History of Flight
On May 26, 2017, about 1230 central daylight time, an Aerotek Pitts S 2A biplane, N67PN, impacted terrain during a descent near Sheboygan Falls, Wisconsin. The pilot and pilot-rated passenger were fatally injured. The airplane sustained substantial damage. The flight was operated under 14 CFR Part 91 as a personal flight. Day visual meteorological conditions prevailed, and no flight plan was filed for the local flight, which originated from Sheboygan County Memorial Airport (SBM) about 1210.
The purpose of the flight was to perform a fly-by over a nearby racetrack. The pilot-rated passenger in the front seat reportedly sent a text about 1220 during the fly-by.
According to a flight instructor at SBM, about 1210, he and students heard the pilot report that a Bonanza was on straight-in final for runway 13. The instructor observed a red biplane (the accident airplane) depart runway 13 and make a sharp left turn to the north, low to the ground, clearing trees by 50 to 100 ft. The airplane then departed to the west/southwest at a lower-than-normal altitude.
A witness near the racetrack reported hearing an airplane about 1230, then the sound abruptly ceased. She observed the airplane traveling eastbound level for several seconds before it entered a nose-down, vertical attitude and spiraled clockwise to the ground.
Another witness reported hearing the airplane, then observed it climb rapidly and enter a 90° angle. At the apex, it sounded like the engine stalled. The airplane then entered a nose-down corkscrewing descent. The witness heard sounds suggesting pilots tried to restart the engine but were unable, then a loud thump upon impact.
A third witness reported the airplane entered a straight-up climb until it stalled, rolled upside down in a flat manner, and the engine stalled. The airplane then entered a nose-down spin. During the spin, rotation slowed, and near the ground, the engine sputtered but did not fire. The airplane disappeared behind trees, followed by a sound of impact.
Personnel Information
The 66-year-old pilot, seated in the aft seat, held an FAA airline transport pilot certificate with multi-engine land rating, commercial privileges in single-engine land and sea, and type ratings for DC-9, B757, B767, and B777. He held a first-class medical certificate dated April 20, 2017, with a corrective lenses limitation. He reported 16,300 total flight hours and 150 hours in the previous six months. He attended a recurrent King Air course in October 2016.
The 19-year-old pilot-rated passenger, seated in the front seat, held a private pilot certificate with single-engine land and instrument ratings. He was issued a third-class medical certificate on June 15, 2015, with no limitations. His flight experience was not reported on the application.
Aircraft Information
The accident airplane was a 1981 Aerotek Pitts S 2A, a tandem two-seat, single-engine, fixed-gear tailwheel biplane, equipped with a 200-horsepower Lycoming AEIO-360-A1E engine and a three-bladed MT propeller. It had a 24-gallon fuselage fuel tank (23 usable). The pilot purchased the airplane on August 20, 2013.
A mechanic recovered and repainted the airplane in January 2016, replaced fuel hoses and the fuel tank flop tube, and installed an additional 5-gallon fuel tank. The mechanic flew the airplane through all aerobatic maneuvers and spins, recovering using normal and emergency methods. An annual inspection was completed on March 23, 2017, at 2,258.7 total hours.
The airplane flight manual listed maximum gross weight as 1,575 lbs (normal) and 1,500 lbs (acrobatic). The most aft center of gravity at max gross was 96.13 inches (normal) and 96.50 inches (acrobatic). The AFM in-flight engine restart procedure specified steps including mixture idle cut-off, glide at 100 MPH, fuel selector on, master on, throttle open 1/4, engage starter, then advance mixture to full rich.
Both the type certificate holder's test pilot and an aerobatic flight school indicated that recovery procedures must be started immediately upon engine failure.
The airplane was based at Burlington Municipal Airport (BUU). A fuel receipt showed 11 gallons of 100LL purchased at BUU at 1535 the day before. The distance from BUU to SBM was about 68 nautical miles. The airplane was observed departing BUU with only the pilot about 1015 on the accident day.
Meteorological Information
At 1153, the recorded weather at SBM included wind from 160° at 5 knots, visibility 10 statute miles, clear sky, temperature 16°C, dew point 13°C, altimeter 29.86 inches of mercury.
Wreckage and Impact Information
The airplane came to rest inverted on plowed terrain about 3 nautical miles west of SBM on a magnetic heading about 300°. It remained intact with no post-impact fire. Depressions were found under the nose, upper wing, and rudder. The engine compartment, fuselage, upper wings, and empennage exhibited crushing and buckling consistent with ground impact. The canopy frame was under the inverted fuselage, and the canopy was fragmented. No baggage or ballast was found in the aft baggage area.
A postaccident examination revealed the fuselage fuel tank had impact damage. Flight control tube separations were consistent with overload and first responder actions. Flight control continuity was established. The electric fuel pump emitted a blue liquid consistent with 100LL fuel when powered. Air pressure application indicated leaks at the gascolator and fuselage tank. Propeller blades were separated from the hub; no chordwise abrasion on curved backs. Wooden rib sections were found embedded in the ground scar. Engine compression was observed in all cylinders. Both magnetos produced spark. The fuel servo screen had no debris; servo contained blue liquid consistent with 100LL. Fuel distribution valve had liquid sheen. A liquid consistent with 100LL exited the engine-driven fuel pump port when its lever arm was manipulated.
Medical and Pathological Information
The Sheboygan County Medical Examiner's Office performed an autopsy on the pilot; the cause of death was multiple injuries. Toxicology testing by CAMI detected 21.78 ug/ml acetaminophen and salicylate in urine. CAMI described acetaminophen as a common over-the-counter analgesic (Tylenol) and salicylate as an over-the-counter analgesic for mild pain.
Weight and Balance Calculations
The airplane manufacturer calculated weight and balance using data from April 16, 2016, and occupant weights at various fuel loads. At full fuel, weight was about 1,623 lbs with CG at 95.49 inches. At half fuel, weight was about 1,554 lbs with CG at 96.15 inches. At minimum fuel, weight was about 1,519.5 lbs with CG at 96.49 inches.