Woodbine, NJ, USA
N623BL
Dennis P. McGurk F1 Rocket
While performing aerobatics, the engine lost all power. Evidence indicates that the pilot attempted to restart the engine, and that the airplane impacted wires while the pilot attempted to execute a forced landing to a road. The airplane came to rest on the road and was partially consumed by the postcrash fire. No evidence of preimpact failure or malfunction of the airframe or engine was discovered. The airplane was equipped with two fuel tanks. The flight manual advised that, “Prolonged uncoordinated flight with low fuel quantities may uncover the fuel tank outlets, causing fuel starvation and engine failure.” The pilot however, had modified the left fuel tank with an inverted fuel system, to allow the engine to operate while the airplane was in unusual attitudes or inverted. Examination of the left fuel tank revealed that it had been modified with the inclusion of a flop tube (a flexible hose with a weight attached at its free end). When the airplane was right side up, the hose would feed fuel from the bottom of the left fuel tank, and when the plane would roll inverted, the weight would cause the hose to flop to the top of the left fuel tank, and feed its fuel from there, allowing the engine to continue to run. Examination of the right side of the fuel system revealed it was similar to the system described in the kit manufacturer’s assembly manual and did not have a flop tube. The floor mounted fuel selector was found set to the right tank.
HISTORY OF FLIGHT On June 20, 2008, at 1943 eastern daylight time, an amateur-built F1 Rocket, N623BL, was substantially damaged when it impacted terrain while maneuvering near Woodbine Municipal Airport (1N4), Woodbine, New Jersey. The certificated private pilot and passenger were fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight conducted under 14 Code of Federal Regulations Part 91. According to a witness, just prior to the accident, the airplane was observed to “roll” once, then “roll” again before going “straight up.” The witness thought that the airplane was going to “roll” again but, the plane then “stalled or shut off.” The airplane then “flipped back,” “tumbled end over end,” and “started to spiral.” The witness then thought that she could hear the pilot try to “start the plane right after it tumbled, but “it did not start.” She than thought that he “tried to start again.” She next observed the airplane to go “below” the tree line in her back yard and she heard an explosion. PERSONNEL INFORMATION According to Federal Aviation Administration (FAA) records, the pilot held a private pilot certificate with ratings for airplane single-engine-land. He reported 500 total hours of flight experience on his most recent application for a FAA third-class medical certificate, dated December 28, 2006. AIRCRAFT INFORMATION The accident airplane was an amateur built, aerobatic, single engine, two place, low wing monoplane, of conventional construction. It was powered by a modified, Lycoming IO-540-D4A5, and was equipped with a three blade, constant speed propeller. According to the FAA and the airplane kit manufacturer, the accident airplane received its special airworthiness certificate on September 20, 2007. At the time of the accident, the airplane had accrued approximately 190 total hours of operation. METEOROLOGICAL INFORMATION A weather observation taken about 8 minutes prior to the accident at Cape May County Airport (WWD), Wildwood, New Jersey, located 13 nautical miles southwest of the accident site, recorded the wind as 180 degrees at 10 knots, visibility 10 statute miles, sky clear, temperature 22 degrees Celsius, dew point 16 degrees Celsius, and an altimeter setting of 30.00 inches of mercury. WRECKAGE AND IMPACT INFORMATION Examination of the accident site and wreckage by a Federal Aviation Administration (FAA) inspector revealed that after the airplane had gone behind the tree line, it struck power lines and then impacted the ground in a nose-low attitude. Both occupants were wearing parachutes. All major components of the airplane were accounted for at the scene. The airplane came to rest inverted, on a 090-degree magnetic heading. A post crash fire had occurred. Flight control continuity was established for all flight controls, and no evidence of in-flight structural failure or in-flight fire was discovered. Examination of the engine revealed that, it had been modified from its original design. No evidence of any preimpact mechanical malfunction was discovered. The engine was intact; however, the oil sump, and the push rods for cylinders No. 1 and No. 4, had sustained impact damage. Examination of the upper spark plugs