The second Palmer trike, the Skyhook (FAA registered N4411) in spite of its early date of origin, had most of the attributes of a modern ultralight trike, except it used a single cylinder snowmobile engine, as the two-stroke twin cylinders were not available yet. It was powered by a 17 hp (13 kW) at 5000 rpm single cylinder JLO L297 two stroke engine, driving a composite propeller designed and built by Palmer himself and driven by a 2.1/1 reduction gearbox. The engine had electric start and the craft had fiberglass composite spring landing gear.

 

The airframe consisted of bolted 6061-T6 aluminum tube, with 6061 T-6 extruded angle. The craft took off, flew, and landed at about 30 mph (48 km/h). Palmer’s trikes were not developed further and remained in obscurity. Palmer moved on to design a successful line of personal hovercraft.