During the development of the Ryan Air aircraft which eventually Charles Lindbergh (played by Jimmy Stewart) flies non-stop to Paris-

After a test flight for duration (about 18 continuous hours), Lindbergh lands and exits the plane, walking alongside to check for flight damage, and walks up to the HOT exhaust fins of the 12 cylinder rotary engine and places his bare hands right upon them! No obvious reaction was made, as this was an oversight by the Producer.