HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025

HC-SL-61-48A rev. 3 12/07/22 Inspection of B-119 Rubber Diaphragm used in propeller models HC-12X20, HC-D2X20, and HC-D3X20. (Ref. AD 65-21-4) 49 obsolete Propeller tip failures of HC-C2YK/7666-2 propeller installed on the Lycoming IO-360 engine of 200 H.P. 50 obsolete Counterweight rework for Hartzell Propeller Model HC-E2YK-2/C8475-4 on the Piper PA-31 aircraft. 51 obsolete Inspection and Maintenance of Model HC-B3TN-3B propeller installed on Beech King Air. 52A obsolete Change in Reverse Pitch Setting for HC-B3TN-5C Turbo-Props Used on the AiResearch TPE-331 Engine. 53 obsolete Incorporated in Manual 202A (Mar/93). Installation of HC-B3(P,R)30-2( )/(P,R)10152-5.5 propellers. 54 obsolete Tip Failures on the HC-C2YK-1/7666-2 Propeller Installed on the Lycoming IO-360 Engine. 55 obsolete Included in Manual 133B. Inspection of Propeller Blade Shanks of the Basic 8433 Design and instructions for Shot Peening. 56A obsolete Conditioning of Propellers for Extreme Cold Weather. 57 obsolete New Pistons Used in the 2-Blade HC-(C,E,F)2Y(L,-K,-R)-2, -2R and 3-Blade HC-(C,E,F)3YR-2 Propellers (Compact) 58 obsolete All units in compliance. Torque increase on Cessna 411 Aircraft. 59 obsolete Increase in Counterweight Mass for HC-B3TN-5/T10282HDE Propellers Installed on TPE-331 Turbo-Prop Powered Handley Page Aircraft. 60 obsolete Hub and blade shank shot peening in the area of A-2202 bearing race contact, of propeller models HC-C( )Y( ), HC-E( )Y( ), and HC-F( )Y( ). HC-SL-61-61Y rev. 17 * 08/13/25 Overhaul periods and service life limits for Hartzell Propeller Inc. aviation components - propellers, governors, accumulators, and propeller dampers assemblies. 62A rev. 1 06/26/08 Spring backup kit for HC-E2Y(K,R)-2RB and HC-E2YL-2( ) installed on Piper PA-23-250 and PA-E23-250 (six place) Aztec, PA-30 Twin Comanche, and PA-39 Twin Comanche C/R. (Ref. AD 71-21-09) 63 obsolete Installation of Propeller Model HC-A2X20-4A1/8833-4, 8433. 64 obsolete De-ice lead wire interference problem for propeller models HC-B3TN-5C/T10178HB-11 and HC-B3TN-5C/T10176HSB-5 installed on Mitsubishi MU-2 series aircraft. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 4 of 17 65C obsolete Incorporated in Manual 202A (Rev. 5) - Aluminum Hub Overhaul. Removing/Replacing Studs in “F” Flange of Compact Hubs. 66 obsolete Inspection of A-3066 springs in propeller model HC-B3TN-5C installed on AiResearch TPE-331 Engines. 67 obsolete Replaced by Service Bulletin 102 and Service Instruction 67( ). Excessive wear of the A-221 rings installed in the oil transfer unit of propeller model HC-A2X20-4A1 propeller. 68B obsolete Included in Governor Manual 130B. Modification of Hartzell “-6- ( )” series governors to improve RPM control. 69 11/30/71 Strengthened pitch change parts in compact propeller series HC-( )(2,3)Y(F,L,K,N)-(1,2). (Ref. AD 77-12-06) 70 obsolete Incorporated in Manual 202A (Rev. 5) - Aluminum Hub Overhaul. Repairing Damaged Threads in the Mounting Flanges of “Compact” Propeller Hubs into Which Studs are installed. 71 obsolete Incorporated in Manual 113B. Conversion of HC-( )3Y( )-1 to -1R propellers. 72B obsolete Miscellaneous minor service problems and remedies relating to propeller models HC-B3TN-3, -5 used on turbine engines. 73A obsolete Increase in counterweight mass for HC-B3TN-5/T10178HE-11, HC-B3TN-5/T10178E-11, HC-B3TN-5/T10178(H)B-11, and HC-B3TN-5/ propellers installed on TPE-331 turboprop powered engines. 74 obsolete Standardizing the use of the B-2457-3 fork in two-way compact propellers including the smaller diameter knob. 75 obsolete Modified Flyball Assembly to Improve RPM Control. 76 obsolete Standardizing the Use of A-1020 Fiber Spacer Washer on Hartzell Manufactured Spinner Assemblies. 77 obsolete Inspection of Blade Knob Radius and Modification of Some A-2217-( ) Pitch Change Blocks in all ( )HC-( )2( )( )-( ) Propeller Assemblies. 78C obsolete Conversion of 831-22 Spring Assembly to 831-42 Spring Assembly Contained in the HC-B4TN-3 Propeller Assembly. 79A obsolete Conversion of 831-28 Spring Assembly to 831-43 Spring Assembly Contained in the HC-B4TN-5 Propeller Assembly. 80 obsolete Compatibility of Certain C7479-2R Propeller Blades Used in the HC-F3YR-2 Propeller Installed on the Beech 60, A60 Aircraft. 81 obsolete The Straightening Processes of Bending and Twisting of the Hartzell Propeller Blades Manufactured of the Hard Alloy. 82A obsolete Incorporated in Manuals 113B and 117D. Elimination of the A-2436 hub parting seal, compact props. 83A obsolete Availability of Replacement Low Stop Rod for Hartzell Reversing Propellers. 