McDonald Lynn B AVID FLYER MARK IV N30456

Summary

On 31 July 2011 at about 15:30 local time, a McDonald Lynn B AVID FLYER MARK IV registered N30456 was involved in an accident near Yamhill, Oregon, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

31 July 2011 at 15:30

Classification

Accident

Location

Yamhill, Oregon, United States

Nearest airport

Flying M (OR05)

Coordinates

45.3614, -123.3531

Aircraft

McDonald Lynn B AVID FLYER MARK IV

Registration

N30456

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Independence → Yamhill

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR11CA358

Nobody was injured.

The pilot’s loss of directional control during landing rollout due to an unlocked tail wheel that was caused by a degradation of the tailwheel assembly mounting angle.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot reported that his approach to, and landing on, the private airstrip in his amateur-built, experimental, conventional gear airplane were normal. During rollout in the calm wind condition, the airplane began an uncommanded right turn. The pilot attempted to correct his loss of directional control by application of rudder and engine power. However, the tail wheel had unlocked and was evidently in a castoring mode. Despite his efforts to straighten the airplane’s path, the airplane veered off the runway and impacted a ditch. During the impact sequence one propeller blade broke, and the left wingtip and a wing rib were broken. The pilot reported that he built and maintained the experimental airplane. He opined that the accident could have been prevented had the angle of the tail wheel assembly been correct. After years of use, the tail wheel spring-to-empennage attachment assembly flattened. The incorrect angle altered the tail wheel’s pivot point. This event, combined with the vibration induced during rollout on the gravel runway, allowed the tail wheel to unlock.

Quoted verbatim from the NTSB record.