service bulletin 221c · servicebulletin221c page 5 of 21 4....

SERVICE BULLETIN 221CALERT

September 7, 1999

TO: FAA-Approved Propeller Repair Stations, Cessna Aircraft Company, Aircraft OwnersandOperators

SUBJECT: Inspection of Propeller Hub for Cracking andRework Procedures

MODEL AFFECTED: 1A103/TCM[XXXX]Serial Numbers: 770001 through 777390 and BC001 up to, butnot including, KC001 (see page 19 for explanation of serialnumbersystem).

SERVICE MANUAL AFFECTED: 730720

AIRCRAFT MODELS AFFECTED: Cessna 152, A152; Reims F152, FA152

NOTE: This bulletin does not contain an exhaustive list of aircraft which utilize this propellerbecause it isnotpossible to identifyall aircraft using theaffectedpropellermodel (e.g.installationapprovalsmadebySupplementalTypeCertificateorFAAForm337MajorRepair and Alteration, or Type Certificated models which have been inadvertentlyomitted). Therefore, it is the responsibility of the operator or person(s) performingaircraft inspections/propeller overhauls to determine if an aircraft has an affectedpropeller.

Thisservice information is tobeadded to theappropriateMcCauleyServiceManualuntil thenextmanual revision is issued.

ServiceBulletin 221C replacesServiceBulletin 221B, datedJanuary23, 1997. ServiceBulletin221Awasnever released to the field. ServiceBulletin 221Callowsmore thanonecrackper bolthole and per propeller but thesemay be reworked one time only. Paint is now required on frontface of hub. Lines in margin indicate changes.

FollowingcompliancewithServiceBulletin221,ServiceBulletin221B,orServiceBulletin221C,periodic inspections required per Service Bulletin 219A dated October 15, 1995, are no longernecessary. Consequently,ServiceBulletin219A isobsolete forall propellersmodifiedper thesebulletins.

TOOBTAIN SATISFACTORYRESULTS, PROCEDURESSPECIFIED IN THIS SERVICE INFORMATIONMUSTBEACCOMPLISHED IN ACCORDANCEWITHACCEPTEDMETHODSANDPREVAILINGGOVERNMENTREGULATIONS. MCCAULEYPROPELLERSYSTEMSCANNOTBERESPONSIBLEFORTHEQUALITYOFWORKPERFORMED INACCOMPLISHINGTHISSERVICE INFORMATION.

McCauley Propeller SystemsA Textron Company3535 McCauley DriveVandalia, Ohio 45377 USA

of 21 Service Bulletin 221C

COMPLIANCE: See Section I on Page 3.

CONDITION: There have been several reports of hub cracking on the affected propeller.Cracks have been found on the camber side of hub near the mounting boltholes, usually in the area where fretting is present. Inspect and rework thepropeller inaccordancewith the following instructions.

Multiplesmall cracks found inbolt holeareamaybe reworked. Bolt holeareamay be reworked one time only. Propeller must be removed from service ifthere is reappearanceof crackat abolt holewhichwaspreviously reworked.

CORRECTION: Inspection and rework may be accomplished by an FAA certified A & Pmechanic (or internationalequivalent).

Service Bulletin 221C Page 3 of 21

SECTION I. COMPLIANCE

1. For propellers with 3,000 hours or more total time in service:

Inspection, perSection II, andRework procedures, perSection III, must beaccomplished within 50 hours of operation since last inspection under ServiceBulletin219A.

2. Repetitive dye check inspection, per Section IV, is to be accomplished every 12calendarmonths or every 800 hours of operationwhich ever occurs first.

SECTION II. DYE PENETRANT INSPECTION PROCEDURES

1. Remove propeller from aircraft as follows (Ref: Figure 11):

a. Removespinner (1).

b. Remove safetywire frommounting bolt heads (3).

c. Remove bolts andwashers and remove forward bulkhead (5).

NOTE: The aft spinner bulkhead (7) is installed between propeller (6) and crankshaftflange (8), and is removed as the propeller is removed.

