Butterfly Gear

[Lspav8r]

I wonder if that butterfly type gear could be adapted to a bensen type airframe? Sure would make softer landings, even if you flared a little high. To me all gyros should have that gear on them to make landings a little safer in case of a too high flair.

[scottessex]

Grant R has done just that recently.
I have modified some Air command, gear for shocks.
Put coil overs on my Dominator.
The best thing besides landing cushion,
is that with a suspension, you will have a shorter takeoff
on a rough field, but it adds weight,
in aviation, as marriage, everything is a compromise.

[GrantR]

Yes I built my own version of the gear. Larry does not sell the gear for other gyros. It is good if you flair high but it will by no means save your butt if you touch down sideways in a yaw or drift. I do not use it like most people do. I have dropped in from a high flair a few times and it worked well. I land normal with it extended. I look at it as an insurance policy for a off field landing where I may have to drop in. I like the fact that it does not rebound when I land hard. It just soaks it up and bottoms out. Also landing soft I can barely tell I touched down.

[Vance]

I wonder if that butterfly type gear could be adapted to a bensen type airframe? Sure would make softer landings, even if you flared a little high. To me all gyros should have that gear on them to make landings a little safer in case of a too high flair.

Hello Jim,

It seems to me that if the long stroke gear, like the Butterfly has, was adapted to a Bensen sort of Gyroplane when the gear is extended it causes two challenges to safe flight.

In my opinion it lowers the center of gravity compared to the thrust line.

In my opinion it lowers the center of drag.

I feel this would exacerbate any tendency the aircraft has to have a power push over.

In my opinion it would be a bad idea to make an aircraft more unstable in order to cushion a poorly executed landing.

Thank you, Vance

[Friendly]

I don't recall any stories of people injured in too high a flair, there probably are some. The Gforce is nice in emergency no place to land situations. At Bensen Days, Roy Davis and Tim V. and Mike B spent hours in front of the crowds performing engine out landings. The only difference Tim V. faired very high and rolled slightly less.
Looking what you are flying over is the best safety device we have, and its free of drag, weight and extra cost. Maybe a simple suspension would be sufficient for the Bensen. The greatest asset I have found in flying several different types of gyros is "the lighter they are, the easier they are to land in a tight spot."

[Lspav8r]

Hello Jim,

It seems to me that if the long stroke gear, like the Butterfly has, was adapted to a Bensen sort of Gyroplane when the gear is extended it causes two challenges to safe flight.

In my opinion it lowers the center of gravity compared to the thrust line.

In my opinion it lowers the center of drag.

I feel this would exacerbate any tendency the aircraft has to have a power push over.

In my opinion it would be a bad idea to make an aircraft more unstable in order to cushion a poorly executed landing.

Thank you, Vance
I would immagine that everyone that flies gyros, as had at one time or another, an instance where wind baloons the machine just before touchdown thus a perfect landing becomes a poorly (not by choice) executed landing no?
Couldnt these things you mention be engineered out of the equation? I dont know therefore I ask.

[Vance]

I would immagine that everyone that flies gyros, as had at one time or another, an instance where wind baloons the machine just before touchdown thus a perfect landing becomes a poorly (not by choice) executed landing no?


Couldnt these things you mention be engineered out of the equation? I dont know therefore I ask.

Hello Jim,

I am cautious and try not to do things that will create a problematic landing and so far my luck has held.

In the areas I fly many of my emergencie landing areas are small and soft so, in my opinion more suspension travel and better energy dissipation would have value.

Sooner or later the engine will go quiet and having more options has an allure for me.


I feel there are ways to compensate for the lowered center of gravity and lowered center of drag. They are compromises with benefit tradeoffs.

You were asking about a Bensen type gyroplane that may already be a little edgy about the location of the center of gravity related to the thrust line and the center of drag. In my opinion compensating for these changes would be more work than designing and building a gyroplane for the long travel gear.

The gyroplane we are building, Mariah Gale, will have more travel and better control of the energy dissipation than the gyroplane I am flying now, The Predator. We are not trying to manage a vertical descent. I am aiming for the ability to manage a 900 feet minute un-arrested descent to the ground without damage. In my opinion a straight vertical descent can reach 1,400 feet per minute in a gyroplane with a high disk loading such as Mariah Gale. I am also trying to manage the tendency to bounce back after impact that can help a gyroplane to tip over.

I have had some experience designing suspension for production motorcycles and have worked at mitigating design weaknesses of existing production motorcycles.

In my opinion the priorities are shifted but the goal is the same, extend the time to reduce the peak loads and manage the stored kinetic energy.

