SAIB SW-04-38 —

1 SPECIAL AIRWORTHINESS INFORMATION BULLETIN

Aircraft Certification Service Washington, DC

U.S. Department of Transportation Federal Aviation Administration

SW-04-38 December 24, 2003 www.faa.gov - Search "SAIBs" This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin alerts owners and operators of Eurocopter France EC120B model helicopters that there could be incorrect positioning of the tail rotor drive shaft damper clamps. This incorrect positioning could lead to interference of the two damper half-clamps with the drive shaft tube and cause scoring on the shaft. In time, the interference could result in tail rotor drive shaft failure.

Reference: Eurocopter Alert Telex Tail Rotor Drive Shaft Damper #65A004

Background

Eurocopter advised that a case of incorrect tail rotor drive shaft damper positioning was discovered during a maintenance operation. This incorrect positioning led to interference of the two damper half-clamps with the drive shaft tube and caused a score on the shaft. In time, this interference could result in tail rotor drive shaft failure.

Recommendations

• For aircraft serial numbers 1362 and lower, follow the recommendations contained in Eurocopter Alert Telex #65A004. • If the two half-clamps (1) are not fully positioned on the friction ring (2) remove, check for scoring of the shaft and if required replace any unairworthy parts.

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FIGURE 1

• An Airworthiness Directive is being considered.

For Further Information Contact

Mr. Eric Haight, Aerospace Engineer, FAA Rotorcraft Directorate, ASW-111 Standards Staff, Fort Worth, Texas 76193-0110; phone: (817) 222-5204; fax: (817) 222-5961; email: [email protected]