84 obsolete Availability of "Spinner Assembly Maintenance Instruction Guide". HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 5 of 17 85 obsolete Clarification of required overhaul procedures as contained in Supplement No.2, Service Bulletin No. 97A, dated May 25, 1973. 86A obsolete Updating Service Letter and Service Bulletin Kit. 87A obsolete Incorporation of a Propeller Log Book into Hartzell Propeller Owner's Manual. 88 obsolete Establishing adequate clearance between the yoke pin of the A-3044 carbon block assembly and its corresponding beta valve linkage. 89 obsolete Incorporation of 1/3 X 20 Slimsert in certain counterweight knobs of "Y" shank blades. 90 obsolete Conversion of 831-30 spring assembly to 831-45 spring assembly contained in the HC-B3TN-5 propeller assembly. 91A obsolete Conversion of 831-33 spring assembly to 831-45 spring assembly contained in the HC-B3TN-3D, -3DY propeller assembly. 92 obsolete Verification of correct number of bleed orifices in B-868AT pilot tube. 93 obsolete Incorporated in Manual 167, Rev. 1 (Apr/06). Replacement of A-944 Link Arm Bushing, HC-B3( )30-2( ). 94A obsolete To provide a procedure for the rework of an estblishment of a minimum repair tolerance in the "O" ring area of "Y" shank blades. 95 obsolete Availability of overhaul instruction for turboprop applications, part number 79-98-118D. 96D obsolete Revised and updated knob location "Y" shank chart and proposed interchangeability. 97 obsolete Incorporated in Manual 133C. Modification and Model Change of Double Shoulder 7636D-( ), 8433( ), 8833( ), 933C( ), and 10133D-( ). 98A obsolete Hartzell Propeller, Inc. warranty. 99A obsolete Inspection of propeller for beta transfer tube alignment in spring assembly. 100 obsolete Incorporated in Manual 113B. Replacement of A-2921-1 Pitch Adjustment Screw in all HC-( )( )Y( )-4( ) propellers with new A-4252 Screw. 101A 03/01/79 Availability of Feather Assist Spring Assembly Kit, A-1587,-1. 102 obsolete Incorporated in Manual 127, Rev. 3 (May/10). Spinner bulkhead requirements to maintain prop balance. Obsolete 05/27/15. 103 obsolete Replacement of "hard" alloy blades with "standard" alloy installed on aircraft powered by turboprop engines. 104 obsolete Lightning strikes on the propeller. 105A obsolete Obsolete per SI 148A. 106 obsolete Inspection of both flat and beveled thrust washers installed on some Hamilton Standard propeller blades manufactured by Hartzell Propeller, Inc. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 6 of 17 107B obsolete Incorporated in Manual 115N. Fretting between cylinder and bulkhead of spinner dome. 108 obsolete Availability of overhaul instructions for model HC-B5MP series turboprop (5-blade), part number 79-98-132. 109 obsolete Incorporated in Manual 127, Rev. 1 (Feb/03) Reinforcement of C-3043-2 and -3 spinners, HC-B3TN-5( ). 110 obsolete Availability of revision pages for manuals 113B (79-98-113B) and 117D (79-98-117D) to supplement Bulletin No. 118A. 111 obsolete Modification of C-3630 reverse valve assembly. 112 obsolete Information can be found in propeller or aircraft Type Certificate. Availability of propeller placard decals. 113 obsolete Installation of propeller decal part number POM. 114 obsolete Hartzell Propeller, Inc. warranty. 115 obsolete Replacement of the A-218 bushing installed in the HC-A2V20-4 propeller. 116 obsolete The use of an optional head on the A-2036-( ) counterweight screw. 117 obsolete Incorporated in Manual 127, Rev. 1 (Feb/03) Optional use of bolts to replace bulkhead rivets on 836-15R Spinner. 118A obsolete Optional modification of the B-3018-2 pilot tube to be installed in HC-B3TN-5 and HC-B4TN-5 propellers. 119 obsolete Incorporated in Manual 127, Rev. 1 (Feb/03) Applicability of B-3264-( ) spinner dome caps when used with C-3567 spinner assembly. 120 obsolete Availability of service information. 121 obsolete Updating of service letter and service bulletin kit. 122 obsolete Applicability and installation procedures of two new type "CAUTION" placards now available, part number CAU-112, CAU-113. 123A obsolete Incorporated in Manual 127, Rev. 1 (Feb/03) Addition of screw to C-4533-1 Dome used on D-4532-1 Spinner Assy. 124A 02/29/79 Applicability of certain “governor drive gear couplings” installed in double-capacity governors identified with the letter “Z” in the model number (coupling P/N B-4175); i. e., F-6-24LZ. 125A obsolete Per SL 155A. A-2043 (3/8 x 24) nut used on both Steel and Aluminum Hub type propellers. 126 obsolete Information out of date. Synchrophaser computer response to electrical noise in aircraft wiring harness. 127 obsolete Information is out of date. Synchrophaser computer response to electrical bus noise. 