Learning To Fly The Bensen Gyrocopter

We learn to fly the Bensen Gyrocopter — tremendously popular, stable and smooth with positive control feel, and certainly one of the seven wonders of the aeronautical world

ARTICLE DATE: February 1985

At the tender age of five, I had already developed an insatiable urge to fly. Aviation was without a doubt the most exciting, intoxicating subject I knew. I was yet to meet with my destiny, the Bensen Gyrocopter.

As a young aviation buff, I was naturally drawn to the more exotic, high-performance aircraft: the walls of my room were literally papered from floor to ceiling with pictures and photos of jets, aerobatic biplanes and a plethora of spacecraft.

One of the most unlikely but nonetheless enticing aircraft to be featured on my wall was the outlandish-looking Bensen Gyrocopter. This craft was the result of a talented Russian immigrant’s attempt to bring safe, affordable flight to everyone who had the desire to fly in a machine of their own making.

Offered as an inexpensive kit, or in plans to the “grow-your-own” style of homebuilders, the Gyrocopter first flew almost 30 years ago but was thrust into national prominence only after Boy’s Life magazine featured an article on the unpowered Gyroglider version. Since that time, the Gyrocopter has been the darling of the rotorcraft homebuilder.

Bensen B 8 Gyro-Glider plans B 8M gyrocopter

Bensen Gyrocopter Kits

Almost 4000 kits and plans are in circulation, making the Bensen Gyro glider and Gyrocopter one of the most popular homebuilt aircraft designs in the history of sport aviation. As the myth and legend of the Gyrocopter grew to prominence, so did this writer’s desire to fly the unlikely looking aerial wonder.

The opportunity finally arose when I was assigned to do a flight report on the craft I soon found myself traveling southward to the wilds of North Carolina. You’ve all seen the Bensen Gyrocopter, haven’t you? During the past 30 years, one could hardly miss it in one of its many appearances in any number of periodical feature stones.

If you have managed to miss it, then you may have seen James Bond buzzing around in one while blasting bad guys into rotordust, or as one of the combative vehicles in Road Warrior or, for that matter, on one of the countless general-interest television pieces that have highlighted this light-weight little bird.

In the midst of all this attention, the Gyrocopter has become something of a love-it-or-leave-it type of machine in the somewhat fickle world of sport aviation. To many knowledgeable persons, the gyro is one of the seven wonders of the aeronautical world.

Bensen 90 hp McCullough gyrocopter engine

The 90-hp McCullough engine and instrument deck.

Conversely, many others have been swayed by incorrect or unfounded rumors of design defects or squirrelly characteristics and have labeled it a deathtrap, a machine to be avoided like the proverbial plague. Even to the most knowledgeable, a reputation like this tends to be a bit unsettling.

A few of my friends were among the skeptics who were aware of this upcoming story and subsequently offered their somewhat premature condolences, while another gave my name to his insurance agent telling him that I was in need of all the help I could get.

With this in mind, the final moments of my trip to the Raleigh-Durham airport (home of Bensen Aircraft) were a bit awkward, as a mixture of a little nervousness and a lot of anticipation filled my travel-numb, road-weary head.

My concerns were mollified by some of the research that I had done prior to heading south. When looking at facts, the Bensen Gyrocopter has a fine record The machine is the brainchild of one of aviation’s most accomplished aircraft designers.

Bensen x 25 b gyroglider

Bensen Gyrocopter Achievements

Dr. Igor Bensen, a former colleague of Igor Sikorsky, the father of the modern helicopter. In keeping with his personal philosophies, Dr. Bensen did his own test-flying and continues to do so. Designed in 1934, the Bensen Gyrocopter has set at least 12 world records.

The Bensen has seen action as a military vehicle and is designated by the U.S. Air Force as the X-25, while other examples are on display in such prestigious institutions as the Smithsonian and EAA museums.

More Bensen Gyrocopters have been built than any other homebuilt aircraft (either fixed or rotary wing). Even more impressive is the fact that of the thousands of these aircraft sold, not a single in-flight failure of any Bensen manufactured part, or Gyro, constructed and flown in accordance with Bensen specifications, has been documented.

