable pressure sprayer, atomize spray preservative oil through the upper spark plug hole of each cylinder with the piston in a down position. Rotate crankshaft as each pair of cylinders is sprayed. i. After completing step "h," rotate crankshaft so that no piston is at a top position. If the aircraft is to be stored outside, stop two-bladed propeller so that blades are as near horizontal as possible to provide maximum clearance for passing aircraft. j. Again, spray each cylinder without moving the crankshaft to thoroughly cover all interior surfaces of the cylinder above the piston. k. Install spark plugs and connect spark plug leads. l. Apply preservative oil to the engine interior by spraying approximately two ounces of the preservative oil through the oil filler tube. m. Seal all engine openings exposed to the atmosphere, using suitable plugs or non- hygroscopic tape. Attach a red streamer at each point that a plug or tape is installed. n. If the aircraft is to be stored outside, perform the procedures in paragraph 2-7. In addition, the pitot tube, static source vents. air vents, openings in the engine cowling. and other similar openings should have protective covers installed to prevent entry of foreign material. o. Attach a warning placard to the propeller to the effect that the propeller shall not be moved while the engine is in storage. 2-7 MODEL 172 SERIES SERVICE MANUAL 2-11. INSPECTION DURING STORAGE. a. Inspect airframe for corrosion at least once a month and remove dust collections as frequently as possible. Clean and wax aircraft as required. b. Inspect the interior of at least one cylinder through the spark plug hole for corrosion at least once a month. NOTE Do not move crankshaft when inspecting interior of cylinder for corrosion. c. If at the end of the 90 day period. the aircraft is to be continued in nonopertional storage, repeat the procedural steps "g" thru "o" of paragraph 2-10. 2-12. RETURNING AIRCRAFT TO SERVICE. After temporary storage. use the following procedures to return the aircraft to service. a. Remove aircraft from blocks and check tires for proper inflation Check for proper nose gear strut inflation. (See figure 1-1.) b. Check battery and install. c. Check that oil sump has proper grade and quantity of engine oil. d. Service induction air filter and remove warning placard from propeller. e. Remove materials used to cover openings. f. Remove spark plugs from engine. g. While spark plugs are removed, rotate propeller several revolutions to clear excess rust preventive oil from cylinders. h. Clean. gap and install spark plugs. Torque plugs to the value specified in Section 11 or 11A and connect spark plug leads. i. Check fuel strainer. Remove and clean filter screen if necessary. Check fuel tanks or bays and fuel lines for moisture and sediment, drain enough fuel to eliminate moisture and sediment. j. Perform a thorough pre-flight inspection, then start and warm-up engine. 2-13. INDEFINITE STORAGE. Indefinite storage is defined as aircraft in a nonoperational status for an indefinite period of time. Engines treated in accordance with the following may be considered protected against normal atmosphere corrosion, provided the procedures outlined in paragraph 2-14 are performed at the intervals specified. a. Operate engine until oil temperature reaches normal operating range. Drain engine oil sump and reinstall drain plug and safety. b. Fill oil sump to normal operating capacity with corrosion preventive mixture which has been thoroughly mixed. NOTE Corrosion-preventive mixture consists of one part com- pound MIL-C-529. Type I. mixed with three parts by volume of MIL-L-6082 mineral aircraft engine oil. c. Immediately after filling the oil sump with corrosion-preventive mixture. fly the aircraft for a period of time not to exceed a maximum of 30 minutes. 