2. Using paint remover, plastic media blasting, or equivalent, strip paint, if present,inside the dimensioned area outlined in Figure 12 on the camber side of thehub.

NOTE: Face side of hub should not be painted. Remove paint if present.

CAUTION: OBSERVEMANUFACTURER'SPRECAUTIONSWHENUSINGPAINTRE-MOVERTOPREVENT INJURY. ALSO,MASKAREA TOBESTRIPPED TOPREVENTPAINTREMOVERFROMBEINGAPPLIEDEXCESSIVELY.

3. Remove anodize and etch camber side of hub using the following procedures:

CAUTION: FOLLOWMANUFACTURER'SPRECAUTIONSANDWARNINGSWHENUSINGCHEMICALETCHINGSOLUTIONS.

a. Remove anodize by chemical etchingwith a solution containing 4% to15%sodiumhydroxide (lye). Such solutions are available inmany (notall) householdovencleaners. "Easy-Off" brand is recommended (Boyle-


Midway, Inc.,NewYork) (useundiluted). Otheroptional productsare: "Mr.Muscle" (Dracket Products Co., Cincinnati, OH) or "DowOvenCleaner"(DowChemical Co., Indianapolis, IN). Brush-on liquid is preferable tospray-on type (if spray-on type is used, additional maskingmay be re-quired).

b. Apply even coat of solution to face of hub,making sure solution reachesto the edge of each bolt hole. Allow solution to remain "active" on hub for10minutes. Reapply solution continuously during this time tomaintain awet, chemically active coating. A black or grey "smut" will appear asanodize is being removed. (If "smut" does not appear, it is an indicationthat the solution is inadequate.)

c. Removesolutionand "smut" after 10minuteswith clean, nonmetallicscouring pad saturatedwith 50%solution of warmwater and vinegar.Clean out any etching solution which may have entered bolt holewith water and vinegar solution and soft brush.

d. Wipe area dry.

e. Repeat steps b through d for additional and necessary etching. (The firstapplication will remove the anodize finish, and the second application willprovide surface etching for optimum results during dyepenetrant inspec-tion.)

f. Scrub camber side of hub and bolt holes with clean cloth soaked withMEK and allow to dry. This will ensure area is clean before visual orpenetrant inspection.

4. Performdyepenetrant inspectionusing the followingprocedures:

a. Requiredmaterials andEquipment

1. Liquid penetrant, Type 1, Level 4, Ultra-high sensitivity as listed inMIL-I-25135/QPL-25135(SherwinRC-88*orequivalent).

2. Penetrant Remover,MethodC/Class 1 as listed inMIL-I-25135/QPL-25135 (SherwinDR-62* or equivalent).

3. Penetrant Developer, FormD, as listed inMIL-I-25135/QPL-25135 (SherwinD-100* or equivalent).


4. Ultraviolet light, 100wattmercury vapor, providing2000uW/cm2at 15" (Spectronics SB-100 or equivalent).

5. Ultraviolet light meter capable ofmeasuring up to 6000 uW/cm2(UVPJ-221 or equivalent).

6. Paper towels, soft, lint free.

*Products available from Sherwin, Inc., 5530 Borwick Ave., SouthGate, CA 90280

b. Apply even coat of Type 1, Level 4 liquid penetrant on propeller camberside of hub, paying particular attention to area near bolt holes.

NOTE: Ensure ambient temperature of propeller and liquid penetrant materials is inrange of 60° to 120°F before performing inspection.

c. Allow liquid penetrant to remain on propeller camber side of hub for 1hourminimum.

d. Remove liquid penetrant from camber side of hub by wiping with papertowel until all penetrant residue appears to be removed.

NOTE: Check100watt ultraviolet light output intensity beforeuse. Output intensityshould beminimum 2000uW/cm2measured at 15 inches from the face of theultraviolet light filter to thesensoron theultraviolet lightmeter.

e. Inspect propeller camber side of hub using a 100watt ultraviolet light;thereshouldbeagreen/yellowpenetrant residuepresent.