128 obsolete A revised edition of the Hartzell Governor Specification Manual No. 130B availability. 129 obsolete Incorporated in Manual 130B. Elimination of body to base parting seal, P/N A3155 in the “F” series governor. 130 obsolete Hartzell Propeller, Inc. warranty. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 7 of 17 131A obsolete Incorporated in Manual 118F. Replacement of the A-1851-T bearing race with the A-1851 bearing race on Hartzell turbine propellers. 132 obsolete Availability of service information. 133B obsolete Replaced by HC-SL-61-169. Blade Clamp Modifications, C-1301 and C-1977, on HC-B( )( )( )-( ). 134 obsolete Replaced by SA 73. Availability of service information. 135 obsolete Clarification of required overhaul procedures as contained in Supplement No. 2, Bulletin No. 97A, dated May 25, 1973. 136C obsolete To provide a procedure for the rework of and establishment of a minimum repair tolerance in the "O" ring area of "Y" and "D" shank blades. 137 obsolete Availability of service information. 138 obsolete Updating of Service Letter, Bulletin, and Instruction Manual No. 126. 139A obsolete Included in Governor Manual 130B. Replacement of Governor Flyweight Assembly and modification to existing parts presently in service. 140D obsolete Replaced by Bulletin No. 118C, supplement no. 1A. Approved Facilities for the incorporation of SB 118( ), supplement 1( ). 141A obsolete Included in Aluminum Blade Repair Manual 133. Change in blade counterweight requirements of the BHC-L2YF-4F/FC8468AR propeller installed on the Beech T-34A aircraft with the Continental IO-470-N engine. 142 obsolete Incorporated in Manual 139. Procedures for Installation of B-3339 Attaching Bolt on HC-B5( )( )-( ) propeller with B-3339 attaching bolt. 143A obsolete Inspection of blade knob radius and modification of pitch change blocks in all ( )HC-( )(2,3,4)( )( )-( ) propeller assemblies. 144 not issued 145 obsolete Updating of Service Letter, Bulletin, and Instruction Manual No. 126. 146 not issued 147 obsolete Included in Aluminum Blade Repair Manual 133. Procedures for Installation of B-3339 Attaching Bolt on HC-B5( )( )-( ) propeller with B-3339 attaching bolt. 148A obsolete Replaced by S.I. 209. O-ring compound changes. 149 obsolete Incorporated in Manual 115N. A-4025 Spring Retainer used in HC-B5MP-3( )/M10282AB+6,M10876(B,K). 150 obsolete Repair of loose steel leading edge for blade model LM10585( )+4. 150 Supl. 1 obsolete Processes and procedures to incorporate Service Letter 150 Dated June 20, 1983. 151 obsolete Hartzell Propeller Products warranty. 152A obsolete Incorporated in Manual 113B. Felt seal part numbers A-863, A-810, and B-1843 (-1and -2), as used on steel hub and aluminum hub propellers. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 8 of 17 153 obsolete Identification of turbine propeller mounting bolts, B-3339 and B-3339-1. 154 obsolete Incorporated into Manual 202A Volume 6, Rev. 30 (Apr/13). Identification of springs as used in various Hartzell propellers. 155A obsolete All stock purged. A-2043 elastic self locking nuts. 156 obsolete Replaced by Bulletin 149. A-1373 flex lock nut. 157 obsolete A-848-2 Flex-Lock Nut. 158 obsolete Replaced by S.B. 215. D-494 Pitch Change Rod. 159 obsolete Superseded by SB 46 and AD 57-08-04 - Proper fitting of link arms to propeller piston unit with AN501-A10-6 Safety Screws. Obsolete 02/22/11. 160 obsolete Heli-Coil inserts. Obsolete 09/16/20 161 not issued 162B obsolete B-1925 Teflon Seal on "compact" and "lightweight" propeller blades. 163 08/26/94 Russian certification of propeller for Beech B300 series A/C, not mailed to field. HC-SL-61-164 rev. 1 obsolete Incorporated in Manual 127, Rev. 1 (Feb/03) Beech 1900C & D, spinner bulkhead, filler plate replacement. HC-SL-61-165 12/07/95 All propellers, warning to evaluate unusual grease leaks or vibration. HC-SL-61-166 obsolete Incorporated in Manual 127, Rev. 1 (Feb/03) Beech 1900C, spinner dome, minor repairs and service limits. HC-SL-61-167 12/07/95 All single shoulder steel props, Delrin washer between link and clamp. HC-SL-61-168 obsolete Incorporated in Manual 135F. Beech 1900D composite blade, heat blanket to accelerate resin curing. HC-SL-61-169 obsolete Incorporated in Manual 202A - Blade Clamp Overhaul (Rev. 7). Blade clamps used on steel hub propellers, part number C-3-( ), C-1301-( ) and C-1977-( ). HC-SL-61-170 obsolete Incorporated in Manual 202A. Hartzell P/N vs. AN, MS, NAS, vendor P/N cross reference. HC-SL-61-171 obsolete Incorporated into Manual 127, Rev. 3 (May/10) - Spinner dome and bulkhead interchangeability. Obsolete 12/17/20 HC-SL-61-172 rev. 1 03/15/00 Hartzell Policy - New Fee for Parts Evaluation. HC-SL-61-173 rev. 1 obsolete Incorporated in Manuals 118F, Rev. 4 (Oct/97) and 132A, Rev. 6 (Mar/01). Part number information concerning turbine engine steel hub replacement. (Ref. AD 96-18-14) HC-SL-61-174 obsolete Incorporated in Manual 114C. Blade Clamp D-6831-1EA supersedes D-6831-1E in 838-1058 Clamp Assembly in ( )HC-A3MV(F,K)-4/MV8433N( ) or MV8433N( ) Propeller Models. HC-SL-61-175 not issued HC-SL-61-176 12/23/99 Introduction of New Propeller Mounting Bolts, HC-E2YL-(2,7) and HC-(A,8)2(X,V,MV)L-2( ) series Propellers. HC-SL-61-177 02/04/97 Ball bearings, new part numbers, usage. