Thrush S2R-T660 N660RB

Summary

On 16 August 2009 at about 22:30 local time, a Thrush S2R-T660 registered N660RB, operated by Boardman Air Service LLC, was involved in an accident near Worthington, Minnesota, 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

16 August 2009 at 22:30

Classification

Accident

Location

Worthington, Minnesota, United States

Nearest airport

Worthington Municipal Airport (OTG)

Coordinates

43.6522, -95.5722

Aircraft

Thrush S2R-T660

Registration

N660RB

Category

Airplane

Engines

1

Operator

Boardman Air Service LLC

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Worthington → Worthington

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN09LA526

Nobody was injured.

A fatigue failure of the elevator push-pull rod which resulted in the pilot's inability to control the aircraft's pitch attitude while landing.

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

Read the full NTSB narrative

The pilot reported he heard and felt a “loud pop” at the end of a spray run and realized he did not have elevator control. The pilot controlled the pitch attitude using power and elevator trim as he flew back to an airport to land. The pilot decided to land at a higher than normal airspeed so he could maintain control of the airplane. The airplane bounced twice during the landing. During the second runway impact, the main gear collapsed. The airplane slid approximately 200 feet and veered off the right side of the runway prior to coming to rest and sustained substantial damage to the right wing. A post accident examination of the airplane revealed the elevator push-pull rod was fractured through the first full thread of the threaded shaft adjacent to the conical section. The remaining threaded section of the rod was threaded into the monoball spherical bearing fitting. A metallurgical examination revealed a fatigue fracture that initiated from both sides of the threaded shank on the rod end. Examination of the monoball bearing revealed several dents in the metallic bearing shield. The shape, size, and location of the dents and the deformation of the bearing shield were consistent with over-travel contact by the boss on the monoball bearing.

Quoted verbatim from the NTSB record.