Stinson’s Big-Guy L-Bird: L-1 Vigilant
As soon as the airplane joined motorized ground vehicles as tools of war, its ability to see over the horizon made it an invaluable tactical device. It was more mobile than a tethered balloon and could be used to transport messages and leaders from point to point, whenever and wherever it was needed. There was one disadvantage, however: An airplane needed a relatively flat, longish piece of ground from which to take off and land. Then Germany’s newly formed Luftwaffe brought the Fiesler Fi 156 Storch to the 1938 Cleveland Air Races. It was seen as the vehicle of long-distance adventurers and airline pioneers.
American military planners observing the races saw a clear definition of the term “short takeoff and landing,” later known as “STOL.” The Storch could work out of a tennis court, and the U.S. government promptly put out a request for proposal to aircraft manufacturers to devise such a machine.
Three companies were selected to build prototypes of their proposed designs: Stinson (O-49), Bellanca (YO50), and Ryan (YO-51 Dragonfly). The O-49, known within the company as the “Model 74” and later named the “Vigilant,” was the winner. Incidentally, the Army changed the “O” for “Observation” to “L” for “Liaison” in 1942, and the O-49 was the first to wear the new designation as the L-1. (For even more confusion, shortly after the plane entered production in 1941, Stinson was absorbed into Vultee, which became Consolidated-Vultee.)
The L-1 was a study in specialty engineering, both structurally and aerodynamically, and was a relatively complex airplane. Everything in it was aimed at producing an aircraft that needed very little forward speed to fly. Besides having huge wings (50 feet, compared to a Mustang’s 37), its flaps were gigantic and went down 43 degrees, with the ailerons drooping 20 degrees at the same time. As if that weren’t enough to generate more lift,
the movable Handley-Page leading edge slats would slide out automatically, letting the wing fly at higher-thannormal angles of attack. Of course, getting 300hp out of the Lycoming R-680-13 in the nose helped.
Pat Harker of C & P Aviation, in Anoka, Minnesota, restored and owns the Oshkosh award-winning L-1 pictured here—one of only three still flying. “I have yet to get it to actually stall,” he says. “The slats start to slowly drift out automatically around 55mph, and it’ll get down to around 22mph with the controls still feeling totally normal. However, you’re still not in a nose-high attitude. You can bring it down over the runway with practically no ground speed, chop the power, plop it on, get on the brakes, and you roll almost no distance at all. It’s amazing. And it’s huge fun!”
Only 324 Vigilants were built, before being replaced on the Stinson production line by the firm’s own L-5 Sentinel (3,896 built). Most surviving L-1s migrated to Alaska, where they were worked to death, but their bones lasted long enough to be collected and rehabilitated by the likes of Pat Harker and Fantasy of Flight’s Kermit Weeks.
Above: According to Pat Harker, the owner/restorer/ pilot, the centermounted gear “waddles” a little but absorbs landing shocks with almost no rebound.
Left: Almost unnoticeable in the blizzard of original detail and tubing are complicated pieces, such as the Y-shaped, compound-formed aluminum cover over the rear control cables. The airplane abounds in such complexities.
Above, right, and below: As part of the Air Transport Command, the airplane was modified for many purposes: in the air, on the ground, and in the water. It was to be “utility” personified. (Photos courtesy of Stan Piet)