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 9 of 17 HC-SL-61-178 not issued HC-SL-61-179 obsolete Incorporated in Manuals 113B, 117D, and 127. New 2 blade "compact" Y shank hubs and spinner modifications. HC-SL-61-180 obsolete Incorporated in Manuals 133C, 135F, and 202A. Alternative spray can touch up paint for blades. HC-SL-61-181 rev. 1 obsolete Incorporated in Manual 141, Rev. 6 (Jun/06). Introduction of new propeller models HC-E4A-3J, HC-E4P-5E, and HC-D4N-5E. Obsolete 05/27/15. HC-SL-61-182 04/17/98 "MV" blade modification procedures - limited distribution. HC-SL-61-183 obsolete Incorporated in Manual 127, Rev. 1 (Feb/03) D-4511 Spinner Assembly change from 4 retention screws to 8 retention screws. HC-SL-61-184 obsolete Incorporated into Manual 202A - Lubrication practices. HC-SL-61-185 rev. 3 obsolete Incorporated into all applicable manuals. Tachometers Obsolete 11/13/24 HC-SL-61-186 03/02/99 Antonov AN-38 aircraft with Hartzell HC-B5MA-5A propeller, de-ice boot installation - not mailed to field. HC-SL-61-187 rev. 5 03/09/22 Introduction of angled lubrication fittings as alternates for straight lubrication fittings on aluminum hub propellers. HC-SL-61-188 06/08/00 Blade/Clamp Sealing on Agricultural Aircraft. HC-SL-61-189 rev. 2 obsolete Incorporated into overhaul manuals - Service tools, consumables, standard parts, blade overhaul requirements, spinner maintenance, application specific information, and standard practices. Obsolete 12/22/15. HC-SL-61-190 obsolete Incorporated in Manual 127 - Spinner repair or modification when approved by local airworthiness agency. HC-SL-61-191 obsolete Incorporated in Manuals 174 and 114C. Lip seal ring - All Hartzell Propeller A-224-( ) oil transfer units. HC-SL-61-192 rev. 1 obsolete Incorporated in Manual 135F. 1900D Low Watt Density De-ice Boot. HC-SL-61-193 obsolete Replaced by HC-SB-61-329 - 7690C( ) to 7690E Propeller Blade Conversion. - Obsolete 5/16/11 HC-SL-61-194 obsolete Incorporated in Manual 145. Aerobatic HC-( )(2,3)YR-1( ) Propeller Overspeed. Obsolete 06/15/10. HC-SL-61-195 obsolete Incorporated in Manual 143A, Rev. 8 (Nov/99). Introduction of Hardened Preload Set Screw. HC-SL-61-196 obsolete Incorporated in Manual 202A, Rev. 18 (Aug/03) - Service Bulletin Reference Decal. HC-SL-61-197 rev. 4 obsolete Incorporated in Manual 115N, Rev. 9 (Aug/03) - Feathering Propeller Air Charge Reduction. HC-SL-61-198 obsolete Incorporated into Manual 135F, Rev. 31 (Dec/18). Introduction of Counterweight Clamp for HC-E4A-3(I,J) propellers. Obsolete July 03/19. HC-SL-61-199 obsolete Incorporated in Manuals 113B, Rev. 22 (Jun/00), 117D, and 127. Introduction of New Hub Design and Spinner Bulkhead Modification. HC-SL-61-200 obsolete Incorporated in Manual 145. Accumulator Pressure Reduction/Part Number Change. Obsolete 06/15/10. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 10 of 17 HC-SL-61-201 obsolete Incorporated in Manual 202A, Rev. 12 (Nov/00). Rework Procedure for D-6831-( ) Clamps. HC-SL-61-202 not issued HC-SL-61-203 obsolete Incorporated in Manual 143A, Rev. 11 (Dec/01). Introduction of an improved Fork Assembly, part number C-6568, for HC-(D,E)4( )-3 propellers incorporating the C-633 fork. HC-SL-61-204 obsolete Incorporated in Manual 133C, Rev. 8 (Aug/00). Introduction of Optical Comparator Overlay CST-2924 (Rev. C). HC-SL-61-205 obsolete Incorporated in Manual 159, (Original). Introduction of Propeller Part and Blade Configuration Numbers. HC-SL-61-206 08/02/00 Reversing Outer Clamp Bolts for Spinner Clearance. HC-SL-61-207 not issued HC-SL-61-208 not issued HC-SL-61-209 rev. 4 obsolete Information is now available on Hartzell website or CD-Rom Recent Service Manual Revisions, Status of Manuals. HC-SL-61-210 obsolete Incorporated in Manual 202A. Introduction of an alternate metallic silver top coat blade paint. HC-SL-61-211 rev. 2 obsolete Incorporated into 202A Volume 4 Revision 29 (Nov/15) and TR-009 - Introduction of New Blade Pilot Tubes P/N 100320-( ) for ( )HC-( )(2,3)(X,V,MV,Z)( )-( ). Obsolete 