Casualties unknown

2008-08-31: Embraer EMB-110P1 C-FPCU — Air Creebec Inc — Cochrane, Ontario, CA

Cochrane, Ontario, CA

On August 31, 2008, an Embraer EMB-110P1 C-FPCU operated by Air Creebec Inc was involved in an aviation accident near Cochrane, Ontario, CA. Investigators recorded the probable cause as: The nose landing gear failure was caused by the fracture of the oleo strut housing trunnion link arm, which was initiated by an existing fatigue crack in the bore of the link arm. This summary draws on records from the Transportation Safety Board of Canada (TSB).

Sourcesthe Transportation Safety Board of Canada (TSB)Primary reportUpdated 1785068748Data APIEditorial standards

During a training flight on an Embraer EMB-110P1 (C-FPCU) at Cochrane, Ontario, the nose landing gear partially collapsed on landing, causing substantial damage. No injuries occurred. The failure was caused by a fatigue crack in the oleo strut housing.

History of the Flight

The Air Creebec Inc. Embraer EMB-110P1 aircraft (registration C-FPCU, serial number 110445) was conducting a training flight with two pilots. The flight originated from Timmins, Ontario. At approximately 1130 eastern daylight time, while landing on Runway 13 at Cochrane Airport, the nose landing gear partially collapsed during the landing roll. The aircraft veered to the right and briefly exited the edge of the runway. The left brake was applied to prevent a complete runway excursion, and directional control was regained. The aircraft was manoeuvred back onto the runway where it stopped. The aircraft sustained substantial damage to the nose section, and the right propeller was damaged when it struck a runway edge light. Neither pilot was injured.

The crew performed a simulated instrument flight rules (IFR) non-directional beacon (NDB) Runway 31 approach circling for Runway 13. After a low approach, a visual circuit was flown leading to the accident landing. The aircraft landed on the main landing gear with the nose gear lowered normally and no excessive force at touchdown.

Flight Crew

The pilot-in-command held an Airline Transport Pilot License with a current medical certificate and pilot proficiency check. The co-pilot held a Commercial Pilot License with a current medical certificate and was undergoing training on type. Both were certified and qualified for the flight.

Weather

Weather at the time was clear skies, visibility 15 miles, and calm wind. The weather was not considered contributory.

Aircraft and Nose Gear Information

The aircraft was certified, equipped, and maintained in accordance with regulations and approved procedures. Weight and centre of gravity were within limits. The nose landing gear assembly, part number 110P2-410-21, serial number 507, was originally manufactured by ERAM (now Messier-Dowty). It had been overhauled and certified by Aeromil in Australia. However, Canada and Australia have no maintenance agreements, so the Australian Authorized Release Certificate is not recognized by Transport Canada.

Examination of the Nose Gear

The nose gear assembly was sent to the TSB Engineering Laboratory. Examination via visual, optical, and SEM methods indicated that the strut housing failure occurred in a single-cycle ductile overstress mode preceded by progressive mode cracks—fatigue cracks. The main fatigue crack had two distinctive areas that grew over an unknown period. One area had clear fatigue striations with little oxidation; the other had severe oxidation, rubbing, and an integrated substance identified as hardened bushing locking adhesive. Multiple initiation sites were observed, with imperfections on the inner surface possibly contributing but not proven due to wear. The origin could not be determined; it may have been induced during machining, tooling condition, or foreign matter.

Probable cause

The nose landing gear failure was caused by the fracture of the oleo strut housing trunnion link arm, which was initiated by an existing fatigue crack in the bore of the link arm.