The free-and-easy visibility, superb maneuverability, reasonable affordability and ease of operation have made the Bensen an aeronautical legend, and I would imagine that some of its best days are yet to come. With these considerations in mind, I plunged eagerly ahead into Bensen’s world. For better or for worse, it was definitely going to be interesting.

Marketing mogul Jerry Roberts met me promptly at the door with a big smile and whisked me off on a whirlwind tour of the manufacturing operation adjoining the business offices of Bensen Aircraft.

original bensen gyrocopter 90 hp

The Bensen plant is not a new or outwardly attractive facility, but inside there are plenty of appealing attractions. The machinery and tooling are impressive, and a careful inspection of machined and tooled components impressed me further. One of the most critical components of any rotorcraft is the rotor system.

Watching the fabrication of components and sub assemblies for the Bensen rotor (of which 10,000 have been built) instilled confidence and dispelled many of the gloom-and-doom rumors. Roberts and the other Bensen staffers were open and seemed willing to provide the information I had asked for, even when the subject of all those nasty rumors arose.

A clear pattern emerged during my questioning: this was a company with some different and admittedly inflexible ideas about what it takes to design, manufacture, sell and support an amateur-built experimental flying machine.

Its test and evaluation programs revealed a thorough and almost fanatical devotion to some tough airworthiness and safety standards — an attitude that often causes mild consternation among Bensen devotees awaiting the approval of new products which have undergone or are in the midst of the necessarily slow and methodical process of research and development.

Igor Bensen flying gyro glider copter

Bensen owners are well supported by the factory, a national dealer network, newsletters and a comprehensive series of manuals for both construction and flight training. It is the flight-training process that makes the Bensen Gyrocopter a distinctive aircraft.

Dr. Bensen has developed an involved and intensive training curriculum to ensure the safe and adequate training of gyrocopter pilots. In the several days after my arrival in Raleigh, I experienced this process as I undertook the complete and unmodified Bensen Gyrocopter flight-training course.

By the time that first afternoon arrived, and we left the building in order to start training at Wilson field, I felt good about what I was about to do. The best part of the deal was the fact that I was to receive my training from Dr. Bensen himself.

With the two-seat Gyroglider trainer already sitting at Wilson field in the back of Charlie Elrod’s pickup truck, Roberts and I arrived ready for air time. Elrod and Roberts set up the trainer in less than 10 minutes. Preparation consisted simply of attaching each main rotor blade to the rotor hub and then attaching the hub to the rotor head.

As this task was finished, Dr. Bensen arrived on the scene and introduced himself. I explained to the doctor that I was a commercially rated fixed-and rotary-winged pilot and flight instructor.

Taking this into account, he began to explain the Bensen Gyrocopter in terms of what I previously had been flying. After 20 minutes of initial ground school. Bensen explained that he would fly the trainer first and demonstrate towed flight and some of the training maneuvers.

The trainer was attached via a long rope to a special tow hitch on the back of the truck and to the trainer with a standard Schweizer tow hitch identical to those used on fixed-wing gliders. Dragging the craft to the end of an unused taxiway, we prepared to launch the doctor.

The two-seat trainer is equipped with both main and nosewheel brakes for the rapid stops that occasionally occur during towing, and a motorized main rotor pre-rotator to help the rotor get to flying speed more quickly and utilize more of the runway for flying instead of taxiing.

A set of simple and highly identifiable hand signals are used to communicate the erstwhile pilots intentions to the driver of the truck. The pilot’s training manual covers all of this in depth (which should be read prior to training), making the transition from printed word to towed flight an easy process.

experimental bensen gyrocopter seat

The Bensen plant turns out carefully machined and tooled components.

Bensen, suitably attired in helmet and eye protection, made several passes up and down the taxiway demonstrating the flight of the tow trainer.

The visual ease of this procedure was apparent, especially since the none-too-bashful doctor spent much of his flight time with his hands out and away from the stick in a convincing effort to demonstrate the stability of his pride and joy. He demonstrated some agile maneuvers at the end of the tow rope, and I was more than ready to take the stick and give it a go.

