History of Flight
On August 24, 2013, about 1630 Pacific daylight time, a Piper PA-28-140 airplane, registration N32582, was substantially damaged when it impacted terrain shortly after takeoff from Mountain Valley Airport (L94) in Tehachapi, California. The pilot and one passenger received minor injuries, and one passenger received serious injuries. The personal flight was conducted under Part 91 of the Federal Aviation Regulations. Visual meteorological conditions prevailed, and no flight plan was filed.
The airplane was based at Fullerton Municipal Airport (FUL) in Fullerton, California, at an elevation of about 100 feet msl. Both passengers were also pilots. The three planned to fly from FUL to L94 for sailplane activities and return in the late afternoon. The outbound flight and the day's soaring were uneventful. The owner/pilot occupied the left seat and served as pilot-in-command (PIC) for both legs.
For the return trip, the PIC conducted a preflight inspection, engine start, taxi to runway 27L, and engine run-up without incident. Due to the high field elevation at L94, he leaned the mixture for takeoff. The takeoff roll and initial climb were uneventful. Following L94 procedures, the PIC turned left onto a southbound crosswind leg to avoid sailplane traffic. As the airplane turned, it appeared to stop climbing and began sinking. The PIC ensured the throttle was full forward and the mixture properly set but could not maintain airspeed or prevent the descent.
The airplane struck terrain nose gear first, about half a mile southwest of the departure end of runway 27L. It hit a chain link fence and came to rest about 170 feet from the initial impact point. The ground scar was oriented on a magnetic heading of approximately 210 degrees. The nose gear separated, the left wing sustained substantial damage, and the cabin remained intact.
Personnel Information
The PIC held a private pilot certificate with an airplane single-engine land rating. He reported about 500 total flight hours, including 250 hours in the accident airplane make and model. His most recent FAA third-class medical certificate was issued in November 2009, and his most recent flight review was in March 2013. He had never operated into or out of L94 before this flight, and had only flown from a high-elevation or high-density-altitude airport once: Big Bear City Airport (L35) in Big Bear, California, elevation about 6,700 feet msl.
The PIC did not use the available shoulder harness for the departure from L94. When asked why, he responded that he did not expect the flight to be involved in an accident.
The right front seat passenger held a flight instructor certificate but was only a passenger during the flights to and from L94. According to a witness, he was the PIC for the sailplane flights that day. He did not use his shoulder harness and sustained facial fractures and had vertebrae fused as a result of the accident.
The rear seat passenger, seated in the right rear seat for both legs, held a private pilot certificate with an airplane single-engine land rating. He reported about 425 total flight hours and about 15 hours flying with the accident PIC. He had no experience operating from high-elevation or high-density-altitude airports. He met the accident PIC through the front seat passenger.
Aircraft Information
The airplane was manufactured in 1974 and equipped with a Lycoming O-320 series engine. Total time in service was about 3,870 hours. The engine was overhauled in January 1996 at tachometer reading 2,600 hours, and the most recent annual inspection was completed in May 2013.
Meteorological Information
At 1635, the automated weather observation at Tehachapi Airport (TSP), about 2 miles northwest of L94, reported wind from 310 degrees at 14 knots, visibility 10 miles, clear skies, temperature 28°C, dew point 4°C, and an altimeter setting of 29.95 inHg. The PIC and rear seat passenger estimated surface wind at L94 as aligned with the runway at about 15 knots. The calculated density altitude at L94 around the accident time was approximately 6,700 feet.
Wreckage and Impact Information
The airplane impacted a flat, slightly inclined area of dry grass and compacted earth. The impact site was about 2,200 feet beyond the departure end of runway 27L and offset about 1,770 feet southwest of the extended centerline. The elevation at the impact site was about 4,380 feet msl, about 160 feet higher than the runway. A ground scar extended about 110 feet on a magnetic heading of 210 degrees before reaching an east-west chain link fence. The fence partially failed and arrested the airplane, which came to rest partly ensnared about 60 feet beyond the fence, upright but pitched about 15 degrees nose down due to the separated nose gear.
On-scene examination of the airplane, engine, and propeller revealed no pre-impact mechanical anomalies that would have prevented continued operation and flight. The airspeed indicator arcs complied with manufacturer's values; accuracy was not verified after the accident.
Additional Information
Before the trip, the PIC performed weight and balance calculations but did not evaluate takeoff or climb performance from FUL. Prior to departure from L94, he obtained weather via smartphone but did not calculate density altitude or conduct takeoff or climb performance evaluations. The PIC explained that he had previously flown the airplane from a higher-elevation airport. He appeared unaware of the concept of density altitude and its effect on aircraft performance.
The investigation reviewed manufacturer takeoff performance data. Based on interviews and evidence, the takeoff configuration (0 degrees flaps, air conditioning off) was per manufacturer guidance. Best angle of climb speed was 78 mph; best rate of climb speed was 89 mph. The investigation did not determine airspeed indicator accuracy or the actual speeds flown.
The airplane was within its weight and balance envelope for the L94 departure, with an estimated gross weight of 2,117 lbs, 34 lbs below maximum. Manufacturer charts, which consider only density altitude and weight, predicted a takeoff ground roll of about 1,500 feet, distance to 50 feet of about 3,300 feet, and a rate of climb at best rate speed of about 310 feet per minute. That rate corresponds to a climb angle of about 2.2 degrees (about 1 foot gain per 25 feet horizontally). Idealized zero-wind calculations assuming no altitude loss during the left turn indicated a net altitude gain of 275 feet, placing the airplane at 115 feet agl at the impact location. These calculations did not account for variations in performance or vertical air motions.
Terrain below the left-hand traffic pattern for runway 27L featured uphill slopes of at least 10 percent, with significantly higher slopes southwest of the pattern. In contrast, terrain straight out from the runway or to the right remained at approximately airport elevation for several miles.
A Go-Pro camera and handheld GPS were recovered but contained no data from the accident flight.
Probable Cause
Not provided in the source.