Gyro with V-Tail

[greeny]

You may have noticed that a new gyro, the diNelly, is being constructed that sports a V-tail.
You can see a picture here if you scroll down to the diNelly page. Or on their own page http://www.dinelly.com/ .

The Beech Bonanza with the V-tail used to be called "doctor killer", but in a fixed wing, a V-tail makes at least some sense (weight).

Yet I am wondering what good such a device could do on a gyro that does need a (big) horizontal stabilizer but where elevators are useless - at the best.

Any opinions on that design idea?

 

[PTKay]

Don't hold your breath.
This machine has never flown and probably will never fly.

The tail is certainly too small for the large cabin.
Compare with certified gyroplanes!

 

[PTKay]

There is another machine with "kind of" V tail that probably didn't work,
so they added a vertical fin. (At least this one was flying.)

It's from Russia, called "Ohotnik" (The Hunter).

 

[scandtours]

There is a video on youtube with this russian V tail gyro flying with three persons. It is a three seater.
If not mistaken the designer is Shioumeiko. Alex from Moscow knows the whole story.

 

[GyrOZprey]

I noticed a V-tail gyro design in the Aussies hanger @ Caboolture when visiting there in February ... I asked Allan about it ! If I remember correctly he said it was not a success & was going to be changed.

 

[WaspAir]

There was a V-tail on an early prototype of the A&S 18A, which was abandoned in favor of three vertical fins and a big horizontal surface, because the V didn't provide enough stability.

 

[Doug Riley]

Jukka Tervamaki tried a V-tail on his ATE-3, the forerunner of the Magni series. He reported better stability, but that's compared to no HS at all. He later went to the triple tail we know today.

Elevators are not necessarily "useless" on gyros; the early Cierva types used fixed rotorheads, and elevators and ailerons for control. Johnny Miller performed the first loop in a gyro using this control system. He said he preferred it. But, no, you probably don't need BOTH direct cyclic AND an elevator. Pick one.

The theoretical benefit of a V-tail on a slick airplane like a Bonanza is drag reduction. Each juncture between a fin and the fuselage produces drag. Two junctures have less drag than three (as in the normal tail).

In a gyro, reducing the drag of the tail unit is largely a wasted effort. So V-tails on gyros have to do with styling, not function. Heaven forbid that styling actually TRUMP function, so that a gyro ends up unstable for the sake of looks. But we know that never happens...

 

[PTKay]

There is an inverted V-tail gyroplane under construction in Poland.
More information and discussion of the concept here:
http://www.rotaryforum.com/forum/showthread.php?t=34125

 

[WaspAir]

I had an anhedral ('inverted") V on my Sikorsky S-52:

 

[hillberg]

That's a nice lookin Sikorsky.

 

[greeny]

Form follows function

Form follows function

.. Heaven forbid that styling actually TRUMP function, so that a gyro ends up unstable for the sake of looks. But we know that never happens...

Never did, never will. - I'm glad you reassured me in that

 

[twistair]

There is a video on youtube with this russian V tail gyro flying with three persons. It is a three seater.
If not mistaken the designer is Shioumeiko. Alex from Moscow knows the whole story.

Hi Giorgos

The Hunter initially has a V-tail and an open cabin which was added by a nose pod a bit later. I flew this second version couple times as a pax and didn't notice any lack of longitudal stability.
When they added an enclosed cabin they decided to add a third fin. In 2012 I made one flight in it without pax or payload and found it very unstable in pitch. There were some other problems with this gyro, all went from design and workmanship. I didn't want to try it anymore. Owners also never offered me to fly it. There is a video at Youtube showing it flown in Southern Osetia but this flight was likely the only there. Aircraft didn't show enough reliability. I don't know what they do now, never heard of their further steps.

Vic Shumeiko is the designer of it but he left this project some years ago.

 

[Doug Riley]

When thinking about dihedral and anhedral in H-stabs, keep in mind the function of dihedral in FW planes: when the wings slide sideways in a slip or skid, the aircraft tries to return to coordinated flight. The wing that's leading the plane into the slip/skid rises, causing the plane to bank away from the direction of slip/skid. Within reason, this effect is helpful. The early ultralighters even used it to create 2-axis controls, eliminating ailerons and turning with rudder only.

But how about the same thing in a gyro tail? We like to rudder our gyros around, in vertical-descent pirouettes and such. With an upright V-tail, there will be a tendency for the tail to lift, and to turn the rudder spin into a banked turn. Good? Bad? Annoying? Unnecessary?

With an inverted V (anhedral), the tail will push the tail down and roll the gyro to the outside of the rudder turn. Personally, I would find that reaction seriously weird.

 

[scandtours]

Here's the video. Best full screen.

Автожир "Охотник" прототип 1. Auto gyro "Okhotnik" prealfa 1. - YouTube

 

[NoWingsAttached]

I did several wind tunnel tests of various empennage configurations.

Guess what? THe V tail is absolutely the best, hands down, for least drag and best performance.

BUT, and that is a HUGE but - like some butts I see around Georgia at the Taco Bell drive-In,

IT HAS TO BE CORRECTLY PLACED in the prop wash.

Looking at the photo of the cool enclosed gyro I see here, (and also this Russian thing) the design has it placed too low. The bottom of the V should be about a foot higher, and the V should be more open at the top. Can't explain why, just know from what the force data results show.

This biggest problem building a V is wit construction. It is just plain simpler and cheaper to do a cruciform tail and get nearly the same results...with a little added drag.

I would do one if I could figure out a good way to support it and do it quickly/cheaply.

To date, ya just cain't beat the RFD flying tail for performance and price. Even a MTO can't outperfom that tail on landing and cross winds authority. Ernie got it right.

 

[bones]

Here's the video. Best full screen.

holy crap is it just me or is that thing flying so nose high, it scared me, the mains definatley need to be moved back to i would think by the way it goes on the tail wheel even before it starts to roll

 

[PTKay]

....
I would do one if I could figure out a good way to support it and do it quickly/cheaply.
...

The inverted V-tail fins of the IL-28 are at the same time rear landing gear
elements and are fixed to carbon fibre torsion bars placed longitudinally
in the tail tube section.

They have castoring wheels attached, so it is kind of "tail dragger".