SEA99FA105
SEA99FA105

HISTORY OF FLIGHT

On July 7, 1999, at 1455 Pacific daylight time, an experimental Gadbury RV-6A, N5987D, impacted the terrain during takeoff from Arlington Municipal Airport, Arlington, Washington. The private pilot received fatal injuries, and the aircraft, which was owned and operated by the pilot, was destroyed by a post-impact fire. The 14CFR Part 91 personal pleasure flight to an undetermined destination was being conducted in visual meteorological conditions. No flight plan had been filed, and there was no report of an ELT activation.

On the day of the accident, at a time that was not able to be determined, the pilot landed his RV-6A at Arlington Airport, during the Experimental Aircraft Association Fly-In. After landing, he taxied to the west side of the field where the fly-in activities were taking place. Then, according to witnesses, after parking his aircraft, the pilot walked over to the aircraft and product display area. How long he spent walking around the area could not be established, but his time in the area was later verified by the collection of aviation and fly-in related advertisements and informational handouts found in his aircraft after the accident. He returned to his aircraft about 1445, about 15 minutes prior to the time the field was scheduled to be closed for the airshow. Then, according to witnesses, the pilot laid a plastic bag containing the information he had gathered in the display area on the aircraft's right seat, and quickly prepared his aircraft for departure. While getting the aircraft ready to go, the pilot talked with a witness who also owned a RV-6 series aircraft. This witness reported that, although the pilot was in a hurry to leave before the field was closed, he appeared otherwise normal. The witness also said that he did not see anything about the aircraft that seemed unusual or that might be a potential problem.

After starting the aircraft's engine, the pilot began to taxi, and told the temporary tower that he wanted to takeoff to the north (runway 34). The tower advised him that because of other traffic, he would need to take off on runway 16 (to the south). According to the controller, the pilot seemed confused about what taxi route to take to get to runway 16, and he eventually ended up where runway 34 and 29 nearly meet at the south end of the airfield. When the pilot arrived at the aforementioned position, the controller decided that since he was the last aircraft waiting to depart, he would clear him to back-taxi north on runway 34 until he was adjacent to taxiway Bravo 2. After taxiing north on runway 34 to the taxiway Bravo 2 intersection, the pilot performed a 180 degree turn on the runway and started his takeoff roll. Some witnesses reported that the pilot appeared to apply full power very rapidly, and that the engine "coughed" as the power was initially applied, but then seemed to produce smooth, full power. The aircraft performed what was described as a very short takeoff roll, and then lifted abruptly into the air. Immediately after leaving the ground, the aircraft entered into a "very steep" climb at "an extreme angle of attack." The aircraft continued to climb very steeply until it reached a height that was estimated as between 75 and 100 feet above the ground. At that point, its airspeed slowed significantly, and it slowly began to roll to the left. The nose of the aircraft then pitched down, and it descended into a parallel taxiway near the east side of the runway. Numerous witnesses reported that it sounded like the aircraft's engine was operating at full power from the time the pilot started the takeoff roll until the aircraft hit the ground. After it hit the surface, the aircraft slid across the taxiway and came to rest on a grassy area just off the east side of the taxiway surface. Almost immediately after sliding off the taxiway, the aircraft burst into flames. As the fire grew, some of the witnesses tried to pull the pilot out of the aircraft, while at the same time other bystanders attempted to put the fire out with dry chemical fire extinguishers. The limited capacity of the portable fire extinguishers proved insufficient to put out the fire, and because the pilot's leg was jammed in the wreckage, witnesses were unable to pull him free before the heat of the fire became to intense to continue attempts to rescue him. Within a minute after the aircraft impacted the ground, the volunteer fire truck arrived at the scene. After pulling out the necessary hose and completing the hook-up of their respirator system, which they began while en route, the firefighters applied water on the flaming wreckage. Within a minute to a minute and a half after their arrival, the fire was extinguished.

PERSONNEL INFORMATION

According to FAA records, the pilot earned his private pilot license on October 21, 1998, approximately nine months prior to the accident. A review of his log book revealed that he had accumulated a pilot-in-command total time of 137.5 hours. In addition, the review disclosed that he purchased the experimental aircraft less than two weeks prior to the accident, and had about 7.5 hours of flight time in it, with about 4 of those hours being "solo" (without the previous owner onboard).

