SANTA PAULA, CA, USA
N91DR
RONNEBERG/MURPHY BERKUT
The pilot was doing a demonstration air show routine, one that he had performed in this aircraft for over 2 years. Near the end of the performance, the pilot entered his standard 8g minimum radius knife edge turn about 200 feet agl. The accident sequence was videotaped by a spectator. About 270 degrees into the turn, the aircraft burbled, or rocked the wings slightly. The videotape showed the aircraft increase the angle of attack just before the burble was observed. Following the burble, the left wing dropped and the aircraft rolled left 270 degrees to a near wings level flight attitude. The aircraft then descended in a nose-up pitch attitude behind a tree line and impacted the ground. The aircraft designer stated that the wing plan form is a modified delta similar to the Vari-EZ/Long-EZ designs, which incorporates a forward canard for pitch control. The pilot sits in a high g-tolerant reclined position. During flight test, no main wing stall has been induced due to g-loads imposed on the aircraft. FAA inspectors examined the aircraft twice and found no discrepancies. Air show pilots who performed just before the accident pilot said that the airmass was smooth with no unusual turbulence or other meteorological phenomena noted.
On August 12, 1995, at 1510 Pacific daylight time, a homebuilt experimental Ronneberg/Murphy Berkut airplane, N91DR, collided with the ground following a loss of control during an air show demonstration routine at Santa Paula, California. The aircraft was operated by Experimental Aviation, Inc., of Santa Monica, California. Visual meteorological conditions prevailed. The aircraft was destroyed in the ground collision sequence. The certificated airline transport pilot sustained fatal injuries. The flight originated at the Santa Paula airport on the day of the accident at 1455. In an interview, the aircraft designer/builder stated that the wing plan form is a modified delta similar to the Vari-EZ/Long-EZ designs, which incorporates a forward canard for pitch control. The pilot sits in a high g-tolerant reclined position. During flight test, no main wing stall has been induced due to g-loads imposed on the aircraft. The ultimate design load factors are g-loadings of 14 positive and 7 negative. The witness said the demonstration routine, including the 8g minimum radius turn, performed at the time of the accident is the same one flown by the accident pilot since 1992. Many ground witnesses, including other air show pilots and Federal Aviation Administration (FAA) inspectors, witnessed the accident sequence. All of the witnesses heard engine power sounds throughout the sequence-to-ground impact. In addition to the witnesses, a spectator videotaped the entire performance of the aircraft to include the accident sequence. Review of the videotape disclosed that the sequence as viewed matched the witness observations of the accident. The videotape is included as part of the public docket. An FAA inspector said he observed the aircraft do what the narrator described as a complete 360-degree 6g turn, which was immediately followed by the 8g knife edge minimum radius turn to the left. About 270 degrees into the turn, many witnesses saw the aircraft "burble" or rock the wings slightly. The videotape showed the aircraft increase the angle of attack just before the "burble" was observed. Following the burble, the left wing dropped and the aircraft rolled left 270 degrees to a near wings level flight attitude. The aircraft then descended in a nose-up pitch attitude behind a tree line and impacted the ground. The aircraft designer/builder stated that the 8g minimum radius turn looked normal until the 270-degree point. The aircraft then looked as if the turn tightened and the aircraft rolled left. His impression was that the aircraft did a full 360-degree roll until the time it disappeared behind the trees. On-site examination of the aircraft by FAA inspectors established that all of the aircraft components were accounted for in the wreckage distribution path. The fuselage was extensively fragmented and distributed over a 210-foot-long path. After recovery of the aircraft from the site it was examined again in detail by FAA airworthiness inspectors. The inspectors reported that no discrepancies were found. Air show pilots who performed immediately before the accident pilot's routine were interviewed. The pilots reported that the airmass was smooth with no unusual turbulence or other meteorological phenomena noted. Other air show pilots familiar with the accident pilot reported that before the flight the pilot appeared rested and his normal self. An autopsy was performed by the Ventura County Medical Examiner with specimens retained for toxicological analysis. The toxicological tests were negative for alcohol and all screened drug substances.
the pilot's inadvertent entry into an accelerated stall in a maximum performance high-g turn at an altitude insufficient to recover aircraft control prior to colliding with the ground.
Source: NTSB Aviation Accident Database
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