Cone James A RV-6A N641JC

Summary

On 15 September 2011 at about 18:23 local time, a Cone James A RV-6A registered N641JC was involved in an accident near West Jordan, Utah, 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

15 September 2011 at 18:23

Classification

Accident

Location

West Jordan, Utah, United States

Nearest airport

South Valley Regional (U42)

Coordinates

40.6083, -111.9747

Aircraft

Cone James A RV-6A

Registration

N641JC

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Sierra Vista → Salt Lake City

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR11FA450

1 person died.

The pilot’s execution of an abrupt maneuver, likely to avoid birds, which resulted in a stall and spin.

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

Read the full NTSB narrative

While approaching the airport at the conclusion of a 4-hour flight, the pilot announced his intention over the common traffic frequency to join the traffic pattern. A short time later, an undiscernible distress transmission was made over the frequency. A few seconds later, the airplane was observed spiraling to the ground. Global positioning system data recovered from the airplane revealed that it was traveling at an appropriate airspeed for entry into the downwind leg of the traffic pattern with a sufficient margin above the stall speed to maintain flight. It then made an abrupt left turn, resulting in a spiral dive, which progressed into a spin. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. No evidence of a bird-strike was found, and review of radar data did not reveal the presence of other aircraft in the vicinity just prior to the accident. However, radar data did reveal that the airplane passed through a cluster of primary targets (with no altitude information) at the time of the accident. Such primary targets could potentially be radar system anomalies, thermal air currents, or bird reflections. According to a bird mitigation specialist, large birds, or flocks of smaller birds, are often present at that time of year, and such birds typically fly circling patterns in thermal air currents at traffic pattern altitudes. The pilot’s abrupt maneuver during the approach was consistent with an avoidance maneuver. The maneuver, which was calculated to be a 65-degree angle of bank to the left, most likely placed the airplane into an accelerated stall condition, which developed into a spin. The airplane was loaded toward its aft center of gravity limit, which could have increased its pitch sensitivity, thereby exacerbating the turn. A successful recovery from an unintentional stall-spin at pattern altitude is extremely unlikely.

Quoted verbatim from the NTSB record.