revealed that they were of an automotive type. Their electrodes were gray in color. The crankshaft was rotated by hand, and thumb compression was obtained on cylinder Nos. 2, 3, 5, and 6. Thumb compression was not obtained on cylinders No. 1 and No. 4 because of impact damage to the push rods, but movement was observed in both cylinders. There was also movement of the rear accessory gear, and the engine driven fuel pump's operability was verified during rotation of the crankshaft. The upper spark plugs were powered by an electronic ignition unit. Examination of the ignition unit revealed that it had sustained impact damage and was inoperable. The ignition system for the lower plugs was of standard design, and was powered by a magneto. It was found separated from the engine, and was also impact damaged. The magneto however, would produce sparks from all six ignition lead towers. Examination of the fuel injection system revealed that the fuel injector had broken off its mounting stub. The fuel injector's inlet finger screen was clear of debris, and had a trace amount of fuel within the injector finger screen chamber. The air impact tubes and venturi were also free of debris, and the throttle linkage and associated air valve mixture arm moved freely. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot by the State of New Jersey, Southern Regional Medical Examiner Office. Toxicological testing of the pilot was conducted at the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The pilot's forensic toxicology report revealed: " >> 21 (mg/dL, mg/hg) ETHANOL detected in Blood >> 73 (mg/dL, mg/hg) ETHANOL detected in Muscle >> NO ETHANOL detected in Liver >> 5 (mg/dL, mg/hg) N-BUTANOL detected in Muscle >> 1 (mg/dL, mg/hg) N-PROPANOL detected in Blood >> 9 (mg/dL, mg/hg) N-PROPANOL detected in Muscle” TESTS AND RESEARCH According to the kit manufacturer, the airplane had “large normal control surfaces,” and “did not like to spin. The pilot had the three bladed propeller installed approximately 1 month prior to the accident. Inverted Oil System The pilot also had the airplane equipped with an inverted oil system however; he had been experiencing problems with the system, which after 18 to 20 minutes of flight would indicate that there was no oil pressure. The pilot had thought it was a “hose collapse” problem caused by a valve in the system, and prior to the accident had removed the inverted oil system. Fuel System Review of the kit manufacturer's flight manual revealed that the airplane was equipped with two wing tanks. Each was capable of holding approximately 21 gallons of usable fuel. Either tank could be selected for either takeoff or landing. The manual advised that, “Prolonged uncoordinated flight with low fuel quantities may uncover the fuel tank outlets, causing fuel starvation and engine failure.” According to the kit manufacturer the pilot however, had modified the fuel system from the standard configuration by equipping the airplane with an inverted fuel system, to allow the engine to continue to operate while the airplane was in unusual attitudes or inverted. Examination of the accident airplanes fuel system by Safety Board investigators, revealed no evidence of any preimpact malfunctions or failures. It was discovered however that only one side of the fuel system could be used during inverted flight. Examination of the left side of the fuel system revealed that it had been modified with the inclusion of a flop tube (a flexible hose with a weight attached at its free end). When the airplane would be right side up, the hose would feed fuel from the bottom of the left fuel tank, and when the plane would roll inverted, the weight would cause the hose to flop to the top of the left fuel tank, and feed its fuel from there, allowing the engine to continue to run. Examination of the right side of the fuel system revealed however, that it was similar in design to the system described in the kit manufacturer’s assembly manual and did not have a flop tube. Examination of the floor mounted fuel selector revealed that, the fuel selector had three selectable positions, OFF, LEFT, and RIGHT. When the fuel selector was in the OFF position, the fuel selector valve was closed. When the fuel selector was in the LEFT position, it would feed from the flop tube in the left fuel tank. When the fuel selector was in the RIGHT position, it would feed from the right fuel tank. Further examination of the fuel selector revealed that it was in the RIGHT position.
A total loss of engine power due to fuel starvation as a result of the pilot's failure to select the proper tank prior to performing aerobatics.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
