Photo courtesy NASA
B-25 bomber's are equipped with radial engines.  See more pictures of radial engines.
If you have ever seen a World War II bomber like the B-25 or the B-17, or if you have ever seen or been on an old commercial airplane like a DC-3, then you are familiar with something called a radial engine. Many planes of the­ WWII era used very large, very powerful radial engines to drive their propellers.

In this article, you will learn how the radial engine works, what makes it different from other engine configurations and why it fits in so well with airplanes.