NOTE: Never spray liquid penetrant remover directly on area to be inspected.

f. Using a soft paper towel dampened with class 1 penetrant remover, wipecamber side of propeller hubwhile viewing under a 100watt ultravioletlight.Continuewipingwithpenetrant removerdampened towel until allevidence of penetrant residue is not visible when examinedwith anultraviolet light.

g. Spray light, even coat of Form D developer on camber side of propellerhub.


NOTE: Do not spray thick, heavy coats of developer onto component being inspectedas this could mask over the defect and allow it to go undetected.

h. Examinehubusinga100watt ultraviolet light.

i. If crack is found, check propeller serial number for change letter stamp-ing. If a letter 'S' is located in front of the serial number (indicating priorrework), area of previous rework must be determined. If currentcrack indication is at same bolt hole as previous rework, propelleris scrap. If previous rework was at another bolt hole, propellermay be reworked. If the change letter 'S' is not present or previousrework was at another bolt hole, mark the location of crack, path andlength with fine point felt tip pen prior to removing ultraviolet light. This isimportant in aiding rework if crack size and location are found to be withinacceptable limits. (Ref: Figure 1) Proceed to Section III for rework in-structions.

Figure 1

j. If no crack is found, glass shot entire camber side of hub using MSH glassshot (MIL- G-9954A or latest revision, MIL Bead #8, 80-100 PSI). Applyalodine to unpainted camber side of hub in accordance with MIL-C-5541.Alodine all surfaceswhere etchingmay have removed anodize,make sure toswab alodine inside bolt holeswhere etching solutionmay have entered.


Paint camber side of hub only, do not paint face side of hub (enginemount-ing surface). Proceed to Reassembly instructions in Section V to returnpropeller to service.

5. Repetitive dye check inspection, per Section IV, is to be accomplished every 12calendarmonths or every 800hours of operationwhichever occurs first.

SECTION III. REWORK

1. Use the following criteria to determine if the cracks can be reworked or if thepropeller is scrap (Ref: Figure 13):

a. Propeller must be scrapped if:

1. Cracks are 1/2" or larger

2. Cracks touch a bolt hole

3. Crack are within 1/4" of hub outside edge

4. Crack are within 1/4" of centerbore

5. Change letter 'S' is located in front of propeller serial numberstamping and location of previous rework can not be determined,or previously rework was in same bolt hole as current crack

b. Propeller can be reworked if:

1. Cracks are less than 1/2"

2. Cracks do not touch a bolt hole

3. Cracks are more than 1/4" from hub outside edge

4. Cracks are more than 1/4" from centerbore

5. Cracks are located in different bolt hole than previous rework.

NOTE: ALL of the above criteria must be met in order for the propeller to be eligible forrework.


2. Follow these procedures to remove cracks frompropeller hub.

OPTION 1 - Bridgeport (Ref: Figure 2)

a. Lay propeller on Bridgeport (or similar machine).

b. Align and center crack with .250" ball endmill in the direction of motion.

Figure 2

c. Clamp propeller tomachine.

d. Lower .250" ball endmill and touch hub surface. This will be the zero (0)dimension.

Figure 3


e. Set depth of cut to .010", and begin removing crack. (Ref: Figure 3)

NOTE: Do not removemore than .040"material total when attempting to remove crack.

NOTE: Ball endmill may extend into bolt hole when removing crack. Do not allowmillcenterline to extendbeyond length of crack. Thiswill allow for endmill runout.(Ref: figure 4)

Figure 4

f. Examine reworked area under 10x powerscope after each cut.(Ref: Figure 5)

g. If crack appears to be totally removed, repeat etch and dye penetrantinspection using instructions in Section II to verify crack has been re-moved.

h. If crack still exists after .040" material is removed, propmust bescrapped.


Figure 5

OPTION 2 - RotaryGrinder (Ref: Figure 6)

a. Using 3/16" Grinding Burr, begin removing crack.

Figure 6

NOTE: Do not removemore than .040"material total when attempting to remove crack.

