National Transportation Safety Board today released the probable cause findings of a private airplane crash in March two years ago as carburetor icing.
It happened near a private air strip on the Eglin Air Force Base reservation and killed both persons on board, 59 year old Donald Marco of Niceville and 66 year old Stanley Bloyer of Ft. Walton Beach.
The two men were flying Marco’s small experimental plane from the Ruckle Airport to the Yellow River Airstrip in Holt.
A road building crew building the Mid Bay Bridge connector Road heard the plane crash into nearby woods.
When rescue teams arrived they found the two men dead near the wreckage. They were both well known in the Okaloosa County community and were both highly experienced pilots..
The NTSB probable Cause report issued this morning said, "The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilots’ inadequate use of carburetor heat, which resulted in carburetor icing and a subsequent loss of engine power."
The report is posted below:
"The pilot/owner had been in a previous airplane accident which resulted in traumatic brain injuries. Subsequent to that accident, he acquired an experimental amateur-built airplane, which he would only taxi because of his lack of medical clearance."
" Anticipating a return to medical status, the pilot asked another pilot to serve as pilot in command and fly with him to another airport for the airplane’s condition inspection.There were no witnesses to the engine start, taxi time, or takeoff to the north. An air traffic controller at a nearby air force base was contacted by one of the pilots, who reported that the airplane just departed the airport, as was the custom. The controller then attempted to contact the airplane twice to determine the pilots’ intentions but received no response."
"Radar data indicated a brief, primary (skin paint) return at the time, but no track or altitude could be determined. During the initial climb, a witness saw the airplane when it was about halfway down, and about 300 to 400 feet above the runway, and heard a power reduction. The airplane did not turn to return to the runway, but continued straight ahead over trees, and the witness eventually lost the sound of the engine. A motorist subsequently saw the airplane, gliding south, back toward the departure airport with the propeller stopped, before he lost sight of it behind trees"
"The airplane later impacted trees, wings level, heading eastbound, just north of a new highway."
"Because both pilots were ejected from the airplane, it was not possible to determine which pilot had been in which seat or who was flying. The engine had also separated from the main wreckage, which likely altered the positions of the engine controls, including the carburetor heat. Torsional bending of one of the propeller blades, as well as malleable bending (heating) of the exhaust system indicated that the engine was under some power at impact; an examination of the engine did not reveal any malfunctions or failures that would have precluded normal operation. Dark spark plug electrodes were noted and are consistent with a very rich mixture, either from carburetor icing or carburetor heat, or both. Weather data recorded near the time of the accident indicated an outside air temperature of 82 degrees F and a dew point of 64 degrees."
"Carburetor icing probability charts indicated the likelihood of serious carburetor icing at glide power for the temperature and dew point conditions. Because one of the pilots made a normal departure call, the effects of carburetor ice were probably first noticed subsequent to that call. At some point, the engine lost power and the pilots attempted to turn back toward the airport. They were then likely able to at least regain at least some power, likely by applying carburetor heat, but were too low to recover."
"The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilots’ inadequate use of carburetor heat, which resulted in carburetor icing and a subsequent loss of engine power."