Friday, September 22, 2017
In CHASING DRAGONS, Duke Kellogg explains to his co-pilot Edwina “Eddie” Watt the legend of Mag Check Charlie. This legend was born on Wake Island (where I initially heard the story in 1971.) During WWII, pilots transiting Wake were told of a 15-foot tiger shark named Mag Check Charlie. Before I tell you how the story goes, I need to give you a little background.
An aircraft piston engine differs from an automobile engine primarily in its ignition system. An automobile has one spark plug per piston, an aircraft engine has two…a left and a right. This is done for redundancy. As long as either is working, the engine runs fine. All the left spark plugs are run off the left magneto and all the right spark plugs off the right. Magnetos are electric generating devices that are mounted on the engine. As long as the engine is turning they work. This is unlike a generator on a car. If the belt breaks or the generator fails, the engine stops. That won’t do in an airplane.
Prior to takeoff, the pilot checks each magneto system by switching one off at a time. If the opposite magneto is working, the engine runs fine, but at a slightly lower RPM. He repeats for the second magneto.