MONSTER TAILDRAGGER. The Antonov AN-2 Colt was introduced in 1949 as an ultimate utility design, certified at a gross weight of up to six tons. It was produced intermittently through 2002.
One of the most common questions I get has to do with the most unusual aircraft I've flown. Lord knows, there have been a plethora of amazing flying machines that have rocked my world over the last 46 years. Since you asked, the total is something like 311 types of certified airplanes (plus probably another 200 or so non-type-certified homebuilts, ultralights and LSAs). I'm sure that's not anywhere near a record. My buddy Barry Schiff claims 325, and I don't doubt for a second that's an accurate number.
One obvious question arises: What comprises a type? For example, how many types are included in the following list: Piper Cherokee 140, 150, Warrior, 160, 180, Archer, 235, Dakota and T-Dakota, Arrow and T-Arrow? Is it 11, one or something in between? They're all PA-28s, but they feature two different airfoils, half-a-dozen different engines, some with turbos, and there are two models with retractable gear. I counted three types.
Any way you count them, the most unusual and slowest aircraft I've flown (excluding helicopters and blimps) is unquestionably the Russian Antonov AN-2 Colt. It's a monster of a taildragger, frequently touted as the largest single-engine biplane in the world. It was introduced in 1949 as an ultimate utility design, intended for everything from crop dusting and cargo hauling to dropping skydivers or transporting passengers.
The top wingspan is 60 feet, and the airplane is certified at a gross weight of up to six tons. The one I flew belonged to Buzz Gothard, at the time a marine engineer in Chehalis, Wash. Gothard had made several trips through Mumbai, India, in the late '70s, and noted a derelict Colt parked in a secluded section of the Bombay Airport. He made inquiries, found out the owner's name and offered to buy the airplane as was, where was.
He made the purchase, had the Antonov disassembled, palletized and trucked to the local harbor, hoisted aboard a ship, and transported across the Pacific to the Port of Seattle.
I flew the airplane three years later out of Gothard's private grass strip south of Chehalis. The owner had just finished a ground-up restoration that had consumed huge amounts of money and time.
The first time you see an Antonov Colt, you're reminded a little of a Ford Trimotor with one extra wing and two missing engines. The AN-2 has all the aerodynamic sophistication of a container ship, but like that machine, it hauls a spectacular load, as much as two tons. It stands some 16 feet tall, and there are struts, brace wires and supports everywhere.
There's little question the airplane is built hell-for-stout, and that's only appropriate since many Colts will spend their lives bouncing on and off unimproved dirt strips. To that end, the Colt has such bush features as an onboard fuel pump specifically for refueling from barrels, and air lines to the wheels and struts that allow air pressure to be adjusted in flight. Ailerons and slats cover the full span of the top wing, while flaps are mounted on the trailing edge of the bottom airfoil.
Predictably, maintenance can be a problem in the U.S. The builder said the good news was that 15,000 Colts of all varieties were produced. The bad news was that they were produced in Russia and Poland (and maybe China—no one is certain), and because of their tough missions, many are no longer serviceable. That means some parts aren't readily available and may need to be manufactured.
The Colt is powered by a Shvetsov ASh-62, radial engine, a Russian/Chinese powerplant built under license from Curtiss-Wright and a virtual copy of the Wright Cyclone R-1820. The Shvetsov employs nine cylinders, each with the displacement of a small Chevy V-8. Total rated power is 1,000 hp, only appropriate since max gross on the AN-2 I flew was 11,574 pounds. In other applications, the Colt can weigh in at as much as 13,000 pounds.
From takeoff to landing, the Antonov Colt was quite a bit different from any other airplane I had flown. It uses pneumatic brakes, ala Mack, Kenworth or Peterbilt, to maneuver on the ground, and you can hear the air system working as you use brakes and asymmetric thrust to control direction during taxi.
Gothard put me in the left seat for takeoff, and after runup on his 2,000-foot strip, I brought power to the limit, released the brakes, and we lumbered down the grass runway. The Colt lifted off in a quarter of that distance, elevating nearly automatically in the three-point position.
We climbed out at around 700 fpm and levitated to 3,000 feet. Predictably, the airplane handled like a six-ton pachyderm, but didn't seem to resent me wrapping it over to 60 degrees of bank in each direction. It manifests a certain locomotive sense of straight ahead, and though there's no autopilot, the Colt will happily fly hands-off for long periods.
When Gothard suggested we try some stalls, I was eager. I knew the huge wings would generate a ridiculously low stall speed, but I had no idea it would be as slow as it was. I reduced power on the big 1,000 hp Shvetsov radial and watched the airspeed wrap backward around the dial. As we decelerated, the Antonov's automatic leading-edge slats banged in and out together or independently when lift was asymmetric. Wrap the Colt into a steep turn, and the slats would adjust to help keep the wing flying.
Speed dropped through 60, 50 and finally all the way down to 40. At that point, the slats were fully extended and the Colt set up a gentle mush downhill, still under total control with no tendency to roll or manifest any other nasty characteristics.
I turned to Gothard and said, "That's impressive for such a big airplane, a 40-knot stall." Gothard smiled. "Those aren't knots," he said.
"Okay," I said, "Forty mph is even more amazing." The owner grinned even wider and said, "Those aren't miles per hour."
My God, I suddenly realized, the ASI was calibrated in kilometers. Stall speed was an indicated 40 kph, equal to 22 knots. Perhaps coincidentally, that's exactly what the book suggests.
Before we returned to land, I had time for a quick cruise check, though Gothard had already suggested speed wasn't the Colt's long suit. At max cruise power, the ASI finally settled on 165 kph, about 90 knots. That was in exchange for 45 gph.
With 770 square feet of wing and such a low stall speed, it's not hard to understand why the AN-2 can land and stop in less than 600 feet. I couldn't check the numbers, but the specs suggest the Colt is one of the few machines that can lift off in less distance than it needs to land. In other words, you can't land someplace you can't get back out of.
The Colt's docile nature at low speeds can be a lifesaver. The flight manual doesn't list a stall speed and even suggests an emergency, zero-zero, IFR procedure of slowing the airplane to minimum flying speed and allowing it to mush through the clouds into the ground.
(According to the manual, "When the airplane slows to a forward speed of about 40 kph [25 mph], the aircraft will sink at about a parachute descent rate until it hits the ground." If the AN-2 is straight and level at touchdown and lands in open terrain, it's liable to be nearly undamaged, and everyone on board is likely to walk away, as well.)
Buzz Gothard's unusual Russian biplane flies like it looks: huge in every respect. Still, the type continues to serve, mostly in Third World countries, all around the globe.