No fatalities

11 Jul 2016: CANADIAN CAR & FOUNDRY HARVARD MK IV — Somerset, KY

Somerset, KY, United States

On 11 Jul 2016, a CANADIAN CAR & FOUNDRY HARVARD MK IV was involved in an aviation accident near Somerset, KY. No fatalities were reported. Investigators recorded the probable cause as: The pilot's failure to maintain directional control during the landing roll, which resulted in runway excursion, and collision with an airport sign. This summary draws on records from NTSB; 2 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

During landing roll, a tailwheel airplane swerved right then left, departing the runway and impacting an airport sign, causing substantial damage to the right aileron. Postaccident bearing examination found no damage.

Accident Details

The pilot of a tailwheel-equipped airplane reported that during the landing roll, after the tail wheel touched down, the airplane swerved to the right, then to the left, and veered off the runway to the right, impacting an airport sign. The airplane sustained substantial damage to the right aileron.

Postaccident Examination

Following a postaccident examination of the right and left main landing gear wheels, the pilot sent an email to a Federal Aviation Administration (FAA) inspector regarding the Timken bearing for the main landing gear wheel. The email stated in part: "The bearing itself is a stock Timken 18200 bearing, nothing special. While jacked up the wheel turns fine by hand. And this is unlike any failed bearing I've seen. And getting close to a CND (cannot duplicate) condition. I think it is possible the bearing was in the process of failing. At touchdown speeds (approximately 60-80 knots) with little weight on wheels the bearing could lock up or freeze momentarily causing the aircraft to veer right."

Manufacturer Examination

A photo of the Timken 18200 tapered roller bearing was sent to the manufacturer for further examination. The manufacturer examined the photo and concluded that there was no evidence of damage or scoring, and further reported that if the bearing would have seized, he would have expected to see damage to the rolling contact surfaces.

Contributing factors

Causes

Directional control — Not attained/maintainedPilot

Other contributing factors

Contributed to outcome