SAIB SW-11-33

FAA Aviation Safety

SPECIAL AIRWORTHINESS

INFORMATION BULLETIN SAIB: SW-11-33 SUBJ: Eurocopter France Model AS 355 Helicopters; Main Gearbox Cowling Lock Improvement Date: May 16, 2011 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin is issued to inform owners and operators of Eurocopter France (Eurocopter) Model AS355E, F, F1, and F2 helicopters of the availability of a product improvement on the engine and main gearbox cowling (cowling) locking mechanism.

Background

On October 9, 2008, Eurocopter issued Service Bulletin No. 53.00.24 (SB) to recommend modifying Model AS355 helicopters with an improved cowling locking mechanism. The European Aviation Safety Agency (EASA) issued Airworthiness Directive No. 2010-0023R1, dated March 18, 2010, to mandate modifying the cowlings. EASA states that they are mandating the modification to minimize the probability of flight with an open cowling.

The FAA reviewed the safety information provided by EASA and does not concur that an unsafe condition exists with the cowling as installed that warrants an airworthiness directive (AD) under Title 14 of the Code of Federal Regulations (14 CFR) part 39. However, we agree that the modification makes an unsecured cowling latch more visible from the ground and reduces the possibility of missing an unlocked latch during the preflight inspection and taking-off with an unsecured cowling.

Recommendations

The FAA recommends owners and operators consider the ben efit of installing the product improvement as specified in the Eurocopter SB.

For Further Information Contact

Jim Grigg, Aerospace Engineer, Safety Managem ent Group, 2601 Meacham Blvd., Fort Worth TX, 76137, phone: (817) 222-5126, fax: (817) 222-5961, e-mail: Jim.Grigg@FAA.Gov.

For Related Service Information Contact

American Eurocopter Corporation, 2701 N. Forum Drive, Grand Prairie, TX 75052; phone:

(972) 641-000; fax: (972) 641-3710.