12/22/15. HC-SL-61-212 rev. 2 11/11/15 Introduction of Overhaul Kits. HC-SL-61-213 obsolete Information is out of date. Introduction of Improved Lubrication fitting cap. HC-SL-61-214 06/18/01 Improved installation of beta rod guide lug and snap ring on Seabee aircraft with reversing propeller HC-A3(X,V,MV)20-3L. HC-SL-61-215 rev. 1 11/03/05 Blade thrust bearing inspection for HC-E4A-3( )/E10950( ) propellers installed on Raytheon Beechcraft 1900D airliners. HC-SL-61-216 obsolete Introduction of spinner mounting bracket for HC-B3TF-7A propellers used with an 835-39( ) spinner assembly. HC-SL-61-217 03/21/03 Replacement of hardware at propeller overhaul. HC-SL-61-218 not issued HC-SL-61-219 obsolete Incorporated in HC-SB-61-261 - Correction of serial number effectivity in AD 96-18-14. HC-SL-61-220 not issued HC-SL-61-221 05/20/02 E-4501-3 Hub Unit Modification for anti-ice slinger ring. HC-SL-61-222 obsolete Incorporated in Manual 202A Rev. 18 (Aug/03) - Propeller hub identification and marking. HC-SL-61-223 obsolete Incorporated into 202a Volume 3 Revision 36 (Dec/15) - Hub/fork interference for ( )HC-( )2Y( )-( )( ) propellers using a B-2457-3 fork manufactured before revision "AZ" and a propeller hub with a "B" serial number suffix. Obsolete 12/22/15. HC-SL-61-224 01/10/03 Replacement of B-7019-2 Preload Set Screws on 1900D Aircraft. HC-SL-61-225 rev. 1 12/18/03 Introduction of new CNC spinner assemblies. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 11 of 17 HC-SL-61-226 rev. 1 obsolete Incorporated in Manual 113B Rev. 30 (Jun/05), Manual 117D Rev. 11 (Jun/05), Manual 133C Rev. 15 (Sept/03) and Manual 202A Rev. 19 (Sept/03) - Shot peening of pitch change knobs on "Y" shank blades with "F" knobs, rework of pitch change block and installation of new bushings. HC-SL-61-227 not issued HC-SL-61-228 03/20/03 Inspection of B-2423-1 cylinders installed on (P)HC-( )(2,3)Y( )-(2,5)( ) propellers for machined ring in cylinder. HC-SL-61-229 rev. 2 obsolete Incorporated in Manual 202A Vol. 6 and Vol. 11. Introduction of new propeller labels and replaced propeller labels. Obsolete 05/27/15. HC-SL-61-230 obsolete Incorporated in Manual 115N and Manual 145. Introduction of one piece spinner dome and new hardware. Obsolete 05/27/15. HC-SL-61-231 04/01/04 Use of propeller jack. HC-SL-61-232 obsolete Incorporated in Manual 133C. Introduction of P, R, W, and Z shank blades with the "N" modification. Obsolete 05/27/15. HC-SL-61-233 02/23/04 HC-B3TW-3( ) propeller modification when installed on Walter 601 engine. HC-SL-61-234 obsolete Incorporated in Manual 182. De-ice and anti-ice boot installation. Obsolete 06/15/10. HC-SL-61-235 rev. 1 09/15/04 D-4026 pitch change rod serial number 1047 or higher for HC-B5M( )-(2,3)( ). HC-SL-61-236 obsolete Incorporated in Manual 180, Rev. 10 (Feb/11). Introducing a new de-ice wire harness and harness installation for Pilatus PC-12. HC-SL-61-237 obsolete No longer applicable - D-5117-1 counterweight clamp insert installation and inspection. HC-SL-61-238 obsolete C-3317-347-2 O-ring recall. Obsolete 05/27/15. HC-SL-61-239 obsolete Incorporated into Manual 181, Rev. 4 (Jun/14). Rework procedures for the slip ring split mounting plate on PHC-J3YF-2 installed on Raytheon 58 Barons equipped with propeller de-ice with aircraft serial number TH1889 through TH2093. HC-SL-61-240 obsolete Incorporated into Manuals 142 and 143A - Introduction of D-6506 pitch change rod for HC-(D,E)4(A,N,P,W)-(2,3) propellers. Obsolete 5/16/11 HC-SL-61-241 rev. 3 02/02/15 Introduction of the new blade seal for "E" shank lightweight turbine propellers. HC-SL-61-242 03/15/05 HC-C2YK-1BF propellers with F7496( ) blades shipped without a "P" suffix letter to indicate installation of "B" suffix serial number hubs only. HC-SL-61-243 03/15/05 New propeller models that can only use a "B" suffix serial number hub. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 12 of 17 HC-SL-61-244 02/28/05 Introduction of the B-3599 self-locking nut as an alternate for the B-3359 nut. HC-SL-61-245 obsolete Incorporated into Manual 133C, Rev. 23 Mar/08. Announcing shot peening of pitch change knobs on "Y" shank blades from the factory. HC-SL-30-246 06/02/05 Spare parts release - de-ice hardware for PHC-J3YF-2 propellers installed on Raytheon Baron. HC-SL-30-247 obsolete Incorporated into Manual 180, Rev. 7 (Dec/09). Introduction of new 101204-( ) anti-ice travel tubes. Obsolete July 03/19. HC-SL-61-248 09/15/05 Introduction of 101224( ) and 101225( ) start lock brackets. HC-SL-61-249 01/13/06 Spinner bulkheads affected by Brazilian AD 80-12-03. HC-SL-61-250 obsolete Introduction of A-1272 inner bearing ring