Bensen

All posts tagged Bensen

I have been interested in gyroplanes since the 80s. I was flying ultralights at the time, and those machines seemed so nimble. I still want to build a CH-701 from a kit, but the total cost of the project would probably be around $30k. A single-seat gyroplane will set me back about $9k. So, I will apply the saying here “Go small, go now!” The two-seater airplane will have to wait a few years..

I chose a design based on a well known safe gyro, the Gyrobee. The new model, called a Hornet, has some improvements, including, and most importantly, a line of thrust aligned with the center of gravity. It also has a large horizontal stabilizer. Those two safety features, though the Gyrobee has a great reputation of stability, will make the Hornet even more stable. Hopefully, it will reduce the risk of bunt-over to near-zero. Bunts are what unrecoverable flat spins are to airplanes.. You make the wrong mistake and wham, lights out, forever. That is why I will also seek professional instruction, even though I know enough to take-off and fly around..

Here are the parts I am starting with:

Airframe Parts

Airframe Parts

I will describe the whole building process here, on the Rotary Forum.

If you are curious about the helicopter’s Grand-Daddy, keep reading…

Gyroplanes are probably the least known and most intriguing flying machines. Invented in 1923 by Juan de la Cierva, a Spanish civil Engineer and pilot, they are the precursor of the helicopter. The first gyroplanes, or autogiros, had an airplane fuselage with a rotor mounted on top of a mast. The engine and propeller were mounted forward, as on a regular airplane. The rotor blades are not powered by the engine, but spin freely. they must be pre-rotated before takeoff, either by hand or using a mechanical system. The propeller ensures forward movement.

The most famous gyroplane is without a doubt “Little Nellie,” piloted by Ken Wallis in the James Bond movie “You Only Live Twice.” There was one also in the Mad-Max movie “The Road Warrior.”

The early machines had an excellent safety record. A gyroplane can not stall like a fixed-wing aircraft. However, a gyro can’t hover without a strong enough head-wind, which prompted the development of the helicopter. These amazing machines faded out of our aviation landscape, and probably would have disappeared if it wasn’t for one Russian immigrant, Igor Bensen, who simplified the design in 1955 by reducing it to a keel tube and mast, with a pusher engine in the back and a seat up-front. Bensen created the Popular Rotorcraft Association (PRA) in 1962, and the aircraft made a huge comeback in the 70s and 80s.

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Unfortunately, people tend to modify designs, install bigger engines, and try new configurations. Many did not have Bensen’s understanding of the aerodynamics of rotorcrafts. Many of these machines did not have a horizontal stabilizer, and their high thrust-line above the center of gravity sometimes caused them to bunt-over. Pilots started dying, and the gyroplane developed a bad reputation. Today’s machines are much safer. Although much of them are based on the Bensen, a few went back to the tractor design of old days; notably the Little Wing models, which I find very attractive.

The Mecca of gyroplanes in the United States is in Wauchula Florida, where the Sunstate Wings & Rotors Club organizes the annual Bensen Days fly-in. That is where I met Joe Pires, a Bensen Days organizer who was kind enough to arrange a ride for me, and give me the information I needed for this article. Joe told me that the movement actually started in Immokalee Florida. When instructor Dave Seace left town for Wauchula, some followed, and the rest is history, as they say. Dave has trained a good number of pilots on his Dominator gyroplane, and I was eager to get a ride in his machine. The Wauchula airport welcomes gyroplanes, unlike many others, thanks to it’s manager, Jim Hay. About eight machines are based on the airport, in a hangar area called “Moron Ville,” name for which I didn’t get an explanation, but would probably be an interesting story. Around eighty five machines were parked on the tarmac, mostly Dominators from Rotor Fligh Dynamics, a few modified RAF-2000s, and numerous other designs such as the Monarch, Gyrobee, Sportcopter, to name a few. More are expected tomorrow, along with a few hundred visitors. Club President Scott Lewis also organizes fly-ins on the 4th of July and New Year’s Eve, though this week-end’s event is the largest.

A great gyro flying video by Shawn Adams
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