SAIB ANM-99-29 —

No. ANM-99-29 July 2, 1999

Published by: FAA, AFS-610, P.O. Box 26460, Oklahoma City, OK 73125 SAIB’s are posted on the internet at http://av-info.faa.gov This is issued for informational purposes only and any recommendation for corrective action is not mandatory.

Introduction: The purpose of this Special Airworthiness Information Bulletin (SAIB) is to advise owners/operators of Boeing model 747 airplanes of certain recommended actions that may prove to be significant to the continued airworthiness of these airplanes.

This SAIB recommends that owners/operators conduct general checks and inspections of various areas of the Sundstrand Integrated Drive Generators and/or Constant Speed Drives. Accomplishment of these actions is recommended, but is not mandatory. Information obtained from the results of the recommended actions may assist the FAA in determining if subsequent rulemaking action is necessary and may help in defining subsequent corrective action.

Background: On June 17, 1996, a Tower Air, Inc., Boeing 747-136, N606FF, Flight 22, sustained minor damage when the No. 2 engine accessory gearbox caught fire during the aircraft's descent to land at the John F. Kennedy International Airport (JFK) in New York. The flightcrew declared an emergency and landed at JFK without further incident. None of the 17 crewmembers and 397 passengers were injured. Instrument meteorological conditions prevailed, and an instrument flight rules flight plan had been filed. The flight originated from the Los Angeles International Airport and was conducted under the provisions of 14 CFR Part 121 as a domestic, scheduled passenger flight. Subsequent investigation by the NTSB found that overhauls accomplished by UNC Accessory Services' Fort Lauderdale facility on Sundstrand Constant Speed Drives did not meet the requirements of the Component Maintenance Manuals (CMM).

Recommendations: The following actions are recommended for Sundstrand Models 60AGD09 (P/N 705117()), 60AGD15 (P/N 716066()), and 60AGD17 (P/N 729490()), Constant Speed Drives:

Operators using constant speed drives overhauled by UNC Accessory Services' Fort Lauderdale facility are requested to remove the units from service, inspect per the applicable Sundstrand CMM and overhaul them as necessary. During the inspection, note whether:

1. Helicoil inserts are within factory recommended tolerances, and

2. Safety wire is used only where recommended by the applicable Sundstrand CMM.

Please provide feedback to the FAA Office noted below.

For Further Information Contact: Federal Aviation Administration, Attn: Mr. Charles Bonnen, ACE-117C Chicago Aircraft Certification Office, 2300 East Devon Avenue, Chicago, IL 60018, Telephone: (847) 294-7125, Fax: (847) 294-7834, Email: [email protected].