Aviation Accident Summaries

Aviation Accident Summary MIA07LA091

Stewartstown, PA, USA

Aircraft #1

UNREG

Lee Stevens Sorrell SNS-2 Guppy

Analysis

The non-current pilot departed in the unregistered single seat airplane from runway 15, and a witness who was located at a hangar on the airfield reported that when the flight was past the departure end of the runway, the airplane turned onto a right crosswind leg. The airplane appeared to be flying slow, then "...nose down vertical into a spin, impacted vertically." Another witness who was driving on a nearby road reported seeing the airplane "...spiral down into the field." The airplane came to rest with the empennage elevated vertically and slightly twisted to the left. The fuselage was crushed to the instrument panel. Flight control continuity was confirmed for roll, and pitch; impact damage to the area of the rudder pedals precluded confirmation of control continuity for yaw. A total of 2.5 gallons of blue tinted 2 cycle fuel/oil mixture were drained from the 5.0 gallon fuel tank, which was free of contamination. One propeller blade was separated at the propeller hub and shattered, while the remaining blade remained secured inside the propeller hub. Examination of the engine revealed numerous discrepancies. A current weight and balance was not available with the installed engine and propeller, therefore, the exact weight and balance at the time of the accident was not determined.

Factual Information

HISTORY OF FLIGHT On May 5, 2007, about 1117 eastern daylight time, an unregistered amateur built SNS-2 Guppy, operated by a private individual, experienced an in-flight loss of control and crashed into an open field shortly after takeoff from Shoestring Aviation Airfield (0P2), Stewartstown, Pennsylvania. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 91 personal flight from 0P2, to Baublitz Commercial Airport, Brogue, Pennsylvania. The airplane was substantially damaged and the private-rated pilot, the sole occupant, was fatally injured. The flight was originating at the time of the accident. The flight departed from runway 15, and a witness who was located at a hangar on the airfield reported watching the flight depart, and once past the departure end of the runway, turn onto a right crosswind leg. The airplane appeared to be flying slow, then "...nose down (vertical into a spin, impacted vertically." Another witness who was driving on a nearby road reported seeing the airplane "...spiral down into the field." PERSONNEL INFORMATION The pilot, age 54, held a private pilot certificate with airplane single engine land rating issued on June 9, 1979. This certificate had a limitation pertaining to the carriage of passengers, which was removed when a new private pilot certificate was issued on June 2, 1999. He was issued a third class medical certificate on March 12, 2003, with the limitation to wear correcting lenses. NTSB review of his second pilot logbook included a carry forward total time of 68 hours (flights between 1968 and 1979). The first individual flight entry was dated March 14, 1999, and the last entry was dated May 3, 2007. He logged a total time of approximately 399 hours. There were no logged flights between August 20, 2005, and April 22, 2007. His last logged flight review in accordance with 14 CFR Part 61.56 occurred on February 21, 2002. The pilot's wife reported that the accident flight was the first time her husband had flown the airplane since purchasing it either in August or September 2006. A certified flight instructor (CFI) provided 3 instructional flights to the accident pilot in a Piper J3 airplane during 3 days in 2007; the last flight occurred 2 days before the accident. The purpose was for the pilot to obtain a tail wheel endorsement. The pilot did not receive an endorsement and the CFI reported he needed an additional 2 to 3 more flights. The CFI further reported the pilot's skills were, "...on the high side of average with the exception of stalls." The accident pilot advised the CFI he felt, "...uncomfortable in stalls as a result of an early flight experience." The accident pilot was given a simulated engine failure at "low-key 500 feet AGL." The pilot handled it correctly with a resulting landing that was satisfactory. AIRCRAFT INFORMATION The amateur built, single seat, unregistered bi-wing airplane was manufactured in 1983, as model Sorrell SNS-2 Guppy, and was designated serial number 79. It was assigned registration N5023C, and was originally powered by a Volkswagen 36 horsepower engine and equipped with a Prince 52-26 propeller. The builder/owner reported to FAA on January 26, 1986, that he sold the airplane. There were no further FAA records pertaining to this registration. The original empty weight and maximum weight were listed at 431.5 and 650.0 pounds, respectively. On an unknown date(s), the engine and propeller were changed to a 45.6 horsepower Rotax 503 engine and a Powerfin B model propeller. There was no current weight and balance associated with the installation of the Rotax engine and Powerfin propeller. The airplane did not meet the requirements of an ultralight airplane based on the licensed empty weight; therefore, it was required to be registered. The pilot purchased the unregistered