with optional oil hole. Obsolete 11/13/24 HC-SL-61-251 rev. 1 01/13/06 B-6509-1 compression spring failures. HC-SL-61-252 11/03/05 Inspection and recall of A-80-( ) bolts. HC-SL-61-253 05/11/06 IRAN inspections for Steel Hub propellers installed on Agricultural installations. HC-SL-61-254 rev. 1 03/09/22 Propeller operation in restricted RPM ranges. HC-SL-61-255 05/11/06 IRAN inspections for Aluminum Hub propellers installed on Agricultural installations. HC-SL-61-256 03/16/06 The hex nut, P/N A-3439, is an alternate for the B-3382 hex nut. HC-SL-61-257 obsolete Incorporated into Manual 127, Rev. 7 (Jul/15) - The B-6626-20 bolt supersedes the B-3384-20H bolt. Obsolete 12/17/20 HC-SL-61-258 rev. 1 01/12/07 Alternate blade clamp sealing procedure. HC-SL-30-259 rev. 15 03/09/22 Introduction of Hartzell Propeller Inc. propeller mounted ice protection components. HC-SL-30-260 rev. 23 09/01/22 Introduction of Hartzell de-ice boots, anti-icing boots, and airframe mounted ice protection components. HC-SL-30-261 obsolete Introduction of Hartzell Propeller Ice Protection System Manual 180 (30-61-80). HC-SL-61-262 obsolete Incorporated in Manual 127, Rev. 3 (May/10). New spinner mounting kit for HC-C3YN-2UF propellers installed on a Cessna 421C by Ram Corporation STC 10185SE. Obsolete 05/27/15. HC-SL-61-263 obsolete Incorporated in Manual 158A. Beta rod end support ring for Piaggio P-180 aircraft. Obsolete 05/27/15. HC-SL-61-264 not issued HC-SL-61-265 rev. 2 10/09/09 Introduction of smooth forged three-bladed compact propeller hubs. HC-SL-61-266 not issued HC-SL-61-267 03/19/07 Introduction of 0.010 inch thick Teflon® tape. HC-SL-61-268 rev. 1 09/10/09 Installation of Teflon® tape on N-shank composite blades. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 13 of 17 HC-SL-61-269 obsolete Inspection requirements for HC-E5N-3 and HC-E5B-5 propellers with vibration. Obsolete 10/24/11. Incorporated into HC-SB-61-295 and other service information. HC-SL-61-270 08/07/07 Part number stamping on A-880-( ) nuts. HC-SL-61-271 obsolete Incorporated into Manual 157, Rev. 1 (Oct/09). Introduction of new feathering spring, spring seat and flanged spring retainer for 5 lightweight turbine propellers. Obsolete July 03/19. HC-SL-61-272 rev. 2 04/15/09 Introduction of new compact propellers for the Aero Commander 500. HC-SL-61-273 rev. 2 01/15/13 Instructions for modification to Oil-Filled configuration as authorized by Hartzell Service Bulletin only. HC-SL-61-274 11/14/07 New configuration for the A-2067 stud. HC-SL-61-275 rev. 1 08/06/09 New cylinder, stop plate and pitch stop plate for HC-E5N-3( ) propellers installed on Piaggio P-180 aircraft. HC-SL-30-276 rev. 2 04/15/09 Introduction of new de-ice kit and de-ice boots for Cessna 400 (formerly Columbia 400). HC-SL-61-277 rev. 6 09/16/20 Governor installation instructions. HC-SL-61-278 11/05/08 Introduction of new low pitch set screw and nut. HC-SL-30-279 rev. 8 03/06/13 Introduction of Hartzell de-ice boots. HC-SL-61-280 not issued HC-SL-61-281 obsolete Incorporated in Manual 202A, Volume 1. Obsolete Oct 27/10. HC-SL-61-282 rev. 1 obsolete New preload plate inspection criteria and wear limits. Obsolete 06/11/25 HC-SL-30-283 rev. 2 obsolete Incorporated in Manual 181 and Manual 182. Repair procedure for loose or damaged de-ice boot leadwires. Obsolete 06/15/10. HC-SL-30-284 rev. 1 08/13/08 Introduction of Hartzell de-ice boot P/N 102643 for Socata TBM 700 and TBM 850. HC-SL-30-285 rev. 1 08/13/08 Introduction of Hartzell de-ice boot P/N 102746 for Beech Baron 58( ). HC-SL-61-286 obsolete Replaced by HC-SB-61-311 Rev. 1 - Spinner Cracking on Mooney M20( ), Piper PA24, and Piper PA28R-180 Aircraft. Obsolete Aug 06/09. HC-SL-61-287 07/18/08 Introduction of the B-7424-1 spacer for installation of composite bulkheads. HC-SL-61-288 08/13/08 Change to blade E10950PC(B,K) bill of material for the D-7745-B blade bearing race. HC-SL-61-289 not issued HC-SL-61-290 rev. 1 04/09/10 Introduction of smooth forged two-bladed compact propeller hubs. HC-SL-61-291 obsolete Replaced by HC-SB-61-324 - Introduction of 102877 feathering spring for steel hub propellers. Obsolete 01/14/11 HC-SL-61-292 01/12/09 Modification of the D-5555-1(P) bulkhead for synchrophaser hardware and dynamic balance. HC-SL-61-293 rev. 1 03/12/10 Introduction of alternate C-3317-340-8 O-ring on "Y" shank aluminum blades. