Airworthiness Directive 2003-04-15
one-timeAirworthiness Directives; Sikorsky Aircraft Corporation Model S-76A, B, and C Helicopters
What this AD requires
This amendment adopts a new airworthiness directive (AD) for the specified Sikorsky Aircraft Corporation (Sikorsky) model helicopters. This action requires determining the manufacturer of a certain part-numbered rotor brake disc (RBD) and if the manufacturer is Parker Hannifin Corporation (PHC), re-identifying the RBD as appropriate. This action also requires before the first flight of the next day following any day in which a certain RBD was used, visually inspecting the RBD for a crack. If a crack is found, this AD also requires replacing the RBD with an airworthy RBD or deactivating it as applicable depending on the nature of the crack. This amendment is prompted by the discovery that certain RBDs manufactured by PHC were improperly heat treated resulting in "soft" RBDs that have an increased wear rate compared to those heat treated in accordance with the type design requirement. Further investigation reveals that "soft" RBDs develop cracks more frequently than previously manufactured RBDs. The actions specified in this AD are intended to prevent failure of the RBD, damage to the rotor blades and nearby hydraulic and fuel lines, and subsequent loss of control of the helicopter.
Which aircraft AD 2003-04-15 applies to
Rotor brake disc (RBD) manufacturer identification/reidentification and cracking requirements per Sikorsky ASB 76-66-36 and 76-66-37: Parker Hannifin (PHC) RBDs marked P/N 76363-09103-102 with S/N 38 through 379 must be remarked as P/N 76363-09103-104 or replaced; P/N 76363-09103-104 RBDs require daily-use crack inspection and replacement/deactivation if cracked; P/N 76363-09101-102 (Goodyear) and 76363-09103-105 (BF Goodrich/PHC) require no further action.
Whether AD 2003-04-15 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.