Service Information Letters – Piston

Service Information Letter (SIL) is used to transmit information, recommendations, and general service instructions to the aircraft owner/operator and maintenance personnel.

The information provided in the SILs will be incorporated into the maintenance manual as needed at a later date.

PISTON SERVICE INFORMATION LETTER INDEX

1. 1. SIL0001 – Engine Crankcase Vent (02/29/1968)
   2. SIL0002 – Fuel Line Chaffing (02/29/1968)
   3. SIL0003 – TR Taper Pins (CXL 10/06/2000)
   4. SIL0004 – Damper Attachment Bolts (CXL 09/11/2000)
   5. SIL0005 – Exhaust Stack (02/10/1969)
   6. SIL 0006  – Damper Rod End (CXL 10/12/2017)
   7. SIL0007 – Cabin Door Handle (02/12/1969)
   8. SIL0008 – Component Service Life (CXL 09/11/2000)
   9. SIL0009 – Belt Idler Shaft (06/04/1969)
   10. SIL0010 – Actuator Arm (CXL 10/06/2000)
   11. SIL0011 – Belt Tension (CXL 09/11/2000)
   12. SIL0012 – Collective, Friction Lock handle (09/19/1969)
   13. SIL0013 – Inlet Air Ducting (09/25/1969)
   14. SIL0014A – Jack Strut Bearing (05/11/1973)
   15. SIL0015 – Pressure and Vent Lines (12/19/1969)
   16. SIL0016-R1 – Alternator Cooling Fan (10/06/2000)
   17. SIL0017 – TR Teetering Hinge Bearings (04/14/1970)
   18. SIL0018 – Stabilizer Attachment Tube (05/05/1970)
   19. SIL0019 – TRGB Housing (11/13/1970)
   20. SIL0020 – Electrical Distribution (02/18/1971)
   21. SIL0021 – Inlet Air Ducting (04/13/1971)
   22. SIL0022 – Engine Instruments (04/30/1971)
   23. SIL0023 – Service Letter Survey (CXL 10/06/2000)
   24. SIL0024 – MR Blade Protection (09/24/1971)
   25. SIL0025 – Swashplate, Rod End (06/26/1972)
   26. SIL0026 – Damper Rod End (05/18/1972)
   27. SIL0027A – Over-Center Mount Pad (04/30/1974)
   28. SIL0028 – Belt Engagement (CXL 10/06/2000)
   29. SIL0029 – MRGB, Oil Filler Cap (CXL 10/06/2000)
   30. SIL0030 – Collective Control, Pilot (10/10/1972)
   31. SIL0031 – Collective Friction Lock (05/31/1973)
   32. SIL0032 – Main Rotor Control Field Phasing (06/04/1973)
   33. SIL0033 – Damper Bleeding Procedure (07/25/1973)
   34. SIL0034 – Abnormal Airframe Vibration (09/20/1973)
   35. SIL0035 – Field Installation TR Blades (12/17/1973)
   36. SIL0036 – Oil Sump (02/04/1974)
   37. SIL0037A – Spindle Nylatron Sleeve (10/01/1983)
   38. SIL0038 – Lubrication, Upper Mast Seal (03/14/1974)
   39. SIL0039 – Setting Autorotation RPM (05/22/1974)
   40. SIL0040 – Certification Eligibility, U.K. (04/26/2017)
   41. SIL0041 – Pulley Alignment, Idler Tracking (CXL 10/06/2000)
   42. SIL0042 – Ground Handling Wheel Procedure (01/17/1975)
   43. SIL0043 – Push-Pull Control Rods (02/20/1975)
   44. SIL0044 – Certification Eligibility, West Germany (CXL 04/26/2017)
   45. SIL0045 – Blade Grip and Spindle (08/11/1975)
   46. SIL0046 – Damper Modification (03/19/1976)
   47. SIL0047 – Service Communications (03/11/1976)
   48. SIL0048 – Cooling Fan Shroud (03/30/1976)
   49. SIL0049 – C Model Factory Conversions (CXL 06/14/1976)
   50. SIL0050 – Rotor Tachometer (CXL 09/05/2018)
   51. SIL0051 – Teeter Bearing (01/27/1977)
   52. SIL0052 – TR Spindle, Narrow Chord (01/27/1977)
   53. SIL0053 – Low Rotor RPM Warning Unit (CXL 10/18/2023)
   54. SIL0054-R1 – Induction System Hose Clamps (04/07/2017)
   55. SIL0055 – Main Rotor Damper Fatigue Life (CXL 10/18/2023)
   56. SIL0056 – TR Input Shaft Nut Torque (01/27/1977)
   57. SIL0057 – MRGB Retention Bolts (01/27/1977)
   58. SIL0058 – Fatigue Retirement Lives (CXL 10/18/2023)