2-8 MODEL 172 SERIES SERVICE MANUAL d. With engine operating at 1200 to 1500 rpm and induction air filter removed, spray corrosion-preventive mixture into induction airbox, at the rate of one-hall gallon per minute, until heavy smoke comes from exhaust stack, then increase the spray until the engine is stopped. CAUTION Injecting corrosion-preventive mixture too fast can cause a hydrostatic lock. e. Do not rotate propeller after completing step "d". f. Remove all spark plugs and spray corrosion-preventive mixture. which has been preheated to 200°F to 220°F, into all spark plug holes to thoroughly cover interior surfaces of cylinders. g. Install lower spark plugs or install solid plugs, and install dehydrator plugs in upper spark plug holes. Be sure that dehydrator plugs are blue in color when installed. h. Cover spark plug lead terminals with shipping plugs (AN4060-1) or other suitable covers. i. With throttle in full open position, place a bag of desiccant in the carburetor intake and seal opening with moisture resistant paper and tape. j. Place a bag of desiccant in the exhaust tailpipe(s) and seal openings with moisture resistant tape. k. Seal cold air inlet to the heater muff with moisture resistant tape. L Seal engine breather by inserting a protex plug in the breather hose and clamping in place. m. Seal all other engine openings exposed to atmosphere using suitable plugs or non- hygroscopic tape. NOTE Attach a red streamer to each place plugs or tape is installed. Either attach red streamers outside of the sealed area with tape or to the inside of the sealed area with safety wire to prevent wicking of moisture into the sealed area. n. Drain corrosion-preventive mixture from engine sump and reinstall drain plug. NOTE The corrosion-preventive, mixture is harmful to paint and should be wiped from painted surfaces immediately. o. Attach a warning placard on the throttle control knob, to the effect that the engine contains no lubricating oil. Placard the propeller to the effect that it should not be moved while the engine is in storage. p. Prepare airframe for storage as outlined in paragraph 2-10 thru step "f". 2-9 MODEL 172 SERIES SERVICE MANUAL NOTE As an alternate method of indefinite storage. the aircraft may be serviced in accordance with paragraph 2-10 providing the aircraft is run up at maximum intervals of 90 days and then reserviced per paragraph 2-10. 2-14. INSPECTION DURING STORAGE. Aircraft in indefinite storage shall be inspected as follows: a. Inspect cylinder protex plugs each 7 days. b. Change protex plugs if their color indicates an unsafe condition. c. If the dehydrator plugs have changed color in one half of the cylinders. all desiccant material in the engine shall be replaced with new material. d. Every 6 months respray the cylinder interiors with corrosion-preventive mixture. NOTE Before spraying, inspect the interior of one cylinder for corrosion through the spark plug hole and remove at least one rocker box cover and inspect the valve mecha- nism. 2-15. RETURNING AIRCRAFT TO SERVICE. After indefinite storage. use the following proce- dure to return the aircraft to service. a. Remove aircraft from blocks and check tires for correct inflation. Check for correct nose gear strut inflation. b. Check battery and install. c. Remove all materials used to seal and cover openings. d. Remove warning placards posted at throttle and propeller. e. Remove and clean engine oil screen, then reinstall and safety. On aircraft that are equipped with an oil filter, install new filter. f. Remove oil sump drain plug (or open quick-drain valve) and drain sump. Install and safety drain plug (or close quick-drain valve) and service engine with correct quantity and grade of engine oil in accordance with figure 2-4. NOTE The corrosion-preventive mixture will mix with the engine lubricating oil. so flushing the oil system is not necessary. Draining the oil sump will remove enough of the corrosion-preventive mixture. g. Service and install the induction air filter. h. Remove dehydrator plugs and spark plugs or plugs installed in spark plug holes and rotate propeller by hand several revolutions to clear corrosion-preventive mixture from cylinders. i. Clean, gap, and install spark plugs. Torque plugs to the value listed in Section 11 or 11A. j. Check fuel strainer. Remove and clean filter screen. Check fuel tanks or bays and fuel lines for moisture and sediment, and drain enough fuel to eliminate. k. Perform a thorough preflight inspection, then start and warm-up engine. l. Thoroughly clean aircraft and flight test aircraft. 2-10 MODEL 172 SERIES SERVICE MANUAL 2-16. SERVICING. 2-17. Servicing requirements are shown in figure 2-4. The following paragraphs supplement this figure by adding details not included in the figure. 2-18. FUEL. Fuel tanks or bays should be filled immediately after flight to lessen moisture con- densation. Tank or bay capacities are listed in Section 1. The recommended fuel grade to be used is given in figure 2-4. WARNING DURING ALL FUELING PROCEDURES, FIRE FIGHTING EQUIPMENT MUST BE AVAILABLE. TWO GROUND WIRES FROM DIFFERENT POINTS ON THE AIRPLANE TO SEPARATE APPROVED GROUND STAKES SHALL BE USED TO PREVENT ACCIDENTAL DISCONNECTION OF ONE GROUND WIRE. ENSURE THAT FUELING NOZZLE IS GROUNDED TO THE AIRPLANE. NOTE Tie-down rings should be used as grounding points for all grounding wires during refueling procedures. 