Keymar, MD, USA
N90458
Kociemba Robert H T-Bird II
Several witnesses observed the experimental, amateur-built airplane in a spin before they lost sight of it when it descended behind a row of trees. Another witness, who heard the engine but did not see the airplane in flight, stated that it sounded like it was "overloaded and struggling." Examination of the airframe revealed severe corrosion on the airframe structural tubing; however, there was no evidence of preimpact mechanical failure. Examination of the two-cylinder engine revealed that the aft cylinder, and the carburetor bowl that supplied fuel to that cylinder, were devoid of fuel, indicative of fuel starvation. Water and particulate contamination was found throughout the fuel system. Fuel sample analysis revealed that the fuel was 92 octane and contained about 9 percent ethanol. The contamination levels were sufficient to result in fuel starvation to one cylinder, and resulted in a complete loss of engine power. The complete loss of power in the rear-mounted engine at low altitude resulted in a pitch-up of the airplane, a reduction of airspeed, and an aerodynamic stall and spin from which the pilot could not recover. About 4 months prior to the accident the engine manufacturer issued guidance allowing for up to 10 percent ethanol blended fuels to be used; however, the owners were urged to confirm with the airframe manufacturer that ethanol blended fuels are allowed. No written guidance by the airframe manufacturer was located concerning the use of ethanol and no entry was located in the airplane maintenance record indicating that any change had been made to the airplane. Postmortem toxicology testing on the pilot was consistent with the use of a short-acting sleep aid the night prior to the accident and recent use of an over-the-counter antihistamine with impairing effects, likely for treatment of seasonal allergy symptoms. The sleep aid was unlikely to have resulted in impairment on the day of the accident, but the antihistamine could have adversely affected the pilot’s actions in response to the loss of power. The pilot did not possess a current airman medical certificate.
HISTORY OF FLIGHT On August 8, 2009, about 0741 eastern daylight time, an experimental amateur-built Kociemba, T-Bird II, N90458, was substantially damaged during an uncontrolled descent to the ground near Keymar, Maryland, shortly after takeoff. The certificated private pilot and passenger were fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight which departed Keymar Airpark (MD42), Keymar, Maryland, a few minutes prior to the accident. The personal flight was conducted under Title 14 Code of Federal Regulations Part 91. According to witnesses, who were outside their residence at the time of the accident, they observed the airplane after it took off from MD42. They saw it disappear behind a line of trees, and then reappear, traveling in the opposite direction. According to the Federal Aviation Administration (FAA) inspector on scene, one witness, using an airplane model, demonstrated that the aircraft banked at a high angle and then nose-dived toward the ground, with some rotation. Two other witnesses located at the departure airport did not observe the airplane in flight; however, they heard the airplane's engine. One of those witnesses described the sound as being "overloaded and struggling and maybe indicated a high angle of attack." The other witness heard the engine "suddenly stop," followed by a "loud bang." PERSONNEL INFORMATION The pilot, age 61, held a private pilot certificate issued July 25, 2003, with a rating for airplane single-engine land. His most recent FAA third-class medical certificate was issued on June 3, 2003. On the application for that medical certificate, the pilot reported a total flight time of 78 hours. A review of the pilot's logbook indicated that the last entry was dated September 15, 2003. As of that entry, his logbook indicated that he had accrued 85.5 total hours of flight experience, including 7 hours in the accident airplane make and model. A review of a separate "Ultralight/Microlight Pilot and Aircraft Log," which was labeled with the pilot's name and accident airplane registration number, revealed that the first entry was dated November 13, 2007. In the row associated with the last entry, dated July 2, 2009, the column titled "Total Time" had an entry of 98.9 hours. On April 13, 2008 an entry was made in the logbook reporting that the battery had been left on and an error in the "HOBBS meter" of 62.6 hours. The error resulted in an adjusted "Total Time" of 36.3 total hours. It could not be definitively determined if the flight time depicted in the two logbooks was an accurate representation of the accident pilot's flight experience. AIRCRAFT INFORMATION According to FAA records the two-seat, high wing, fixed-gear, kit built airplane was designed by Golden Circle Air, and built by the pilot. It was powered by a Rotax 582UL DCDI, 65 horsepower, rear-mounted engine, and equipped with a 2-bladed Warp Drive propeller. The engine was configured with two in-line cylinders, and dual carburetors. The airplane was registered to the pilot on March 31, 2004 and was issued a special operating certificate on November 13, 2007. A copy of the aircraft logbooks were examined by the NTSB investigator. The June 28, 2008 entry indicated the airplane had accomplished at least 5 hours of total flight time, which was required for the phase I flight testing. An entry dated July 1, 2009 was for a test flight that had been flown with 160 pounds of salt. The last logged flight entry was conducted on July 8, 2009. The logbooks did not contain any maintenance or inspection entries subsequent to the airplane's certification date. METEOROLOGICAL INFORMATION At 0748, the recorded weather observation at Fredrick Municipal Airport (FDK), Fredrick, Maryland, located about 15 miles southwest of the accident site, included calm winds, 10 miles of visibility, scattered clouds at 7,000 feet above ground level, temperature 19 degrees C, dew point 17 degrees C; altimeter 30.26 inches of mercury. AIRPORT INFORMATION MD42 was a privately owned airport. It had a single turf runway orientated northeast to southwest. The runway was designated 5/23 and was 2,000-feet-long by 120-feet-wide. The airport