   59. SIL0059 – Sealed Bearings (02/15/1977)
   60. SIL0060 – TR Spindle and Teeter Stop (03/10/1977)
   61. SIL0061 – Weight and Balance Fulcrum (04/25/1977)
   62. SIL0062 – Fuel Line Insulation (06/22/1977)
   63. SIL0063 – Turbocharger Oil Inlet Adapter (05/27/1977)
   64. SIL0064 – Idler Stabilizer (06/01/1977)
   65. SIL0065 – Certification Eligibility, U.K. (CXL 04/26/2017)
   66. SIL0066  – Certification  Eligibility, U.K. (CXL 04/26/2017)
   67. SIL0067 – Delivered Configuration, Australia (07/27/1977)
   68. SIL0068 – Oleo Boot (08/23/1977)
   69. SIL0069 – Engine Troubleshooting (10/07/1977)
   70. SIL0070 – Certification Eligibility, U.K. (CXL 04/26/2017)
   71. SIL0071 – (CXL 11/21/2023)
   72. SIL0072 – Certification Eligibility, Germany (05/01/1978)
   73. SIL0073A – MR Retention, O-Ring (05/24/1979)
   74. SIL0074-R3  – Drive Belt inspection (11/21/2023) 
   75. SIL0075A – MR Blade Damper (11/20/1980)
   76. SIL0076 – (CXL 11/21/2023)
   77. SIL0077 – MR XMSN, Nut Torque (12/12/1978)
   78. SIL0078 – Fire Wall (12/13/1978)
   79. SIL0079A – Over-Running Clutch (02/14/1980)
   80. SIL0080A – Clutch Control, Belt Tension (08/04/1982)
   81. SIL0081 – Turbocharger, Oil Leakage (12/12/1978)
   82. SIL0082 – Oil Lines (12/13/1978)
   83. SIL0083 – Static Vent System (12/14/1978)
   84. SIL0084 – Pinion Shaft (12/19/1978)
   85. SIL0085 – XMSN Overhaul Interval (12/19/1978)
   86. SIL0086 – TR Rigging Tool (03/05/1979)
   87. SIL0087 – TR Blade Bearing (03/06/1979)
   88. SIL0088-R2 – Blade Strike (11/13/2019)
   89. SIL0089 – MR Blade Tape (01/22/1979)
   90. SIL0090 – Fuel Nozzle Air Vent (05/23/1979)
   91. SIL0091A – Engine Starting System (09/26/1980)
   92. SIL0092 – Monitoring EGT System (02/14/1980)
   93. SIL0093 – Starter Ring Gear (02/13/1980)
   94. SIL0094 – Preflight Control System Check (02/25/1980)
   95. SIL0095 – Blades, Corrosion (07/17/1980)
   96. SIL0096 – Fuel Lines, Inspection (07/17/1980)
   97. SIL0097 – (CXL 11/21/2023)
   98. SIL0098 – Turbocharger Gasket (08/06/1980)
   99. SIL0099 – Corrosion Control (08/06/1980)
   100. SIL0100 – MR Flapping Bearing (08/06/1980)
   101. SIL0101 – Position and Strobe Light (08/18/1980)
   102. SIL0102 – TR Teeter Bearing (09/26/1980)
   103. SIL0103 – Overrunning Clutch (11/13/1980)
   104. SIL0104 – TR Blade Tape (CXL 08/14/2019)
   105. SIL0105 – Mageto Retard Timing (11/13/1980)
   106. SIL0106 – Mixture Control (11/13/1980)
   107. SIL0107 – Solar Shield (CXL 04/02/2019)
   108. SIL0108 – Lower Jack Strut (03/17/1981)
   109. SIL0109 – MR and TR Slinger Rings  (03/10/1981)
   110. SIL0110B – Swashplate (03/18/1993)
   111. SIL0111 – Engine Starting (03/11/1981)
   112. SIL0112-R1 – MRGB Pinion Drive Key (03/14/2018)
   113. SIL0113 – Landing Light (04/23/1981)
   114. SIL0114 – Safety Equipment (04/28/1981)
   115. SIL0115 – MR Blade Damper (03/09/1981)
   116. SIL0116-R8 – Service Life Limits (11/13/2019)
   117. SIL0117 – Auxiliary Oil Cooler (08/26/1981)
   118. SIL0118 – Engine Oil (08/26/1981)
   119. SIL0119 – Magneto Timing (12/02/1981)
   120. SIL0120 – Teeter Bearing (12/02/1981)
   121. SIL0121 – Rotor System Tracking (12/02/1981)
   122. SIL0122 – Starter (04/14/1982)
   123. SIL0123 – Oil Cooler Access (04/14/1982)
   124. SIL0124 – Fuel System (04/14/1982)
   125. SIL0125 – Overboost Warning (07/27/1982)
   126. SIL0126 – Flapping Bearing (07/27/1982)
   127. SIL0127A – MR and TR Blade (12/15/1987)
   128. SIL0128 – (CXL 11/21/2023)
   129. SIL0129 – MR & TR Blade Maintenance and Repair (11/12/1982)
