Interstate L-6 “Grasshopper” By The Interstate Co. entered the aviation industry in 1940 with the S-1B "Cadet," a tandem seat liaison airplane. When the United States entered World War II, the U.S. Army Air Forces contracted with Interstate for 250 S-1B aircraft, designating the prototype as the XO-63. It was the last airplane to use the "O" (for observation) designation. Later, the USAAF designated the production airplane as the L-6. The aircraft, however, had significant overheating problems that were only partially solved. It had the dubious distinction that fewer L-6s were built than any other USAAF liaison aircraft. The USAAF used the L-6 as a utility transport, liaison and training aircraft in the United States but never shipped it overseas. After the war, the remaining L-6s were sold as surplus. TECHNICAL NOTES: Engine: Franklin XO-200-5 115 hp Maximum speed: 105 mph Range: 540 miles Span: 35 ft. 6 in. Length: 23 ft. 5.5 in. Height: 7 ft. 3 in. Weight: 1,650 lbs. loaded Serial number: 43-2680 Click here to return to the World War II Gallery.