Ellsberg ONE DESIGN N55TE

Summary

On 6 October 2001 at about 00:00 local time, a Ellsberg ONE DESIGN registered N55TE was involved in an accident near Bend, Oregon, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 October 2001 at 00:00

Classification

Accident

Location

Bend, Oregon, United States

Coordinates

44.0709, -121.2507

Aircraft

Ellsberg ONE DESIGN

Registration

N55TE

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Bend Municipal → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

SEA02LA003

1 person had minor injuries.

the separation of a propeller counterweight mounting bracket due to incorrect mounting bolt torque. Factors include significant powerplant vibration during the forced landing, no suitable landing area, and soft terrain next to the narrow road on which the pilot attempted his emergency landing.

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

Read the full NTSB narrative

Just after the pilot entered the aerobatic box in his experimental One Design aircraft, the airplane developed an "extreme vibration." The pilot therefore shut the engine off and began a glide toward a nearby road. During the descent, with the propeller windmilling, the aircraft shook so violently that it was very difficult for the pilot to see, and he became concerned that the engine might separate from the airframe. When the aircraft reached the ground, the pilot tried to land on a narrow road, but with his visibility still significantly effected by the vibration of the airframe, he was unable to keep the One Design within the lateral confines of the road. During the landing roll, one of the main wheels departed the side of the road and encountered soft terrain. The main gear wheel then began to sink into the soft terrain, and the aircraft nosed over onto its back. It was later determined that one of the propeller counterweight mounting brackets (along with the counterweight itself) had separated from the propeller. A post-accident inspection of the counterweight on the apposing blade revealed that one of its mounting bolts was under-torqued approximately 115 inch-pounds below the value listed in the associated assembly torque table. The propeller, which was a non-certified model with composite blades, had been loaned to the pilot by the manufacturer, while his propeller was undergoing a periodic inspection.

Quoted verbatim from the NTSB record.