<p>A product of the Aero Design and Engineering Company, the Commander series of high-wing twins was highly successful through a succession of variants in the civilian world, later being acquired by Rockwell and marketed under that manufacturer's name. Small numbers were procured by both the Army and Air Force for transport and other tasks.
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<p>The first USAF aircraft was a single YL-26A acquired for evaluation purposes, essentially the civilian Model 560 powered by Avco Lycoming GO-480-B engines of 270 hp. The successful outcome of these trials was the purchase of 14 L-26B aircraft, these being Model 560As with the uprated GO-480-C1B6 engine of 295 hp. One of these was used as the personal aircraft of President Eisenhower, and all were subsequently redesignated U-4A.
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<p>Two more Commanders were bought by the Air Force, both for presidential transport duties. These were designated L-26C (later U-4B) and were similar to the civilian Model 680 Super. They differed primarily by having 340-hp supercharged GSO-480-A1A6 engines.
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<hi style=hdr1>Specification</hi>
<hi style=hdr2>Aero Commander—U-4A</hi>
<list style=aflst>
<item><hi format=bold>Type:</hi> five/seven-seat staff transport
<item><hi format=bold>Powerplant:</hi> two Avco Lycoming GO-480-C1B6 piston engines, each rated at 295 hp
<item><hi format=bold>Performance:</hi> maximum speed 250 mph; service ceiling 19,400 ft; range 1,500 miles
<item><hi format=bold>Weight:</hi> maximum take-off 7,000 lb
<item><hi format=bold>Dimensions:</hi> wing span 49 ft 6 in; length 35 ft 111/2 in; height 14 ft 6 in
