A Transport Canada, government of Canada which is responsible for developing regulations, policies and services of transportation has issued a safety alert calling the attention to a recent change by Bell Helicopter that removed tail rotor pitch change chain assembly part number (P/N) 205-001-721-001 from the Original Equipment Manufacturer (OEM) illustrated parts breakdown for the Bell 204B Helicopter.
The purpose of this Civil Aviation Safety Alert (CASA) is to ensure that affected personnel are aware that use of tail rotor pitch change chain assembly, part number (P/N) 205-001-721-001 on the model 204B helicopter is no longer supported by Bell Helicopter.
Transport Canada on August 31, this year release the notice that stated “Operators should ensure that the systems they use to maintain configuration control are updated to ensure P/N 205-001-721-001 is not installed on the model 204B Helicopter”. In early 2017, Bell Helicopter Textron Inc. revised the Illustrated Parts Breakdown for the model 204B, BHT 205B IPB Figure 07-78, to remove P/N 205 001-721-001.
Bell 204B and Bell 205A pitch-change chain cracking has been a known issue for years, with the FAA’s initial Airworthiness Directive (AD) coming out in 1976. In 2013, the agency issued an AD against a new chain, designed for the Bell 204B.
Operators should note that use of P/N 205 001 721 001 on the model 204B is not supported by the manufacturer. Operators should ensure that the systems they use to maintain configuration control are updated to ensure P/N 205-001-721-001 is not installed on the model 204B, Transport Canada said.
Currently, two Nepalese helicopters operators; Fishtail Air and Simrik Air operate their Bell 206 and 407 GXP helicopter, manufactured by Bell Helicopter Textron Inc in Nepalese Sky. Fishtail Air and Heli-Air Nepal is looking forward to add the newly manufactured Bell505 Helicopter on its fleet soon. Rest of all the helicopter operators operates AS 350 B3 series helicopter manufactured by Airbus Helicopter in France.