History of Flight
On January 2, 2013, about 1605 Pacific standard time, a Luscombe 8A, registration N45923, sustained substantial damage when it impacted terrain approximately 2 miles south of Oceano County Airport (L52) in Oceano, California. The commercial pilot, who was the sole occupant and owner-operator, was fatally injured. The flight was conducted under 14 Code of Federal Regulations Part 91 as a local personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The departure time from L52 was not recorded.
Witnesses reported seeing the airplane flying low above the beach. It suddenly ascended abruptly. When the airplane reached an estimated altitude of 150 to 200 feet above ground, it appeared to stop and then descended abruptly, impacting the sand dunes. Witnesses did not see the initial impact but observed the airplane bounce. They stated that the engine sound was normal throughout the accident sequence.
Personnel Information
The pilot, aged 56, held a commercial pilot certificate with airplane single-engine and multi-engine land privileges, as well as an airframe and powerplant mechanics certificate. His most recent Federal Aviation Administration (FAA) second-class medical certificate was issued on October 1, 2012, with the restriction that he must possess glasses for near and intermediate vision. At the time of that examination, he reported 7,000 total flight hours, with 185 hours in the preceding six months. His personal logbooks were not located.
Aircraft Information
The two-seat, high-wing, fixed-gear airplane, serial number 2450, was manufactured in 1946. It was powered by a Continental Motors A-65-8, 65-horsepower engine and equipped with a fixed-pitch propeller. The airplane's maintenance logbooks were not located.
Meteorological Information
The nearest weather reporting station, San Luis Obispo Regional Airport (SBP), located about 10 miles north of the accident site, reported at 1756: calm wind, 10 statute miles visibility, clear skies, temperature 17°C, dewpoint -6°C, and an altimeter setting of 30.08 inches of mercury.
Wreckage and Impact Information
The wreckage debris path extended approximately 720 feet with a heading of about 19 degrees. The first identified point of impact was a divot on a sand dune ridge consistent with a tire mark. Immediately after, there was an approximately 8-foot by 3-foot section of heavily disrupted sand, with three-foot-wide sliding marks leading to an impact point about 2 feet by 6 inches. Beyond that, about 7 feet of undisturbed sand preceded the main wreckage, located about 120 feet beyond the first point of impact. The final piece of debris, a wheel, was found about 600 feet beyond the main wreckage on the opposite side of a second sand dune.
The main wreckage came to rest in a nose-low attitude. The forward fuselage sustained extensive crush damage, and the cabin area rested on top of the engine. The aft fuselage and empennage remained attached by the belly skin but were folded under the wings, inverted in the sand. The empennage had minimal damage. The left and right horizontal stabilizers had a different paint scheme from the rest of the yellow empennage and airframe. The wings were still attached to the cabin and mostly intact, with leading edge crushing throughout. Evidence of corrosion was observed at the wing spar attachment points and scattered throughout the airframe. Flight control continuity was established from the cockpit controls to the respective flight control surfaces.
Medical and Pathological Information
An autopsy performed by the San Luis Obispo County Sheriff-Coroner Office determined the cause of death as sharp force injury. The autopsy noted the pilot had an enlarged heart. Toxicology testing detected tetrahydrocannabinol in lung (0.0485 ug/ml), liver (0.011 ug/ml), and blood (0.0062 ug/ml). Tetrahydrocannabinol carboxylic acid was detected in urine (0.0965 ug/ml), liver (0.0369 ug/ml), blood (0.0067 ug/ml), and lung (0.0053 ug/ml).
The pilot had a history of cannabis abuse, with a positive Department of Transportation-required random test in 1999. The FAA evaluated his history and determined him eligible for a second-class medical certificate in 2003 and thereafter. Although additional random drug tests were recommended, they were not performed.
Tests and Research
Engine Examination
The engine was removed from the firewall and suspended from a hoist. Initial visual inspection revealed no anomalies. Cylinder rocker covers and spark plugs were removed; spark plug electrode areas were consistent with "worn out - normal" when compared to the Champion AV-27 chart. Valves were undamaged with no abnormal thermal discoloration. When the propeller was rotated by hand, thumb compression was established on all cylinders, all valves moved in sequence with similar lift, and accessory gears rotated. The carburetor was fracture-separated at the throttle plate neck; both pieces were removed from the engine. Sand found inside the carburetor was consistent with the on-scene sand. Both throttle and mixture levers moved freely from stop to stop when manipulated by hand. The carburetor bowl was removed; no fuel was present in the bowl or the undamaged metal float. The oil screen was removed and contained some carbon flakes.