Accident Overview
On July 14, 2009, at approximately 1010 mountain daylight time, a Cessna U206G, registration N71BS, collided with trees shortly after taking off from a remote airstrip near Yellow Pine, Idaho. The private pilot, acting as pilot-in-command (PIC), sustained minor injuries. The instructor pilot on board received serious injuries. The airplane, owned by the private pilot, sustained substantial damage. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a Flight Review evaluation, in visual meteorological conditions. No flight plan was filed.
Flight Sequence
The flight initially departed Hailey, Idaho, at 0750. Prior to the accident, the PIC and his instructor had landed at three other back-country airstrips. While flying near Yellow Pine, the instructor suggested landing at Simonds Airstrip. Although the PIC had not planned to land there, had never been there before, and had not familiarized himself with the airstrip, he agreed to do so because one of the other airstrips he had landed at that day was of similar length.
The landing at Simonds Airstrip, described by the PIC as "routine," was made on a sloping rough surface. The airplane came to a stop near the uphill end. The two occupants spent about four minutes discussing the landing and the upcoming takeoff and departure. The PIC then turned back onto the runway, adding power during the turn, and headed downhill for takeoff.
Takeoff and Impact
According to the PIC, everything seemed normal until just after the airplane became airborne. At that point, the amount of aft pressure needed on the control yoke to climb increased substantially. No more than two seconds after passing the end of the runway, at about 50 feet above ground level (AGL), the airplane began impacting the tops of dead standing pines, each six to ten inches in diameter. Shortly thereafter, the airplane descended rapidly into the terrain.
Environmental Conditions
During a post-accident phone interview, the pilot reported that the temperature at the time was between 50 and 60 degrees Fahrenheit, and the field elevation was 5,243 feet mean sea level (MSL). These conditions resulted in a density altitude of about 6,300 feet (based on 55 degrees). The pilot stated that he had not performed any performance calculations before landing or takeoff, and had not checked the airplane's Outside Air Temperature (OAT) gauge prior to takeoff. He also mentioned that he had landed at many back-country airstrips in the area over many years, but would not have gone into this one except for the instructor's suggestion.
Engine and Airframe Examination
The PIC reported that from the time he added power for takeoff until the airplane impacted trees, he did not detect any unusual engine behavior, such as missing, coughing, sputtering, or rpm changes.
A post-accident inspection of the engine revealed fuel in the fuel pump, fuel distribution valve, and fuel injector lines. Both magnetos produced spark at all spark leads. No evidence of engine anomalies or malfunctions that would have affected performance was found.
Inspection of the airframe found two issues: the elevator trim was set at five degrees tab up (airplane nose down) position. Additionally, although the cockpit flap position lever was in the 20 degrees extended position, the flap jackscrew extended 4.6 inches, corresponding to a flap position of 25 degrees. According to Cessna Aircraft Company, both conditions may have contributed to the need for more backpressure on the yoke just after liftoff.
Cessna also indicated that the discrepancy between the cockpit flap indicator and the jackscrew was likely due to 30 years of system wear since the airplane was manufactured in 1979, or from adjustments made during installation of a Supplemental Type Certificate (STC) for a Short Takeoff and Landing (STOL) kit.
Pilot Statement
In a report submitted to the NTSB, the PIC stated, "For my airplane, this runway leaves too little margin for the unexpected." He also said that "it would have been helpful if the departure end trees were removed or shortened."