N2206LBeech A36 · 1976

On June 23, 2011, about 1845 Pacific daylight time, a Beech A36, N2206L, landed hard after experiencing a loss of engine power at El Monte Airport, El Monte, California. The pilot operated the airplane under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. The commercial pilot was not injured. The airplane sustained substantial damage. The personal flight departed Chino Airport, Chino, California, about 1835, with a planned destination of Camarillo Airport, Camarillo, California. Visual meteorological conditions prevailed, and no flight plan had been filed.

The airplane had just undergone an avionics and flight instrument upgrade at a maintenance facility at Chino Airport. At 1300, an employee from the facility flew the airplane to Van Nuys to pickup the pilot. During the outbound and return flights he observed a spurious fuel pressure indication on the engine monitoring system. The engine appeared to operate normally, and it was assumed that the problem was associated with the indication system. The airplane landed at Chino uneventfully, and for the next 3 hours technicians diagnosed and rectified the malfunction by disconnecting and cleaning out the fuel pressure monitoring lines.

The pilot had initially planned to fly the airplane to Concord, California, that afternoon; however, due to the delay he decided to fly the airplane back to his residence in Camarillo, and complete the rest of the journey via commercial airline. He reported that the maintenance delay had left him tired and frustrated, and that he declined an offer by the maintenance facility manager to drive him to the airport for the commercial flight.

This was to be the first time he had flown the airplane solo since the installation of the new system, and although he was instrument rated, he did not want to perform an instrument flight rules (IFR) approach with the new panel. He called flight service for a weather briefing, and although the weather was clear, the briefer recommended that the pilot call back after 1800 for an update. About 1800, the pilot performed what he described as a cursory walk-around, and then checked back for a weather update. He could not recall if he checked the fuel tank quantity or used his checklist at that time.

He reported an uneventful takeoff and initial cruise to 4,500 feet agl. He stated that he normally flies higher, but on this occasion, he was in a hurry. During the initial cruise, he became concerned, and was distracted when sun glare began to interfere with his traffic scan and outside visual reference.

Shortly thereafter he heard a popping sound emanate from the engine, followed by a total loss of power. The propeller continued to turn, but the airplane immediately began to descend. He contacted Air Traffic Control, notifying them of the emergency, and received vectors to El Monte. He stated that he became convinced that the loss of power was due to a maintenance oversight performed earlier in the day, and as such, he did not think to switch the fuel tank selector, turn on the fuel boost pump, or perform any other troubleshooting steps. He maintained an airspeed of 90 knots during the descent, and stated that during the turn to final he inadvertently allowed the airplane to stall.

The airplane landed hard, bending both wing spars, collapsing the right main landing gear, and separating the nose gear.

Post accident examination by the NTSB investigator-in-charge revealed that the right wing main fuel tank contained fuel to the brim of the filler cap. The left main tank appeared empty when viewed through the filler cap, and about 12 ounces of fuel was subsequently drained from the wing sump. Neither main fuel tank appeared to have been breached during the accident sequence. Further examination of the fuel system revealed about 2 teaspoons of fuel in the belly-strainer, and 6 drops of total fuel in the lines from the strainer through to the fuel injector servo. No fuel staining or indications of a fuel leak were noted. A member of the fire crew, who responded to the accident site, reported that the fuel selector valve was in the left tank position immediately following the accident.

The airplane was equipped with an Electronics International, Inc., MVP-50 engine analyzer and systems monitor. The MVP-50 is capable of recording engine and airplane system parameters at 1 second intervals. The data from the day's three flights were downloaded and examined. The data revealed that for the final flight the engine started at 1807, with the left fuel tank quantity gauge indicating 9 gallons of total fuel, and the right tank indicating 34.5 gallons. For the next 20 minutes, the engine speed remained at approximately 1100 rpm, with intermittent increases to about 2,000 rpm. At the end of that period the right tank fuel quantity remained constant, with the left tank indicating 6.5 gallons. At 1627, the engine speed increased to 2,570 rpm, with a corresponding fuel pressure increase to 100 pounds per square inch (psi). For the next 2 minutes, the right fuel tank level, engine speed, and fuel pressure remained constant, with the left fuel tank level now indicating 2.5 gallons. After a few seconds, the left tank level dropped to 0 gallons, followed 8 minutes later by an engine speed and fuel pressure decrease to 1,400 rpm, and 1.5 psi, respectively. The data recording ended 4 minutes later.