EASA AD US-2020-19-08
Main Rotor - Main Rotor Hub Tension-torsion Strap Assembly - Life Limit / Removal
Summary
Federal Register Volume 85, Number 180 (September 16, 2020) is a final rule airworthiness directive issued by the FAA addressing Bell Textron Inc. Model 204B, 205A-1, and 212 helicopters. It focuses on the main rotor hub tension-torsion strap assembly part number 204-012-112-005 due to corrosion issues. The directive mandates reducing the life limit of this TT strap assembly and prohibits its installation on any helicopter.
What Changed
This new airworthiness directive reduces the life limit of the affected TT strap assembly from 2,400 total hours time-in-service to 1,200 total hours or 18 months since initial installation, whichever occurs first. It also prohibits installing this TT strap assembly on any helicopter after the effective date. These changes address premature corrosion and fatigue cracking risks identified in the component.
Why It Matters
This directive is critical for aviation professionals because it prevents potential failure of the main rotor hub TT strap assembly, which could lead to loss of a main rotor blade and subsequent loss of helicopter control. Operators and maintenance organizations must track the reduced life limits carefully to ensure continued airworthiness and safety. Compliance reduces the risk of in-flight failures and enhances overall rotorcraft safety.
What To Do
Operators must determine the total hours time-in-service and months since initial installation of each affected TT strap assembly within 25 hours TIS. If the assembly has reached or exceeded 1,200 hours or 18 months, it must be removed from service before further flight. Additionally, no installation of the affected TT strap assembly is permitted after October 21, 2020, the effective date of the directive.
Your fleet's weekly compliance brief
AI-summarized regulatory changes, compliance deadlines, and action items — filtered to your aircraft, every Monday.
AI-generated summary from official EASA source document. Always verify against the original.