HISTORY OF FLIGHT On June 28, 2003, at 1120 mountain daylight time, a Stugart Vans RV-6A, N29PT, piloted by a commercial pilot, was destroyed when it impacted terrain southeast of the Fort Collins Downtown Airpark (3V5), Fort Collins, Colorado. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being operated under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot and a pilot-rated passenger on board the airplane were fatally injured. The cross-country flight was originating at the time of the accident. Witnesses reported the airplane had just taken off and was climbing to the east when they heard the engine stop. The witnesses observed the airplane turn around towards the airport, depart controlled flight, and impact the ground near the southeast corner of the airport. The witnesses also said they heard the engine sputter as the airplane was attempting to return to the airport. PERSONNEL INFORMATION The pilot held a commercial pilot certificate with single and multiengine land, and instrument ratings. The pilot also held a certified flight instructor certificate with an airplane single engine land rating, dated December 12, 2001. According to his logbook, on June 19, 2003, the pilot had 3,586.3 total flying hours. The pilot successfully completed a flight review on December 28, 2001. The pilot held a third class medical certificate dated December 3, 2002. The certificate showed the following limitation: Must wear corrective lenses. The pilot-rated passenger held a private pilot certificate with airplane single engine land ratings, issued on March 27, 1958. According to FAA airman records, the pilot-rated passenger had approximately 2,500 total flying hours. The pilot-rated passenger held a third class medical certificate dated June 13, 2002. The certificate showed the following limitation: Must wear corrective lenses. AIRCRAFT INFORMATION The airplane, serial number 20033 was an experimental amateur-built. The airplane was owned by the pilot and used for pleasure. The airplane was issued a special airworthiness certificate on April 18, 1991. The airplane underwent a conditional inspection on October 15, 2002. The tachometer time recorded at the conditional inspection was 475 hours. The airplane's tachometer reading recorded at the accident site was 508.6 hours. WRECKAGE AND IMPACT INFORMATION The accident site was located on the southeast edge of the airport at geographical coordinates 40 degrees, 35.27 minutes north latitude, and 105 degrees, 02.45 minutes west longitude. The airplane wreckage was located in a muddy bog approximately 3/10 mile north and abeam the departure end of runway 11. The main wreckage consisted of all of the airplane's components. The airplane's bottom cowling was crushed and broken aft. The top cowling was broken out and crushed downward. The engine was broken downward at the mounts, crushed aft and canted 30 degrees left. The firewall was crushed inward. The nose gear was bent aft. The nose wheel pant was crushed and broken aft. The propeller spinner was crushed and broken aft. One of the two propeller blades showed no damage. The second blade was bent aft and showed leading edge nicks and chordwise scratches near the blade tip. The cockpit floor was crushed upward. The cockpit walls were crushed aft. The canopy was broken out and fragmented. The instrument panel and glareshield were broken aft. The top portion of the instrument panel was bent forward. Several of the flight and engine instruments, and radios were destroyed. The wind screen was broken out and fragmented. The aft cockpit windows were broken out and fragmented. The main landing gear were bent aft. The aft fuselage was buckled. The empennage showed minor damage. The right horizontal stabilizer was broken downward at the root. The left and right elevator, horizontal stabilizer, and rudder showed no damage. Flight control continuity to the elevator and rudder were confirmed. The airplane's right wing was crushed aft and upward along the leading edge starting at the root and running outward to the wing tip. The right wing fuel tank was broken open and crushed aft. The wing tip was broken aft longitudinally along the rivet line. The right flap was broken downward and showed downward buckles. The right aileron was broken aft from its hinges and was buckled. Flight control continuity to the right aileron was confirmed. The left wing was crushed aft and upward along the leading edge starting at the root and running outward to the wing tip. The left wing fuel tank was broken open and crushed aft. The wing tip was broken aft longitudinally along the rivet line. The left flap was broken downward and was buckled. The left aileron was bent and buckled. Flight control continuity to the left aileron was confirmed. The airplane's engine controls showed the following indications: Throttle - full forward. Mixture control knob - leaned approximately 3 inches. Propeller control knob - full in. Carburetor heat knob - full in. Primer - in and locked. Ignition switch - "Both." Master switch - "On." Fuel pump - "On." Other airplane controls showed the following positions: Flaps - "Up." Cabin heat knob - full in. Cabin air knob - full in. Autopilot - "Off." The airplane's engine instruments showed the following indication: Manifold pressure - 26 inches. Tachometer - 0. Oil temperature - 0. Oil pressure - 0. Fuel pressure - 0. Cylinder head temperature - 0. Exhaust gas temperature - 500 degrees Celsius. The airplane's flight and navigation instruments showed the following indications: Airspeed indicator - 90 miles per hour. Altimeter - 4,780 feet. Kolsman window - 30.00. Directional gyro - 178 degrees. Accelerometer - 0. Witness marks in the cockpit floor panel were consistent with the fuel selector valve handle being in the "Off" position at impact. The airplane's engine was retained for further examination. An examination of the remaining airplane systems showed no pre-impact anomalies. MEDICAL AND PATHOLOGICAL INFORMATION Autopsies of the pilot and pilot-rated passenger were conducted by the Larimer County Coroner at Fort Collins, Colorado, on June 28, 2003. The results of FAA toxicology testing of specimens taken from the pilot revealed Ephedrine, Pseudoephedrine, and Azacyclonol detected in urine. The results of FAA toxicology testing of specimens taken from the pilot-rated passenger revealed 21.08 (ug/ml, ug/g) Salicylate detected in blood. TESTS AND RESEARCH The airplane's engine and related components were examined at Greeley, Colorado, on August 19, 2003. The engine showed continuity from the flange to the accessory section. An examination of the engine intake valves and spark plugs showed evidence consistent with operating the engine with a lean fuel-air mixture. On removal of the number 3 cylinder bottom spark plug, the smell of alcohol was evident. The number 4 piston was cracked. The carburetor was disassembled and examined. The throttle plate was jammed in the fully closed position. The mixture arm was observed in the full rich position. The mixture arm moved freely when examined. No evidence of fuel was found in the carburetor. A faint smell of aviation fuel was evident in the carburetor bowl. The engine manufacturer stated that the presence of alcohol evidence in an airplane engine is consistent with the use of starter fluid. Starter fluid is used to start an engine that is cold-soaked or has a maintenance problem making the engine difficult to start. When used, starter fluid is introduced into the engine's air intake. The use of starter fluid can cause an airplane engine to operate at temperatures exceeding the manufacturer's specifications. ADDITIONAL INFORMATION Parties to the investigation were the FAA Flight Standards District Office, Denver, Colorado, and Textron, Lycoming. The airplane wreckage was released and returned to Beegles Aircraft, Incorporated, on July 2, 2003.