ERA09LA184

A loss of engine power due to contamination and clogging of the fuel system by a post-assembly fuel tank sealant.

About 6 years before the accident, the owner/pilot purchased the disassembled experimental amateur-built airplane from its builder, who had flown the airplane on multiple occasions. The pilot reassembled the airplane, and spent several months attempting to resolve fuel leaks in the airplane's integral wing tanks. Subsequent to the pilot's use of a slosh sealant in the fuel tanks, the engine lost power during two separate high-speed taxi tests, due to clogged fuel screens. The day prior to the accident, the pilot conducted his first flight in the airplane, which lasted about 18 minutes. During his second flight in the airplane, the pilot was fatally injured when the airplane impacted trees and terrain about 11 miles from his home airport, and a post-crash fire ensued. Many witnesses reported that the airplane was low, and that the engine sounded unusual. Five witnesses reported that the engine had stopped. Several witnesses reported that the airplane banked sharply in order to avoid a 500-foot-tall cell phone tower located about 500 feet from the impact location. Airplane assembly guidance specified the use of a commercial sealant called "Pro-Seal" during fuel tank assembly, but did not specify or prohibit the use of a slosh sealant, which was intended to be used after assembly. The technical information for the slosh sealant that was found in the pilot's hangar stated that the condition and cleanliness of the surface can affect sealant adhesion. Examination of the wreckage revealed that the interior surfaces of the wing bays that were used to contain fuel exhibited a charred brown/black material consistent with a fire-damaged internal tank coating. One in-tank fuel pickup finger screen was partially occluded by the material, but the pre-accident condition of the finger screen could not be determined.