WRECKAGE AND IMPACT INFOMATION

The aircraft impacted taxiway Alpha about half way between intersections Alpha 1 and Alpha 2, and about 100 feet west of Hangar Alpha 1. The initial impact point, which consisted of surface scrapes on the asphalt, was about 10 feet east of the west edge of the taxiway. About 15 feet beyond the initial impact point, there were deep scrapes and gouges in the asphalt surface, as well as a large area stained by oil. After the initial impact, the aircraft slid across the taxiway on a magnetic track of 020 degrees. The aforementioned scrape marks continued down-track to a point where the aircraft slide off the taxiway surface and onto a grassy area adjacent to the east side of the taxiway. The left wing tip was located about 10 feet south of the track centerline approximately half way between the point of initial impact and spot where the aircraft slide onto the grass. The aircraft came to rest with its nose on a magnetic heading of 240 degrees. There were numerous small chunks of the propeller along the accident track, and there was also a large concentration of wood propeller splinters in a 60 foot wide area just off the west side of the taxiway.

Except for the left wing tip and the shattered propeller, the remainder of the aircraft came to rest intact. The left wing showed direct rearward crushing of the leading edge along almost its entire span, with the most outboard four feet crushed back at about a 30 degree angle, with the damage reaching the rear spar near the tip. The right wing, cabin area, instrument panel, and engine compartment were extensively damaged or consumed by the post-impact fire. The fuselage aft of the cabin area, as well as the empennage, did not receive direct impact damage. All three landing gear were still in place and were holding the aircraft in normal upright position. The aileron and flap were still attached to the left wing, although the flap was hanging straight down due to impact damage to the flap actuating system. Control continuity was established from the rudder pedals to the rudder, from the control stick to the elevator, and from the control stick to the left aileron. Control continuity to the right aileron could not be established due to the fact that the right aileron control torque tube was melted away where it exited the right side of the fuselage. Elevator trim control system continuity was established, and the trailing edge of the trim tab was found to be one-half inch up from the trailing edge of the elevator. No evidence was found of any pre-impact separation or malfunction of any of the flight control components.

As part of the investigation, the engine and its accessories were inspected for evidence of any malfunction or anomaly. During this inspection it was noted that the hubs of both propeller blades remained attached to the crankshaft flange, and all of the accessories except the left magneto remained attached to the engine. The magnetos were destroyed by the fire, but the spark plugs displayed coloration consistent with normal combustion. The number-one cylinder was removed to provide a view of the internal components, and it was noted that oil was present internally and there was no evidence of overheat or lack of lubrication. Although the crankshaft could not be turned by hand because of a fracture of the crankcase in the area of the number-two cylinder, an inspection of the rocker and valve assemblies showed no evidence of malfunction or lack of lubrication. All intake tubes and exhaust pipes were still attached to the cylinders, but the carburetor was destroyed by the impact. At the completion of the teardown inspection, no evidence of any problem had been found that would preclude normal operation.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed by the Snohomish County Medical Examiner's office, and the manner of death was classified as accidental. The cause was attributed to thermal injuries to the total body surface and the inhalation of the products of combustion.

A forensic toxicology examination was performed by the Federal Aviation Administration's Toxicology and Accident Research Laboratory, with no ethanol or drugs being found in the urine, and no carbon monoxide detected in the blood. The examination detected 0.78 ug/ml of cyanide in the blood, which is consistent with the inhalation of combustion products produced when the cabin upholstery was consumed by the fire.

ADDITIONAL DATA AND INFORMATION

Two witnesses, both of whom were familiar with RV-6 series aircraft, said that they remember that when they were looking at the accident aircraft in the parking area, the right seatbelt had been looped around the front of the right control stick, and the stick seemed to be pulled nearly to the full-back position (a common parking practice among many pilots). One of the witnesses said that he had observed the seatbelt in this position as the pilot hurriedly prepared the aircraft for departure just prior to the airshow. One of the witnesses was not near the aircraft when it started up for departure, but the other was. This witness said that although he watched the pilot start the aircraft and taxi for departure, he was not in a position where he could see whether the pilot had removed the belt from around the control stick. He further commented that, although he could not see the position of the belt itself, he does not remember noting that the elevator was in the up position as the aircraft was taxied toward the runway. Other witnesses also remembered seeing the aircraft taxi to the runway, and none of them reported specifically noting that the elevator was significantly deflected toward the up position.

During the investigation, the right control stick was inspected to determine if any evidence could be found that would indicate the pilot had left the right seat belt looped around the stick. Although there were other places in the cockpit where portions of burned or melted seatbelt material was found, no such indications were seen on the right control stick. In addition, there were no gouges, scrapes, scarring or any other indication consistent with seatbelt buckle interference/contact on the front of the stick.

The aircraft was released to Tracy Barrus, a representative of the family, at Arlington Airport on July 29, 1999.

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