airplane in either August or September 2006, and kept it in a hangar at 0P2. Work performed to the airplane since purchase consisted of replacement of the propeller blades due to propeller blade contact while taxiing, replacement of the fuel pump, and "cleaned air cleaner." METEOROLOGICAL INFORMATION A surface observation weather report taken at York Airport, York, Pennsylvania, at 1053, or approximately 24 minutes before the accident indicates the wind was calm, the visibility was 10 statute miles, overcast clouds existed at 6000 feet, the temperature and dew point were 18 and 09 degrees Celsius, respectively, and the altimeter setting was 30.14 inHg. The York Airport is located 12.7 nautical miles and 316 degrees magnetic from 0P2. AIRPORT INFORMATION The 0P2 airport is equipped with several turf runways. The departure runway, runway 15, is 1,000 feet long and 100 feet wide. WRECKAGE AND IMPACT INFORMATION Examination of the accident site and wreckage was performed by an FAA inspector. The accident site was located approximately .3 nautical mile and 159 degrees from the center of the departure airport. The airplane came to rest with the empennage elevated vertically and slightly twisted to the left. The fuselage was crushed to the instrument panel. Flight control continuity was confirmed for roll, and pitch; impact damage to the area of the rudder pedals precluded confirmation of control continuity for yaw. A total of 2.5 gallons of blue tinted 2 cycle fuel/oil mixture were drained from the 5.0 gallon fuel tank, which was clean. Examination of the cockpit revealed the exhaust gas temperature (EGT) gauge was indicating 1,100 degrees Fahrenheit. the airspeed indicator needle was trapped at 56 knots, and the attitude indicator was indicating a 45 degree right wing low attitude. Examination of the engine before removal for further examination revealed 1 propeller blade remained secured inside the propeller hub while the remaining propeller blade was shattered at the propeller hub. Both spark plugs were white in color with no deposits. The fuel supply lines consisted of aluminum tubing and clear plastic tubing. The clear plastic tubing was "full of air bubbles" and the carburetor fuel bowl was nearly empty. Further examination of the engine by a representative of the engine manufacturer with NTSB oversight revealed the fuel pump operationally checked good but was incorrectly attached to the engine. A section of throttle cable remained secured to the carburetor, which was spring loaded to the closed position. The carburetor vent line had 1 hole, while the factory vent line has multiple holes. The fuel inlet filer, and main jet of the carburetor were clear. The needle jet of the carburetor was correct. The floats and float level of the carburetor appeared normal. Both point gaps were within limits, and the "PTO" side of the magneto timing was within limits while the "Mag Side" of the magneto timing was .007 inch before top dead center limit. The spark plug gaps were both .030 inch (specification is .016 to .020 inch), had screw on caps contrary to the original equipment manufacturer (OEM) type recommended, but were the correct heat range. Both EGT probes were incorrectly located. The power take off (PTO) probe was touching the far wall of the pipe, and the magneto side (MAG) probe was approximately .020 inch from contact. Disassembly of the engine revealed the PTO piston to wall clearance was within limits, while the MAG piston to wall clearance was .0025 inch greater than specification. Inspection of the MAG piston revealed evidence it had been sanded. The crankshaft bearings had failed retainers on the PTO side which caused high drag during engine hand rotation. MEDICAL AND PATHOLOGICAL INFORMATION A postmortem examination of the pilot was performed by Forensic Pathology Associates, Inc., located in Allentown, PA. The cause of death was listed as "multiple blunt force trauma." Forensic toxicology was performed on specimens of the pilot by the FAA Bioaeronautical Sciences Research Laboratory (CAMI), Oklahoma City, Oklahoma, and by Health Network Laboratories (Health Network), Allentown, PA. The CAMI toxicology report was negative for carbon monoxide, cyanide, volatiles, and tested drugs. The Health Network toxicology report was negative for volatiles and tested drugs. TESTS AND RESEARCH Weight and balance calculations were performed using the only known weight and balance for the airplane, which included the original VW engine and Prince propeller. The calculations indicate that based on the empty weight (431.5 pounds), the pilot's weight based on the autopsy report (199 pounds), and the weight of fuel drained from the fuel tank (15 pounds), the airplane weight at the time of engine start was approximately 645.5 pounds, which was within 4.5 pounds of maximum gross weight. The calculations do not include the empty weight change as a result of the different engine and propeller installed, which was not determined.

Probable Cause and Findings

The pilot's failure to maintain airspeed resulting in inadvertent stall. Contributing to the accident was the pilot's lack of experience in the airplane.

 

Source: NTSB Aviation Accident Database

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