Stinson L - 1 Vigilant The Stinson L - 1 Vigilant ( company designation Model 74 ) was a 1940s American light observation aircraft built by the Stinson Aircraft Company at Wayne , Michigan ( by November 1940 a division of Vultee Aircraft Corporation ) . The aircraft was operated by the United States Army Air Corps as the O - 49 until 1942 . Design and development . The Vigilant was designed in response to a 1938 United States Army Air Corps design competition for a two - seat light observation aircraft . When the German - manufactured Fieseler Storch was demonstrated at the Cleveland Air Races , the Air Corps revised its specifications in an attempt to match the performance of the Storch . Stinson ( later a division of Vultee ) , won the $ 1 . 5 million contract over 11 competitors , including the Bellanca YO - 50 and Ryan YO - 51 Dragonfly . The Model 74 was a single radial engined high - wing monoplane with trailing - edge high - lift devices for low speed and high lift performance . The prototype aircraft was built full - span leading - edge automatic slots manufactured by Handley Page , and slotted flaps . The Model V - 74 was given the Army designation YO - 49 for evaluation , with the first flight by test pilot Al Schramm on 15 July 1940 . The aircraft was built of steel tubing and fabric , with the fuselage forward of the wing enclosed in sheet metal . Control surfaces and the empennage were fabric - covered stainless steel . The Lycoming power plant was hand - cranked inertia starting , and was fitted with a Hamilton Standard constant speed propeller . At least 12 ambulance conversions were fitted with Edo 49 - 4000 pontoons ( 4 , 000 - pound displacement ) for amphibious landings and takeoffs . The Vigilant was capable of stopping in less than its own length , and could maintain stable flight at 31 miles per hour . Anecdotally , the Vigilant was said to be capable of backwards flight in a strong headwind . Operational history . The Stinson Vigilant was used in diverse roles such as towing training gliders , artillery spotting , liaison , emergency rescue , transporting supplies and special espionage flights . Another contract was later awarded for the O - 49A which had a slightly longer fuselage and other equipment changes . In April 1942 the aircraft were redesignated the L - 1 and L - 1A ( liaison ) . Up to 17 L - 1 and 96 L - 1A aircraft were allocated to the British Royal Air Force under the Lend - Lease Act , with varying numbers given for aircraft actually delivered ( see Variants , below ) . The RAF designated the aircraft the Vigilant Mk I and Vigilant Mk II respectively . General Harry Crerar , Commander of the First Canadian Army in Europe during World War II , maintained a Vigilant for his personal use . Aircraft were modified for a variety of roles including as an ambulance aircraft . No further production orders were placed as the aircraft was superseded by procurement of vast numbers of the L - 5 Sentinel and L - 4 Grasshopper " puddle - jumper " aircraft . A Vigilant was modified in 1943 - 44 for experiment in boundary layer control . Five examples of the Stinson O - 49 Vigilant currently survive in museums in the United States . The one owned by the Fantasy of Flight museum in Polk City , Florida , was returned to flying condition , and flew in July 2013 .