EASA AD CF-2026-06 — Landing Gear — Main Landing Gear Aft Door Mechanism — Lock Link Apex Pin/Bolt Fracture
Summary
EASA Airworthiness Directive CF-2026-06 addresses a fracture issue in the main landing gear aft door mechanism lock link apex pin/bolt on De Havilland DHC-8-401 and -402 aircraft, serial numbers 4001 and 4003 through 4633. The directive mandates inspections and replacement of specific apex pins and bolts to prevent asymmetric main landing gear extension. It applies to aircraft equipped with part numbers 46852-1 and NAS6207-17D and introduces a new apex pin P/N 46857-1.
What Changed
This new airworthiness directive introduces repetitive in-situ visual inspections for damage or failure of the apex pin/bolt and surrounding structure. It requires replacement of the existing apex pin/bolt with a new part number 46857-1 according to specified compliance schedules based on accumulated air time. Additionally, it establishes a new safe life maintenance task for repetitive replacement of the new apex pin in the Maintenance Requirements Manual.
Why It Matters
This directive is critical for aviation professionals to prevent potential landing gear malfunctions caused by fractured apex pins or bolts, which could lead to asymmetric main landing gear extension and compromise flight safety. Operators and maintenance teams must ensure timely inspections and part replacements to maintain airworthiness and regulatory compliance. Failure to comply could result in unsafe conditions and regulatory penalties.
What To Do
Operators of affected DHC-8-401 and -402 aircraft must perform visual inspections within 195 flight hours of the directive's effective date and every 65 flight hours thereafter. They must replace existing apex pins/bolts with the new P/N 46857-1 within specified flight hour thresholds depending on current part usage. Maintenance teams must also incorporate the new safe life task for repetitive pin replacement as detailed in the updated Maintenance Requirements Manual.