N1949HKnott Vernon W ZENITH 750 · 2011

On September 7, 2022, about 1520 central daylight time, a Zenith 750, N1949H, was substantially damaged when it was involved in an accident near Silex, Missouri. The pilot sustained minor injuries and the pilot-rated passenger sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot reported that, during takeoff of the first flight after assembly, the airplane lifted off the ground about 400 ft down the 1,100-ft turf runway. During the initial climb, the pilot turned right to avoid a rural power line at the end of the runway. The airplane subsequently impacted the powerline and terrain, which substantially damaged both wings and the fuselage.

The pilot reported, and a postaccident examination corroborated, that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The pilot observed the airplane’s “Y” yoke, located between the two pilots’ knees, made pitch control more difficult, as compared to a control wheel or control stick.

The airplane’s weight during the takeoff was estimated to be 1,291 lbs. The accident airplane was equipped with a Jabiru 120 HP engine and the density altitude during the accident was calculated to be 2,234 ft. Takeoff performance information for the accident airplane was not available to the pilot.

At the airplane’s maximum gross weight of 1,320 lbs, the kit manufacturer’s takeoff performance information indicated a takeoff roll of 100 ft and climb rate of 1,000 ft per minute with a 100 horsepower (HP) engine at sea level. According to the pilot, takeoff performance information contained in kit manufacturer advertisements were unrealistic for most conditions.

A pilot operating handbook (POH) was released in March 2009 by a company producing factory-built airplanes. The POH included takeoff performance information with turf runway corrections. At the airplane’s maximum gross weight, 3,000 ft density altitude, and equipped with a 100-horsepower engine, the POH listed the takeoff roll from a turf runway as 552 ft and the distance to clear a 50 ft obstacle as 960 ft. The pilot was not aware of takeoff performance information from this POH.

The Experimental Aircraft Association (EAA) Flight Test Manual includes the following information regarding takeoff performance:

Knowing your airplane’s takeoff performance is key to planning safe departures, especially on short runways and on different surfaces.

To account for performance variation caused by environmental factors, such as wind or density altitude, always add a margin of safety.

The pilot reflected that a better risk management decision for the initial takeoff would have been to depart solo and meet the pilot-rated passenger at another airport with a longer runway.