R44 Service Letters

R44 SL-75A
Supersedes R44 SL-75
RHC Maintenance Manuals & Illustrated Parts Catalogs Digital Updates18 JUN 2020
R44 SL-74A
Supersedes R44 SL-74
C792-5 Dual Tachometer12 MAR 2020
R44 SL-72Inspection After Stabilizer Damage11 MAR 2020
R44 SL-71Kannad ELT Service Bulletin11 MAR 2020
R44 SL-70Main Rotor Blade Tip Maintenance29 JUL 2019
R44 SL-69C627-6 Five-point Harness Assembly Lower Strap22 MAR 2019
R44 SL-68B
Superseded by R44 SB-103
Main Rotor Blade Tip Plate Permanent Removal29 JUL 2019
R44 SL-67Component Maintenance Course25 JUN 2018
R44 SL-66Gearbox Chip Detector Maintenance08 JUN 2018
R44 SL-65Unauthorized Repairs on Main Rotor Blades in Brazil08 JUN 2018
R44 SL-64A
Supersedes R44 SL-64
Fire Extinguisher Handling and Maintenance20 DEC 2017
R44 SL-63A
Supersedes R44 SL-63
Lycoming Engine Connecting Rod Small-end Bushings27 JUL 2017
R44 SL-62
Supersedes R44 SL-18
Governor Troubleshooting/Magneto Maintenance21 JUL 2017
R44 SL-61A
Supersedes R44 SL-61
A185 Brackets Installation & Fiberglass Scroll Repair20 DEC 2017
R44 SL-60Revised Instrument Marking Metric Decals06 JUN 2017
R44 SL-59High CHT Indication06 JUN 2017
R44 SL-58C258-5 Pitch Link Assembly30 JAN 2017
R44 SL-57A
Supersedes R44 SL-57
Avionics Software20 DEC 2017
R44 SL-56Genesys Aerosystems (Autopilot) Service Letter07 NOV 2016
R44 SL-55Main Rotor Blade Tip Fasteners07 NOV 2016
R44 SL-54Inhibited Glideslope Reception14 JUN 2016
R44 SL-53Altimeters04 APR 2016
R44 SL-52Full Throttle Caution Light Kit08 DEC 2014
R44 SL-51A
Supersedes R44 SL-51
B526 (TORX PlusĀ®) Truss Head Screws13 OCT 2014
R44 SL-50D210 Corrosion-Resistant (CRES) Nuts13 OCT 2014
R44 SL-49C016-7 Main Rotor Blades10 SEP 2014
R44 SL-48Precision Airmotive Service Bulletin PRS-10901 AUG 2014
R44 SL-47Magneto Tachometer Points Wires01 AUG 2014
R44 SL-46Cleanable Air Filters03 JUL 2013
R44 SL-45Deleted Safety Wire03 JUL 2013
R44 SL-44Kannad ELT Service Bulletin
Ref. Kannad ELT Service Bulletin S1820514-25-04
19 JUL 2012
R44 SL-43C343-1 Push-Pull Tube Assembly30 MAY 2012
R44 SL-42R44 II Starting Circuit Time-Delay30 MAY 2012
R44 SL-41Ground Handling Wheels and Wheel Supports07 SEP 2011
R44 SL-40MRGB Oil Level Fluctuation07 SEP 2011
R44 SL-39Fuel Servo Diaphragms18 AUG 2011
R44 SL-38Cracked MS21042L-series Nuts18 AUG 2011
R44 SL-37C
Supersedes R44 SL-37B
C016-7 Main Rotor Blade Installation 05 MAR 2020
R44 SL-36Bladder Fuel Tank Factory Modification17 DEC 2009
R44 SL-35AServo Plugs25 MAR 2009
R44 SL-34Alternator V-Belts22 FEB 2008
R44 SL-33
Superseded by R44 SB-79
Additional Inspection Criteria for Sprag Clutches19 DEC 2007
R44 SL-32BA016-4, C016-2, and C016-5 Main Rotor Blade Bond Maintenance