   130. SIL0130 – Eligibility, Gross Weight (10/01/1984)
   131. SIL0131 – Engine Operation (10/01/1984)
   132. SIL0132 – TRDS Flex Couplings (CXL 03/06/2000)
   133. SIL0133 – TR Bearings (06/08/1987)
   134. SIL0134 – Certification Eligibility, U.K. (CXL 04/26/2017)
   135. SIL0135 – Certification Eligibility (CXL 04/26/2017)
   136. SIL0136 – Greases Almagard & Almaplex (10/18/1989)
   137. SIL0137 – Lubrication, Fuels (CXL 09/25/2012)
   138. SIL0138 – Pinion Nut, Jack Strut Bearing (09/11/1995)
   139. SIL0139-R1 – Rotor Tachometer (10/14/2008)
   140. SIL0140 – Seat Belts (09/11/1995)
   141. SIL0141-R1 – Tail Rotor Teeter Bearing Assembly (12/02/2024)
   142. SIL0142 – TR Bumper (CXL 05/17/2024)
   143. SIL0143 – Trim Motor Operation, 24 V (05/28/1997)
   144. SIL0144 – Chip Indications (10/03/1997)
   145. SIL0145 – Tracking (10/03/1997)
   146. SIL0146 – MR Control Rod (10/03/1997)
   147. SIL0147-R1 – Flapping Bearing (05/29/2015)
   148. SIL0148 – Low Rotor Speed Warning (03/31/1999)
   149. SIL0149 – Lamiflex Bearing (05/03/1999)
   150. SIL0150-R1 – Lower Swashplate (03/06/2000)
   151. SIL0151 – Low Rotor, Tone Generator (03/06/2000)
   152. SIL0152 – Belt Tension, Idler Pulley (05/31/2001)
   153. SIL0153 – TR Configuration (02/15/2002)
   154. SIL0154 – Starter Circuit Wiring (09/05/2002)
   155. SIL0155-R1 – Drive Belt (09/10/2003)
   156. SIL0156 – MR Push-Pull Rod (12/09/2003)
   157. SIL0157 – MR Damper Valve (01/31/2005)
   158. SIL0158 – TR Pitch Change Link (CXL 05/12/2015)
   159. SIL0159 – Left Side TR Installation (01/31/2005)
   160. SIL0160 – MR Control Rods, Swashplate (10/30/2006)
   161. SIL0161 – MR Damper Oil (05/04/2007)
   162. SIL0162-R1 – Tail Rotor Thrust Bearings (11/21/2023)
   163. SIL0163-R1 – Turbocharger Adapter Assembly (04/02/2019)
   164. SIL0164 – Cyclic Trim (07/24/2007)
   165. SIL0165-R4 – TR Pitch Link (11/10/2017)
   166. SIL0166 – MRGB Bolts, Torque (05/21/2008)
   167. SIL0167-R1 – Sliding Window (01/05/2010)
   168. SIL0168 – Rotor System Bearings, Grease (01/20/2009)
   169. SIL0169 – MR Blade Corrosion Maps (04/28/2009)
   170. SIL0170 – Corrosion Prevention (03/22/2010)
   171. SIL0171 – Fuel Filter Servicing (03/26/2012)
   172. SIL0172 – Blade Tape Repair (01/20/2011)
   173. SIL0173 – Pylon Structure (09/02/2010)
   174. SIL0174 – Blade Interchangeability (01/20/2011)
   175. SIL0175-R1 – Turbocharger Adapter (12/12/2023)
   176. SIL0176 – ECD016  & ECD018 Bearings (07/11/2011)
   177. SIL0177 – MR Tracking (08/19/2011)
   178. SIL0178 – Upper Swashplate (04/15/2014)
   179. SIL0179-R1 – Copilot Flight Controls (12/20/2017)
   180. SIL0180 – Hi-Lo RPM Switch (11/30/2012)
   181. SIL0181 – Production Certificate (CXL 10/14/2024)
   182. SIL0182-R1 – Fuel Management (11/07/2017)
   183. SIL0183 – Collective Stick Socket (08/19/2015)
   184. SIL0184-R3 – Collective Trim Adjustment Rod Assembly (05/16/2013)
   185. SIL0185 – EDM CHT Probe Installation (05/19/2016)
   186. SIL0186 – Wastegate Linkage and Throttle Cable Installation 03/30/2016)
   187. SIL0187-R1 – Universal Block (04/02/2024)
   188. SIL0188 – Oil Pressure Gauge Troubleshooting (12/01/2016)
   189. SIL0189 – Magneto Retard Terminal P-Lead Insulator (02/04/2019)
   190. SIL0190 – Cabin Door Removal (04/02/2019)
   191. SIL0191 – Lamiflex Bearing Discontinuation (08/14/2019)
   192. SIL0192 – Tail Rotor Cable Assembly (12/09/2019)
   193. SIL 0193-R1 – TRGB Oil Check and Servicing (05/09/2023)