Landing Gear – Main Landing Gear Aft Door Mechanism – Lock Link Apex Pin/Bolt Fracture
- Published
- Effective
AI-generated summary of the official EASA document. Verify against the PDF before acting.
What to do
Operators must perform initial and repetitive visual inspections of the main landing gear aft door linkage until the new apex pin P/N 46857-1 is installed, following the specified flight cycle compliance schedule. Replacement of existing apex pins/bolts must be completed within the defined flight cycle limits based on accumulated cycles as of 17 February 2026. After installation, a new safe life task requires repetitive discard and replacement of the new pin according to the updated Maintenance Requirements Manual.
Summary
Canadian Airworthiness Directive CF-2026-06R1 addresses the fracture risk of the lock link apex pin/bolt in the main landing gear aft door mechanism on De Havilland DHC-8-401 and DHC-8-402 aircraft, serial numbers 4001 and 4003 through 4633. The directive mandates inspections and replacement of specific apex pins and bolts to prevent asymmetric landing gear extension caused by pin or bolt failure. It applies to apex pin P/N 46852-1 and apex bolt NAS6207-17D, requiring installation of a new pin P/N 46857-1.
What changed
This revision changes the compliance metric for removal and replacement of the apex pins and bolts from hours air time to flight cycles. It also eliminates the requirement for repetitive in-situ visual inspections once the new pin installation is completed. The directive otherwise retains the original inspection and replacement requirements from AD CF-2026-06.
Why it matters
This directive is critical for operators and maintenance personnel to prevent potential landing gear door malfunctions that could lead to asymmetric gear extension, posing safety risks during landing. Compliance ensures continued airworthiness and reduces the risk of in-flight mechanical failures related to the landing gear aft door mechanism. Maintenance teams must update their inspection and replacement schedules to align with flight cycle-based intervals.
More for De Havilland Canada DHC-8
All 58- EASA AD CF-2026-47R1Wing – Wing Access Panels with Un-trimmed Stiffeners and/or Reduced Thickness - InspectionOct 13, 2026
- EASA AD CF-2026-47Wing – Wing Access Panels with Un-trimmed Stiffeners and/or Reduced ThicknessSep 28, 2026
- EASA AD CF-2026-38Maintenance Requirements Manual Part 2 - Airworthiness Limitation Items - AmendmentAug 17, 2026
- EASA AD CF-2026-37Time Limits / Maintenance Checks – Airworthiness Limitation Items – AmendmentAug 6, 2026
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