SIAI-Marchetti SF-260 near Belfast, ME — 2008-04-06

Probable cause

The pilot's failure to maintain control of the airplane due to spatial disorientation during an aerobatic maneuver.

NTSB narrative

Just after departure from the airport, the airplane was observed by several witnesses performing a "lazy barrel roll" over a bay. After the first "barrel roll" the airplane was observed starting to perform a climb toward an overcast cloud layer. One eyewitness observed the airplane begin a second maneuver and as it was "still upside down," the nose of the airplane pointed down to the water and disappeared from view. Another eyewitness had turned his back when he assumed the airplane was going into the overcast cloud layer; however, he and several other witnesses heard the "loudest bang" that sounded similar to an engine "back fire." Due to the depths of the water and the size of the debris area, the airplane was not recovered; however, the wreckage was video-taped on the bottom of the bay. Deformation of the wing spars indicated positive high g-loading just prior to impact. The Federal Aviation Administration Advisory Circular 60-4A states in part, "Surface references and the natural horizon may at times become obscured, although visibility may be above visual flight rule minimums. Lack of natural horizon or surface reference is common on overwater flights…" Witness accounts of the accident suggest the pilot became disoriented while performing the aerobatic maneuvers over the water and in proximity to the clouds.

Analysis

Primary failure mode

Spatial disorientation

First missed decision gate

Pilot could have avoided the maneuver that led to disorientation.

NTSB coding

• Loss of visual reference · Maneuvering-aerobatics
• Spatial Disorientation

Evidence available

• Video
• ADS-B / radar
• 11 docket documents

Docket documents11

• Bangor Air Traffic Control Radar Filesatc
• Witness Interview - Kellyinterview
• Witness Interview - Parkinsoninterview
• Witness Interview - Seyrinterview
• Airframe Logbooks (Excerpts)other
• Eddy Current Inspectionother
• Engine Logbooks (Excerpts)other
• Propeller Logbook (Excerpt)other
• Rockland Maine Weatherother
• Toxicological Reportreport
• FBI USERT Dive Videovideo

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