N6269R

On September 8, 1998, at 1900 central daylight time (cdt), a Culver-Revolution Mini 500, N6269R, piloted by a private pilot, was substantially damaged when it collided with the ground shortly after a total loss of power while hovering. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot reported no injuries. The flight departed Eden Prairie, Minnesota, at 1850 cdt.

The pilot said he had been hover-taxiing the helicopter between the approach end of runway 36 and the south taxiway for runway 09R. He said he had been hover-taxiing for about 10-minutes when "...the engine stopped unexpectedly [and it] settled to the runway and rolled over."

The on-scene investigation revealed no anomalies with the airframe, engine or control system that would prevent flight. Examination of the fuel system revealed a silicon-type sealant had completely blocked the supply side of the fuel filter.

According to the pilot/builder, he had used this material as a seal between the helicopter's fuel tank filler neck flange and fuel tank body. The helicopter's kit manufacturers instruction states that the builder is to "Place a 1/8-inch bead of MA300 from the adhesive kit around [the] hole circle through the centerline of [the mounting] holes." A copy of these instructions are appended to this report.

The kit manufacturer was contacted regarding the accident and pilot/builders use of the silicon-type material. The manufacturer representative was asked if there were any warnings in the construction manual against the use of the silicon-type sealant as the builder had done. He said there were no warnings, only instructions to use the MA300 material. He said the MA300 is an epoxy- type glue/sealant that does not break down when contacted by gasoline. He said the silicon-type sealant will dissolve when contacted by gasoline. The IIC suggested the company publish a manual change or communicate the need to use only the sealant recommended by them. The company representative agreed and said they would put a notice in the next builder's newsletter. A copy of the company's December 1998 newsletter is appended to this report.