N9540Beech 3NM · 1952

On May 12, 2012, about 1230 Pacific daylight time, a Beech model 3NM twin-engine airplane, N9540, was substantially damaged during a forced landing shortly after takeoff from Pope Valley airport (05CL), Pope Valley, California. The pilot/owner and the 2 passengers received minor injuries. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no Federal Aviation Administration (FAA) flight plan was filed for the flight.

According to the owner-pilot, engine start and runup were normal. After takeoff from runway 10, when the airplane had reached an altitude of about 50 feet above ground level, the right engine "died." The airspeed was still about 25 mph below the minimum single engine control speed, and the landing gear had not yet been retracted, so the pilot continued straight ahead, and landed the airplane in a vineyard just beyond the end of the runway. The vineyard was strung with multiple rows of trellises oriented perpendicular to the direction of travel, and the airplane was arrested and then nosed-over onto its back by the trellises. The pilot secured the airplane, and all 3 persons exited on their own. Fuel was observed to be leaking from the airplane, but there was no fire. The nose, fuselage, wings and vertical stabilizers all sustained substantial damage. Several hours after the event, the airplane was righted and moved to a hangar for subsequent examination by NTSB and FAA personnel.

FAA records indicated that the pilot held a commercial pilot certificate with airplane single engine land, single engine sea, multi-engine land and instrument airplane ratings. According to the pilot, he had a total flight experience of approximately 7,900 hours, including approximately 1,800 hours in the accident airplane make and model. His most recent flight review was completed in September 2011.

FAA information indicated that the airplane was manufactured in 1952, and was equipped with Pratt and Whitney R-985 engines. The airplane originally served in the Canadian armed forces, and was sold to an individual in the United States in 1972. It was registered to the pilot in 2002. According to the maintenance records, the airplane had a total time in service of approximately 7,908 hours, and its most recent annual inspection was completed in November 2011.

The left engine had accumulated about 220 hours in service since its most recent overhaul, and the right engine had accumulated about 480 hours since its most recent overhaul.

The airplane was equipped with a total of 5 fuel tanks. The bladder-style nose tank had a capacity of 80 gallons. Each wing was equipped with a forward main tank of 78 gallons capacity, and an aft auxiliary tank of 25 gallons capacity. Each tank was equipped with its own sump drain, and each engine was equipped with a fuel strainer. The airplane was equipped with three fuel selector valves; one four-position valve for each engine, plus a two-position suction crossfeed valve. According to the airplane flight manual, takeoff was to be conducted using the main tanks, and the crossfeed was to be OFF except in level flight.

The 1953 automated weather observation at an airport located 21 miles west of 05CL included winds from 190 degrees at 8 knots, visibility 10 miles, clear skies, temperature 26 degrees C, dew point 12 degrees C, and an altimeter setting of 30.01 inches of mercury.

The departure airport was equipped with a single paved runway designated 10/28. The runway measured 3,700 by 60 feet, and the airport elevation was 618 feet above mean sea level. The airport was located in a region of gently rolling hills and agricultural fields.

The fields to the immediate south and east of the airport were employed as vineyards at the time of the accident. The vineyard off the departure end of runway 10 was strung with multiple rows of metal stake- and wire-trellises oriented perpendicular to the runway. The metal stakes projected about 5 feet above the ground, and multiple high-tensile strength steel wires were strung between the stakes at several levels.

The airplane came to rest inverted, about 500 feet beyond the departure end of runway 10. Both propeller/engine assemblies were heavily entangled by multiple steel trellis wires. Later on the day of the accident, the airplane was righted and towed to the pilot's hangar at 05CL. Examination of the airframe and engine was conducted about 2 weeks after the accident, in the pilot's hangar.

The airplane was upright on its landing gear. The lower cowlings from both engines had been removed. Numerous strands of steel wire (from the vineyard) were wrapped around each propeller hub. The primary visible damage was to the nose and upper fuselage structure above the cockpit. The wings and vertical stabilizers also exhibited damage, primarily small punctures and/or crush damage. The elevator and left horizontal stabilizer exhibited moderate crush, bending and displacement damage; the pilot stated that that damage occurred during the righting operation.

The pilot reported that during his preflight inspection, he had sumped all five fuel tanks and both fuel strainers, and did not observe water in any of the samples. During the NTSB examination, about 5 drops of water were recovered from the right main fuel tank.

The condition of the cockpit, as well as the settings, indications, and markings of the controls and instruments, was documented. The pilot stated that after the accident, many first-responder personnel entered the cockpit, and that he did not know what, if any, controls they touched or altered. Most electrical switches were found in their OFF positions; many were turned off by the pilot after the event. Both the left and right fuel selector handles were set to their OFF positions; this was also accomplished by the pilot after the accident. The pilot stated that each engine was set to its respective forward main tank for the takeoff.

The fuel "suction crossfeed" valve was located under the right pilot's seat. It had two marked positions (ON and OFF) situated 90 degrees apart on the placard under the rotary selector handle. The handle was found set about 70 degrees toward (but not at) the OFF position. The investigation was unable to determine the valve position at the time of the takeoff. The handle was able to be actuated through its full 90-degree range of travel, to align the pointer with both the ON and OFF index marks on the placard.

The carburetor and engine-driven fuel pump were removed from the right engine and examined. No mechanical anomalies were observed with either the carburetor or fuel pump. According to Beech documentation, a total of 13 different fuel pump "Part Numbers" were eligible for installation on the airplane. The 13 included one with a part number of AN4100-1 but with no manufacturer specified. The two Chandler-Evans manufactured fuel pumps were listed as part numbers 9141 and 9105. The right engine fuel pump was a Chandler Evans "Type AN 4101-CE" with a "Part" number of CE-9135. The investigation was unable to determine the differences (if any) between the eligible and installed fuel pumps, or the suitability of the installed pump on the R-985 engine. Review of the available maintenance records did not indicate either whether, or when, the AN 4101-CE CE-9135 fuel pump was installed on the engine.

Examination of the remainder of the airframe and right engine did not reveal any anomalies or pre-impact mechanical deficiencies that would have precluded normal engine operation. However, a lack of appropriate or specialized tools prevented complete examination or testing of certain components.