NTSB Identification: ERA11FA074
14 CFR Part 91: General Aviation
Accident occurred Monday, November 29, 2010 in Theodore, AL
Probable Cause Approval Date: 08/22/2011
Aircraft: BEECH A36, registration: N1860P
Injuries: 1 Fatal.
NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.
The pilot was conducting a night currency flight during marginal visual meteorological flight conditions. He did not file a flight plan or obtain a weather briefing prior to departure. About 4 minutes after departing, the pilot contacted air traffic control and stated the weather was worse than he anticipated. He requested an instrument clearance and approach back to his departure airport. The airplane was radar identified, the pilot was instructed to climb to 2,000 feet and then proceed direct to an intermediate fix. The pilot acknowledged the clearance and there was no further communication between him and the controller. A review of radar data revealed the airplane was first observed at 700 feet mean sea level, in a climbing right turn. It continued to climb while turning to the left and right, to 1,100 feet. The airplane was last observed by radar at 700 feet in a descending right turn.
A witness stated he observed the airplane flying below a cloud layer estimated between 500 to 1,000 feet agl, with the strobe lights on. He described the area as very dark with no ambient light. Another witness stated he observed the airplane in straight and level flight, flying in and out of the clouds.
The pilot's last recorded night flight was 14 months prior to the accident, and no flights had been conducted in the accident airplane. The pilot obtained an instrument rating 2 months before the accident and he had flown 4.5 hours of actual instrument flight time; of which, 1 hour was in another model airplane. The pilot had logged 15 minutes of instrument flight time in the accident airplane.
At the time of the accident, the moon's phase was "waxing crescent" with 18 percent of the disk illuminated. If neither horizon nor surface references exist, the attitude of an airplane must be determined by artificial means from the flight instruments. However, during periods of low visibility, the supporting senses sometimes conflict with what is seen, and when this happens, a pilot is particularly vulnerable to spatial disorientation. Federal Aviation Administration guidance indicates that spatial disorientation can occur when there is no natural horizon or surface reference, such as a night flight in sparsely populated areas similar to that of the accident area and conditions. Based on the wreckage and the visual reference conditions present at the time of the accident it is likely that the pilot experienced spatial disorientation.
Examination of the airframe, flight controls, engine assembly and accessories revealed no pre-impact mechanical anomalies.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilot's failure to maintain aircraft control while maneuvering at night in deteriorating weather conditions due to spatial disorientation. Contributing to the accident was the pilot's failure to obtain a weather briefing. Full narrative available
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