History of Flight
On August 13, 2013, about 1130 Pacific daylight time, a Champion 7GCAA (registration N9607S) collided with the ground while maneuvering near Paradise, California. The aircraft was operated by AA Aerial Surveillance (AAAS), LLC under Part 91 as an aerial observation flight. The commercial pilot and a non-pilot Aerial Patrol Observer (APO) were on board. The flight originated from Nut Tree Airport, Vacaville, at about 0850 with a destination of Chico Municipal Airport. Visual meteorological conditions prevailed.
A witness driving on Highway 99 saw the airplane flying near Hamlin Canyon. The airplane was flying northbound when it pitched up, banked right, and nosed down, spiraling to the ground. The witness observed about 1.5 spirals before losing sight.
The flight was a pipeline patrol for Pacific Gas & Electric (PG&E). The pilot was a co-owner of AAAS, and the APO was employed by Frontline Energy Services Inc. (FES). The patrol inspected a gas transmission line along a flat ridge surrounded by canyons. An external video recorder mounted on the aircraft captured the flight.
Aircraft Information
The Champion 7GCAA is a two-seat, high-wing airplane manufactured in 1966, serial number 52. It was powered by a Lycoming O-320-A2B engine (160 hp) with a fixed-pitch propeller. Maintenance was under the manufacturer's approved inspection program; logbooks were not obtained. A Contour+2 video recorder was mounted on the left forward wing strut.
Meteorological Information
Weather observations from Chico Municipal Airport (CIC) at 1059 indicated calm wind, 25 miles visibility, clear sky, temperature 26°C, dew point 9°C, altimeter 29.97 inHg, with smoke in the area. At 1150, wind from 200° at 4 knots, 25 miles visibility, clear sky, temperature 29°C, dew point 10°C, altimeter 29.96 inHg, smoke in all quadrants. Observations from Oroville Municipal Airport (OVE) at 1053 showed variable wind at 4 knots, 10 miles visibility, clear sky, temperature 27°C, dew point 14°C, altimeter 29.97 inHg.
Wreckage and Impact
The wreckage was on an east-facing 30° slope of a canyon. A postimpact fire burned about 21 acres. The debris path was about 50 feet long and 20 feet wide. The first identified point of contact was a rocky outcropping. The main wreckage was inverted and mostly consumed by fire. Flight control continuity was established. The engine and propeller showed thermal damage but no preimpact malfunctions were found. A video recorder was recovered with impact and thermal damage.
Medical and Pathological Information
Autopsies determined the cause of death for both occupants as multiple traumas due to the airplane accident. Toxicological testing of the pilot revealed no findings for volatiles or tested drugs.
Tests and Research
The video recorder's microSD card was intact and the accident flight video was recovered without audio or GPS. The video showed the airplane's upset beginning about 300 feet above a canyon wall. Just prior, the nose pitched up and down, then the airplane rolled right and made three 360-degree rotations before hitting terrain. The propeller speed appeared constant. A video study estimated the airplane's ground speed at about 61 mph (10 mph above the 51 mph stall speed) just before upset. Pitch angle increased by 8 degrees over two seconds. Roll angle increased slowly then rapidly. The cause of the rapid roll increase was not determined from the video.
Probable Cause
No probable cause was stated in the investigation report.