NTSB Factual Report

On June 14, 2001, at 1130 central daylight time, a Cessna 340A, multiengine airplane, N820B, exited the runway following a collapse of the landing gear during a single-engine landing at Lancaster, Texas. The airplane was owned and operated by Aeroplane Services, Inc., of Waxahachie, Texas. The private pilot was not injured; however, the airplane sustained substantial damage. Visual meteorological conditions prevailed, and a flight plan was not filed for the personal flight. The flight departed Houston, Texas, approximately 1030, with a planned destination of Lancaster.

The pilot reported the airplane was at a cruise altitude of 12,500 feet msl and he was receiving en route flight following from air traffic control. When the airplane was approximately 72 nautical miles from the Lancaster Municipal Airport, the pilot advised the controller that he was going to descend the airplane. The pilot switched both fuel selectors from the auxiliary tanks to the main fuel tanks. The pilot reduced the power to 25 inches of manifold pressure, the right engine lost power, and the fuel flow indicator dropped to 0.4 gph from the 20.4 gph that had been indicated. The pilot selected the low position on the fuel boost pump, advanced the mixture and the throttle; however, the engine did not restart. The pilot selected the high position on the boost pump, verified the fuel selector was on the main tank; however, the engine did not restart. The pilot then selected the cross feed fuel position for the right main fuel selector, and the left engine lost power. The pilot moved the right fuel selector to the main tank, turned the boost pump off, and feathered the right propeller. The power on the left engine was restored. The pilot continued to the destination airport, and subsequently, restarted the right engine. At 1125:07, the pilot reported to the controller that he had the airport in sight. At 1125:56, approximately 7 nautical miles south of the airport, the pilot reported the right engine again lost power. On final approach for runway 13, the pilot completed the before landing checklist, including the selection of the landing gear extension. The gear warning lights in the cockpit indicated that the gear was not fully extended. During the landing roll, the gear collapsed, and the airplane exited the runway.

Two witnesses who observed the airplane during the approach and landing, reported that only the left engine was operating. One of the witnesses reported observing the landing gear in the extended position as the airplane turned to the final approach for runway 13. The other witness reported that on final approach the landing gear did not appear to be in the locked down position. Both witnesses reported that following the touchdown, the landing gear collapsed, and the airplane departed the left side of the runway before coming to rest.

The pilot reported that the right wing was bent. The right engine was separated from the engine mounts, and the forward bulkhead sustained structural damage. The pilot stated that the "fuel selector valve failed to seal poppet valves internally, resulting in no fuel to right engine. Landing gear did not fully deploy on approach."

A review of maintenance records, by the NTSB investigator-in-charge, revealed the airplane, serial number (S/N) 340A-0328, was manufactured in 1977, and the manufacturer was issued authority, in lieu of an FAA airworthiness certificate, for export delivery of the aircraft. Subsequently, in 1995, the aircraft was imported to the United States. On October 13, 1995, the FAA airworthiness certificate was issued for the aircraft. At the last annual inspection, performed on January 5, 2001, the airframe had accumulated 4,678.5 hours, the left engine, S/N 813663-R, 1,839.7 hours (215.3 since rebuilt at the factory in June 1999), and the right engine, S/N 521422, 1,839.7 hours (902.9 since major overhaul in July 1995 at Griffin, Indiana).

On June 15, 2002, the FAA inspector, the engine representative, and the aircraft representative, examined the aircraft. Impact damage to the main landing gear assembly precluded a determination of the reason for the collapse of the landing gear; however, the landing gear motor operated when electrical power was supplied. The gear selector handle was found in an intermediate position. Flight control continuity was confirmed. The left propeller blades exhibited twisting and bending, and the right propeller blades were in the feathered position. When the crankshaft was rotated for each engine, thumb compression and continuity to the accessory case was confirmed. Operation of the boost pumps, transfer pumps, and fuel vents was verified, and fuel system continuity was confirmed. There were 20 gallons of fuel in the left main fuel tank, 32 gallons of fuel in the right main fuel tank, 2 gallons in the left auxiliary fuel tank, and 4 gallons in the right auxiliary fuel tank. The handles for the left and right fuel selectors were positioned on the left and right main fuel tanks, respectively. Both fuel selectors were removed for further examination.

Both fuel valves were disassembled under the supervision of the FAA inspector. During the disassembly of the right fuel selector valve, the three Rulon-A seals were observed depressed (stuck in the downed position) level with the housing. The spring follower bushings for all three Rulon-A seals were not present. During disassembly of the left fuel selector valve, one of the Rulon-A seals, where fuel enters the valve from the main fuel tank (tip tank), was down below the housing. No foreign matter was observed in either valve during the disassembly process. There were no part numbers found on either fuel selector assembly.

On August 16, 2001, the FAA inspector and a failure analysis specialist, re-assembled and pressure tested the fuel selectors in accordance with manufacturer specifications. When the right fuel selector valve was set in the off position, leakage from the main port to the engine port was 212.904 cubic centimeters (cc) (specification 0.5 cc with 40 psig). When the fuel selector was set in the main position, leakage from the auxiliary port to the engine port was 319.3456 cc (specification 0.5 cc with 8 psig). The left fuel selector valve leaked through the crossfeed port when 8 psi was introduced into the auxiliary port. When pressure was applied to the crossfeed port, fuel leaked out of every position. According to the manufacturer's representative, with the "right engine fuel selector valve in the right main tank position the leakage would not prevent the right engine from operating when the fuel boost pumps were in the on position."

NTSB Probable Cause

A loss of engine power for undetermined reasons. Contributing to the accident was the collapse of the landing gear for undetermined reasons.