"What was it like flying The Bensen Gyrocopter"

Vance

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cloudhopper;n1126334 said:
Nice to get the info on the cable. I have a Benson with a Mac 90 . It takes some getting used too. I still wack my head on it. Headed out to El Mirage next weekend for the first time. Hoping to meet some people and make new friends.

It reads to me like you are building up to self-training Vernon.

It is my observation that most people don't have the patience to follow the syllabus.

It is my observation that many people have been hurt or killed truncating the self-training syllabus.

I hope you will at least find someone who will mentor you during the process.
 

Doug Riley

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As for self-training -- the Bensen syllabus requires a number of steps before you strap on a powered machine. First, you built a static trainer using your airframe, no rotor or engine. Next you convert this static trainer to a ground trainer using the rotor blades, spun only by the wind (still no engine). Next you fly the gyro as a towed glider (again, no engine). After that come hours of practice with the engine running, lifting the nosewheel only and getting used to coordinating the controls (especially the powerful interaction between rudder and throttle).

It's safer, and a lot more time-efficient, to take some lessons.

As for the mast-keel cable, the Bensen manual has you string it by flexing the frame, like stringing a bow. You are to put two people in the seat with the aircraft sitting on its main wheels. This partially closes the open "C" formed by the mast and forward keel. You string the cable with the frame deflected in this way -- so it'll be tight (even at rest). If you follow the directions, that is.

Many later builders have left off the entire tow boom (or bowsprit, to sailors). This, of course, leaves no lower attachment point far enough away from the pilot to run the cable. I kinda like the old bowsprit for the small forward "crush zone" it creates.
 

C. Beaty

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The cable was essential for towed flight where in conjunction with the bowsprit, the towline'’s line of pull passed nearly through the CG. The cable also eliminated the chance of snapping off the mast when the towline was jerked.

Although not essential for powered flight, I left the cable in place for the bit of protection it afforded; I preferred having the cable catch power lines and barbed wire fences rather than my neck should the need arise.

An SRC member in Orlando, Tom Mahaffy survived a powerline strike when, judging from the copper trail, the wire slid up the cable to the rotorhead and unwound from the rotorhead by one blade going under the wire. Tom landed with no damage other than the copper trail.
 

Doug Riley

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Chuck, it's interesting that the original Bensen B-7 and B-8 frame designs both used a small "pyramid" tow pylon, sticking up between the pilot's knees. Nothing projected forward of the front end of the keel tube. The pilot could reach the tow hook directly to release it. An angle-aluminum brace ran from about seat-bottom level on the mast forward to this little tow pylon. With the tow-rope attachment point so close to the pilot, a cable to the masthead was impossible. The "alpha" version of the B-8M didn't have a cable.

The familiar bowsprit and cable were a later modification. One can speculate about the change -- either it was an attempt to create a more direct load path from the end of the tow rope up to the rotorhead, or maybe the close-in attachment point made the nose bob around too much every time the tow car hit a pothole ( I experienced this when towing on uneven grass, even with the longer bowsprit). Or perhaps the close-in pylon got in the way of the (then-new) pump-handle joystick control option.

Anyway, Bensen was a simplicity fanatic. He must have had a good reason for tolerating the extra parts (and the need to trip the tow hitch indirectly, with a cord).
 

C. Beaty

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Doug, Bensen not only avoided unnecessary complication but he was also quite pragmatic; I expect the cable was added after a few bent masts from towline snatches.
We used a cable for towing and the snatching could get pretty violent if the tow driver wasn’t careful about taking up towline slack.
 

gyroplanes

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No Title

Little Mike Milton having fun on a Bensen circa early 1980's. Mike turned 37 a couple days ago and told me he enjoys working for Rotorcraft Leasing Corp in Mouton Cove, Louisiana. Mike recently went to repair a Bell Long Ranger on an oil rig. No room for 2 copters on the platform, so Mike got a crane lift 200ft up, from a work boat to the helipad, hanging on a net. I loved flying my Bensen MAC 90 for 13 years, until I built a Bensen Rotax 532. I liked the Rotax long prop thrust and never having an engine failure.
 

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Resasi

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Most of my small ammount of gyro time is on a 532 Bensen,

Have been fortunate enough to fly a few other types.

RAF, Magni M-16, MT-Sport, Twin Dominator, Predator, (In an ArrowCopter), Merlin, Cricket, Hornet, Layzelle AV-18A, 503 Bensen, and a VW Bensen.

The one I enjoyed the most was the 532 Bensen, by far.
 
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