DEN07LA108

A witness observed the airplane on a "close and tight" downwind leg for the runway at an altitude of approximately 400 feet above ground level. While on the downwind leg, the airplane was in "slow flight in a nose high attitude." The witness observed the airplane enter a steep left turn from the downwind to base leg, and "at that time, I thought it was going to stall and spin.". The airplane's wings rolled level and the airplane began to porpoise. During the porpoise, the witness noted hearing changes to the engine power. The airplane then entered another steep left turn with the wings almost vertical to terrain. "I could see the entire top of the plane during the turn and the engine RPM was increased dramatically, maybe to full power." The witness observed the "nose pitch up and the right wing stall...as if a falling leaf." Subsequently, the airplane entered a spin (1.5 rotations) and impacted terrain. The witness stated that during his observation "the engine was operating under power the entire time." The airplane came to rest inverted in grass terrain adjacent to a drainage ditch approximately 1/2 mile from the threshold of the runway and was destroyed by post impact fire. Examination of the airframe and engine revealed no anomalies.

History of flight

On June 25, 2007, approximately 1145 mountain daylight time, a Schwarz RV-6A single-engine experimental airplane, N94KA, was destroyed when it impacted terrain following a loss of control while maneuvering in the traffic pattern at Greeley-Weld County Airport (GXY), Greeley, Colorado. The private pilot and pilot-rated passenger sustained fatal injuries. The airplane was registered to LPV LLC, Denver, Colorado, and operated by the pilot. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 Code of Federal Regulations Part 91 personal flight. The flight departed the Erie Municipal Airport, Erie, Colorado, approximately 1115, and was destined for GXY.

According to a witness, located at GXY, he observed the airplane on a "close and tight" downwind leg for runway 34 at an altitude of approximately 400 feet above ground level. While on the downwind leg, the airplane was in "slow flight in a nose high attitude." The witness observed the airplane enter a steep left turn from the downwind to base leg, and "at that time, I thought it was going to stall and spin." The airplane's wings rolled level and the airplane began to porpoise. During the porpoise, the witness noted hearing changes to the engine power. The airplane then entered another steep left turn with the wings almost vertical to terrain. "I could see the entire top of the plane during the turn and the engine RPM was increased dramatically, maybe to full power." The witness observed the "nose pitch up and the right wing stall...as if a falling leaf." Subsequently, the airplane entered a spin (1.5 rotations) and impacted terrain. The witness stated that during his observation "the engine was operating under power the entire time."

Personnel information

The pilot, age 70, held a private pilot certificate with airplane single-engine land and instrument ratings. The pilot's most recent third-class medical certificate was issued on October 11, 2006. The pilot's most recent flight review was conducted on March 17, 2007, in the accident airplane.

A review of the pilot's logbook revealed that pilot had accumulated 815.9 total flight hours and 19.7 flight hours in the accident airplane. The pilot had accumulated 6.9 hours and 1.6 hours in the preceding 90 and 30 days, respectively. The pilot's first flight in the accident airplane was conducted on December 15, 2006.

According to a friend of the pilot, the pilot started flying in 1984. In December 2006, the pilot purchased a 1/3 share of the accident airplane. The friend stated the pilot was in good health and was "a very conservative individual."

Aircraft information

The 1996-model Schwarz RV-6A, serial number 22162, was a low-wing, fixed tricycle gear, experimental amateur-built airplane. The airplane was powered by a four-cylinder, direct drive, air cooled, horizontally-opposed, carbureted Lycoming O-320-E2D engine (serial number L-3936-27A), rated at 160 horsepower, and equipped with a two-bladed Sensenich propeller. The airplane was configured to carry two occupants.

The airplane was issued a special airworthiness certificate and was certificated for experimental category operations. The airplane was registered to LPV LLC on January 3, 2000.

According to the aircraft logbooks, the airframe and engine underwent its most recent conditional inspection on August 13, 2006, at a HOBBS time of 980.2 hours. On February 17, 2004, at a HOBBS time of 676.8, the engine underwent a major overhaul. On March 4, 2007, at a HOBBS time of 1,035.0, the engine oil and filter were changed. The total airframe and engine times at the time of the accident could not be determined.

Meteorological information

At 1155, the GXY automated weather observing system (AWOS) reported the wind from 110 degrees at 3 knots, visibility 5 statute miles, sky clear, temperature 32 degrees Celsius, dew point 12 degrees Celsius, and an altimeter setting of 29.95 inches of Mercury. The calculated density altitude was approximately 7,850 feet.

Wreckage and impact information

According to a Federal Aviation Administration (FAA) inspector, who responded to the accident site, the airplane came to rest inverted in grass terrain adjacent to a drainage ditch approximately 1/2 mile from the threshold of runway 34, and was destroyed by post impact fire. The wreckage was recovered to the facilities of Beegles Aircraft Service, Inc., Greeley, Colorado, for further examination.

Medical and pathological information

An autopsy was performed on the pilot by the McKee Medical Center, Greeley, Colorado, on June 26, 2007, and specimens were retained for toxicological analysis by the FAA Civil Aeromedical Institute's (CAMI) Forensic and Accident Research Center, Oklahoma City, Oklahoma.

Toxicological tests were negative for carbon monoxide, cyanide, alcohol and drugs.

Tests and research

On July 5, 2007, at the facilities of Beegles Aircraft Services, Greeley, Colorado, the airframe and engine were examined by the NTSB investigator-in-charge, a FAA inspector, a Lycoming representative, and a friend of the pilot. Examination of the airframe revealed the outboard 4 to 6 feet of the left wing was crushed aft. The left aileron was separated and the left flap remained attached to the wing. The right wing was partially consumed by fire and the aileron and flap remained attached. Flap position at the time of impact could not be determined. The top of the vertical stabilizer and rudder were crushed, and the rudder remained attached. The outboard 1 to 2 feet of the left horizontal stabilizer was crushed aft, and the right horizontal stabilizer was intact. The elevator remained attached to the left and right horizontal stabilizers. The fuselage was consumed by fire and was destroyed. The instrument panel was consumed by fire and was destroyed. Flight control continuity could not be established due to thermal damage.

Examination of the engine revealed the propeller assembly remained attached to the engine crankshaft. The propeller was turned by hand and thumb compression was established on cylinders 1, 2, and 4. Cylinder number 3 was examined, and the intake valve displayed thermal damage and was deformed. Mechanical continuity was established throughout the engine. Borescope examination of the cylinders revealed no anomalies. The fuel pump displayed thermal damage. The magnetos displayed thermal damage and could not be functionally tested. The carburetor inlet screen and oil suction screen were clear of contaminants and debris. Continuity was established to the throttle and mixture controls.

Both propeller blades displayed leading edge gouging, chordwise scratches, and blade polishing. One blade was slightly bent aft and the outboard 6 inches of the other blade was bent aft.

Additional information

Parties to the investigation included the Federal Aviation Administration and Lycoming.

The airplane was released to the owner's representative on July 5, 2007.