2-18A. USE OF FUEL ADDITIVES FOR COLD WEATHER OPERATION. Strict adherence to recommended preflight draining instructions will eliminate any free water accumulations from the tank sumps. While small amounts of water may still remain in solution in the gasoline, it will normally be consumed and go unnoticed in the operation of the engine. One exception to this can be encountered when operating under the combined effect of: (1) use of certain fuels, with (2) high humidity conditions on the ground (3) followed by flight at high altitude and low temperature. Under these unusual conditions small amounts of water in solution can precipitate from the fuel stream and freeze in sufficient quantities to induce partial icing of the engine fuel system. While these conditions are quite rare and will not normally pose a problem to owners and operators, they do exist in certain areas of the world and consequently must be dealt with. when encountered. Therefore, to alleviate the possibility of fuel icing occuring under these unusual conditions it is permissible to add isopropyl alcohol or ethylene glycol monomethyl ether (EGME) compound to the fuel supply. See Figure 2-2A for fuel additive mixing ratio. The introduction of alcohol or EGME compound into the fuel provides two distinct effects: (1) it absorbs the dissolved water from the gasoline and (2) alcohol has a freezing temperature depressant effect. Alcohol, if used, is to be blended with the fuel in a concentration of 1% by volume. Concentrations greater than 1% are not recommended since they can be detrimental to fuel tank materials. Revision 1 2-11 MODEL 172 SERIES SERVICE MANUAL The manner in which the alcohol is added to the fuel is significant because alcohol is most effective when it is completely dissolved in the fuel. To insure proper mixing the following is recommended: 1. For best results the alcohol should be added during the fueling operation by pouring the alcohol directly on the fuel stream issuing from the fueling nozzle. 2. An alternate method that may be used is to premix the complete alcohol dosage with some fuel in a separate clean container (approximately 2-3 gallon capacity) and then transfer this mixture to the tank or bay prior to the fuel operation. Any high quality isopropyl alcohol may be used, such as: Anti-icing fluid (MIL-F-5566) or Isopropyl alcohol (Federal Specification TT-I-735a). Ethylene glycol monomethyl ether (EGME) compound in compliance with MIL-I-27686 or Phillips PFA-55MB, if used, must be carefully mixed with the fuel in concentrations not to exceed 0.15% by volume. CAUTION Mixing of the EGME compound with the fuel is extremely important because concentration in excess of that recom- mended (0.15 percent by volume maximum) will result in detrimental affects to the fuel tanks, such as deterioration of protective primer and sealants and damage to O-rings and seals in the fuel system and engine components. Use only blending equipment that is recommended by the manufacturer to obtain proper proportioning. Do not allow the concentrated EGME compound to come in contact with the airplane finish or fuel cell as damage can result. Prolonged storage of the airplane will result in a water build-up in the fuel which "leeches out" the additive. An indication of this is when an excessive amount of water accumulates in the fuel tank sumps. The concentration can be checked using a differential refractometer. It is imperative that the technical manual for the differential refractometer be followed explicitly when checking the additive concentration. 2-19. FUEL DRAINS. On aircraft serials 17267585 thru 17275034 and F17201515 thru F17202134, the fuel drains are located in the fuel tanks or bays, fuel strainer, and carburetor. Drain plugs are installed in the fuel selector valve and carburetor; drain valves are located in the fuel tanks or bays and fuel strainer. Beginning with 17275035 and F17202135, a drain valve is located in the bottom of the fuel selector valve for sampling and draining of fuel. To activate the drain valves for fuel sampling, place cup up to valve and depress valve with rod protruding from cup. Refer to Section 12 for illustration of fuel tank and bay drain valve. The strainer valve is an integral part of the fuel strainer assembly. The strainer drain is equipped with a control which is located adjacent to the oil dipstick. Access to the control is through the oil dipstick access door. Open drains and remove drain plugs at intervals specified in figure 2-4. Also, during daily inspection of the fuel strainer, fuel selector, and tanks or bays, if water is found in the system, all fuel drain plugs should be opened and all water drained from the system. 