EASA AD 2019-0258
Tail Rotor Drive — Titanium Bolts — Inspection / Replacement
Summary
EASA Airworthiness Directive 2019-0258 is an airworthiness directive addressing the inspection and replacement of titanium bolts, part number EN3740-060022F, installed on the tail rotor drive of Airbus Helicopters Deutschland GmbH MBB-BK117 D-2 helicopters. The directive requires a one-time inspection of these titanium bolts for potential defects due to improper heat treatment that could lead to hydrogen embrittlement. It applies to all serial numbers of the MBB-BK117 D-2 helicopter model.
What Changed
This new airworthiness directive introduces mandatory inspections of specific titanium bolts installed on the tail rotor drive of MBB-BK117 D-2 helicopters. It requires operators to inspect the bolts within 50 flight hours or 3 months and prohibits the installation or reinstallation of affected parts. If defective bolts are found, operators must contact Airbus Helicopters Deutschland GmbH for approved corrective instructions.
Why It Matters
This directive is critical for aviation professionals because the affected titanium bolts, if compromised, could rupture and lead to reduced helicopter control, posing a safety risk. Operators and maintenance organizations must ensure compliance to maintain airworthiness and avoid potential accidents. Compliance teams need to track and verify inspections and part replacements to meet regulatory requirements.
What To Do
Operators of MBB-BK117 D-2 helicopters must inspect the titanium bolts part number EN3740-060022F installed on the aft connection of the ball bearing control within 50 flight hours or 3 months from 1 November 2019. If affected parts are found, they must contact Airbus Helicopters Deutschland GmbH for approved repair or replacement instructions and must not install or reinstall any affected titanium bolts after the effective date.
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