94-09-06: Blade Taper Bore

94-09-06 Hamilton Standard: Amendment 39-8894. Docket 94-ANE-15. Applicability: Hamilton Standard Models 14RF-9, 14RF-19, 14RF-21, and 14SF-5, 14SF-7, 14SF-11, 14SFL11, 14SF-15, 14SF-17, 14SF-19, and 14SF-23; and Hamilton Standard/British Aerospace 6/5500/F propellers installed on but not limited to Embraer EMB-120 and EMB 120-RT; SAAB-SCANIA SF 340B; Aerospatiale ATR42- 100, ATR42-300, ATR42-320, ATR72; DeHavilland DHC-8-100 series, DHC-8-300 Series; Construcciones Aeronauticas SA (CASA) CN-235 and CN-235-100; Canadair CL-215T and CL-415; and British Aerospace ATP airplanes. Compliance: Required as indicated, unless accomplished previously. To prevent loss of the propeller blade due to cracks initiating in the blade taper bore, that can result in possible aircraft damage, and possible loss of aircraft control, accomplish the following: (a) Within 45 days after the effective date of this AD, perform an ultrasonic shear wave inspection for cracks in the bladetaper bore, in accordance with the following Hamilton Standard Service Bulletins as applicable: 14RF-21-61-A53, dated April 18, 1994; 14SF-61-A73, dated April 18, 1994; 14RF-19-61-A34, dated April 18, 1994; 14RF-9-61-A66, dated April 18, 1994; 6/5500/F-61-A27, dated April 18, 1994, (b) Remove cracked propeller blades and replace with a serviceable blade prior to further flight. (c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Boston Aircraft Certification Office. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Boston Aircraft Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Boston Aircraft Certification Office. (d) Specialflight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the aircraft to a location where the requirements of this AD can be accomplished. (e) The inspection shall be done in accordance with the following Hamilton Standard service documents: Document No. Pages Date 14RF-21-61-A53 Total pages: 19 19 April 18, 1994 14SF-61-A73 Total pages: 19 19 April 18, 1994 14RF-19-61-A34 Total pages: 19 19 April 18, 1994 14RF-9-61-A66 Total pages: 19 19 April 18, 1994 6/5500/F-61-A27 Total pages: 19 19 April 18, 1994 This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Hamilton Standard, One Hamilton Road, Windsor Locks, CT 06096- 1010. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (f) This amendment becomes effective on May 2, 1994.