Satisfied that all was right and the conditions were adequate for training. Bensen gave the “cut” sign to Elrod. and the whole team slowed to a stop at the end of the taxiway. The doctor briefed me on what we were going to do as I belted myself in to the left side of the wide bench seat.

He instructed me to take the stick loosely and said that he would cover my hand with his and give me any needed corrections. From his right-hand seat, his left arm hung behind me and to my left so as to be able to control a secondary main-wheel hand brake control and give backup signals to Elrod.

With the pre-rotator started. Bensen gave Elrod the thumbs-up (accelerate) signal until we got to 10 to 12 mph, at which point he turned the pre-rotator off and allowed the relative wind produced by our forward speed to accelerate the rotor beyond the established speed.

Bensen gyrocopter hydraulic disc brake

Detail of disc brake installation.

When the rotor started to really pick up, Bensen gave Elrod another thumbs-up and we sped to an airspeed of 35 to 40 mph. The nosewheel lifted off the ground as Bensen moved the stick forward to balance the trainer on the main wheels, keeping the nose and tailwheel elevated prior to lifting off.

Liftoff, so effortless, was a bit anti-climactic. Despite all of the exciting action, I could hear the doctor’s instructions easily and clearly. Once in flight, the gyroglider was controlled nicely by small, light pressured movements of the well-placed control stick.

My teacher’s calm and patient instruction soon allowed me to lift off on the mains without dragging the tail skid, and then fly to and maintain a specified altitude while holding my position directly behind Roberts and Elrod in the tow truck. As my reflexes caught up with the trainer, the doctor allowed me to graduate on to climbs, descents and slight S turns across the taxiway.

My progress was rapid. Bensen is an exceptional engineer, designer and scientist, but he is also an excellent instructor. He used an easy-going dialogue to illustrate each point of the task at hand and allowed me to perform as much of the flying as possible.

Before long, I had graduated to flying a boxy maneuver that required me to lift off, stabilize the trainer about three feet off the ground and then swing to the left while maintaining that same altitude. Once stabilized, I would then climb 20 or 30 feet and stabilize on that side as well.

After establishing myself in that position, I would swing over to the right and hold the same altitude again before descending to three feet, and then to the center to complete the maneuver.

This “box” was an excellent way to fine tune my control over the gyroglider. especially as the wind decided to make a more forceful appearance, and I learned to fly the box upwind, downwind and crosswind.

A few things about the gyroglider were exceptionally interesting. In particular, this must be the most stable rotary-winged flying machine that I know of. My experience as a commercial helicopter pilot has shown me that many helicopters have all the natural stability of a tipsy tightrope walker.

fitting bensen gyrocopter rotorblades

The “chief” takes his creation for a spin.

The smooth, positive control feel is wonderful, and at no time did I find the cyclic control (that which controls the rotor head) to be anything but easily responsive. The instruction in the trainer was a confidence booster and an excellent introduction to this mode of flight.

Late that afternoon, Bensen voiced enough confidence in my fledgling abilities to unbuckle himself from the trainer and allow me to solo his precious bird; the flight up and down the taxiway was uneventful and comfortable.

The day was drawing to an end. and tomorrow was to be no less eventful as I worked toward a solo flight in the powered gyrocopter. Elrod. Roberts and Bensen offered me their congratulations on a job well done. The next day would be something else.

That night was spent with my nose buried in the training manual, reading and re-reading each word. I had really been turned on by the day’s activities and I wanted nothing less than to do well the next day. both for myself and for my new friends at Bensen Aircraft.

The next day could not come too soon. It was an even nicer one than the previous, and I was soon back in the tow trainer, polishing my solo skills under the watchful eye of the Gyro’s designer.

Bensen gyrocopter vertical stabilizer

Vertical stabilizer and prop protection plate.

Many runs were made under his supervision. Before long he gave me the cut sign and motioned me to taxi with the truck over to the hangar, where the powered gyrocopter was awaiting my attention.

Finally, I traded my wide seat in the trainer for the narrower single seat of the gyrocopter. Elrod hooked up the tow rope to the front of the machine so that I could acclimate myself to flight in the heavier bird.

