This section of Air Cache will eventually be a weekly contest with prizes and bragging rights, but as we get the website off the ground, it will just be informative for now.

An H-13 with med-evac panniers (U.S. Army photo)

An H-13 with med-evac panniers (U.S. Army photo)

Radar O’Reilly could always hear them coming before anyone else — the choppers, bringing the day’s wounded from the battlefields of the Korean War. The chopper was so central to “M*A*S*H” that sometimes only the sound of the spinning blade could signal drama about to unfold.

There is a particular poignant episode, “Dr. Pierce and Mr. Hyde” where the main character, Hawkeye, goes three days without sleep as the wounded keep coming and coming aboard the helicopters. Whenever he hears the sound of the choppers, he reacts like Pavlov’s dog.

The unique-looking bubble canopy helicopter is almost as unique as the television show itself, but what helicopter did “M*A*S*H” feature?

It is the Bell H-13 “Sioux” light helicopter. It was developed from the Bell 47 model built by Texas’s own Bell Helicopter.

The H-13 had a long and storied history in all five branches of the United States armed forces and those of many other countries as well. More than 2,400 were built, including hundreds built by Westland Helicopters for the Royal Air Force.

The “Sioux” was extremely reliable and utterly simple to fly, as far as helicopters go. The helicopter served U.S. forces from the late 1940s through the start of the Vietnam War before it was replaced by the Hughes OH-6 “Cayuse,” based on the MD 500. A variant of the MD 500, called the MH-6 “Little Bird” is in service to this day and was the smaller helicopter featured in the book/movie/real-life battle “Black Hawk Down.”

The “Sioux” was used for observation and medevac missions. It was also used as a trainer. It could be armed with machine guns, but the recoil put too much of a strain on the chopper’s engine, and it was rarely used in an armed role.