Additional Information Regarding Main Rotor Blade Skin Debonding
20 APR 2010
R44 SL-31Main Rotor Blade Inspection01 JUN 2006
R44 SL-30Crankshaft Replacement20 JUL 2005
R44 SL-29Optional Four-Point Harnesses with Detachable Shoulder Straps15 OCT 2004
R44 SL-28D040-1 Aft Cowling Assembly15 OCT 2004
R44 SL-27Tail Pipe Extension15 OCT 2004
R44 SL-26Low RPM Warning Horn24 NOV 2003
R44 SL-25Hydraulic Reservoir Vent10 JUN 2002
R44 SL-24
superseded by R44 SB-72A
Main Rotor Blade Tip Inspection21 SEP 2001
R44 SL-23
Supersedes R44 SL-16
Master Battery Relay Upgrade01 AUG 2001
R44 SL-22Belt Tension Actuator Troubleshooting10 FEB 2000
R44 SL-21Stuck Exhaust Valves in Engine17 JAN 2000
R44 SL-20Pitot Line Contact with Push-Pull Tube17 JAN 2000
R44 SL-19Oil Cooler16 SEP 1999
R44 SL-18
Superseded by R44 SL-62
Tachometer Contact Assembly in Magneto14 APR 1999
R44 SL-17Collective Spring and Support08 SEP 1998
R44 SL-16
Superseded by R44 SL-23
Master Battery Relay08 SEP 1998
R44 SL-15AMixture Control Cable Clamp06 OCT 1998
R44 SL-14Carburetor Modification30 MAY 1997
R44 SL-13Lateral Cyclic Trim Assembly Spring Shaft Wear24 OCT 1996
R44 SL-12Upgraded Battery with Battery Cooling24 OCT 1996
R44 SL-11Replacement of A185-2 and -5 Brackets25 OCT 1996
R44 SL-10
Supersedes R44 SL-05
C439-7 Guide Assembly02 AUG 1996
R44 SL-09ACyclic Trim System02 MAY 1996
R44 SL-08Cyclic Trim Elastic Cord26 DEC 1995
R44 SL-07Cyclic Friction26 DEC 1995
R44 SL-06Autorotation RPM Adjustment05 MAY 1995
R44 SL-05
Superseded by R44 SL-10
Inspection of Push-Pull Tube Guides04 NOV 1994
R44 SL-04Engine Breather Coupling07 SEP 1994
R44 SL-03Cyclic "Shot Bag" Damper28 JUL 1994
R44 SL-02Air Intake Hose Chafing Frame30 JUN 1994
R44 SL-01Adjustment of Main Rotor Spindle Boot and Fluid Level24 MAY 1994

R44 Service Letters to Selected Owners

N/ARaven II Fuel Control P/N 2576630-109 MAY 2003
N/AGovernor Controller20 MAR 2003
N/APRV/Topping Valves22 JAN 2003
N/AMixture Guard19 DEC 2002
N/ATailcone Battery Retention Straps31 AUG 2000
N/APop-Out Float Covers31 JUL 2000
N/A28-Volt National Airparts Alternator Bolts08 JUL 1999
N/ASpindle Removal and Installation Fixture MT152-111 NOV 1998
N/ALateral Trim Spring Assembly09 OCT 1998
N/ASwashplate Assembly16 FEB 1998
N/AFan Shaft Spacers14 NOV 1997
N/ACarburetor Modification30 MAY 1997
N/ADoor Lock Decal23 MAR 1994
N/AInstallation of Angle for Strobe Power Supply07 FEB 1994
N/ARequired Recalibration of RPM Governor and Tach07 JAN 1994
N/AUpgrades for Fanwheel and Fanshaft01 NOV 1993
N/AAddition of Washers on Tail Rotor Pitch Arm01 OCT 1993
N/AReplacement of Fuel Cap Gasket16 JUL 1993