Aviation Accident Summaries

Aviation Accident Summary WPR15LA104

Hayward, CA, USA

Aircraft #1

N706BD

SCOTTISH AVIATION BULLDOG - 120 121

Analysis

The pilot reported that, during initial climb and as the airplane reached about 200 to 300 ft above ground level, the engine lost total power. The pilot attempted to restart the engine without success. He subsequently conducted a forced landing, and the right wing impacted a tree, which resulted in substantial damage to the wing. A postaccident examination of the airframe and engine revealed no mechanical failures. After the airplane was placed on a level surface, about 0.75 gallon of water was drained from the fuel system between the airframe fuel filter to the engine fuel flow divider and the fuel flow divider pressure line. The pilot reported that the last time he had fueled the airplane was about 4 months before the accident. He added that he had not experienced fuel contamination previously with the airplane and that he had sumped the fuel system before takeoff. The pilot added that the airplane did sit with one wing lower than the other and that the airplane's nose up-and-level orientation during taxi may have shifted the water in the fuel system. The loss of engine power during the initial climb was likely due to fuel contamination.

Factual Information

On February 15, 2015, about 1245 Pacific standard time, a Scottish Aviation Bulldog MDL 120/121 experimental airplane, N706BD, sustained substantial damage as a result of a forced landing and impact with terrain due to a total loss of engine power near the Hayward Executive Airport (HWD), Hayward, California. The private pilot, who was the owner and sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed for the proposed local flight, which was being operated in accordance with Title 14 Code of Federal Regulations Part 91, and a flight plan was not filed. The flight, which was originating at the time of the accident, was destined for the Palo Alto Airport of Santa Clara County (PAO), Palo Alto, California. In a report submitted to the National Transportation Safety Board (NTSB) investigator-in-charge, the pilot reported that after taking off and during a normal climb to about 200 to 300 feet above ground level, the engine quit producing power. The pilot stated that he pushed the throttle and mixture forward, checked the fuel boost pump, and thought the [fuel selector] was positioned to BOTH. The pilot recalled that during the emergency approach to land on a golf course, the right wing collided with a tree, which resulted in substantial damage to the outboard section of the wing. The airplane then slid about 150 feet before coming to rest upright. During the investigation, a Federal Aviation Administration aviation safety inspector advised the pilot that significant amounts of water was found in the fuel system after the airplane had been placed level. The inspector then questioned the pilot relative to when the airplane was fueled last, whether the pilot had experienced fuel contamination previously with the accident airplane, and whether the pilot had drained or sumped the wing fuel tanks prior to the day of the flight. The pilot reported he had not fueled the airplane since October 2014, that he had not seen water in the fuel over the last 14 years, and that he had sumped on the day of the accident. The pilot stated that maybe the nose up and level orientation had shifted the water. The pilot added that the airplane did sit with one wing lower than the other, that he had extended the taxi, and that he had waited about 5 minutes before taking off. Examination of the recovered airframe and engine by an NTSB Aviation Accident Investigator, revealed that the Lycoming IO-360-A1B6 remained attached to the airframe via all mounts. Information provided by the Federal Aviation Administration inspector, who responded to the accident site, revealed that he had disconnected various fuel lines from the fuel nozzles to the fuel flow divider, and did not secure them tightly. The top spark plugs were removed. The engine was rotated by hand using the propeller. Thumb compression on all 4 cylinders was obtained. In addition, spark was observed on all 8 ignition leads. Liquid was observed expelling from the fuel pressure hose fitting at the fuel flow divider. The liquid was captured in an empty, dry cup, and was a murky white color. The liquid was tested using water finding paste and was positive for water. The fuel line extending from the airframe fuel filter to the throttle body fuel control unit was removed at the fuel control unit. Residual liquid in the fuel line was captured and tested using water finding paste with positive results. The airframe fuel boost pump was turned on and liquid expelled from the fuel line. About 0.75 gallons of fuel was recovered from the fuel line before the boost pump was turned off. About one-quarter of the liquid removed appeared consistent with water; the remainder of the liquid was consistent with aviation fuel, and was blue in color. Examination of the airframe revealed that both the left and right fuel caps were intact and in place. The left wing was sitting in a left wing low position (left main landing gear was separated), and fuel was observed expelling from the left fuel cap, which was secured and appeared tight. The cap was removed and the seal appeared intact and was not cracked or hardened. Fuel samples were obtained via the left and right wings and were blue in color and free of debris.

Probable Cause and Findings

A total loss of engine power during the initial climb due to fuel contamination. Contributing to the accident was the pilot’s inadequate preflight inspection of the fuel system.

 

Source: NTSB Aviation Accident Database

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