Aviat A-1C-180 N28WY

Summary

On 6 April 2011 at about 15:05 local time, a Aviat A-1C-180 registered N28WY, operated by Alpine Aviation, was involved in an accident near Laramie, Wyoming, 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

6 April 2011 at 15:05

Classification

Accident

Location

Laramie, Wyoming, United States

Coordinates

41.3119, -105.6750

Aircraft

Aviat A-1C-180

Registration

N28WY

Category

Airplane

Engines

1

Operator

Alpine Aviation

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Fort Collins → Alpine

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR11FA188

1 person died.

The pilot’s failure to maintain airplane control and to recover from an aerodynamic stall, which resulted in a spin.

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

Read the full NTSB narrative

Two airplanes of the same make and model were repositioning together to the same destination and were flying about 1 mile apart from one another. The pilot of the lead airplane reported that shortly after departure, they encountered some light rain, but saw no evidence of ice. As both airplanes approached a mountain pass near the accident site, they encountered light snow with a cloud ceiling of about 1,200 feet above ground level and 3 to 4 miles visibility. The lead pilot heard a blind transmission from the pilot of the accident airplane saying he was "on the edge of a stall." No further radio transmissions were received from the accident pilot. The lead pilot stated that at the time of the radio transmission, he had no evidence of icing on his airplane or anything abnormal about the flight characteristics of his airplane. Witnesses located near the accident site reported observing the two airplanes and that the second airplane, which was about 1/2 to 1 mile behind the first airplane, appeared to be "wobbling" back and forth before it suddenly nosed downward into terrain. Review of weather conditions near the time of the accident revealed no potential for icing below about 11,000 feet. Review of the recovered data from the accident airplane's GPS revealed that the airplane began a descent in the last 3 minutes 57 seconds of recorded data. The data showed an increase in groundspeed for the immediate 44 seconds following the start of the descent from 78 knots to 85 knots; however, the groundspeed then decreased to about 53 knots over the following 2 minutes 56 seconds. The last recorded data point was located about 0.3 mile south of the accident site and about 50 feet above ground level. Wreckage and impact signatures were consistent with a stall and subsequent spin with a right-wing, nose-low impact. Postaccident examination of the airframe, flight control system, and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Toxicology tests on the pilot were positive for quinine, commonly found in tonic water and occasionally used to treat leg cramps, and sertraline, an antidepressant, which is commonly marketed as Zoloft, and its metabolite, desmethylsertraline. Review of the pilot's medical records revealed that the pilot did not report the usage of these medications on his most recent medical certification application. The degree of the pilot’s cognitive impairment from these medications could not be determined.

Quoted verbatim from the NTSB record.