did not have an air traffic control tower. WRECKAGE AND IMPACT INFORMATION An examination of the airplane by FAA personnel revealed that the airplane came to rest in a nose down attitude approximately 4,200 feet southwest of the departure airport. The wooden propeller had little damage, and was devoid of chordwise scratches. Structural tubing located in the forward portion of the cabin was fractured and "severe corrosion" was noted near the fractures. The airframe and flight control cables were inspected. The only abnormality observed was that each of the rudder control cables had another 6 inch cable attached to the aft end to increase the overall length. According to the manufacturer the rudder cable was interchangeable between the conventional gear and the tail wheel version and that the additional length was to be attached to the tail wheel if installed. No evidence of any preimpact mechanical malfunction or failures was observed. According to the FAA inspector, the fuel tank was approximately "7/8's full," and fuel was found throughout the fuel system. Contaminants were found in the fuel samples obtained from the inline fuel filter, the fuel line downstream of the fuel filter, and the forward carburetor. Fuel samples acquired by the FAA from the aircraft were submitted to a commercial fuel laboratory in Aston, Pennsylvania for analysis. The laboratory results concluded that the fuel samples were "92 (octane) gasoline." A sample taken from the fuel tank contained 8.88 percent ethanol by volume, 0.2040 percent water, and was absent of any particulate. Samples taken from the fuel pump and inline filters indicated similar amounts of water. On August 18, 2009, the engine was removed from the aircraft and examined by a representative of the engine manufacturer, with the FAA inspector providing oversight. According to the engine manufacturer's report, "water contamination and other particles were found in the fuel tank, fuel filter, and in the carburetor bowl." According to the representative, "there was enough water and particles in the mag [aft] end fuel bowl to shut the fuel flow off to the mag [aft] end cylinder. The mag [aft] end crankshaft throws and lower conrod [connecting rod from the crankshaft to piston] bearing appeared to be dry from the lack of fuel. Examination of the fuel supply pickup fitting, which was located in the bottom of the sump in the fuel tank, revealed that it was absent of any screen or mechanism to remove contamination from the fuel line." Both cylinders were examined and appeared to be in "good condition." MEDICAL AND PATHOLOGICAL INFORMATION According to the Office of the Chief Medical Examiner for the State of Maryland, an autopsy was performed on August 9, 2009 and the cause of death was "multiple injuries." The FAA's Civil Aerospace Medical Institute performed forensic toxicology on specimens from the pilot. The report stated 0.243 ug/ml, ug/g Diphenhydramine was detected in the blood and in the urine and 0/018 ug/ml, ug/g Zolpidem was detected in the blood and in the urine. Local toxicology testing performed in conjunction with the autopsy was noted to have been performed on "heart blood." The pilot’s most recent application for airman medical certificate dated June 3, 2003 noted the diagnosis of "seasonal allergies" and the use of desloratadine. ADDITIONAL INFORMATION FAA Special Airworthiness Information Bulletin CE-07-06 states in part, "There are two primary sources of automobile gasoline STCs [Supplemental Type Certificates] for general aviation aircraft….Neither allow the use of automobile gasoline containing alcohol (ethanol or methanol). ..Automobile gasoline containing alcohol is not allowed to be used in aircraft for the following reasons: • The addition of alcohol to automobile gasoline adversely affects the volatility of the fuel, which could cause vapor lock. • Alcohol present in automobile gasoline is corrosive and not compatible with the rubber seals and other materials used in aircraft, which could lead to fuel system deterioration and malfunction. • Alcohol present in automobile gasoline is subject to phase separation, which happens when the fuel is cooled as a result of the aircraft’s climbing to higher altitude. When the alcohol separates from the gasoline, it may carry water that has been held in solution and that cannot be handled by the sediment bowl." According to Rotax Service Instruction, SI-2ST-008, Selection of Suitable Operating Fluids for Rotax 2-Stroke UL Engines, dated April 8, 2009 "In addition to AVGAS and unleaded automotive fuel (Mogas) the ROTAX engine type 503UL and 582UL are now approved for use with E10. At an ethanol amount of maximum 10%...ROTAX urges owners to confirm with there [sic] airframe manufacturer that ethanol blended fuels of up to 10% (E10) are compatible with all fuel systems components." Rotax Installation Manual Chapter 15, Fuel System states in part, "Fuel contamination is a major cause of engine failure…The fuel tank must have a drain cock for condensed water. A screen of 0.3 mm mesh size should be fitted to the fuel line in the tank." According to a representative of the kit-plane manufacturer, on July 1, 2009, the pilot reported to them that he had aborted a takeoff and the airplane struck a fence. A jury strut, which was a structural grade aluminum tube that connected the wing to the main wing strut, was damaged in that collision. The pilot purchased a replacement strut from the manufacturer. Manufacturer's invoices indicate that the pilot purchased new aileron cables on January 5, 2009, and new elevator cables on January 20, 2009. No corresponding entries were located in the aircraft maintenance records. No written guidance by the airframe manufacturer was located concerning the use of ethanol based fuels in their recommended fuel system. The FAA approved experimental operating limitations for the accident airplane states in part, "No person may operate this aircraft unless within the preceding 12 calendar months it has had a condition inspection performed…This inspection will be recorded in the aircraft maintenance records."
The pilot's failure to maintain adequate airspeed following a total loss of engine power due to fuel contamination.
Source: NTSB Aviation Accident Database
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