HISTORY OF FLIGHT On March 6, 2009, about 1453 eastern standard time, an experimental amateur-built Stewart S51, N551X, was substantially damaged when it impacted trees and terrain in a recreational vehicle park in Ocala, Florida. The owner/pilot, the sole occupant, was fatally injured. The personal test flight was operated under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the flight, and no flight plan was filed. According to a Federal Aviation Administration (FAA) inspector and the pilot's relatives, the pilot was not the builder of the airplane, and he was its third owner. The pilot had just started the first phase of the flight test program, and the airplane's first flight by the accident pilot occurred on the day prior to the accident. The pilot told his wife that it was a "beautiful" flight, and his notes indicated that the duration was "0.3" hours. A total of 17 witnesses provided information regarding the final portion of the accident flight. Almost all reported that the airplane was flying at a low altitude, and some reported it to be flying at a low speed. Nine witnesses reported that the engine was "sputtering" or making unusual sounds, and five witnesses, including a Florida Highway Patrol officer, observed that the engine was not operating. Most witnesses reported that the airplane was west- or north-bound and descending. Several reported that the airplane banked sharply in order to avoid a cell phone tower. They also reported that it struck trees in the final few seconds of flight. The airplane impacted the ground between two unoccupied recreational vehicles, and a fire ensued. PERSONNEL INFORMATION FAA records indicated that the 80 year old pilot held an airline transport certificate with an airplane multi engine land rating; a commercial pilot certificate with airplane single engine land, single engine sea, rotorcraft helicopter, and glider ratings; a flight instructor certificate with airplane single engine, multi engine, rotorcraft, and instrument airplane ratings; and a mechanic certificate with airframe and powerplant ratings. According to several persons who knew the pilot, he was a former test pilot on the North American P-51 airplane. The pilot's most recent FAA third-class medical certificate was issued in March 2007, and he reported 13,917 total hours of flight experience on the application. A review of the pilot's logbook revealed that as of the day prior to the accident, he had a total of approximately 13,980 hours of flight experience. He had logged a total of 0.3 hours in the accident airplane; which occurred on the day prior to the accident flight. His next most recent flight occurred on February 12, about 3 weeks prior to the accident. In the 30, 60, and 90 days prior to the accident, the pilot had respectively logged 0.7, 1.3 and 3.5 hours, in four different airplanes. The airplanes were a Bellanca 7ECA ("Citabria"), an Aeronca 7AC ("Champ"), a Cessna 195, and the accident airplane. His most recent flight review was completed in September 2007, in a Cessna 195. AIRCRAFT INFORMATION According to information on an S51 builder's website, the airplane was a two place, 70% scale kit-version replica of the North American P-51 fighter. Both the company that created the original plans, and the company that manufactured the kits, had ceased operations prior to the accident. The airplane was of all-metal construction, and equipped with retractable landing gear and electrically-driven flaps. The standard fuel system configuration had a total capacity of 68 gallons, stored in integral wing tanks referred to as "wet wings." The primary fuel pump was the engine driven, rotary vane pump, which was supplemented by an electric auxiliary pump. The maximum gross weight was cited as 3,500 pounds. Nominal airplane performance values were cited as follows: Stall (at gross weight) 74 mph; Cruise (at 75 percent power) 289 mph at 28.5 gallons per hour (gph); Top speed (level flight) 334 mph at 38 gph; Maximum flap speed 150 mph; Maximum landing gear speed 130 mph. The data plate affixed to the airplane listed the maximum gross weight as 3,900 pounds. The accident airplane was equipped with a liquid-cooled, port-injection Chevrolet 612 cubic inch displacement engine that produced approximately 400 to 600 horsepower, and a four-blade Hartzell constant speed propeller. The airplane kit was purchased, but not completed, by its first owner. According to the second owner, he purchased the partially-assembled kit from the first owner, with the intention of racing the airplane. The second owner completed the construction in 2002, and he stated that the airplane had accumulated approximately 15 total hours of flight time while he owned it. Since the airplane was not "fast enough" to suit the second owner's needs, he partially disassembled it, and sold it to the accident pilot in March 2003. The disassembled airplane was transported by truck to the accident pilot's residence on his private grass airstrip, which was Idle Wild Airport (FL63), Ocala, Florida, According to FAA records, a special airworthiness certificate was issued to the pilot for the airplane in July 2008. The operating limitations associated with the airworthiness certificate limited the airplane to flights of within a 40 mile radius of the Ocala very high frequency omnidirectional radio range (VOR). The airplane was based at FL63, which was located approximately 10 miles northwest of the Ocala VOR. METEOROLOGICAL INFORMATION The 1455 automated weather observation at Ocala International Airport-Jim Taylor Field (OCF), Ocala, Florida, located 5.6 miles southwest of the accident site, included winds from 170 degrees at 4 knots, clear skies, 10 miles visibility, temperature 25 degrees C, dew point 6 degrees C, and an altimeter setting of 30.34 inches of mercury. COMMUNICATIONS A review of FAA air traffic control voice recordings and ground based radar tracking data did not reveal any communications with the accident airplane, or any radar targets that could be associated with the accident airplane. WRECKAGE AND IMPACT INFORMATION According to information provided by the FAA inspector who responded to the accident, the accident location was 11.3 miles south-southeast of FL63. The airplane impacted the ground between two unoccupied recreational vehicles (RVs), which were damaged by airplane and tree debris. The airplane incurred significant fire damage. A fence on the south side of the RV park separated a wooded area from the RV park. The ground impact point and main wreckage, which consisted of most of the airplane, was approximately 60 feet north of the fence, inside the RV park. A portion of the left wing was found approximately 35 feet south of the fence, and several trees in that area were damaged. The southern-most component was the tailwheel, which was found approximately 225 feet south of the fence. A cell phone tower was located in the wooded area, approximately 475 feet south-southwest of the main wreckage. According to the FAA inspector, the cell phone tower was braced by multiple guy wires affixed at various heights and azimuth locations on the tower. The inspector stated that the "upper guy wires on the east side of the tower were near the suspected flight path," but his inspection of the tower and wires indicated that "no damage was evident." A review of the relevant aeronautical chart indicated that the tower height was approximately 500 feet above ground level. The airplane, engine and propeller exhibited significant fire damage. The FAA inspector was able to confirm the propeller "blade connection to the pitch change mechanism," but he was unable to ascertain any engine control positions. The inspector observed that all engine "drive belts appeared to be on the pulleys" at the time of the post impact fire. He "suspected" that the tai