86-19-13 AVCO LYCOMING: Amendment 39-5374. Applies to Avco Lycoming model T5508D turboshaft engines.
Compliance is required as indicated, unless already accomplished.
To prevent failure of the first stage turbine disk that can cause an uncontained engine failure, accomplish the following:
(a) Visual and fluorescent penetrant inspect the first turbine rotor assembly, Part Number (P/N) 2-120- 030-43, within the next 50 hours time in service after the effective date of this AD, in accordance with the Accomplishment Instructions contained in Avco Lycoming Service Bulletin (SB) 5508-0031, Revision 1, dated August 19, 1986, or FAA approved equivalent.
(b) Remove and replace with new parts, bolts P/N 2-100-079-05 and their associated locking plates P/N 2-100-078-01, when accomplishing the inspections of Paragraph (a) above, in accordance with the Accomplishment Instructions contained in Avco Lycoming SB 5508-0031, Revision 1, dated August 19, 1986, or FAA approved equivalent.(c) Remove from service and replace with a serviceable part, prior to further flight, all first turbine disks that exhibit fretting on the disk to shaft mating face and/or a crack indication during inspection.
(d) Report the following information in writing for each inspection within 30 days of the inspection to the Manager, Engine Certification Office, Aircraft Certification Division, Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, (Telex Number 949301 FAANE BURL) (Reporting approved by the Office of Management and Budget (OMB) under OBM Number 2120-0056):
(1) Engine serial number
(2) Inspection date
(3) Disk part number and serial number
(4) Disk total time and cycles
(5) Disk time and cycles since last installation
(6) Breakaway up torque for bolts, P/N 2-100-079-05
(7) Any evidence of oil leakage and/or fire in the Number 2 bearing area
(8) Disk disposition (crack indication or, no crack indication, fretting or, no fretting, thread marks inside the boltholes or not)
NOTE: For the purpose of this AD fretting is defined as metal removal below the original machined surface that is exemplified by a pitting pattern.
Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished.
Upon request, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Engine Certification Office, Aircraft Certification Division, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803.
Upon submission of substantiating data by an owner or operator through an FAA maintenance inspector, the Manager, Engine Certification Office, Aircraft Certification Division, Federal Aviation Administration, New England Region, may adjust the compliance times specified in this AD.
Avco Lycoming SB 5508-0031, Revision 1, dated August 19, 1986, identified and described in this document, is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain copies upon request to Avco Lycoming, 550 South Main Street, Stratford, Connecticut 06497. This document also may be examined at the Office of the Regional Counsel, Rules Docket Number 86-ANE-31, Federal Aviation Administration, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803, Rules Docket Number 86-ANE-31, Room 311, between the hours of 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.
This amendment becomes effective on October 6, 1986.