SAIB SW-04-81 —

1 SPECIAL AIRWORTHINESS INFORMATION BULLETIN

Aircraft Certification Service Washington, DC

U.S. Department of Transportation Federal Aviation Administration

SW-04-81 August 27, 2004 www.faa.gov/certification/aircraft This is information only. Recommendations aren’t mandatory.

[We inadvertently published this SAIB with the wrong SAIB number. The correct number should be SW-04-81. We republished it on our website at www.faa.gov/certification/aircraft]

Introduction

This Special Airworthiness Information Bulletin alerts you, owners and operators of Eurocopter SA341G and SA342J helicopters that Eurocopter has issued an Alert Service Bulletin (ASB) No. 65.63. The ASB requires a visual inspection of the special washers located on the flexible disks of the inclined and horizontal drive shafts of the tail rotor transmission. These disks (or couplings) transfer power between the drive shafts and the tail rotor transmission.

Reference Eurocopter Alert Service Bulletin No. 65.63, dated March 10, 2004

Background

During installation of a tail rotor drive shaft on an aircraft, an operator found that the special washers at the jo-bolt rivets that are fitted to the flexible disks were installed in the opposite direction to that specified on the Work Card in Repair Manual Chapter 52.10. The flexible disk is designed to bear against the rounded face of the special washer. On some tail rotor transmissions, the operator found that the flexible disk bore against the other face of the special washer. With the improper installation of the washer, normal flexure/movement of the tail rotor drive system during operation might cause damage to the flexible disk, in the location of this unsuitable seating, when the disk rotates. Therefore, incorrect installation of the special washers might lead to crack initiation at the attachment points of the flexible disk.

Recommendations

Due to the potential consequences of improper installation of the special washers on the flexible disks, we highly recommend that you comply with the referenced Eurocopter Alert Safety Bulletin to ensure the correct placement of washers.

2 For Further Information Contact

Ed Cuevas, Aviation Safety Engineer, FAA Safety Management Group, ASW-112, 2601 Meacham Blvd., Fort Worth, TX 76137; phone: (817) 222-5355; e-mail: [email protected].

For copies of the Alert Service Bulletin, contact American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, TX 75053-4005, phone (972) 641-3460, fax, (972) 641-3527 (for Eurocopter Deutschland and Eurocopter France products).