Você paga quanto? Eu tenho um pra vender

Although the Japanese copter has two scary-looking single points of failure: 1. A Subaru automotive engine. 2. A large belt coupling it to the rotors.

@@Baribrotzer oh that changes things

​@@Baribrotzer 1. What's wrong with the Subaru engine? Aftermarket parts are widely availble to fix any common problems. It's better than having to just deal with it if it was a certified engine. Valve sticking and spark plug fouling are common due to the mandated use of leaded fuel in certified engines and both cause severe loss of power. 2. What's wrong with a belt drive? They make a lot of sense for aviation applications. They are lighter than either gears or chains, and much simpler, as well as not reliant on the major point of failure common to both chains and gears that is lubrication. Lubrication systems are often not as simple as just an oil bath, in many cases, pumps and coolers are needed. For chains, complex tensioners are needed to deal with significant stretch over time, something that modern carbon fiber belts have eliminated. Belts also absorb vibrations which would otherwise require a complex and heavy damper, or risk catastrophic rotor blade failure due to metal fatigue.

@@quentagonthornton49 1. What's wrong with the Subaru engine? It wasn't designed as an aviation engine - which are typically lightly stressed, mechanically simple, of large displacement but low weight, fairly slow-turning, and designed to run at near full-throttle for hours. They're optimized for reliability. Auto engines aren't, they're optimized for cost and power. 2. What's wrong with a belt drive? It can catastrophically fail, and fails all at once.