Thank you, Vance

[Alan_Cheatham]

It seems to me that if the long stroke gear, like the Butterfly has, was adapted to a Bensen sort of Gyroplane when the gear is extended it causes two challenges to safe flight.

In my opinion it lowers the center of gravity compared to the thrust line.

In my opinion it lowers the center of drag.

I feel this would exacerbate any tendency the aircraft has to have a power push over.

In my opinion it would be a bad idea to make an aircraft more unstable in order to cushion a poorly executed landing.


There's no reason the gear can't be locked in the up position for high speed flight and lowered right before touch down, in fact Larry does this very thing having equipped some of his ships with such a device.

One could also use the same argument about enclosures as they can decrease stability requiring an increase in tail power to compensate.

The main benefit of a long stroke landing gear is the ability to land at larger flair angles without dragging the tail, much like STOL aircraft such as the Storch and CH701.

.

[Joe Pires]

The recent issue of the EAA mag had a cover story about the Storch. If you have never seen one of these land its pretty amazing. With its STOL characteristics and peculiar landing gear it makes for an unusually capable aircraft. I was wondering if anyone considered taking whatever arrangement this plane uses and putting it on a gyro.
I was posting the same time as you Allen.

YouTube - Storch landing (http://www.youtube.com/watch?v=WKmY1-y2UYk)

[Earthboundmisft]

MY 2 cents worth. Lee Scatt talked me out of adding suspension while I was designing my gyro. I had what I thought would be an excellent design. I reluctantly gave in to save weight and complexity. Now after nearly 50 hours of flight time, I'm glad I went rigid. I use wide, flat profile tires with tubes, and inflate to 8psi. I have buggered up a landing or two, and was surprised how forgiving it is. I have dropped it from up to about a foot, and it just stays planted. I suppose the spinning rotor has a stabilizing effect? I like how stable it is on the roll-out, to the moment the wheels leave the ground. I do realize a grass field is another story. I plan to use only paved strips.

[GyroDoug]

Hello Jim,
It seems to me that if the long stroke gear, like the Butterfly has, was adapted to a Bensen sort of Gyroplane when the gear is extended it causes two challenges to safe flight.

In my opinion it lowers the center of gravity compared to the thrust line.

In my opinion it lowers the center of drag.

I feel this would exacerbate any tendency the aircraft has to have a power push over. In my opinion it would be a bad idea to make an aircraft more unstable in order to cushion a poorly executed landing.
Thank you, Vance

Vance is absolutely correct. Having a long stroke landing gear hanging down low on a machine can lower the center of gravity or raise the thrust line compared to the center of gravity. It can also lower the center of drag. Both of which can tend to push the nose downward which will decrease the stability of a machine.

The Butterfly line of Gyroplanes was designed specifically for this gear, so that was taken into account with the design. Even with the gear in the extended position, the thrust line on a Butterfly Gyro is slightly below the center of gravity on the machine. It truly is designed to be "Centerline Thrust". machine and it is. There is no high thrust line pushing the nose down on any of the Butterfly machines.

The other area that Vance mentioned is the center of drag. If you look at any Gyro that has any kind of a pod or enclosure on it at all, they all are producing a nose down pressure on the machine. The shape of the pod and the windshield guarantees there will be some nose down force here to deal with. I believe the Butterfly line of Gyros address's this issue better than any other line out there. Look at the nose pod on an Aurora or Super Sky Cycle and you will see a very symmetrical shaped pod with the point of the pod set right in line with the center of gravity and the thrust line. While the small windshield added above the pod will generate some nose down force, the design greatly reduces this issue compared to other designs out there. But in addition to that, Larry uses a Large, Airfoil Shaped, Horizontal Stabilizer, mounted on a Long Moment Arm to make it very powerful and to counter any nose down tendencies other aspects of his machine may induce.

Larry has also designed a system to hold his G-Force Landing Gear in the up position so while you are out flying and cruising around you do not have that landing gear hanging down and creating drag low on the airframe. He has also made a airfoil shaped cover for the gear legs to greatly reduce the drag they have, whether in the up position or dropped down low in preparation for a drop in landing. Like has been mentioned before, everything in aviation is a compromise and the G-Force Landing Gear has it's drawbacks too. However, carefully designed, you can minimize the disadvantages and take full advantage of it's strengths. It is truly an incredible system.

G-Force type landing gear is a great idea and can be incorporated into any design but there is a lot more to it than the average person realizes. Making design changes without adequate knowledge and understanding of all the consequences, has taken our sport in a direction we are still trying to overcome the reputation from. But done right, I think it is a great idea that will be used more and more. I am sure there are other ways to accomplish this goal too. I understand the Sport Copter 2 has some incredible energy absorbing gear on it. If they can ever bring it to market, that is going to be a great machine (for those that can afford it)