NTSB Factual Report

HISTORY OF FLIGHT

On September 24, 2015, at 1908 central daylight time, a kit-built Mustang II airplane, N929DS, impacted terrain during initial climb at Granbury Regional Airport (GDJ), Granbury, Texas. The pilot and the passenger were fatally injured, and the airplane was destroyed. The airplane was registered to and operated by a private individual, as a 14 Code of Federal Regulations Part 91 personal flight. Day visual meteorological conditions prevailed and a flight plan had not been filed. At the time of the accident the airplane was departing GDJ for a local flight.

Witnesses at the north end of the runway, reported that after the airplane took off to the south, it briefly leveled off and flew down the runway at low altitude. It then entered a steep nose-up climb, followed by a sudden roll to the right, and a steep nose-down descent. Video images from a security camera, about 700 feet away, showed the airplane descended in a 20° to 30° nose-down attitude. The airplane impacted the terrain and a postimpact fire ensued.

PERSONNEL INFORMATION

The pilot was employed as a helicopter pilot for an air ambulance company. He normally operated Bell 206L3 and 407 helicopters. He purchased, N929DS, a completed Mustang II on August 18, 2015. The pilot had accumulated 33.5 hours in the accident airplane. The pilot's last biannual flight review was conducted on June 3, 2014, in a Bell 206L3. The pilot's last biannual flight review in a fixed-wing aircraft was not located during the investigation. It could not be determined when the pilot last practiced stall recoveries.

AIRCRAFT INFORMATION

N929DS, was an amateur built, low wing, single engine airplane. On May 19, 2015, the airplane was inspected in accordance with Federal Aviation Rule 43 Appendix D and found to be in a condition for safe operation. At the time of that inspection, the airplane and engine had accumulated 402.88 hours. Using data obtained from the pilot's log book, at the time of the accident, the airplane had accrued no less than 436.3 hours.

METEOROLOGICAL INFORMATION

AIRPORT INFORMATION

WRECKAGE AND IMPACT INFORMATION

The wreckage came to rest in a grass field near the departure end of runway 14. Impact signatures were consistent with a nose low collision with terrain. The airplane's propeller, spinner, and hub fractured from the engine at the propeller flange and was partially embedded in the ground. The main wreckage was several yards away from the propeller and consisted of the remainder of the airplane. A postimpact fire consumed much of the wreckage. Flight control continuity was established. Examination of the propeller found deep pitting and gouging on the leading edges of both blades. In addition, both blades exhibited deep chord wise scratches. One blade was fractured near its mid-span with grainy, gravelly fracture surfaces. No anomalies were detected with the airframe.

The engine was examined. Engine continuity and compression was verified to each cylinder. The carburetor and magentos were heat damaged and could not be tested. There were no preimpact defects noted with the engine.

Several cockpit electronic devices which had the potential for retaining data via non-volatile memory were sent to the NTSB laboratory for examination and data download. Fire damage precluded the download of data from any of the devices. A GoPro Hero 2 camera found in the wreckage was also sent to the lab for download.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed on the pilot by Tarrant County Medical Examiner as authorized by the Justice of the Peace of Hood County. The cause of death was "multiple blunt force injuries due to [an] aircraft crash with [a] post-crash fire." The manner of death was ruled an accident.

The FAA Civil Aerospace Medical Institute performed forensic toxicology on specimens from the pilot. Testing was negative for all tested substances.

TESTS AND RESEARCH

GoPro Camera

An exterior examination revealed the camera unit had not sustained any damage and image recording information was extracted from the associated SD card. The card contained 26 aviation related video files. Of the 26 video files, 18 were determined to have been recorded in the accident airplane. None of the 18 video files recorded in the accident airplane contained a recording of the accident flight.

Of the 18 video files, eight recordings contained a maneuver similar to the maneuver described by witnesses. In the eight recordings, the aircraft began a takeoff roll, became airborne, and remained at a low altitude as it traveled down the runway. Near the departure end of the runway, the aircraft climbed quickly and subsequently was brought to a level attitude. In most recordings where this maneuver was conducted, the aircraft exhibited a varying degree of right roll, either at the same time the aircraft was brought to a level attitude or within moments thereafter. During the 8 recordings when this maneuver was conducted, the aircraft's airspeed indicator never displayed a value of less than 80 mph. During one recording in which this maneuver was conducted, an electronic tone was heard on the audio track. The electronic tone was consistent with the stall warning tone heard on the aircraft's previous landings. The indicated airspeed at the time of this tone was approximately 105 mph and the aircraft's attitude was about 10° in pitch and 45° in roll to the right. At this time, the pilot was exiting the climb maneuver and leveling the airplane. Though the stall warning horn did briefly sound, there were no other indications the aircraft was approaching a stalled condition.

NTSB Probable Cause

The pilot's exceedance of the airplane's critical angle of attack resulting in an aerodynamic stall and collision with terrain.