Tail Rotor Drive - Ti-Bolt - Inspection / Replacement
- Published
- Effective
- Deadline
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators must inspect all Ti-bolts with part number L535M2001203 installed on the forward tail rotor drive shaft within 50 flight hours or 3 months from 30 August 2019, whichever occurs first. If any affected parts are found, they must be replaced with serviceable parts before the next flight. From the effective date, only serviceable Ti-bolts may be installed on these helicopters.
Summary
EASA Airworthiness Directive 2019-0199 is an airworthiness directive addressing the inspection and replacement of titanium (Ti) bolts, part number L535M2001203, installed on the forward tail rotor drive shaft of Airbus Helicopters Deutschland GmbH EC135 and EC635 helicopter models. The directive applies to all variants and serial numbers of these helicopters. It mandates inspection and, if necessary, replacement of affected Ti-bolts to ensure continued airworthiness.
What changed
This new airworthiness directive introduces a one-time inspection requirement for specific titanium bolts on the forward tail rotor drive shaft of EC135 and EC635 helicopters. It prohibits the installation or reinstallation of affected Ti-bolts that may have undergone improper heat treatment leading to hydrogen embrittlement. The directive also provides instructions for replacement if affected parts are found.
Why it matters
This directive is critical for aviation professionals because the affected Ti-bolts, if compromised, could rupture and lead to reduced helicopter control, posing a significant safety risk. Operators and maintenance organizations must ensure compliance to prevent potential accidents and maintain regulatory conformity. The directive helps maintain the structural integrity of the tail rotor drive system, which is vital for safe helicopter operation.
More for Airbus Helicopters EC135
All 49- EASA AD 2026-0188Instruments – Warning Unit Emergency Off Switches – Operational CheckSep 30, 2026
- EASA AD 2026-0131Engine Fuel & Control – Electronic Engine Control Unit – Software Update; Engine Fuel & Control – Preference Injector – Non-extinguishing Test / ReplacementJul 6, 2026
- EASA AD 2026-0032Tail Rotor — Tail Rotor Blades — InspectionFeb 19, 2026
- EASA AD 2026-0031Tail Rotor — Tail Rotor Blades — InspectionFeb 19, 2026
- EASA AD 2026-0024
Get the next one by email
New ADs and bulletins for Airbus Helicopters EC135, Helicopters 635 and Helicopters EC635, summarized like this page, every Monday.