ERA16FA161

The pilot's decision to takeoff on the grass runway given the conditions at the time; his excessive aft control input during the takeoff roll, which resulted in the aft fuselage contacting the runway surface; and his failure to attain sufficient airspeed and exceedance of the airplane's critical angle of attack, which resulted in an aerodynamic stall.

The private pilot was taking off for a personal flight from a private turf airstrip to return to his home base airport. He initiated takeoff with a 10° flap extension and about 1,130 ft of the 1,344 ft of usable runway remaining, despite a recommendation from the airstrip owner that he begin the takeoff from a point that would have provided an additional 200 feet of runway. After beginning the takeoff, and as the airplane approached the departure end of the runway, the aft fuselage bottom contacted the runway several times due to the pilot's control input, which likely slowed the airplane. Shortly after becoming airborne while in a nose-high attitude, the airplane entered an aerodynamic stall before colliding with a tree and then the ground. After coming to rest, all occupants were conscious and alert, but the rear seat occupant required assistance exiting the airplane. The pilot attempted to assist him from the wreckage, but an explosion occurred about that time. The pilot and rear seat occupant sustained burns and died 6 days and 1 day after the accident, respectively, due to their injuries from the fire. Examination of the flight controls, engine, and engine accessories revealed no evidence of preimpact failure or malfunction that would have precluded normal operation. Extensive heat damage to the engine and engine accessories precluded an operational test of the engine. A sound spectrum analysis of a video recording of the takeoff provided by the airstrip owner revealed that the reduced engine rpm near rotation was attributed to the slow airspeed and not a loss of engine power. The airplane was within weight and center of gravity limits. Takeoff performance data for the airplane indicated that, given the weather at the time of the accident, the distance required for the airplane to take off was about 786 ft and to clear a 50-ft obstacle was about 1,370 ft with no flaps on a hard surface runway. The chart did not contain figures for a soft, grass runway, which would increase the takeoff distance. Flaps at 10° would decrease the ground run by about 10% but would the advantage was lost to climb over a 50-ft obstacle. A speed study using the video showed that the average groundspeed between becoming airborne and the time of impact was about 47 knots, or 54 mph, which was the stall speed at gross weight and 0° bank angle. Even if the pilot had used the full usable runway distance, his decision to takeoff on this runway was poor given the performance capabilities of the airplane and the fact that the grass runway would likely have increased the takeoff and climb distance beyond that available. Further, it is likely that the pilot, when he noted that the airplane was nearing the end of the runway, increased the airplane's pitch, which resulted in the tail dragging, and lifted off the airplane with inadequate airspeed and exceeded the airplane's critical angle of attack, which resulted in an aerodynamic stall.