2-12 Revision 1 MODEL 172 SERIES SERVICE MANUAL 18 4.5 140 - 16 - 4.0 120- GALLONS OF GASOLINE Figure 2-2A. Fuel Additive Mixing Ratio Chart. 2-20. CARBURETOR DRAIN PLUG INSPECTION. In order to prevent the possibility of thread sealant contamination in the carburetor float chamber, cleaning and inspection of the carburetor should be accomplished at each 100-hour inspection and anytime water in the fuel is suspected. a. With the fuel selector valve OFF, remove carburetor drain plug and clean off any sealant present on the end of the plug or in the threads on the plug. b. Inspect drain plug hole in the carburetor and remove any sealant remaining in the hole. c. Turn fuel selector valve to BOTH to flush float chamber and drain plug chamber while probing drain plug hole to ascertain that all residue of sealant material is dislodged and washed out of the chamber. Flushing operation should last 15 to 30 seconds. d. A second flushing should then be accomplished and the drained fuel retained for inspection to ensure that no sealant particles are present. e. Install drain plug as follows: 1. Install drain plug in carburetor 1-1/2 to 2 turns. 2. Apply sealant to drain plug threads (use NS-40 [RAS-4] or equivalent). 3. Tighten and safety drain plug. f. Turn fuel selector valve to BOTH and inspect for evidence of fuel leakage. 2-21. ENGINE OIL. Check engine lubricating oil with the dipstick five to ten minutes after the en- gine has been stopped. The aircraft should be in as near a level position as possible when checking the engine oil, so that a true reading is obtained. Engine oil should be drained while the engine is still hot, and the nose of the aircraft should be raised slightly for more Revision 1 2-13 MODEL 172 SERIES SERVICE MANUAL positive draining of any sludge which may have collected in the engine oil sump. Engine oil should be changed as specified in servicing intervals figure 2-4. Reduce these intervals for prolonged operations in dusty areas, in cold climates where sludging conditions exist, or where short flights and long idle periods are encountered, which cause sludging conditions. Always change oil and oil filter whenever oil on the dipstick appears dirty. Aviation grade oil conforming to AVCO Lycoming Service Instruction No. 1392 for the 0-320-H2AD engine, and AVCO Lycoming Service Instruction No. 1014 for the O-320-D2J engine (Model 172 and F172 Series) and 0-360-A4N engine (Model 171Q only) and any revisions or supplements thereto, shall be used. NOTE O-320-H2AD ENGINES Service with 20W-50 Ashless Dispersant Oil conforming to MIL-L-22851. (See figure 2-4, sheet 2 of 6.) O-320-D2J AND 0-360-A4N ENGINES Service with SAE 20W-50 (MIL-L-6082) Aviation Grade Mineral Oil when new or newly overhauled, during the first 25 hours of operation, at the first 25 hour oil change, and until 50 hours have accumulated or oil con- sumption has stabilized. (See figure 2-4, sheet 3 of 6.) WARNING The U.S. Environmental Protection Agency advises that mechanics and other workers who handle engine oil are advised to minimize skin contact with used oil and promptly remove used oil from the skin. In a laboratory study, mice developed skin cancer after skin was exposed to used engine oil twice a week without being washed off, for most of their life span. Substances found to cause cancer in laboratory animals may also cause cancer in humans. Valve shown open. To close, twist screwdriver until valve unlocks and snaps down to closed position. Figure 2-3. Quick-Drain Valve 2-14 Revision 1 MODEL 172 SERIES SERVICE MANUAL An oil quick-drain valve may be installed. This valve provides a quicker and cleaner method of draining the engine oil. This valve is installed in the oil drain port of the oil sump and allows oil to be drained by attaching a hose over the fitting end and pushing up, causing the oil to drain through the hose into a container. To drain the engine oil, proceed as follows: a. Operate engine until oil temperature is at normal operating temperature. b. (With Quick-Drain Valve.) Attach a hose to the quick-drain valve in the oil sump. P