Transport: Low Level

About six weeks ago American Airlines got a new advertising agency—Blackett-Sample-Hummert, Inc. Shortly afterward there began to appear in newspapers and magazines large advertisements, decorated with a photograph of an exuberant girl in a bathing suit and captioned rhetorically: Is there a Low-Level Airway through Southern Sunshine to California? "Fortunately" said the advertisement, "the answer is—YES."

The main American Airlines route across the country slants off from Newark southwest through Washington and Memphis to Fort Worth, then skirts the Mexican border and enters Los Angeles from the south. American also has a line from Chicago to Los Angeles through St. Louis and...