NTSB Factual Report

HISTORY OF FLIGHT

On June 24, 2008, about 0730 mountain daylight time, a Snow S2C, N1661S, impacted terrain while maneuvering to land about 6 miles south of Glenn's Ferry, Idaho. Valley Air Service, Inc., operated the airplane under 14 Code of Federal Regulations (CFR) Part 137 as an agricultural crop dusting operation. The commercial pilot was killed; the airplane sustained substantial damage. Visual meteorological conditions prevailed for the local area flight, and no flight plan had been filed. The flight had departed Hubler Field Airport (ID00), Caldwell, Idaho, about 0600 the morning of the accident, and was destined for Glenn's Ferry.

According to the chief pilot, the field to be sprayed was in Glenn's Ferry, and the operation had been set up as a flight of two airplanes. As one airplane was spreading the dry fertilizer, the other airplane would be reloading with the fertilizer and refueling. The chief pilot and the accident pilot were flying the day of the accident, and had arrived at the accident location about an hour prior. The operation had been in progress for about 1 hour when the accident occurred; each pilot had dropped 3 loads prior to the accident. The chief pilot was on the ground having his airplane refueled and reloaded, when the accident occurred. During the reload he was able to observe the accident airplane as it circled overhead waiting for him to take off, so that the accident airplane could land. The chief pilot stated that the accident airplane was circling to the left. He saw the left wing fall and then the airplane started to spin in a counterclockwise direction. He then watched as the airplane struck the ground in a flat attitude.

The chief pilot and an additional witness estimated the accident airplane to be about 500 to 600 feet above the ground when the left wing dipped and it spun to the ground. The airplane made three 360-degree revolutions before impacting the ground in a 60-degree nose low attitude. Due to the engine noise in his airplane, the chief pilot was not able to hear the accident airplane.

PERSONNEL INFORMATION

The 21-year-old certificated commercial pilot held ratings for single and multi-engine land airplane, and instrument airplane. He also held a flight instructor certificate with ratings for airplane single and multiengine land and instrument airplane. The pilot held a second-class medical issued on March 27, 2008, with no limitations.

The pilot had been employed by Valley Air Service for about 2 years. The operator stated that the pilot had accumulated about 140 hours in the accident airplane make and model for the 2008 season. They estimated he had about 2,000 hours of total flight time. No personal flight records were recovered for the pilot.

AIRCRAFT INFORMATION

A Pratt and Whitney R-985 engine was originally installed on the 1964 Snow S2C airplane. In 1980, the engine was replaced with a Pratt and Whitney (P&W) PT6 per Civil Aeronautics Manual (CAM) 8 authority. In 1997, the current P&W PT6-20B, serial number PCE 21794, was installed on the airplane.

METEOROLOGICAL CONDITIONS

The chief pilot reported the weather conditions as clear, with winds from 270 degrees at 15 knots on the surface.

WRECKAGE AND IMPACT INFORMATION

A Federal Aviation Administration (FAA) inspector responded to the site. The airplane came to rest in an open field. The entire airplane was contained within the main wreckage. He reported that all three of the propeller blades remained attached to the propeller assembly. One propeller blade was broken at the tip and was bent back about midspan. Another propeller blade had some chordwise scratching at the tip, with minor s-bending through the span of the blade. The last propeller blade was buried in the dirt with s-bending and chordwise scratching evident along the length of the blade. He was able to establish flight control continuity.

MEDICAL AND PATHOLOGICAL INFORMATION

The Elmore County Coroner's Office, Mountain Home, Idaho, performed the autopsy on June 25, 2008. The manner of death was listed as blunt force trauma due to an aircraft accident.

The FAA Forensic Toxicology Research Team, Oklahoma City, Oklahoma, performed a toxicological analysis from samples obtained during the autopsy. The toxicological results were negative for carbon monoxide, cyanide, ethanol, and tested drugs.

TEST AND RESEARCH

The FAA inspector, along with a representative from P&W, performed a field evaluation of the engine. They found no mechanical anomalies with the engine. The examination report is contained in the public docket for this report.

The engine was shipped to Pratt and Whitney - Canada's facility in Longueuil, Quebec, Canada, for further examination under the supervision of Transportation Safety Board - Canada. They found contact signatures to the compressor 1st stage blades and shroud, the compressor turbine shroud, the compressor turbine, the power turbine guide vane ring, the inter-stage baffle, the power turbine shroud, and the power turbine, which the manufacturer reported are characteristic of the engine producing power at the time of impact. P & W personnel stated that there were no indications of any pre impact mechanical anomalies. A detailed report of the examination is contained in the public docket for this report.

NTSB Probable Cause

Failure of the pilot to maintain an adequate airspeed resulting in an aerodynamic stall/spin while maneuvering.