Over 39,000 of these engines were built, and many are still in service today.
Over 1.2 million engines in the series have been built.
Just eight years ago, the 30-man crew was using an engine built in 1957.
The R-540 sold well at first, with over 400 engines being built in 1929.
Next came a 301cc engine built on a new platform.
One way to address this issue would be to build larger engines.
Their engines are built to travel at about half the speed they're moving.
It's possible that the engine can be built at home from plans or a kit.
Also in many parts of the world are engines built to his designs.
Ten more engines were then built to this modified design.