NTSB Factual Report

HISTORY OF FLIGHT

On May 29, 2004, at 1440 central daylight time, an Aviat A-1 single-engine tailwheel equipped airplane, N623KD, was substantially damaged when it impacted terrain following a loss of control during takeoff from a private airstrip near Harwood, Texas. The airplane was registered to and operated by the pilot. The private pilot and the passenger sustained fatal injuries. Visual meteorological conditions prevailed and no flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight. The local flight was originating at the time of the accident.

The owner of the private airstrip, known locally as "Coover Flying Field," reported that he was hosting an annual Memorial Day Weekend fly-in for remote control airplane enthusiasts. One of the participants flew his airplane to the airstrip on the morning of the accident, and during the day, offered to take people for a ride in his airplane. The accident occurred on his third passenger ride of the day.

Several people witnessed the accident and provided the Safety Board with written and verbal statements.

During a telephone interview, conducted by the NTSB investigator-in-charge (IIC), a witness reported that he had observed the pilot make three take-offs. He reported that on the first take-off, the pilot made a "sharp climb" that was "steeper than normal." The witness videotaped the pilot's second take-off. He said the airplane departed "quickly" from the ground with full flaps and full power, but the climb-out was "slower" than and not as steep as the previous take-off. The witness videotaped the entire third flight. He said that he had reviewed the videotape several times, and reported the following:

The airplane departed to the south and climbed vertically at an approximate 85 degree angle, with the rudder deflected to the right. When it reached the apex of the climb, approximately 200-250 feet above ground level (agl), it began to "fly backwards like a kite" (the witness was not sure if this was due to the strong winds that were blowing at the time), and the engine was "throttled back." The airplane then made a descending left hand turn, and descended in an approximate 45-50 degree nose down attitude. While in the descent, the elevator was deflected to the full up position. The witness then observed the left wing "drop" and the upward deflection on the elevator decreased. At this point, and while still in the descent, the right aileron was deflected to the full up position, and the airplane's wings leveled out, while the engine "throttled back up to full power." The right aileron stayed deflected, and the airplane turned to the right and contacted the ground with the right wing tip first. As the airplane contacted the ground, the fuselage twisted and came to rest in the opposite direction of where it initially contacted the ground.

In addition, the witness also observed the airplane as it flew around the airfield on its previous flights. At one point, he said the airplane flew over the eastern portion of the airfield at a very low altitude.

A review of the video tape by the NTSB IIC confirmed the witnesses' statement.

A second witness reported that he was standing about 500 feet away from the airplane when he observed it make a near vertical climb after take-off. When the airplane reached an altitude of 250-300 feet agl, engine power was reduced, and the airplane did a "hammerhead stall" to the left. As the airplane descended, he saw the pilot try to pull out of the dive about 50 feet above the ground, but the right wing dropped and collided with the ground, and followed by the nose of the airplane. The witness stated that the pilot "almost always" performed this type of take-off, and he had observed the pilot perform this maneuver "recently and frequently."

A third witness reported that the airplane departed with full flaps and "went into a straight vertical climb" with an approximate 30 mile per hour (mph) head wind. As the airplane reached a 90 degrees nose-up attitude, it was "pushed backwards" as the airplane performed a "hammerhead turn." As the airplane started to descend, the witness observed the "engine running" as the pilot "tried to pull out of the descent."

A fourth witness reported that the airplane "took off and went almost vertical." At an approximate altitude of 200 feet agl, the airplane "stalled" and attempted to turn left as it impacted terrain.

A fifth witness reported that as the airplane lifted off the runway, "it went almost vertical. At the top of the vertical climb, it turned to the left." The engine "sounded like it throttled back as the airplane started to descend."

A sixth witness reported that the airplane "pulled up to a vertical line of approximately 85 degrees" after takeoff. At an altitude of approximately 300 feet agl, the airplane "turned to the left in a stall turn." As the airplane established the "downline," the wind pushed [the airplane] downwind as [the airplane] went into a stall." The witness stated "there was not enough altitude to recover."

PERSONNEL INFORMATION

The pilot held a private pilot certificate with ratings for airplane single engine land, and instrument airplane. His most recent Federal Aviation Administration (FAA) third class medical certificate was issued on September, 18, 2002.

A review of the private pilot's logbook revealed that he accumulated approximately 410.2 flight hours, of which 282.9 hours was in the accident make/model airplane. In the preceding 90 days, the pilot had logged 37.1 hours of flight time, and in the preceding 30 days, he had logged 13.8 hours of flight time.

AIRCRAFT INFORMATION

The 1994-model Aviat A-1, serial number 1274, was a high wing, fabric covered tubular structure airplane, with a fixed landing gear, configured to carry a maximum of two occupants in a tandem seating configuration. The airplane was powered by a normally aspirated, direct drive, air-cooled, horizontally opposed, carbureted, four-cylinder Lycoming O-360-A1P engine (serial number L-34257-36A), rated at 180 horsepower at sea level.

Review of the airframe and engine logbooks, revealed the airplane's most recent 100-hour/annual inspection was on April 11, 2004, with a total time of 428 hours. At the time of the accident, the airframe and engine had accumulated a total of 23.1 hours since the last inspection.

METEOROLOGICAL INFORMATION

Weather at San Marcos Municipal Airport (HYI), near San Marcos, Texas, approximately 26 nautical miles northwest of the accident site, at 1435, was reported as wind from 170 degrees at 22 knots, gusting to 25 knots, visibility 10 statute miles, sky clear, temperature 89 degrees Fahrenheit, dew point 71 degrees Fahrenheit, and an altimeter setting of 29.73 inches of Mercury.

