NTSB Factual Report

On September 2, 2000, at approximately 1800 mountain daylight time, a Nicholson Thorp T-18CWS experimental homebuilt airplane, N24WN, was destroyed when it impacted the ground while maneuvering near Tooele, Utah. The commercial pilot and passenger received fatal injuries. Visual meteorological conditions prevailed, and no flight plan had been filed for this local personal flight being operated under Title 14 CFR Part 91. The flight originated at Wendover Airport, Wendover, Utah, at approximately 1730.

According to the Tooele County Sheriff's Department, campers in the Knolls Recreational Park, located approximately 40 miles west of Tooele, Utah, and 5 miles south of Interstate Highway 80, saw the accident. They had seen the airplane doing aerobatics and said that the airplane was flying low when it experienced engine problems just prior to the accident.

One witness stated that he heard the airplane approaching from the west on an eastbound heading. The witness said, "The airplane was at about 100 to 150 feet above the ground, traveling around 125 to 150 knots, when it appeared to attempt a 'wing-over maneuver' and pulled up to a steep, almost 'hammer-heading' stall, the nose came over in a slow loop. All foreword speed was gone and the airplane was upside down. The pilot managed to get his right wing down to roll the airplane correct and he throttled in to pull out of this stall. He was heading straight at our motor home, and the pilot maneuvered his airplane to avoid hitting us."

Another witness stated, "The airplane was flying very low and then it headed straight up and made a half turn. The airplane continued to climb until it ran out of power. 'I saw the prop stop.' At this point the airplane started to drop tail first and then it rolled over and started to dive. It appeared that the pilot intended to throttle up and pull out of the loop, but the airplane did not have enough elevation. I could not see the airplane over the road and I knew it would be close and that's when I heard the airplane hit the ground."

The pilot, age 59, held a commercial pilot certificate with airplane single and multi-engine land and instrument ratings, dated April 6, 1978. He held a flight instructor certificate with airplane single and multi-engine land ratings, dated November 20, 1978, which expired on November 30, 1980. The pilot also held a repairman experimental aircraft builder certificate for the accident airplane. His second-class airman medical certificate, dated August 9, 1999, had no wavers or restrictions. The pilot estimated he had a total time in all aircraft of 2200 hours and 50 hours in the last six months at the time of his last medical certificate.

N24WN, a Thorp T-18CWS experimental airplane, was manufactured from a homebuilt kit, designed by John Thorp and licensed under Eklund Engineering Inc. The Thorp T-18 is a single engine, 2-place, high performance, all metal, tailwheel all fixed landing gear, low-wing monoplane. According to Eklund Engineering Inc., the plans set for this Thorp T-18 were sold to the pilot as serial number 1424, on June 15, 1981. The airworthiness certificate was issued on February 13, 1989.

At 1830, the weather conditions at Wendover Airport, KENV, elevation 4,235 feet above mean sea level (msl), at 270 degrees and 40 nautical miles from the accident site, were as follows: wind 230 at 10 knots gusting to 14 knots; visibility 10 statute miles; cloud condition clear; temperature 75 degrees Fahrenheit; dew point 28 degrees Fahrenheit; altimeter setting 29.89 inches of mercury; density altitude 6,326 feet msl. Witnesses stated that, at the time of the accident, the weather was warm, sunny and clear with little or no wind.

A Tooele County Sheriff reported that both occupants were wearing seat belts and shoulder harnesses. The sheriff found empty beer cans in the airplane and said the cockpit smelled of alcohol.

The following is based on a verbal statement by a Federal Aviation Administration inspector, who examined the accident site: The impact site was in a relatively flat sandy area with little vegetation. There was evidence of propeller ground scars upon impact. All components of the aircraft were accounted for and a control continuity check was completed. The airplane impacted the ground in a wings level, near vertical attitude leaving very little ground scar. There was no evidence of an in flight break up.

Weight and Balance calculations estimated that the airplane weighed 1322 pounds including the pilot, passenger and fuel. This estimated weight calculationswas within its center of gravity range and below its maximum gross weight of 1600 pounds. However, these calculations put the airplane over its aerobatic limit of 1250 pounds.

An autopsy was performed on the pilot by the State of Utah's Department of Health, Office of the Medical Examiner, Salt Lake City, on September 3, 2000. The FAA's Civil Aeromedical Institute (CAMI), in Oklahoma City, Oklahoma performed toxicology tests on the pilot. According to CAMI's report (#200000248001), volatile tests identified the following levels: 216 mg/dL ethanol detected in muscle, and 232 mg/dL ethanol detected in kidney. These ethanol levels are comparable to a blood alcohol concentration (BAC) of .22% and .23% respectively. At these levels, the BAC is almost three times Utah's legal intoxication level of .08%. These levels are not attributed to putrefaction.

On February 27, 1996, the pilot was involved in another accident (#SEA96LA065) in the same airplane, which occurred within a few miles of this accident site. The airplane received substantial damage when it collided with power lines during a precautionary landing. The Tooele County Sheriff's Office accident report (#96000665) stated that, upon arriving at the site, the trooper could not locate the pilot. He reported evidence of alcohol at the scene, and stated that witnesses said the pilot appeared to be intoxicated.

NTSB Probable Cause

Failure by the pilot to maintain control of the airplane during aerobatic maneuvers as a result of his alcohol impairment. Factors were: The pilot's inadequate planning and decision making and the inadequate altitude he choose for maneuvering.