NTSB Factual Report

HISTORY OF FLIGHT

On September 5, 1998, about 1008 central daylight time, a Thurston Sumner Glasair SH-2R, N534TS, registered to a private individual, operating as a 14 CFR Part 91 personal flight, crashed while attempting a precautionary landing to Sandy Creek Airpark, Panama City, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The airplane was destroyed, and the private-rated pilot, the sole occupant, sustained fatal injuries. The flight originated from the same airport about 1000, the same day.

According to witnesses who were the pilot's neighbors in the airpark who assembled to watch the newly finished airplane's first flight, the engine was heard to cough and sputter at about 100 feet agl, on takeoff from runway 9. The spectators included the pilot's main helper and neighbor, a pilot/mechanic who was communicating with him by handheld radio, The engine sputter smoothed out and the airplane was observed to enter a shallow left bank at 500 to 600 feet agl, go out of sight beyond a tree line, then reappear and set up for a right base leg to a downwind landing on runway 27. The propeller was turning, but witnesses could not confirm the amount of power the engine was developing. The pilot overshot the runway centerline, entered a steep right bank to correct, brought the nose up to a landing attitude at about 50 to 75 feet agl, and held that attitude until touchdown. The airplane impacted level grass terrain at a high rate of descent about 40 feet left of the runway's left edge, shed the nose landing gear and the left main gear, broke the right main gear, bounced, and slid onto the runway and burned.

Witnesses said the touchdown was very hard and extreme wing flexing was observed. A vapor cloud could be seen emanating from the airplane's lower center section upon touchdown. Some witnesses thought the "cloud" was fuel spewing from a ruptured fuel tank, because fire ignited from that same location as the airplane slid to a stop. Fire quickly spread from the lower firewall area upward to engulf the cockpit. Several of the crowd ran to the burning airplane but were repulsed due to the intense heat. One witness observed the pilot trying to release the canopy latch, but he characterized the effort as "barely". The fire was extinguished by the Calloway Fire Department, using 250 gallons of water.

The previously mentioned main helper/neighbor spoke with the pilot before the flight. He thought the pilot was "really excited" and told him, "calm down before you fly the airplane". He suggested that the pilot, "go up and down the runway four or five times". After the first high speed taxi run, they conferred again about the pilot not getting an airspeed indication, and that the pilot had put 16 gallons aboard, but that the fuel indicator read, "10". The pilot/neighbor blew into the pitot tube with a resultant airspeed indication, and he looked for fuel leaks with negative results to allay the pilot's concerns. He stated, in part, "I told him again, Thurston we've looked at it a couple times, calm down. This is your last chance, if you want me to fly this thing for you. He gave me a funny look and he went out of there." Additionally, the Bay County Sheriff's Department recorded statements from the main helper/neighbor. Excerpts include, "..while we were building the airplane and he seemed calm and cool and he was very methodic, one-step-at-a-time person. When it was time for him to get in the airplane he was really excited and kind of breathing heavy and we talked about slow down Thurston, go up and down the runway four or five times. Calm down before you fly the airplane." Additional personnel information is included in this report under First Pilot Information and Witness Statements, which are attachments to this report.

PERSONNEL INFORMATION

The pilot had attended the Stoddard-Hamilton factory introductory/flight course in June, 1998, and had logged 1 hour of Glasair flight time and five landings with a company instructor pilot. The pilot's personal logbook lists 1,335 hours total flight time. For the calendar year 1998, the pilot's total logged flight time was 4.0 hours, including 2.1 hours pilot-in-command time.

AIRCRAFT INFORMATION

The flight was the first flight of the homebuilt, experimental airplane. The engine had been bought and stored for use on the project since its major overhaul by Aviation Engines, Inc. of Hueytown, Alabama, on February 21, 1986. After some difficulty with magneto timing, the engine's first ground run, installed on the airplane was on May 6, 1998. The retractable landing gear were pinned down for this first flight in accordance with factory recommendations. The neighbor/builder stated that fuel used for the flight was 87 octane automotive fuel, and that fuel was loaded: 12 gallons in the wing tank, and 4 gallons in the fuselage header tank.

