History of Flight
On August 24, 2012, about 1800 eastern daylight time, an experimental Destiny XLT powered-parachute, registration N1674A, impacted terrain following a downwind turn at Silver Lake State Park near Hart, Michigan. The airline transport pilot and the passenger sustained fatal injuries. The powered-parachute's frame structure sustained substantial damage. The aircraft was registered to and operated by the pilot under 14 CFR Part 91 as a personal flight. Day VFR conditions prevailed, and no VFR flight plan was filed. The flight's origination and destination are unknown.
Witnesses driving Jeeps on the sand dunes recorded a video showing the powered parachute flying above the dunes. The video captured the parachute turning into an area where wind flags indicated gusty downwind conditions. The cart porpoised and rocked fore and aft, while the parachute also moved fore and aft above the cart. The left side of the parachute deformed and collapsed, leading to a descending left spiral. During the descent, the left side reinflated, and the powered parachute impacted the terrain nose-down with an inflated canopy.
Personnel Information
The 66-year-old pilot held an FAA Airline Transport Pilot certificate with an airplane multi-engine land rating, commercial privileges in gliders and single-engine land/sea airplanes, and flight instructor ratings in gliders and single/multi-engine airplanes. He held a second-class medical certificate dated December 30, 2010, reporting 24,500 total flight hours and 200 hours in the preceding six months.
Aircraft Information
N1674A was a Destiny XLY powered parachute, serial number 4C0633, powered by a Rotax 582 DCDI engine driving a 64-inch, ground-adjustable IVO Prop propeller.
Meteorological Information
At 1754, weather recorded at Fremont Municipal Airport near Fremont, Michigan, reported wind from 150 degrees at 5 knots, visibility 7 statute miles, clear sky, temperature 30°C, dew point 13°C, and altimeter 30.02 inches of mercury.
Wreckage and Impact Information
The wreckage impacted sand dunes at Silver Lake State Park. An FAA inspector examined the scene and, together with a review of the amateur video, found no pre-impact anomalies.
Additional Information
The FAA Powered Parachute Flying Handbook notes that a ram-air wing retains its airfoil shape through air pressure from relative wind entering the front openings. Greater speed increases internal pressure and wing rigidity.
A powered parachute flight instructor who reviewed the accident video communicated observations to the NTSB. He noted that two additional links per side had been added to the rear risers, raising the rear of the chute about 3 inches. Additionally, the front lines appeared knotted, possibly to shorten them. He believed these modifications decreased the angle of attack, contributing to the collapse when gusts and a downward pitch occurred.
An Accredited Representative from Israel's Ministry of Transport also reviewed the video and reports. He stated that the modifications—a knot on the front lines shortening them by 15–20 mm, and two extra links on the back riser adding about 130 mm—reduced the angle of attack by approximately 3 degrees at the wing center and 6.5 degrees at the wing tip. Normal angle of attack is around 16–17 degrees, making this reduction 30–40%, decreasing stability and collapse resistance. The modifications increased flight speed by about 10–15 kph but hindered the wing's ability to recover from a collapse. The representative observed that the pilot pushed both legs forward after the collapse, which did not allow proper correction. He also noted wind flags indicating 20–30 kph winds, a speed difference between downwind and headwind segments, and turbulence from hills near the collapse point.