With Bensen’s guidance, we did quite a bit of towing in this vehicle, until my skills in the ship equaled those I had developed in the trainer Since the powered gyro uses a power takeoff system as a pre-rotator, the engine had to be running in order for it to work.

And since tow training was unpowered for the moment. I had to pre-rotate the rotor by hand. This was a slower process and was aided by slow taxiing, which allowed for enough translations movement to help in accelerating the rotor.

experimental B 8M experimental gyrocopter

It should be noted that this process needs to be accomplished with a bit of care, since high relative wind with low-rotor rpm can set up a flapping motion which can cause the rotor to strike the ground (and cause a severe wallet injury) if not corrected.

The corrective procedure is simply to move the stick forward to level and unload the main rotor. Taking another break later in the afternoon, I watched Roberts and Elrod remove the rotor from the gyrocopter.

The last step before untethered powered flight required that I taxi the copter sans rotor in order to get a good feel for the sensitive ground handling of the 90-hp McCullough-powered machine.

The nosewheel steering was sensitive, and I spent much time speeding up and down the centerline of the taxiway, trying to keep everything on the straight and narrow The nosewheel sensitivity was the only tricky part of the operation, requiring some patient practice before attempting high-speed runs.

It wasn’t too long, however, before I was boogying along doing S turns and figure-eights under the benevolent yet critical gaze of the “chief.” I helped Elrod re-install the rotor as we prepared to complete the training process with my solo in the powered gyro.

My first cautious aerial excursions in the copter were straight down the runway as I grew accustomed to the throttle response and speed range, followed by gentle S turns to get the feel of the control system. It didn’t take long before I was cranking down the runway doing daringly steep S turns across the runway, just having a ball.

With the doctor’s blessing, I was bopping along several hundred feet in the air after a 1000-fpm rate of climb, enjoying the lush green vegetation surrounding the North Carolina airport. The pattern hops were augmented by the incredible visibility of this little rotary-winged flying machine.

Cruise speeds of 45 to 65 mph are equally stable, though flying slower was decidedly more fun since it afforded me more stick time. I made two landings with the power reduced to idle and found the power-off approaches easy.

Dead-stick landings can be accomplished in less than 100 feet with little effort and minimal braking action. The only real annoyance was the high and somewhat obnoxious noise level of the McCullough.

My always-faithful David Clark helicopter helmet helped to attenuate much of the noise, and I would highly recommend that Gyro pilots who have these engines make great use of some kind of similar hearing protection.

Bensen aircraft corporation gyrocopter

LEFT: Fuel tanks and plumbing system.
RIGHT: The Bensen Aircraft Corporation guarantee.

Before I knew it, it was over. I can’t remember enjoying an aircraft and a group of people as much as I did this bunch. They are great people and the good doctor in particular is one of the most outstanding gentlemen that I have had the good fortune to meet.

The gyro is a real thrill and a much more capable and substantial machine than the rumor mill has it. The slightly less-than-perfect personality of the McCullough appears to be its only real drawback — temporarily.

At press time, the Bensen folks were getting ready to ship the first of the newest version of their whirlybird. The new liquid-cooled Rotax-532-powered Bensen gyrocopter should eliminate the noise problems and prove to be an even more powerful and reliable powerplant than the older McCullough.

Although I haven’t flown it, the flight performance that I observed during a demonstration was awfully impressive. This little engine should catapult the Bensen gyro to an even greater level of popularity than it has enjoyed thus far.

Since this new engine should change things a bit. I will be picking up one of the new kits when they become available, and taking an in-depth look at what it takes to build, register and test-fly one of these birds.

In the meantime, I have added a new type of aircraft and a fresh experience in flying machines to my logbook. There’s nothing like the gyrocopter. and I highly recommend it to those who are tired of the same old thing.

I must admit that I enjoyed it much more than a lot of other aircraft. I’m only sorry that I took so long to get around to flying it. but I guarantee that I won’t be so lackadaisical about this machine in the future — it’s a thrill.

