87-12-05: Gas Producer Turbine and Power Turbine Disks

87-12-05 AVCO LYCOMING: Amendment 39-5640. Applies to Avco Lycoming T5313B turboshaft engines. Compliance is required as indicated, unless already accomplished. To prevent an uncontained engine failure, remove gas producer turbine (GPT) and power turbine (PT) disks and spacers from service, and replace with serviceable parts, in accordance with the following schedules: (a) GPT disk, Part Number (P/N) 1-100-133-01: (1) Within the next 250 hours in service (HIS) or 100 cycles in service (CIS) after the effective date of this AD, whichever occurs first, for those disks that have accumulated a total service life in excess of 24,750 HIS or 9,900 CIS since new on the effective date of this AD. (2) Prior to accumulating 25,000 HIS or 10,000 CIS since new, whichever occurs first, for those disks that have accumulated a total service life equal to or less than 24,750 HIS or 9,900 CIS since new on the effective date of this AD. (b) PT disk, P/N 1-140-272-01: (1) Withinthe next 100 HIS or 50 CIS after the effective date of this AD, whichever occurs first, for those disks that have accumulated a total service life in excess of 9,000 HIS or 4,550 CIS since new on the effective date of this AD. (2) Prior to accumulating 9,100 HIS or 4,600 CIS since new, whichever occurs first, for those disks that have accumulated a total service life equal to or less than 9,000 HIS or 4,550 CIS since new on the effective date of this AD. (c) GPT spacer, P/N 1-100-294-03: (1) Within the next 250 HIS or CIS, after the effective date of this AD, whichever occurs first, for those spacers that have accumulated a total service life in excess of 24,750 HIS or CIS since new on the effective date of this AD. (2) Within the next 12,500 HIS or CIS, after the effective date of this AD, whichever occurs first, for those spacers on which the total service life is not known on the effective date of this AD. (3) Prior to accumulating 25,000 HIS or CIS since new, whichever occurs first, for those spacers that have accumulated a total service life equal to or less than 24,750 HIS or CIS since new on the effective date of this AD. (d) PT spacer, P/N 1-140-169-03: (1) Within the next 250 HIS or 100 CIS, after the effective date of this AD, whichever occurs first, for those spacers that have accumulated a total service life in excess of 24,750 HIS or 9,900 CIS since new on the effective date of this AD. (2) At the next PT second stage disk removal, after the effective date of this AD, for those spacers on which the service life is not known on the effective date of this AD. (3) Prior to accumulating 25,000 HIS or 10,000 CIS since new, whichever occurs first, for those spacers that have accumulated a total service life equal to or less than 24,750 HIS or 9,900 CIS since new on the effective date of this AD. (e) PT spacer, P/N 1-140-169-04: (1) Within the next 250 HIS or CIS after the effective date of this AD, whichever occurs first, for those spacers that have accumulated a total service life in excess of 24,750 HIS or CIS since new on the effective date of this AD. (2) Within the next 12,500 HIS or CIS after the effective date of this AD, whichever occurs first, for those spacers on which the total service life is not known on the effective date of this AD. (3) Prior to accumulating 25,000 HIS or CIS since new, whichever occurs first, for those spacers that have accumulated a total service life equal to or less than 24,750 HIS or CIS since new on the effective date of this AD. NOTE: Avco Lycoming Service Bulletin Number 0020, Revision 2, dated January 3, 1986, reflects the new lives specified in this AD, and provides instruction for computing and recording part life. Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD may 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, Federal Aviation Administration, 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, New England Region, may adjust the compliance times specified in this AD. This amendment becomes effective on July 20, 1987.