Bensen Days Pictures

[r.coplen]

Can anyone post Bensen Days pictures. Are there any SparrowHawks around yet? Thanks

[route66]

Just posted some on the Pra website, Maybe the weather will be better tomorrow.
www.pra.org/index.php?module=photoalbum&PHPWS_Album_op=view&PHPWS_Album_id=10

[Madewooden]

Photos. . . here are a couple of photos!

[Madewooden]

A couple more. . .

From Ernie Boyette's SkunkWorks. . . the LFINO! And Stan Foster taking a flight lesson in a Sparrowhawk.

[jdalexa]

Brandon,

Please include descriptions with the photos you post to the PRA page.

[route66]

John, Sorry for not describing the pics. I'll do better and ask what I have a pic of. I'm not a reporter, just an observer. Hope it was ok! B

[jdalexa]

No prob! First priority is to get pics up. I went back and put in descriptions as much as I could. Man... I wish I could be there. Sigh.. Thanks for taking the time to act as PRA News Group (PRANG).. heh..

[route66]

John, I'm glad to have you to back me up! Randy, I would have had more Sparrow pictures although they kept them on a trailer wrapped up in plastic and Steve hanging out with his dog. Maybe tomorrow. Terry was flying and I did get a few of him. It's only Thursday, it'll get better. Enjoy!

[KenSandyEggo]

Anyone know what engine is under Ernie's cowlings?

[Madewooden]

Couldn't tell with the quick look I had. The cowling wraps tight to the prop and there's a see-through plastic shield behinds the seats providing an internal cowling. But things are tight in there and not much visibility. Weather was deteriorating, so Ernie hustled his total inventory into a hangar.

Maybe much more today. . .

[Heron]

Isn't that ELFAINO (like in elefaino?)
Heron

[scottessex]

Yes, kinda like L F I N O (Leap Flight In Normal Operation)
I think it has an EA-EJ? 22 soob, I'll get a better look at it this afternoon.

[Al_Hammer]

I looked up the N number on Landings.com It's registered as model LFINO. Sounds like "hell if i know" to me.
Dick's rotor does not appear to have any lead lag dampers. Normally these are required to avoid ground resonance.

Maybe jump take off is less prone to induce resonance than normal rolling takeoff, since the rotor doesn't need to flap during spin up. I'm sure we'll find out from Chuck when he gets a chance to post more details.

[C. Beaty]

Rubber springs, Al.

Dick is very fond of Honda motorcycle rubber/metal bonded bushings.

Apparently, the rubber springs raise the inplane frequency high enough to stay away from ground resonance.

I also expect luck plays a major role.

[jdalexa]

It was my understanding that ground resonance is caused by lead/lag imbalances between blades on odd numbered systems - each blade not being 120 degrees apart and causing a weight imbalance.

How about a technical discourse on ground resonance. It would make a great article for the PRA website. And I'm just curious.

[C. Beaty]

I’ll try, John, at some later date. I’m off for Wauchula shortly.

Ground resonance is a complex phenomenon where if the CG of the rotor gets off, the stirring of the rotorhead in a circle rocks the whole machine also. Crossing the resonant frequency of the landing gear suspension begins shaking the rotor, causing lead/lag motion which in turn is coupled back to the landing gear springs. Machines with lead/lag hinges require damping of both landing gear and blade lag hinges.

Brantly (B-2) avoided ground resonance by placing the drag hinges at ~1/3 radius outboard which raises the inplane frequency high enough to stay away from it. The B-2 does not use drag dampers; there are rubber bumpers on the drag hinges that are sometimes erroneously called dampers.

Two blade rotors fitted with lead/lag hinges are nearly as prone to ground resonance as are rotors with 3 or more blades. I speak from personal experience.

[jdalexa]

To experience it sounds bad. The phenomenon of the whole thing is fascinating though. I definitely want to hear more.

[Al_Hammer]

For an example of what ground resonance does....
http://www.helicopterflight.net/photos.htm

[jdalexa]

Holey frijole!! As I understand, the only thing is to get in the air asap. This thread might be better moved though. This is the Flying Photos section.

[KDOG]

I don't know about that one gyro in the first pic...looks like a flying egg...couldn't they point the nose just a little for aesthetics?

[et3dotcom]

Holey frijole!! As I understand, the only thing is to get in the air asap. This thread might be better moved though. This is the Flying Photos section.


Another solution is to hit the rotor brake

[GyroRon]

Anyone know what engine is under Ernie's cowlings?

Subaru EJ-25

[PTKay]

Lot of pics on all the Bensen Days reports,
but NO information or new pics on the famous

LEINO Gyro.

Please, can anybody say anything about it ???

Anybody flown it ??

How does it perform ???

You are all already back home, so please,
let us know more... ;)

We are so far, far away... :(

PTKay