According to the front seat passenger, after the airplane came to rest, all occupants were alert and conscious. She was unable to open the right door and attributed this to either the impact or operational issues. The private, decommissioned airstrip had a grass runway oriented 8/26 and was about 1,980 ft long. A "break" near the west side of the runway allowed for a usable runway distance of 1,344 ft when departing from runway 8. The runway was down-sloping from the "break" to the departure end of runway 8. A functioning windsock was located north of the runway and about 263 ft from its departure end. Examination of the airstrip revealed marks/impressions in the grass from three tires, which were consistent with that from a tricycle-gear-equipped airplane taxiing on the runway for an east departure. From that point, about 1,130 ft of runway remained, all of which was down-sloping. (The airstrip owner indicated that the elevation at the point where the pilot initiated the takeoff was about 633 ft, whereas the elevation at the departure end of the runway was about 603 ft.) The marks from the three tires continued for about 362 ft from the start of the takeoff roll, at which point the nose tire mark disappeared. The marks from the main landing gear tires continued to about abeam the windsock, and at that point, a narrow 30-ft-long mark consistent with contact by the tail tiedown loop was noted. Further examination of the runway revealed that the grass was about 2 inches high. In general, the portion of runway 08 from its start to the "break" was noted to be slightly soft, whereas the remainder of the runway was noted to be harder. Weight and Balance Weight calculations were performed using the empty weight listed from a weight and balance form dated October 23, 2008 (1,516.83 lbs), the weight of oil (15.0 lbs), the pilot's weight per his last medical application (168 lbs), the weight of the right front seat passenger (138 lbs), the estimated weight of the rear seat occupant (162 lbs), and the estimated fuel load (161 lbs). The airplane weight at engine start was estimated to be about 2,161 lbs, or about 89 lbs less than the maximum certificated gross weight of 2,250 lbs. Center-of-gravity calculations indicated that the loaded aircraft moment was 87.85 lb-inches, which was within the normal category envelope of 2,161 lbs. Takeoff Performance According to the takeoff data chart contained in the owner's manual, which was for a hard-surfaced runway with flaps retracted, based on the airport elevation (average 618 ft), the temperature about the time of the accident (68°F), the estimated airplane weight at the time of the accident (2,161 lbs), and no headwind, the ground run was calculated to be about 786 ft, and the distance to clear a 50-ft obstacle was calculated to be about 1,370 ft. The chart did not contain figures for a grass surface nor any tailwind or sloped runway components. The owner's manual also indicated that 10° of flap extension shortened the ground run about 10%, but the advantage was lost to climb over a 50-ft obstacle. The owner's manual also contained a chart for stall speeds, which was predicated on the airplane being operated at gross weight and power off, and true airspeeds were provided in mph. Based on a flap position of 10°, the stall speeds at 0°, 20°, and 40° of bank were 54, 56, and 62 mph, respectively. Sound Spectrum Study According to a sound spectrum study of the provided takeoff video, the engine was operating about 2,340 rpm, or 360 rpm below the full red line rpm of 2,700 at the time the airplane passed the camera (near the departure end of the runway) during takeoff. The study also indicated that, because the airplane's speed was unknown, it was not possible to accurately determine the engine rpm throughout the takeoff roll. Speed Study According to a speed study of the provided takeoff video, the impact occurred 9.25 seconds after the airplane passed the windsock. The average groundspeed from the point where the airplane passed the windsock just before becoming airborne to the accident site was about 47 knots (54 mph). According to a representative of the propeller manufacturer, based on the temperature at the time of the accident and the airstrip elevation, the required theoretical true airspeed that would have allowed the propeller to achieve 2,700 rpm (full red line rpm) would have been 84 knots. The representative also indicated that, based on the temperature, elevation, and the average groundspeed calculated by the NTSB, the engine rpm was 2,402, the power absorbed (hp) was about 124, and the lbs of thrust was about 462. The 1853 recorded weather at RME, located 7 nautical miles north-northeast from the accident site, included wind from 300° at 10 knots, visibility 10 statute miles, clear skies, temperature 20°C (or 68°F), dew point -01°C, and an altimeter setting of 30.13 inches of mercury. A review of an FAA Special Airworthiness Information Bulletin pertaining to carburetor ice revealed that the atmospheric conditions at the time of the accident were not favorable for the formation of carburetor ice. According to the airstrip owner, the wind at the time of the accident was nearly calm, or no more than 1 to 2 knots from the west. The pilot died 6 days after the accident while hospitalized, and an autopsy was not performed. According to the death certificate, the cause of death was listed as "complications of smoke inhalation and thermal injuries." The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, conducted toxicological testing on the pilot's serum samples. The FAA toxicology report stated that it did not perform testing for carbon monoxide and cyanide and that no volatiles were detected in the serum samples. Unquantified amounts of ketamine and midazolam and 0.13 ug/ml norketamine were detected in the serum samples. These medications are only available in IV form and are generally used during resuscitation efforts. The rear seat occupant died the day after the accident while hospitalized, and an autopsy was not performed. According to the external examination report, the cause of death was listed as "complications of thermal and inhalational injuries due to airplane crash." According to Federal Aviation Administration (FAA) records, the pilot held a private pilot certificate with an airplane single-engine land rating. His most recent FAA first-class medical certificate was issued on August 31, 2015, with no limitations. Including a 2.3-hour flight earlier that day, but excluding subsequent flights later that day, the pilot logged a total time of about 458 hours, 382 hours of which were in the accident airplane make and model and 298 hours of which were as pilot-in-command. According to FAA records, the pilot-rated passenger in the right front seat held a private pilot certificate with an airplane single-engine land rating. She estimated her total flight time was between 100 and 300 hours. The four-seat, high-wing airplane was manufactured in 1962. It was powered by a 145-horsepower Continental O-300-D engine and equipped with a two-blade McCauley 1C172/EM7653 fixed-pitch propeller. A review of the airplane's Type Certificate Data Sheet revealed that the maximum red line engine rpm was 2,700. The maintenance records were reportedly in the airplane at the time of the accident. A review of documents provided by the facility that performed the airplane's last annual inspection revealed it was signed off as being completed on April 5, 2016, at an airframe total time of 3,302.55 hours. Based on pilot logbook entries, including the logged 2.3-hour flight earlier on the accident date but excluding the subsequent unlogged flights later that day, the airplane had been operated 6.2 hours since the annual inspection was completed. The airplane crashed in the yard of a residence; the main wreckage was located about 089° a