Production. Airplane manufacture, general. Sorting rivets may seem a lowly task in the making of war planes. But it plays an essential part in the mass production of aircraft and in the conservation of vital materials. These workers at the Long Beach, California, plant of Douglas Aircraft Company help to keep many others working. Most important of the many types of aircraft made at this plant are the B-17F ("Flying Fortress") heavy bomber, the A-20 ("Havoc") assault bomber and the C-47 heavy transport plane for the carrying of troops and cargo