Le Rhone Rotary Engine Startup on 1917 Thomas-Morse Scout

A Biplane From 1917

It’s not every day we see a decades-old biplane start up its engine, yet here we are.

This Thomas-Morse S-4 Scout was America’s preferred single-seat training airplane during WWI. It is powered by a Le Rhone 9C rotary engine capable of producing 80 horsepower. 

These air-cooled engines helped the Scout achieve a maximum speed of 97 mph and a service ceiling of 15,000 feet.

As you can see, the Scout needs to be primed manually by spinning its two-bladed propeller. The whole process took three tries for the biplane to finally start.

The two-minute wait was worth it, though, as we finally heard the distinct sound of its 80-hp engine. 

Surprisingly, this S-4C (38898) is still airworthy today. You might be able to catch this old bird at the Eagles Mere Air Museum in Pennsylvania if you’re lucky!