History of Flight
On July 27, 2015, at 1947 central daylight time, a Wheeler Express amateur-built airplane, N3FC, was substantially damaged after impacting terrain near Holland, Minnesota. The pilot and two passengers were fatally injured. The airplane was registered to and operated by the pilot under 14 CFR Part 91 as a personal flight. Day visual meteorological conditions prevailed, and no flight plan was filed. The local flight departed Pipestone Municipal Airport (PQN) about 1932.
Air traffic control radar track data showed the airplane proceeded 4 miles northeast of PQN and performed several turning maneuvers between 2,100 and 3,400 ft msl. It then climbed and continued northeast for 4 miles, overflew Holland at 6,600 ft msl, turned right, and proceeded south about 1 mile. Over the accident site at 6,200 ft msl, the airplane turned right and entered a rapid descent. The last two radar returns, 12 seconds apart, were at 5,400 and 3,600 ft msl.
A witness about ¾ mile from the site observed the airplane spin about 1 to 1½ revolutions in a nose-down attitude. The witness heard the engine sputter twice followed by a loud bang.
Personnel Information
The pilot, age 59, held a private pilot certificate with airplane single-engine land and instrument ratings, and a repairman certificate for experimental aircraft builder. On December 6, 2013, he was issued a Class 3 medical certificate with a limitation requiring glasses for near vision. The pilot had logged 1,204 total flight hours, with 475 hours in the accident airplane. In the last year he logged 36 hours, and 7 hours in the last 90 days in that airplane.
Aircraft Information
N3FC was an experimental amateur-built airplane based on the Wheeler Express design. The four-place, low-wing airplane was completed by the pilot in August 2008, equipped with a cruciform tail (mid-mounted horizontal stabilizer). The fuselage and empennage were composite, powered by a 260-hp Lycoming IO-540-C4B5 engine. On October 1, 2014, a conditional inspection was performed at 481.4 airframe hours.
The airplane carried a Chelton (Sierra Flight Systems) EFIS, a Garmin 12-channel GPS, and an Appareo Stratus unit containing an AHRS, GPS receiver, and ADS-B receiver.
Meteorological Information
At 2014, the weather observation at PQN, 7 miles southwest of the accident site, reported wind 150° at 5 knots, 10 miles visibility, clear skies, temperature 27°C, dew point 22°C, altimeter 29.83 inHg.
Wreckage and Impact Information
The airplane impacted a grassy drainage ditch adjacent to a corn field and came to rest upright. Both wings and fuselage showed damage consistent with high vertical and low forward speed impact.
Examination at a recovery facility found two propeller blades bent aft, one relatively straight with minimal rotation. Top spark plugs were automotive Denso 27 Iridium Racing plugs, bottom were Champion REM40E; both appeared normal. Crankshaft rotation established compression on all cylinders and drive continuity. Cylinders borescope inspection revealed no anomalies. Flight control cables from cockpit to surfaces remained attached; flaps were up. No mechanical malfunctions or failures precluding normal operation were found.
Additional Information
The airplane's flight manual listed level flight stall speed with flaps retracted at 55 knots IAS. An FAA/EAA-sponsored performance report on the Wheeler Express (1997) noted the design debuted at the 1987 EAA Oshkosh fly-in. A fatal accident in 1990 led to kit sales contraction and the original designer's company bankruptcy. Seventeen owners later developed a variant with a larger tail (40% more wetted area).
Eight test flights with the original (smaller) tail in 1997 showed that the cruciform tail, wide fuselage, and highly swept vertical stabilizer combined for low yaw stability. The report indicated that during post-stall and high yaw maneuvering, the horizontal tail and elevators appeared inadequate.
Medical and Pathological Information
An autopsy on July 29, 2015, determined the pilot's cause of death as blunt force injuries. FAA toxicology tests on the pilot were negative.
Tests and Research
Recovered avionics (Chelton EFIS, Garmin GPS, Appareo Stratus) were examined. The Garmin and Stratus contained no data from the accident flight. EFIS data matched radar tracks: as the airplane flew over the accident site, it pitched up to 34° nose high at low engine rpm, indicated airspeed decreased to 48 knots while banking 47° right. As the bank steepened, engine rpm increased, and the airplane pitched down to 84° nose low, then descended in a right-turning upright spin until impact. No engine anomalies were noted in the EFIS data.