NOTE: Do not grind beyond length of crack.

b. Verify amount ofmaterial removedwith depth gauge.

c. Examine reworked area under 10x powerscope after each cut.

d. If crack appears to be totally removed (Ref: Figure 7), repeat etch and


dye penetrant inspection using instructions in Section IV to verify crackhasbeen removed.

e. If crack still exists after .040" material is removed, propmust bescrapped.

Figure 7

3. Sand hub face with sanding bob (Cratex Rubberized Abrasives, p/n 11M) toremove any sharp edges. (Ref: Figure 8 and Figure 9)

Figure 8


Figure 9

4. Glass shot entire hub usingMSHglass shot (MIL- G-9954A or latest revision,MIL Bead #8, 80-100 PSI). (Ref: Figure 10)

Figure 10

5. Stamp change letter 'S', using a 1/8 inch steel stamp, in front of the propellerserialnumber.

6 Apply alodine to unpainted hub in accordancewithMIL-C-5541. Alodine all


surfaces, including insidebolt holes,where etchingmayhave removedanodize.Paint camber side of hub only. Do not paint hubmounting surface.

NOTE: Repaint all areas of hub where paint was accidentally removed. Paint camberside of hub. DONOT paint enginemounting surface of hub within dimensionedarea as shown in figure 12.

7. Repetitive dye check inspection, per Section IV, is to accomplished every 12calendarmonths or every 800 hours of operationwhich ever occurs first.

NOTE: Propeller which has been reworked, indicated by change letter 'S', per instruc-tions in Section III may only be reworked again if area of previous rework canbe determined. If current crack indication is at same bolt hole as previ-ous rework, propeller is scrap. If previous rework was at another bolthole, propeller may be reworked. Bolt hole may be reworked one time.

8. Reassemble per Section V.

SECTION IV. REPETITIVE DYE PENETRANT INSPECTION PROCEDURES

1. Remove propeller from aircraft as follows (Ref: Figure 14):

a. Removespinner (1).

b. Remove safetywire frommounting bolt heads (3).

c. Remove bolts, plate, forward bulkhead, andmylar gasket (Ref: Figure14)

NOTE: The aft spinner bulkhead (7) is installed between propeller (6) and crankshaftflange (8), and is removed as the propeller is removed.

2. Performdyepentrant inspectionperSection II.

3. If crack is found, check propeller serial number for change letter stamping. If aletter 'S' is located in front of the serial number (indicating prior rework), area ofprevious rework must be determined. If current crack indication is atsame bolt hole as previous rework, propeller is scrap. If previous reworkwas at another bolt hole, propeller may be reworked. If the change letter 'S'is not present or previous rework was at another bolt hole, mark the location ofcrack, path and lengthwith fine point felt tip pen prior to removing ultraviolet light.


This is important in aiding rework if crack size and location are found to bewithin acceptable limits. Proceed toSection III for rework instructions.

NOTE : It is required thatMcCauley Product Support be notified if any propeller whichpassed the initial inspection and has been reworked is later found to have crackreappearance. Use the form on page 21 for notification.

4. Reassemble per Section V.

5. Repetitive dye check inspection, per Section IV, is to accomplished every 12calendarmonths or every 800 hours of operationwhich ever occurs first.

SECTION V. REASSEMBLY

1. ReferencingFigure 14, reinstall propeller as follows:

a. Cleanmating surfaceof propeller, crankshaft flange, andspinner bulkheads.

WARNING: BESURETHATMAGNETO ISGROUNDEDBEFORETURNINGPROPEL-LER,ORCONNECTINGEXTERNALPOWER.

b. Position aft spinner bulkheadbetweenpropeller and crankshaft flange.

c. Align propeller blade with t.c. mark on aft side of ring gear, and rotate propel-ler clockwise, as viewed from the front, to first bolt hole.

d. Installmylargasket (p/nB-7306).

e. Install forward spinner bulkhead. If holes on front bulkheadare cuppeddue toprevious torques frombolts andwashers, place bulkhead on flat surface andlightly pound cuppedholes flatwith hammer. Removeanyburrs or roughedges. Diameter of holes should be 0.375". Ream holes if necessary.

f. Install steel reinforcementplate (p/nB-7287).

g. Install newbolts, A-2513-78, or boltsmagnafluxed per ASTME1444-91,without washers. Bolts, plate and gasket may be purchased in kit form,B-4622-43.

h. Tightenbolts evenly, then torque to300-360 in.-lb. or 25-30 ft.-lb (dry).


i. Safetywire propellermounting bolts, ensuring that safetywire is around boltheads, not over top. Use .041" diameter safety wire.

j. Installspinnershell.