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 14 of 17 HC-SL-61-294 rev. 1 obsolete Field inspection criteria and minor repair by certified Airframe and Powerplant Mechanics, or international equivalent, for the affected blade models. - Replaced by Manual 170. HC-SL-30-295 rev. 3 11/06/13 Introduction of new de-ice boot, de-ice wire harness, and installation configuration for HC-E4A-3D propellers installed on Pilatus PC-12. HC-SL-30-296 not issued HC-SL-61-297 not issued HC-SL-61-298 not issued HC-SL-61-299 obsolete Incorporated in Manual 133C. Permit use of previous revision comparator overlays for limited time. Programs expired - obsolete 12/1/09. HC-SL-61-300 rev. 1 08/06/09 Stamping correct TC number on serial number specific hubs. HC-SL-61-301 obsolete Introduction of the C-3317-340-8 O-ring as a supercedure to the C-3317-340 O-ring. Obsolete 07/13/16. HC-SL-61-302 not issued HC-SL-61-303 04/09/10 Introduction of the C-3317-340-8 O-ring for use in Hawker Beechcraft 1900D applications. HC-SL-30-304 rev. 3 obsolete Incorporated into Manual 180, Rev. 27 (Aug/18). Modification to anti-ice configuration and new anti-ice kit for the HC-E4N-3P(Y)/D9511FSB propeller installed on the Quest Aircraft, LLC. Kodiak 100. Obsolete 12/17/20. HC-SL-61-305 obsolete Incorporated in Manual 113B, Rev. 40 (Aug/12). Introduction of a new hub design for -1 compact propellers with an engine-side pitch change rod bushing. Obsolete 07/01/15. HC-SL-30-306 03/11/11 Introduction of Hartzell de-ice boot P/N 4H1601-14 for Cessna 414A. HC-SL-30-307 03/11/11 Introduction of Hartzell de-ice boot P/N 102878 for Korean Aerospace KT-1, KT-1C, and KT-1T. HC-SL-30-308 rev. 1 12/07/22 Introduction of Hartzell PMA approval for de-ice boots and de-ice wire harnesses. HC-SL-30-309 03/11/11 Introduction of Hartzell de-ice boot P/N 4H2271-12 for Hawker Beachcraft 65-A90, B90, C90, C90A, and E90. HC-SL-30-310 03/11/11 Introduction of Hartzell de-ice boot P/N 4H1601-14 for Cessna P337H and T337G (front). HC-SL-30-311 03/11/11 Introduction of Hartzell de-ice boot P/N 4H2271-12 for Hawker Beechcraft 200 and B200. HC-SL-30-312 03/11/11 Introduction of Hartzell de-ice boot P/N 4H2271-12 for De Havilland Twin Otter DHC-6-300 HC-SL-30-313 03/11/11 Introduction of Hartzell de-ice boot P/N 4H1601-14 for Cessna 310( ), 310(I,P,Q,R), and T310(P,Q,R). HC-SL-30-314 03/11/11 Introduction of Hartzell de-ice boot P/N 4H2271-12 for Hawker Beechcraft C90, C90A, and E90. HC-SL-30-315 rev. 1 03/16/11 Introduction of Hartzell de-ice boot P/N 4H2271-12 for Hawker Beechcraft F90. HC-SL-30-316 03/11/11 Introduction of Hartzell de-ice boot P/N 4H2271-12 for Hawker Beechcraft 100 and A100. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 15 of 17 HC-SL-30-317 03/11/11 Introduction of Hartzell de-ice boot P/N 102878 for Fairchild Aircraft Metro II, SA226-TC. HC-SL-61-318 07/13/11 D-630-8(P) spinner assembly for Quest Kodiak HC-SL-61-319 02/22/11 Modification of the C-2294-11(P) spinner bulkhead for travel tube clearance. Used on HC-C2YR-1BFP/F7497 on M20J. HC-SL-61-320 03/14/12 Because commercial support (parts availability) and ICA for the X shank propeller models affected by this Service Letter are no longer available, upgrade to an MV shank style propeller is recommended. HC-SL-61-321 obsolete Introduction of 104364 UID plate for HC-E4A-2(A)/E9612( ) on Hawker Beechcraft Model 3000, Texan T-6A Texan II. Obsolete 07/13/16. HC-SL-30-322 rev. 2 08/27/12 Introduction of Hartzell de-ice boot P/N 103880 for Hawker Beechcraft B200(C)(G)(T). HC-SL-30-323 11/10/11 Introduction of Hartzell de-ice boot P/N 4H2271-12 for Hawker Beechcraft C90GT. HC-SL-61-324 10/21/11 Changes penetrant inspection to a recommendation after field repair of Hartzell aluminum blades. HC-SL-61-325 rev. 1 obsolete Introduction of beta rod bore hub modification of HC-E5N-3(A)(L)/(H,L)E8218 propellers for Piaggio P-180. Obsolete 07/13/16. HC-SL-30-326 09/05/12 Introduction of Hartzell de-ice boot P/N 102878 for Piper PA-46. HC-SL-30-327 09/05/12 Introduction of Hartzell de-ice boot P/N 102878 for Piper PA-46-500TP HC-SL-30-328 rev. 2 03/06/13 Introduction of Hartzell de-ice boot P/N 102643 for Cessna 441. HC-SL-61-329 08/27/12 Introduction of new blade paint process. HC-SL-61-330 05/15/12 Installation of electrically actuated governors - not mailed to the field. HC-SL-61-331 obsolete Incorporated into Manual 127, Rev. 6 (Feb/14). Alternate screw for spinner dome attaching for D-5710-(2,3)(P) spinner assembly. Obsolete 06/01/17. HC-SL-61-332 obsolete Incorporated into Manual 113B, Rev. 43 (Jul/16). New 104737 blade plug for use in N( )7605( )( )( ) and N( )7893( )( ) composite blades. Obsolete 06/01/17. HC-SL-30-333 11/16/12 Introduction of Hartzell de-ice boot P/N 103020 for Polish Aviation (MIELEC) M28B. HC-SL-30-334 rev. 1 obsolete Incorporated into Manual 180. Introduction of de-ice overhaul kits. Obsolete 03/15/16. HC-SL-30-335 rev. 3 11/01/19 Restrainer strap installation. HC-SL-61-336 