United States Government Publishing Office publisher pbl distributor dst United States National Archives and Records Administration Office of the Federal Register author aut Government Organization text government publication eng FR Regulatory Information 1999_register executive 2010-09-24 article Proposed Rules D09002ee1bdfe286c D09002ee1bdfe28e3 United States Department of Transportation originator org United States Government Agency or Subagency United States Federal Aviation Administration originator org United States Government Agency or Subagency This document proposes to supersede priority letter airworthiness directive (AD) 90-02-23 by adopting a new AD applicable to Hartzell Propeller Inc. ( )HC-( )2Y( )-( ) propellers. Priority letter AD 90-02-23 currently requires repetitive visual inspections of propeller hubs for cracks using a 10X glass, and, if necessary, removal and replacement of cracked hubs with serviceable parts. This proposal would change the frequency and method of inspection by requiring initial and repetitive eddy current inspections (ECI) of the propeller hub fillet radius for cracks. In addition, this proposed AD would allow installation of an improved design propeller hub as terminating action to the repetitive ECI. This proposal is prompted by reports of cracked propeller hubs found in service after they had been inspected in accordance with the visual inspections required by the priority letter AD. The actions specified by the proposed AD are intended to improve the method for detecting propeller hub cracks, which can result in an inflight separation of propeller blades and damage to the aircraft. 64 FR 4061 https://www.govinfo.gov/app/details/FR-1999-01-27/99-1828 99-1828 fr27ja99-11 RIN 2120-AA64 4910-13-U Docket No. 89-ANE-44 https://www.govinfo.gov/app/details/FR-1999-01-27/99-1828 https://www.govinfo.gov/content/pkg/FR-1999-01-27/html/99-1828.htm https://www.govinfo.gov/content/pkg/FR-1999-01-27/pdf/99-1828.pdf 3 p. 4061 4063 64 FR 4061 Title 14 Part 39 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Hartzell Propeller Inc. ( )HC-( )2Y( )- ( ) Propellers; Federal Register Vol. 64, Issue PRORULE 99-1828 DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 1999-03-29 Docket No. 89-ANE-44 4910-13-U 99-1828 Notice of proposed rulemaking (NPRM).

This document proposes to supersede priority letter airworthiness directive (AD) 90-02-23 by adopting a new AD applicable to Hartzell Propeller Inc. ( )HC-( )2Y( )-( ) propellers. Priority letter AD 90-02-23 currently requires repetitive visual inspections of propeller hubs for cracks using a 10X glass, and, if necessary, removal and replacement of cracked hubs with serviceable parts. This proposal would change the frequency and method of inspection by requiring initial and repetitive eddy current inspections (ECI) of the propeller hub fillet radius for cracks. In addition, this proposed AD would allow installation of an improved design propeller hub as terminating action to the repetitive ECI. This proposal is prompted by reports of cracked propeller hubs found in service after they had been inspected in accordance with the visual inspections required by the priority letter AD. The actions specified by the proposed AD are intended to improve the method for detecting propeller hub cracks, which can result in an inflight separation of propeller blades and damage to the aircraft.

Comments must be received by March 29, 1999. Tomaso DiPaolo, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, Small Airplane Directorate, 2300 East Devon Avenue, Des Plaines, IL 60018; telephone (847) 294- 7031, fax (847) 294-7834. Vol. 64, no. 17 Office of the Federal Register, National Archives and Records Administration 1999-01-27 continuing daily deposited born digital 264 p. Table of Contents: AE 2.7: GS 4.107: AE 2.106: KF70.A2 https://www.govinfo.gov/app/details/FR-1999-01-27 P0b002ee180a71fe9 0097-6326 0042-1219 0364-1406 769-004-00000-9 000582072 f:fr27ja99 https://www.govinfo.gov/app/details/FR-1999-01-27 https://www.govinfo.gov/content/pkg/FR-1999-01-27/pdf/FR-1999-01-27.pdf fdlp 4029 4284 DGPO 2010-09-24 2023-05-05 FR-1999-01-27 machine generated eng FR FR-1999-01-27 64 17