AD 88-18-03

88-18-03 GARRETT ENGINE DIVISION, ALLIED-SIGNAL, INC. (formerly Garrett Turbine Engine Company, GTEC): Amendment 39-6248. Final copy of priority letter AD issued August 30, 1988.

Applicability: Garrett TFE731-3 turbofan engine models installed in airplane models as follows:

GARRETT MODEL NO. AIRPLANE MODEL TFE731-3-1C FALCON 50 TFE731-3-1E 731 JETSTAR TFE731-3-1F JETSTAR II TFE731-3-1G WESTWIND 1124 TFE731-3-1H BAe HS125-SERIES TFE731-3-1J CASA 101 TFE731-3-1K JETSTAR II (SPRINGFIELD) TFE731-3A-2B LEARJET 55 TFE731-3A-2B1 LEARJET 55 TFE731-3A-200G WESTWIND 1125 TFE731-3AR-2B LEARJET 55 TFE731-3AR-2B1 LEARJET 55 TFE731-3AR-200G WESTWIND 1125 TFE731-3R-1D SABERLINER 65/65A TFE731-3R-1G WESTWIND 1124 TFE731-3R-1H BAe HS125-SERIES

Compliance: Required as indicated, unless already accomplished.

To prevent uncontained engine failures, accomplish the following within 25 cycles in service, after the effective date of this AD.

(a) Review the engine maintenance records on the above listed engine models to determine if part number 3072316-2 or -3, or 3073110-1 or -2, high pressure turbine rotor (HPTR) disc with one of the following serial numbers is installed. Spare discs must also be checked for applicable part number and serial number.

1-18040-9514 6-12112-960 4-12112-167 6-12112-1938 4-12112-1536 7-12112-875 4-12112-1564 8-12112-199 6-12112-938 9-12112-3862 6-12112-954 9-12112-3878

(b) Inspect and remove from service, if necessary, suspect serial number disc installed in engines in accordance with the accomplishment instructions of Garrett Alert Service Bulletin TFE731-A72-3376, dated August 19, 1988, and replace with serviceable HPTR disc.

(c) Inspection of the disc is required per paragraph (b) above, before further flight operation, if a suspect serial number disc is located in a spare engine or as a spare part.

(d) 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.

(e) Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, the Manager, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, Aircraft Certification Service, Federal Aviation Administration, 3229 East Spring Street, Long Beach, California 90806- 2425, may approve an equivalent means of compliance or an adjustment of the compliance schedule which provides an equivalent level of safety.

The HPTR disc inspection shall be done in accordance with Garrett SB TFE731-A72-3376, dated August 19, 1988. 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 Garrett General Aviation Services Division, Distribution Center, 2340 East University, Phoenix, Arizona 85034; telephone (602) 225-2548. Copies may be inspected at the Regional Rules Docket, Office of the Assistant Chief Counsel, Federal Aviation Administration, New England Region, 12 New England Executive Park, Room 311, Burlington, Massachusetts 01803, or at the Office of the Federal Register, 1100 L Street, Room 8301, Washington, DC 20591.

This amendment (39-6248) becomes effective on July 21, 1989, as to all persons except those persons to whom it was made immediately effective by Priority Letter AD 88-18-03 issued August 30, 1988, which contained this amendment.