It is unclear how may Mini-500s have been built, with the company claiming to have sold over 500 Mini-500s kits with more than 400 built and flown, it has also been claimed by critics that no more than 100 have been actually built and flown.
[1] On 10 February 2010, 172 Mini-500s remained on the
Federal Aviation Administration registry, with an additional 81 registrations cancelled. (Although registered, this does not indicate these aircraft have flown.)
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Of those that did fly there were many component failures, dozens of accidents and incidents and nine fatalities. The aircraft quickly developed a poor safety reputation and this curtailed kit sales.
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The
Rotax 582 two stroke engine proved to be underpowered in this application and many failed in flight. The engine's vibration levels also proved to be a problem as they, combined with excessive rotor vibrations, lead to cracked frames and other component failures.
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Owners complained that the aircraft was not well designed. The president of the International Experimental Helicopter Association, the Mini-500
aircraft type club, Bill Phillips, who completed a kit, but did not fly it stated: "You can tell it is junk just by looking at it" and described Revolution Helicopter Corporation president Dennis Fetters as "one of the biggest cons that’s ever hit the kit industry".
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Fetters strongly denied that the design had safety issues and issued statements indicating that all accidents were due to improper maintenance, failure of builders to carry out rotor tracking and balancing or lack of piloting skills. In response to customer complaints in 1998 Fetters did add a tuned exhaust system to increase engine output, stronger transmission gears and a mast support kit to reduce vibrations.
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Это не мои слова, а от настоящих экспертов.