On September 28, 2023, about 1830 central daylight time, a Powrachute Pegasus powered parachute, N31520, was substantially damaged when it was involved in an accident at Caddo Mills Municipal Airport (7F3), Caddo Mills, Texas. The pilot sustained serious injuries and the passenger sustained minor injuries. The aircraft was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot reported that he had flown the aircraft for an hour earlier that day without issue. Before the accident flight, there were no anomalies noted during the preflight inspection. During the rolling preflight, he observed the wing was inflated overhead and he did not notice any anomalies with the wing or the control lines. Shortly after takeoff, about 60 ft above ground level (agl), the pilot experienced an uncommanded left turn, so he continued the turn and intended to land. He descended and maneuvered to avoid colliding with power lines, then impacted a parked trailer during the landing roll.

The passenger reported to a law enforcement officer that after takeoff the pilot stated that there was a problem and that the parachute was tangled.

Postaccident examination of the wreckage by a Federal Aviation Administration (FAA) inspector revealed the powered parachute’s tubular frame was fractured. The wing’s control lines and risers were attached to their respective mounting locations and flight control continuity was established from the airframe to the wing.

According to the FAA Powered Parachute Handbook, FAA-H-8083-29, “pressure knots are harder to determine during a rolling preflight. It may be very hard to see what is going on with the lines themselves, so the pilot may find it better to look for deformations on the bottom surface of the wing caused by one line being pulled more than it should be.” The handbook also notes that,

Small twigs, stems from weeds, and other debris can get caught in the lines to form pressure knots. Pressure knots are a concern because they are only “knots” when there is tension on the lines. That means they are only a problem when your wing is inflated. As soon as you land, the foreign object often shakes free and there is no knot. However, while you are flying, that pressure knot can cause the powered parachute to go into a steep turn. Make sure there is nothing around to catch into your line sets.

It continues,

During the inflation and takeoff roll, you need to divide your attention between the direction the cart is going and the wing. When the wing is overhead, perform the “rolling preflight.” You need to quickly inspect the wing to make sure it is fully inflated and there are no line-overs, end cell closures, pressure knots, or huge oscillations before adding full power for takeoff. This all has to be done with quick glances.