SPECIAL AIRWORTHINESS INFORMATION BULLETIN

Aircraft Certification Service Washington, DC U.S. Department of Transportation Federal Aviation Administration

AIR-21-09

June 10, 2021

This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin alerts owners and operators that cracks have been found on left-hand (LH) and right-hand (RH) landing gear skid tubes of Airbus Helicopters (formerly Eurocopter France) Model EC 120 B helicopters that have more than 1,450 autorotation landings with full touchdown completed. This high number of autorotation landings exceeds the normal usage spectrum for EC 120 B helicopters. The affected part numbers are shown in the table below:

Landing gear skid tube P/N	Installed on landing gear with P/N
C321A2107101 (LH) C321A2108101 (RH) C321A2107102 (LH) C321A2108102 (RH) C321A2502102 (LH) C321A2503102 (RH)	C321A2101053 C321A2101054 C321A2501051 C321A2601053

At this time, the airworthiness concern is not an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.

Background

A specific French operator provides EC 120 B helicopters to military pilots for training purposes. The training exercises include using the aircraft for a high number of autorotation landings with full touchdown completed. Cracks were found on a landing gear skid tube of one of the French operator’s aircraft used for this purpose. EASA issued AD 2020-0247 on November 10, 2020, to address the unsafe condition of cracking in the landing gear skid due to the high autorotation landings, since an undetected or uncorrected crack could lead to failure of the landing gear skid, possibly resulting in rollover of the helicopter after a hard landing and consequent injury to occupants.

Recommendations

The Federal Aviation Administration (FAA) recommends that all owners and operators of EC120B helicopters with more than 1,450 autorotation landings with full touchdown contact Airbus Helicopters for additional maintenance requirements.

For Further Information Contact

Andrea Jimenez, Aerospace Engineer, 1600 Stewart Avenue, Westbury, NY 11590, United States; phone: (516) 228-7330; e-mail: andrea.jimenez@faa.gov.

For Related Service Information Contact

Airbus Helicopters, 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone (972) 641-0000 or (800) 232-0323; fax (972) 641-3775; or at http://www.airbushelicopters.com/techpub.