And now for something truly different - STOL Redefined
Text and Photos by Budd Davisson, Air Progress, Aug, 1990

Let’s talk about funky airplanes. While we’re at it, let’s mention relatively unknown airplanes. Then, let’s get into humongous and wildly STOL machines. However, in the interest of brevity, let’s roll all those factors into one airplane and call it the Convair L-13.

As we were headed towards the numbers at Winter Haven, Florida in Dan O’Connell’s L-13, I kept telling myself that this was absolutely crazy. We were so close to the runway, I couldn’t even see the numbers over the end of that stubby R-680 Lycoming and we were still at something like 800 feet. The airspeed was on 60 mph, which is a fairly normal approach for the L-13 and Jack Yount in the left seat said, “Crank the flaps out.”

L-13 Panel
What is not obvious from this picture is that the flight deck actually is a "deck" and has to be five feet wide with Plexiglass everywhere you look.

I had played with the flaps earlier in the flight and knew I wasn’t about to go for full flaps. As I toggled the switch in the middle of the panel and those gigantic boards started coming out of the wings, even though I stopped them at 2/3rds extension, the nose was going down, down and then down some more. I looked over and Jack was also on the controls, and for good reason: To maintain 60 mph, the nose was down nearly 45 degrees ande we were coming down like a de-fuzzed dandelion in a slow speed ballistic trajectory toward the runway. To gain any meaningful information, I should have timed the rate of descent, but I couldn’t take my eyes off the rapidly approaching numbers. Then, I couldn’t believe it when I saw them moving up in the windshield, indicating we were going to be short and a little power was screwed in to insure makaing the runway. Well past the point a normal airplane would have been flaired, Jack woke up a bunch of ponies with the throttle and rotated just in time to put the gear on the ground. At the same time, the air speed needle clanked against the bottom of the dial.

That was the final landing in one of my more interesting 60-minute fight evaluations. In many ways the Convair L-13 is truly a unique airplane. At the same time, it has to be one of the least known mass produced airplanes used by the post war military. Even the most hard-core military and civilian enthusiast is likely to puzzle over what the airplane is. This is the general state of the L-13’s image, even though the  military took delivery of 300 between 1946 and 1947.

As originally designed and built, the L-13 was to be equipped with a 245 hp, six-cylinder Frankling0-425-9 of questionable heritage. A multi-mission airplane, it was supposed to be the ultimate in liaison birds, meant to carry as many as six people, a camera assembly and two litters side-by-side. It was to be a flying 4x4 truck, or maybe a Jeep.

Originally designed by Stinson and produced by the Consolidated Vultee Division of Convair, the structure was pretty unique. The main cabin section, from the firewall to the tailcone, was steel tube — almost all of which was exposed because of the overwhelming use of plexiglass and the total lack of anything even remotely resembling an interior. The upholstery was straight military is-sue — zinc chromate applied with a spray gun. Provisions were made on the right side for every inch to be opened when putting litters in place. The small diameter tailcone was of monocoque aluminum structure going back to a tail which featured a super-high position for the horizontal tail to keep it out of the way of short trees and tall bushes.

The wings are the usual all-metal construction, but feature a set of slotted flaps that could easily double as wings for practically any homebuilt. They probably run the lift coeff of the wing out the roof for the first 15 degrees but from that point on, the drag rise is right off the scale.

The neatest feature of the airplane is the fit-in-the-box design. Using a Jeep as a standard unit of measurement, the military had the engineers design the machine so it could be towed through a hole just large enough to accept a Jeep (height obviously not-withstanding), meaning the wings folded back up against the tail, the stabilizer folded upward and the landing gear legs each rotated 180 degrees, which reduced its tread to that of a Jeep. Imagine pulling up behind one of those on Interstate 80 some early Sun-day morning, as it was trucking along behind someone's VW on the way to the airport. The driver would look like he had a giant sleeping Katy-Did in tow.

The military seemed obsessed with being able to deliver the airplane in unique ways so, besides designing it to slip into a box, the L-13 was also designed to be towed behind C-47s. Its own internal fuel gave a range of 398 miles which would normally be pretty short, unless it was hung on the rear of a Gooney Bird which gave it a range (most of which was one-way) measured in the thou-sands. Apparently, they could hang the plane on a rope, drive the Gooney Bird to where the L-13 was needed, cut it loose, and the L-13 would fire up and trundle merrily on its way. Weird concept!

All the L-13s were taken into the military in a matter of a year and a half and they were just as quickly spit back out shortly after Korea. Ramp rumors say the military had severe and unsolvable problems with the Franklin engine. According to equally unsubstantiated but official sounding scuttlebutt, the military had contracted for an engineering mod for replacing the Franklin with a 300 hp R-680 Lycoming radial. This didn't do much for the air-plane's already toad-like streamlining, but it was a known quantity and the military probably still had hundreds of engines sitting around in dark warehouse corners left over from the Bamboo Bomber days.

Whether the round engine mod tales are true or not is unimportant since the government got rid of the airplane before they modified any. Almost as soon as the airplane hit the streets as a civilian, the round Lycomings were nailed in place.