2. Make logbook entry indicating compliancewith this service bulletin.

3. Using form on page 21, report findings to McCauley.


1. Spinner2. Screw3. Bolt4.Washer5. ForwardSpinner Bulkhead6. Propeller7. Rear Spinner Bulkhead8.Crankshaft (WithRingGear)

1

2

34

5

6

78

Figure 11. Original Configuration of 1A103/TCMXXXXPropeller and Spinner Installation

ServiceBulletin

221CPage

17of21Figure 12. Typical Crack Appearance and Location


Within 1/4(0.250) inch

Within 1/4(0.250) inch

Crack less than1/2 (0.500) inchin length.

Figure 13. Reworkable & Non-Reworkable Cracks

All cracks shorter than 1/2 (0.500) inch, do not contact bolt hole,and aremore than 1/4 (0.250) inch from hub edge and hubcenterbore is acceptable. Propeller may be reworked.

Any crack longer than 1/2 (0.500) inch, contacts a bolthole, is less than 1/4 (0.250) inch from hub centerbore isunacceptable, or is located in area of previous rework.Removeunrepairablepropeller fromservice.

Any crack longer than 1/2 (0.500) inch, contacts a bolt hole,is less than 1/4 (0.250) inch from hub edge is unacceptableor is located in area of previous rework.Removeunrepairablepropeller fromservice.


D J 241

241stpropellermanufactured in thatmonth

Month: October

Year: 1983

In 1980McCauley began a new serial number systemas shown below:

A A XXX

Numberofpropellermanufactured thatmonth

Month: (A) January, (B) February, (C) March, etc...

Year: (A) 1980, (B) 1981, (C) 1982, etc...

Example of serializing system is shown below:

NOTE - Some propellers may have an "R", "P", "PR", or "RP" stamped in front of the serialnumber, indicating compliancewith earlier service information. These identifiersare not a part of the serial number designation and are to be disregarded whenconsidering applicability of this service bulletin.

APPROVAL: FAAapproval hasbeenobtainedon technical data in this publication that affectsproduct type design.


1. Spinner2. Screw3. Bolt4. Steel Reinforced Plate5. ForwardSpinner Bulkhead6.MylarGasket7. Propeller8. Rear Spinner Bulkhead9.Crankshaft (WithRingGear)

1 23

45

67

89

Figure 14: Reworked Configuration for 1A103/TCMXXXX Propeller andSpinner Installation


This form must be completed following dye penetrant inspection of propeller per McCauley Service Bulletin 221C. See Section II orSection III of Service Bulletin 221C for further details.

This completed form may be either mailed or telefaxed to McCauley at the following:

McCauley Propeller SystemsProduct Support Department

3535 McCauley DriveVandalia, Ohio 45377

Telefax: (937) 890-6001Telephone: (937) 890-5246

Date of Compliance with S.B. 221C:_________________

Propeller S/N:________________________ Propeller Total Time:___________________ Propeller T.S.O.:__________________

Aircraft N-number:_____________________ Aircraft S/N:__________________________Aircraft TotalTime:_________________

OwnersName:______________________________________________________________________________________________________

Telephone:( )________________________________

Contact Person (if different thanowner):__________________________________________________________________________________

Telephone: ( )________________________________

Please Sketch Exact Appearance of Crack Above

Report Form for Compliance with McCauley Service Bulletin 221C

Was crack found

Length of crack

Depth of material removed

Was propeller removed from service due to crack

keywords: E2A34C73

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