The Tribune photo, dated May 11, 1942, has the folloing caption on the back: "This is a fighting base, not a repair depot, but no plane goes out unless it is in top mechanical condition. Here mechanics repair one motor before the interceptor is sent out again. They are as vital to the pilot as the guns he uses." The location of the shop is Mills Field, as San Francisco Airport was also known. Two men are kneeling on the wing of what appears to be a Lockheed P-38 fighter plane. They are at work on the engine, whose nacelle [the covering of the engine JM 2/21/2001] has been removed.