Igor Bensen flying gyrocopter McCullough

Igor himself with his aeronautical wonder.

Bensen Aircraft Corporation

B 9 Little Zipster helicopter contra rotating twin rotors

Elaboration of the Bensen B-8 design philosophy resulted in the B-9 Little Zipster helicopter, with contra-rotating twin motors to overcome torque reaction problems.

Dr. Igor Bensen, formerly chief research engineer of helicopter-building Kaman Aircraft Corporation, established his own company at Raleigh, North Carolina, in the early 1950s.

Intending initially to develop a series of lightweight commercial helicopters, he soon began to appreciate that the inherent safety of a rotary wing would make a suitable aircraft of this type very attractive to private pilots.

For such a market a low initial cost was essential, so he developed an unpowered rotor-kite which could be towed behind a motor car. Known as the Bensen B-8 Gyro-Glider, this could be flown without a pilot-license in the United States, and if costs had to be kept to a minimum it could be built from detailed plans and building instructions.

bensen glider copter

There was even a do-it-yourself flight instruction manual. An enthusiast with a little more money in the kitty could obtain from Igor Bensen a kit of easily-assembled components: for the more affluent the company produced completed aircraft.

The company’s production of rotor blades, and of kits for the home construction of rotor blades for the Gyro-Glider and the powered Bensen Gyro-Copter, continued until 1987. Aircraft have been built in thousands over a period of more than 25 years. Brief details of other Bensen products that were available are given below.

Bensen Gyro Variants

Model B-8HD: variant of the Model B-8 Super Bug (below) which has a hydraulic drive to turn the rotor during all aspects of flight. This absorbs some 3 kW (4 hp) of the main engine output, allowing shorter take-off runs and near-vertical landings.

Model B-8M Gyro-Copter: an autogyro version of the Gyro-Glider, powered by a McCulloch engine driving a pusher propeller.

Model B-8MH Hover-Gyro: advanced version of the B-8M with hovering capability, plus backwards and sideways flight; achieved by two coaxial rotors, the upper auto-rotating, the lower powered by a separate engine.

Model B-8MW Hydro-Copter: versions of the B-8VI with float landing gear.

Model B-8V Gyro-Copter: designation of a version of the B-BM with an alternative powerplant comprising a modified Volkswagen motor car engine

Model B-8 Super Bug: advanced version of the B-8M with a twin-engine installation; this allows the rotor to be spun-up prior to take-off, and reduces considerably the take-off run.

Bensen B-8M Gyrocopter Specification

  • Model: B-8M (standard)

  • Type: single-seat light autogyro

  • Powerplant: one 54-kW (72-hp) or 67-kW (90-hp) McCulloch Model 431B flat-four piston engine

  • Performance: maximum speed at sea level 137km/h (85mph); economic cruising speed 72km/h 145rmph); service ceiling 3810m (12r50Qft); normal range 161 km (100 miles)

  • Weights: empty 112 kg (247l;: maximum take-off 227kg (500lb)

  • Dimensions; rotor diameter 6.1 m (20ft 0in); fuselage length 3.45m (11ft 4in); height 1.19m (6ft 3in); rotor disc area 29.19 m² (314.16 sq ft)

benson gyrocopter models

LEFT TO RIGHT: 1. The Bensen autogyro was briefly evaluated by the US Air Force under the military designation X25B. 2. This B-8 has two engines, mounted one over the other. Note the control column attached directly to the rotor head. 3. Among the more unusual designs originated by Igor Bensen was the B-10 Flying Platform. This was supported by two small rotors, each driven by a 53.7-kW (72-hp) McCulloch engine. 4. Powered by a pair of tip-mounted ramjets, the Bensen Mid-Jet weighed only 45kg (1001b) empty. It is here seen with Betty Skelton, a celebrated stunt pilot of the early 1950s.

Learning To Fly The Bensen Gyrocopter
Article Name
Learning To Fly The Bensen Gyrocopter
There are many stories to tell about the Bensen Gyrocopter and this is one of them. Learn how to fly a gyrocopter, in particular, the Bensen B-8M gyrocopter.

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