ALPINE, CA, USA
N5027F
Bellanca 8KCAB
The pilots were conducting flight instructor training and practicing power on and power off aerodynamic stalls of the airplane. After performing a spin recovery during an uncoordinated stall, the engine lost power. The pilots were unable to get the engine restarted and forced landed the airplane on a road with a 90-degree turn. The airplane ground looped and struck a fence when the left wheel went into the soft shoulder while exiting the 90-degree turn. The engine had been recently overhauled during which time the airframe was stored. There were two previous occasions where the airplane's engine quit after the engine was reinstalled in the airframe. On the first occasion maintenance personnel increased the idle rpm, and on the second occasion they replaced the fuel servo, which had recently been overhauled with the engine. The engine was run on the airframe after the accident. There was no evidence of mechanical failure or malfunction found with the engine. Particle contamination was found in the fuel in the header tank. The inverted fuel vent was found to be over 50 percent obstructed at an elbow fitting with a solid material that covered the inlet. During the examination, another particle fell out of the elbow. The shape of the particle conformed to the shape of the unobstructed portion of the elbow inlet and the edge of the obstruction.
On March 3, 1997, at 1438 hours Pacific standard time, a Bellanca 8KCAB, N5027F, lost engine power and collided with a fence during a forced landing on the Viejas Indian Reservation near Alpine, California. The airplane sustained substantial damage and the two flight instructors were not injured. The airplane was being operated as an aerobatic instructional flight by Scandanavian Flight Academy, San Diego, California, when the accident occurred. The local flight originated from Montgomery Field, San Diego, about 1345. Visual meteorological conditions prevailed at the time. The pilots were conducting flight instructor training and practicing power on and power off aerodynamic stalls of the airplane. They had completed six stalls without incident. They planned the seventh stall to be an uncoordinated stall (aircraft out of trim). After the stall the right wing dropped, the flight instructor took the controls and performed a normal spin recovery by leveling the wings with the rudder and reducing power. The airplane was at 6,000 feet msl when the instructor added throttle; however, there was no power. The propeller was windmilling and the pilot receiving the training attempted to restart the engine while the flight instructor selected a forced landing area. Both pilot's smelled the odor of fuel in the cockpit and there was no obvious evidence of a leak. The flight instructor turned the fuel selector off and brought the mixture to idle cutoff. The magnetos were still switched on and the engine began to sputter for 5 to 10 seconds. The flight instructor turned the fuel selector back on and began to move the mixture forward. The engine started when the mixture moved 1/2 inch forward, but quit again. The instructor attempted to start the engine again several more times without success. The flight instructor decided to then secure the engine and concentrate on landing because the airplane's altitude above the ground was getting low over mountainous terrain. The instructor selected a hard surface road bounded by a fence on both sides. During the approach, the airplane encountered windy conditions and downdrafts. The instructor decided to land on another portion of the road which had a 90-degree bend. The left main landing gear tire rolled into the soft shoulder while exiting the 90-degree bend during the ground roll. The airplane ground looped into the fence. The engine was test run on March 13, 1997, utilizing the aircraft systems. There was no evidence of mechanical failure or malfunction found with the engine. The airplane's fuel system was examined. Particle contamination was found in the fuel in the header tank when it was drained. The inverted fuel vent was found to be over 50 percent obstructed at an elbow fitting. The obstruction was a solid material that covered the inlet. During the examination, another particle fell out of the elbow. The shape of the particle conformed to the shape of the unobstructed portion of the elbow inlet and the edge of the obstruction. Review of the airplane's maintenance records revealed the airplane's engine was installed on January 20, 1997, after an overhaul. The engine had been removed about 1 month prior, and during that period the fuselage was stored. The operator's records disclosed two instances of unexplained power loss events with the aircraft: On February 18, 1997, while practicing aerodynamic stalls the engine quit, but was easily restarted. The maintenance facility that installed the engine adjusted the engine's idle from 500 to 700 rpm as a corrective measure. On February 19, 1997, the engine quit again while on final approach when the throttle was retarded to the idle position. The maintenance facility again adjusted the idle rpm, this time to 900 rpm. After the adjustment, the engine would not accelerate properly. The maintenance facility then removed the fuel servo and sent it to be overhauled. The fuel servo had been previously overhauled in conjunction with the engine and had accumulated less than 30 flight hours. The airplane was flown .7 of an hour after the fuel servo was replaced. The accident flight was the first after the test flight. The wreckage was released to the representatives of the owner on March 13, 1997.
A loss of engine power due to fuel starvation caused by an obstruction in the fuel vapor return system. An additional causal finding is the failure of maintenance personnel to properly troubleshoot a discrepancy with the fuel system.
Source: NTSB Aviation Accident Database
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