Cantrell Lw CHALLENGER II SP N65VG

Summary

On 8 September 2013 at about 18:30 local time, a Cantrell Lw CHALLENGER II SP registered N65VG, operated by Murray Allan Crowe, was involved in an accident near Prineville, Oregon, United States. One person was on board and one died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

8 September 2013 at 18:30

Classification

Accident

Location

Prineville, Oregon, United States

Nearest airport

Prineville (S39)

Coordinates

44.2903, -120.8878

Aircraft

Cantrell Lw CHALLENGER II SP

Registration

N65VG

Category

Airplane

Year built

1998

Engines

1

Operator

Murray Allan Crowe

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Prineville → Prineville

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR13FA400

1 person died.

The in-flight failure of the left elevator control torque tube. Contributing to the accident was the improper assembly of the elevator control torque tubes.

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

Read the full NTSB narrative

Witnesses near the accident site reported observing the accident airplane fly near their location at a low altitude. They reported that the airplane oscillated up and down multiple times and that the tail's flight control surfaces appeared to be moving erratically before the airplane descended into terrain. Postaccident examination of the wreckage revealed that both the left and right elevator control torque tubes were fractured and that the fracture areas were consistent with overload. Also, both the forward and aft set of rivets on the right control tube and the aft rivet on the left control tube that connect the outer sleeve to the smaller portions of the control torque tubes were made of an aluminum alloy material; the manufacturer's assembly instructions require that stainless steel rivets to be installed. Evidence of chafing and impact marks were observed near the separation area of the left control tube, indicating that the torque tube likely separated in flight and restricted the right elevator control movement. A family member, who had previously flown in the accident airplane with the pilot, reported that the airplane had been experiencing abnormally high vibrations from the tail section during high-speed flight (when approaching about 90 miles per hour [mph]) and that the control stick would slam forward. The mechanic who conducted the airplane's last condition inspection about 3 months before the accident reported that he did not note any abnormal wear on the elevator flight controls. When he flew the airplane after completing the inspection, he noticed a buffet during and after throttling back in descent. The mechanic noted that the pilot had mentioned to him that he had the same problem in addition to the airplane experiencing heavy vibrations and the control stick slamming forward during flight at 90 mph, which is consistent with the family member's statement. The mechanic reported that he and the pilot inserted gap strips between the horizontal stabilizer and elevators. He also stated that the pilot had increased the angle of incidence on the elevators but that he was not sure how or when the pilot performed these adjustments. The airplane maintenance records were not located, and it could not be determined when the torque tube rivets were last installed or when maintenance was last performed on the elevator flight controls.

Quoted verbatim from the NTSB record.