LAX06LA293

The airplane's wreckage was found in mountainous terrain. Investigators found no anomalies to preclude normal operation of the airframe or engine. The owner had recently received a check out in the airplane. However, he was told not to take passengers or fly around in the mountains until receiving training in mountain flying techniques. The toxicology report for the pilot notes the finding of tetrahydrocannabinol (THC - the primary active substance in marijuana) and tetrahydrocannabinol carboxylic acid (THC-COOH - an inactive metabolite of THC) at levels suggesting very recent use, certainly within 3 hours prior to the crash, and possibly much more recently. The pilot's judgment and/or abilities were likely impaired.

History of flight

On September 10, 2006, about 1450 Pacific daylight time, a Champion 7EC, N9575S, collided with terrain near Clipper Mills, California. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot and one passenger were killed; the airplane was destroyed. The local personal flight departed Paradise, California, at an unknown time. Visual meteorological conditions prevailed, and no flight plan had been filed.

Smoke jumpers responding to a forest fire located the wreckage in a burned out area of rough and rocky mountainous terrain. They reported that they only observed metal tubing, an engine, and the two victims. They were unable to locate a serial number or registration number for the airplane.

Medical

The Butte County Sheriff-Coroner completed an autopsy, and listed multiple trauma as the cause of death. The FAA Forensic Toxicology Research Team, Oklahoma City, Oklahoma, performed toxicological testing of specimens of the pilot.

Analysis of the specimens contained no findings for carbon monoxide, cyanide, and volatiles.

The report contained the following findings for tested drugs:

0.0649 (ug/ml, ug/g) TETRAHYDROCANNABINOL (MARIHUANA) detected in Blood

0.0434 (ug/ml, ug/g) TETRAHYDROCANNABINOL (MARIHUANA) detected in Liver

1.2207 (ug/ml, ug/g) TETRAHYDROCANNABINOL (MARIHUANA) detected in Lung

0.1681 (ug/ml, ug/g) TETRAHYDROCANNABINOL CARBOXYLIC ACID (MARIHUANA) detected in Blood

2.5154 (ug/ml, ug/g) TETRAHYDROCANNABINOL CARBOXYLIC ACID (MARIHUANA) detected in Liver

0.313 (ug/ml, ug/g) TETRAHYDROCANNABINOL CARBOXYLIC ACID (MARIHUANA) detected in Lung

NAPROXEN detected in Blood

Tests and research

The National Transportation Safety Board investigator-in-charge (IIC) examined the wreckage. The airplane sustained heavy thermal damage; all of the fabric burned away leaving only the metal frame.

The IIC established control continuity for the elevator and rudder. The right wing sustained more damage than the left. The right aileron was not located. The left aileron remained attached to the metal framework; its operating rod fractured and separated at the rod ends. The rod end bent in the area of the separation point, and the fracture surface was angular with a matte appearance. The left aileron cable separated in a broomstraw appearance. Both elevator balance weights remained attached. The rudder stops were undamaged. Both fuel caps were secure on each wing tank.

Investigators removed the engine, and slung it from a hoist. The engine and accessories were charred. The right side sustained more mechanical damage than the left side. The head for cylinder number one separated and melted. The head for cylinder number three had heavy mechanical damage and partially melted.

The IIC removed the top spark plugs for cylinders number two and four. The spark plugs' interiors were clean with no mechanical deformation, and the gaps were similar. The center electrodes were elliptical and gray, which corresponded to normal operation according to the Champion Aviation Check-A-Plug AV-27 Chart.

The IIC cut a hole in top of the case to examine the internal components. The inside of the engine was dry. The camshaft lobes appeared unremarkable, and the valve lifters were in contact with the camshaft lobes. The lifters did not appear to be distorted.

The accessories sustained thermal damage. The magnetos could not be tested. The oil screen was dry, but uncontaminated.

The propeller spinner was flattened on one side. One propeller blade exhibited twist toward the low pitch, high revolution per minute position. This blade also had the tip missing; the fracture surface was angular to the span and jagged. This blade also had trailing edge buckling, and exhibited some melting. The outer third of the other blade was missing; the fracture surface was jagged and angular to the span. Part of the blade melted.

Additional information

The pilot's partner in the airplane reported that he had endorsed the pilot for flight in a tailwheel-equipped airplane about 2 weeks prior to the accident. He told the pilot not to take passengers for the first 10 to 20 hours of flight time. He also told the pilot not to fly around the mountains; they would do mountain flying training when the partner returned from a fishing trip.

After the partner returned from the fishing trip, he learned of the accident. He determined that the airplane was not in its tie down. He discovered that the pilot fueled it at Rancho Chico Airport on September 10th. An abandoned car that he believed belonged to the passenger was discovered at the Paradise Airport.