METEOROLOGICAL INFORMATION

Visual meteorological conditions prevailed at the time of the accident. For additional information, see Weather Information on page 4 of this report.

WRECKAGE AND IMPACT INFORMATION

Sandy Creek Airpark is a fly-in community clustered around a single, east-west grass runway about 15 miles southeast of Panama City. The accident occurred near the runway's east end. Scarring of the sod periphery of the runway revealed that initial touchdown of the airplane was in a slightly left wing low, three-point attitude at a high rate of descent, about 675 feet inside the east end and about 40 feet outside the southern edge of the runway on a heading of about 290 degrees, magnetic. The airplane bounced once and shed the nose and left landing gear, spewing fuel from the ruptured fuel tank during the bounce. Brown, recently killed grass at the first ground impact site confirmed that the vapor cloud observed by many witnesses was fuel spewage. Burned grass along the wreckage path indicated the fire started when the airplane touched down from the bounce. The resultant slide was about 90 feet, ending on the runway, 20 feet inside the southern edge, heading 270 degrees. The fire consumed everything for a diameter of about 7 feet, centered at the firewall, except for the core engine, propeller and spinner, both outer wing panels, the aft fuselage and empennage. A diagram of the wreckage site and runway is attached under, Maps or charts of accident area.

All airframe components were found in the immediate area. Flight controls and airframe components showed no signs of precrash malfunction or failure outside of the 7-foot diameter of fire destruction previously mentioned. The separated landing gear showed overload stress at their respective fracture sites. Severe heat damage to the firewall and aft engine section prevented operational examination of fuel system components, magnetos, ignition harnesses, propeller governor, and hoses. The spark plugs appeared new, electrode gaps proper, and the deposit coloration was sooty black to brown, indicative of a overly rich air to fuel mixture. Propeller blade striations and bending indicated that some power was being developed at ground contact. The induction air box had been crushed, and its air filter was missing. Other than impact related crushing, the induction system and the exhaust system showed no obstructions.

Subsequent disassembly inspection of the engine and associated components was performed. All engine accessories and components were checked for security of mounting hardware and removed. Exact engine to magneto timing was impossible, but magneto firing-order-to-piston stroke/valve relationship was checked, and was proper for both magnetos. The left magneto was found installed with the timing slot adjustment counter clockwise to the full limit of left travel. The right magneto was installed at about the center position of the timing slot. The full rocker arm, valve, and gear train was intact, correctly installed, and a thumb compression check of each cylinder was good. The carburetor was relatively undamaged, and showed a fully open throttle valve, the mixture control at midrange, and a small amount of 87 octane automotive fuel. Water content testing of the fuel was negative and the fuel inlet screen was clean. The propeller governor sustained fire damage, but the drive coupling was intact and the gasket screen was clean. The oil filter revealed no contamination and no lubrication system abnormalities were found. No evidence of preimpact mechanical malfunction was noted.

MEDICAL AND PATHOLOGICAL INFORMATION

Postmortem examination of the pilot was conducted by Dr. Thomas R. Beaver, M. D., Associate Medical Examiner, District 14, Panama City, Florida, on August 8, 1998. The cause of death was attributed to conflagration. No findings that could be considered causal were noted. Toxicological tests were conducted at the Federal Aviation Administration Research Laboratory, Oklahoma City, Oklahoma, and by the University of Florida Diagnostic Referral Laboratories. Ethanol was positive in urine, postmortem, and negative in blood. Carbon monoxide was positive in blood at a level of 21per cent. Salicyclic acid was detected in blood and urine at a level of 44 miligrams/liter.

TESTS AND RESEARCH

The plastic fueling cans in the pilot's hangar, reported to be those used for fueling of the airplane, were examined and found to be free of water and contamination. It was confirmed that the type of fuel was 87 octane automotive fuel.

ADDITIONAL INFORMATION

The aircraft wreckage, minus the engine and propeller assembly, was released to the estate of the operator on September 7, 1998. The engine and propeller assembly was released to the operator's insurance representative on January 22, 1999.

NTSB Probable Cause

The pilot's failure to maintain a proper descent rate during a precautionary landing following a loss of engine power for undetermined reasons.