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This is a collection of Hartzell Non-Aviation Service Letters. All active Hartzell Non-Aviation Service Bulletins, Service Letters, and Service Advisories
are available for purchase as part of the Hartzell Technical Documents Library on CD Rom.
Contact New Parts Sales at 001(937) 778-4201 (option 1) or e-mail

NOTE: The following Service Letters are arranged in descending numerical order.

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Title Date Revision Description
Non-Aviation (Maritime) Service Bulletin Index Jan 05, 2023 Non-Aviation (Maritime) Service Bulletin Index
 Non-Aviation (Maritime) Service Letter Index Aug 3, 2022  Non-Aviation (Maritime) Service Letter Index
HM-SB-001 Feb 13, 2015 Hovercraft – Hub/Blade Identification and Component Replating
HM-SB-002 Jan 05, 2023 Pitch Change Knob Bracket/Mounting Hardware
HM-SL-001 Aug 3, 2022 3  Overhaul Periods and Life Limits for Hartzell Propeller Inc. Non-Aviation (Maritime) Propellers
HM-SL-002 July 1, 2015 Product Propeller – Hub Clamping Bolt Inspection
Hartzell Propeller