The density altitude was calculated by the NTSB IIC to be 2,754 feet.

AERODROME INFORMATION

The private airstrip featured a 1,700-foot long by 100-foot wide unlit grass runway oriented on a north/south heading. The grass runway was cut to approximately 2-3 inches in height.

WRECKAGE AND IMPACT INFORMATION

The airplane came to rest in a field approximately 500 feet from the north end of the runway, and 300 feet east of the runway approximately 29 degrees 41 minutes north latitude and 097 degrees 29 minutes west longitude, at a field elevation of approximately 447 feet mean sea level (msl). The airplane impacted terrain on a magnetic heading of 085 degrees, and came to rest on its left side on a heading of 210 degrees. The wreckage debris distribution area remained within an 75-foot radius to the main wreckage.

The initial impact mark was about 34 feet from where the airplane came to rest. The initial impact mark included two horizontal impact marks (consistent with the leading edge of the wings) that expanded to the left and right of a 3- foot by 2- foot- wide crater. A piece of green navigational lens was found embedded at the far most end of the right impact mark, and a piece of red navigational lens was found at the far most end of the left impact mark.

Examination of the wreckage revealed that the left wing was separated from the fuselage at the wing attach points. The leading edge of the left wing was crushed aft throughout the entire length of the wing. The leading edge of the wing was twisted downwards and the trailing edge of the wing was twisted upwards outboard of the wing lift strut attach point. The wingtip structure was also damaged. Flight control continuity was established from the aileron through the bell crank, to the wing strut, and throughout the leading edge to the wing attach point. Fuel was observed in the fuel tank, and the fuel cap was found secure.

The right wing was removed by fly-in attendees in an attempt to assist the pilot and passenger. The leading edge of the right wing was crushed aft throughout the enter length of the wing. The leading edge outboard of the wing lift strut to the wing tip was crushed aft at an angle of approximately 45 degrees to the wingtip. The wingtip structure was also damaged. Flight control continuity was established from the aileron through the bell crank, to the wing strut, and throughout the leading edge to the wing attach point. Fuel was observed in the fuel tank, and the fuel cap was found secure.

The empennage was found with minor cosmetic damage. Flight control continuity was established from the front and rear seat flight control column to the elevators. Control continuity was also established to the rudder from the forward and rear rudder pedals.

The roof of the cockpit was also removed by fly-inn attendees. The right main landing gear was pushed aft, and the left main landing gear was deformed. The fuselage, forward of the main landing gear, was bent upwards at an approximate 20 degree angle. The cockpit area sustained impact damage, including the instrument panel. Both seats remained attached to their respective mounts. The wooden floor forward of the rear seat was crushed upwards. The floor board, forward of the front seat, was also crushed upward. The throttle, mixture, and propeller controls were found in the full forward position. The carburetor heat was observed in the "off" position and the engine primer was found "in and locked." The fuel selector handle was in the "on" position.

The engine remained attached to the fuselage, but was pushed into the firewall. The propeller remained attached to the propeller flange, but the crankshaft was partially sheered on the aft side of the flange.

During the on-scene examination of the engine, the propeller was cut away from the engine aft of the crankshaft propeller flange. The engine was rotated from the vacuum pump accessory drive, and valve training continuity and compression were established on each cylinder. During the compression check, spark was observed on all ignition leads. The engine oil sump screen was absent of debris. The spark plugs were removed. When compared to the Champion Aviation Check-A-Plug Wear Guide (Part Number AV-27), the cylinder #1, 2, 3, 4 top and #2 bottom spark plugs displayed signatures consistent to normal operation. The #3 and 4 bottom cylinder spark plugs were found saturated with oil. The bottom #1 cylinder spark plug was bent and contained a grit like substance that was consistent with dirt observed in the electrode area.

The carburetor had separated from the engine during impact. No fuel was observed in the carburetor float bowl; however, the carburetor was breeched. No fuel was expelled when the throttle arm was actuated. The fuel screen was absent of debris.

The two-bladed variable pitch propeller assembly remained attached to the crankshaft flange. One blade was bent aft approximately 35 degrees, 7 inches inboard from the blade tip. Leading edge gouging and polishing was observed at the tip of the blade. The other blade displayed aft bending 7 inches outboard of the hub, at an angle of approximately 20 degrees. The blade was twisted about 10 degrees toward low pitch. The tip of the blade was bent forward approximately 10 degrees. Leading edge polishing was observed throughout the length of the blade.

FIRE

There was no post-impact.

MEDICAL AND PATHOLOGICAL INFORMATION

The Office of the Medical Examiner, Travis County, of Austin, Texas, performed an autopsy on the pilot on May 30, 2004. Specimens for toxicological tests were taken from the pilot by the medical examiner. According to the autopsy, the cause of death was multiple traumatic injuries.

The FAA's Civil Aeromedical Institute's (CAMI) Forensic and Accident Research Center examined the specimens taken by the medical examiner. The toxicological tests were negative for carbon monoxide, cyanide and alcohol.

SURVIVAL ASPECTS

A five-point seat restraint system was observed in the airplane for both the front and rear seats. It was reported by the emergency personnel that the pilot and passenger were using their respective restraint systems.

TESTS AND RESEARCH

The airplane manufacturer calculated the weight and balance of the airplane at the time of departure using the reported weights of the occupants and the estimated fuel weights. The weight and balance was found to be within limits at the time of departure.

ADDITIONAL INFORMATION

The wreckage was released to the owner's representative on May 31, 2004.

NTSB Probable Cause

The pilot's failure to maintain airspeed sufficient for flight resulting in an inadvertent stall/spin during takeoff.