12/18/12 Installation of the seal washer on S-1-44F governors. HC-SL-61-337 obsolete Incorporated into Manual 130B, Rev. 15 (Apr/14). Redesigned head for S Series governors. HC-SL-61-338 obsolete Incorporated into 202a Volume 3 Revision 36 (Dec/15) - Mounting bore repair procedure for F-flange compact propeller hubs. Obsolete 12/22/15. HC-SL-61-339 rev. 2 obsolete Incorporated into HC-SB-61-392, Rev. 1. Hub/rod bushing modification procedures. Obsolete 07/07/21. HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 16 of 17 HC-SL-61-340 08/19/13 Introduction of an alternate pitch change fork B-3252-2(l). HC-SL-61-341 obsolete Incorporated into Manual 130B, Rev. 15 (May/14) New governor control lever for S-1-24 governors. HC-SL-61-342 08/19/13 Introduction of a new cylinder for specific compact -4 propellers to include a 5/8 inch stop screw. HC-SL-61-343 04/01/14 New lubrication grease gun fitting. HC-SL-61-344 not issued HC-SL-61-345 rev. 1 06/01/15 Change to the A-2247-1 stud used in HC-(C,E,F)2YL-(1,2,4) propellers. HC-SL-61-346 10/01/15 Instructions for adding drain holes to affected spinner bulkheads. HC-SL-61-347 10/01/15 Introduction of the 102691 bolt as an alternate for the A-2433 hub clamping bolt used on affected propeller models, spinner mounting kits, and de-ice kits. HC-SL-61-348 obsolete Incorporated into all applicable manuals. Hub clamping bolt inspection. Obsolete 11/13/24 HC-SL-61-349 not issued HC-SL-61-350 rev. 1 obsolete Incorporated into Manuals 141, 143A, and 360. Assembly/disassembly instructions for C-497( ) piston unit. HC-SL-61-351 10/01/15 Introduction of the A-2051-1 bolt as an alternate for the A-2051 bolt used to attach the spinner mounting plate on affected steel hub propeller models. HC-SL-61-352 obsolete Incorporated into Manual 158A, Rev. 15 (Dec/16). Introduction of the 106212 pitch change rod as an alternate for the D-3657 pitch change rod on affected propellers. HC-SL-61-353 11/11/15 Shell Aviation withdrawal of AeroShell Grease 5 and Hartzell Propeller Inc. recommended alternative HC-SL-61-354 08/01/16 Introduction of the 106545 lubrication hole plugs for Hartzell Propeller Inc. aluminum hub propellers. HC-SL-61-355 08/01/16 Introduction of the 106561 composite blade minor repair kit and the A-6741-335 composite blade cosmetic touch-up kit. HC-SL-61-356 obsolete Incorporated into Manual 202A Volume 7, Rev. 42 (Aug/16). Primer Sealer Color Change HC-SL-61-357 not issued HC-SL-61-358 12/01/16 Introduction of the plate kit TE615 for use with the beta system puller TE100. HC-SL-61-359 10/02/17 Introduction of a different formula of A-6741-163(-1) silver Polane® paint, CM163. HC-SL-61-360 rev. 1 08/01/18 Blade damage evaluation for NC10245( ) blades installed on (but not limited to) Pilatus PC-12 aircraft. HC-SL-61-361 04/27/17 Modification of the unfeathering tool TE316. HC-SL-61-362 09/05/18 Introduction of redesigned A-1851-T blade retention bearings. HC-SL-61-363 not issued HC-SL-61-364 04/03/20 Corrosion inhibitor on counterweights HC-SL-61-365 obsolete Incorporated into Manual 180, Rev. 30 (Nov/19). Introduction of the 107083 hub clamping bolt as an alternate for the A-3219-1 bolt used on affected propellers. Obsolete 02/10/22 HARTZELL PROPELLER SERVICE LETTER INDEX - August 13, 2025 (excluding HD series propeller and systems) * Asterisk indicates new documents, revisions, and/or status changes (ex. obsolete) that were released on the revision date of this index. Page 17 of 17 HC-SL-61-366 01/06/20 Introduction of NYCO GN3058 as the preferred grease for all affected propellers. HC-SL-61-367 rev. 1 12/17/20 Introduction of 107995-( ) bolts as replacements for A-2036-( ) cap screws used to attach counterweights on affected propellers. HC-SL-61-368 11/18/21 Introduction of redesigned hubs for compact propellers HC-SL-30-369 11/03/21 Erosion tape installation on blades with de-ice boots HC-SL-61-370 07/07/21 Introduction of an approved cleaning process for propellers used in agricultural/firefighting installations. HC-SL-61-371 08/05/21 Introduction of alternate blade clamp O-ring p/n C-3317-AR-157 for HC-92(W,Z)(F,K)-(1,8) propellers. HC-SL-61-372 12/07/22 Introduction of revised Hartzell blade decal HC-SL-61-373 12/07/22 Introduction of adhesive CM94 as an alternate for CM16 when installing split bearing races on affected blades. HC-SL-61-374 03/08/23 Introduction of the online product registration form. HC-SL-61-375 rev. 2 09/18/24 Tanis Aircraft Products/Hartzell Propeller Inc. part number cross-reference HC-SL-61-376 12/13/23 Tool modification and alternate propeller mounting hardware HC-SL-61-377 06/11/25 Counterweight clamp corrosion removal