V-tails - whatcha think about 'em? (x-x-post!!)

etsisk

etsisk

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I've been thinking a lot about building a Personal Cruiser (click on Personal Cruiser) - single seat, but good speed and a fair amount of room in there (me like elbow room!).

PcSide.jpg


Y'all might have noticed the v-tail. ;)

Sonex makes the Waiex (pronounced "Y-ex" - a y-tailed sort of plane (though it's a bit different from the Cruiser).

waiex_flight_better.jpg


I'm interested in hearing what folks have to say about planes with tails like these - I'm not "Mr. Aeronautical Engineer" guy, so if I want to know, I gotta ask! :) And I'm asking everyone on all the boards, 'cause not everyone reads red, blue and purple!
 
Never flown a V-tail anything, but I am pretty impressed with the Waiex. It's cheap to build and fly, builds quick, and it's pretty damn fast. Looks like a toy, sorta, but if I were ready to build a kit (on a "less than a RV" budget), that'd probably be what I'd get.

I haven't heard anything bad about building or flying them... talked to a couple of Sonex/Waiex nuts at Airventure last year, and they were very enthusiastic; I also got the impression that there's a strong, friendly builders' network out there for this type.
 
Sonex has a GREAT support network, and the company is as responsive as I have EVER seen in any category of product. They're truly great - and the plans, well, you'll never see a better set of plans for an experimental airplane. They're pretty stunning. I just don't want to work in aluminum right now, otherwise that would be a way to go. :)
 
That's a nice looking plane!

Also, it's fair to say that V-Tails these days are as good or better than straight tails. Cirrus Jet, F22, etc. all have them. Any aerodynamic deficiencies that might have existed in the past are gone.

-Felix
 
sba55 said:
That's a nice looking plane!

Also, it's fair to say that V-Tails these days are as good or better than straight tails. Cirrus Jet, F22, etc. all have them. Any aerodynamic deficiencies that might have existed in the past are gone.

-Felix
Click to expand...

The main deficiency was that the expected reduction in drag due to reduction of the number of surfaces never really happened.

Couple that with the more complex to build and maintain ruddervators, and it's a wonder the v tails are still popping up.

Beech (as we all know) set the standard for Vs but too many in-flight breakups (due more to disorientation in IMC in a slick airplane than to weakness of the airframe) caused them to go backl to conventional.

It would be interesting to have the transcripts of Beech engineering reviews during that time...

FWIW, My experience in a very early V (1947 Straight 35) is that you learn to pressure out the dutch roll tendency with your feet.
 
given that this is a composite plane, I don't know that it's all that more difficult to build, and may (in fact) be simpler!

And I don't have to worry about what the pax might have to say about any wagging, given that it's a single seat airplane! :) or :( ... but my wife ain't going anywhere in an airplane, I don't believe, so that's not an issue for me. sigh.
 
Actually Beech put a straight tail on the Bonanza and called it a Debonair because they wanted to differentiate it from the Bonanza. The idea was to produce a plane they could sell at a lower price that would be competitive with the Cessna 210 while maintaining higher margins on the latest version of the V-tailed Bonanza. The first Debs were offered with a spartan interior and lacked several "luxury" features of the forked tail sibling. A smaller engine was also standard. The straight tailed Deb/Bo (the Debonair name was eventually dropped) did overtake the V-tail in sales and the concerns over the structural integrity of the original were indeed a factor albeit an subjective one with little basis in fact.

Also, FWIW the roll yaw coupling (commonly but incorrectly called Dutch Roll) which makes the airplane oscillate on the yaw axis in turbulence has little or nothing to do with the tail and the straight tailed short body Bonanzas share this characteristic to almost exactly the same level. Even my Baron which has a much bigger tail than either short body Bonanza will wag it's tail in turbulence.

It's been estimated that the aerodynamic efficiency gains of the V-tail should produce about a 3Kt advantage but AFaIK this isn't borne out is careful comparisons of the two versions. There is a slight weight advantage, I believe that's something like 20-30 lbs.

dmccormack said:
The main deficiency was that the expected reduction in drag due to reduction of the number of surfaces never really happened.

Couple that with the more complex to build and maintain ruddervators, and it's a wonder the v tails are still popping up.

Beech (as we all know) set the standard for Vs but too many in-flight breakups (due more to disorientation in IMC in a slick airplane than to weakness of the airframe) caused them to go backl to conventional.

It would be interesting to have the transcripts of Beech engineering reviews during that time...

FWIW, My experience in a very early V (1947 Straight 35) is that you learn to pressure out the dutch roll tendency with your feet.
Click to expand...
 
There was a report about the waiex not too long ago in one of the aviation magazine (eaa Sport pilot or kitplanes?) The author's conclusion was that while it was a nice little plane, he found it "twitchy". The following month the president of Sonex wrote back a letter basically saying that claim of the unstableness of the plane was unfounded.. :dunno:

I've never riden in one, but they sure seem to give you a lot of bang for your buck...
 
While I'm looking at the Personal Cruiser, I do remember that article on the Waiex - and it was full of it. The plane (all sonexii) are responsive, but they are NOT "twitchy" or dangerous to handle, as that guy implied. Plus it was a newly finished plane, wasn't it?

I remember that the sonex lists were HOT after that came out... people with many hours in Sonex planes knew better than that writer, and it irked 'em.
 
lancefisher said:
Actually Beech put a straight tail on the Bonanza and called it a Debonair because they wanted to differentiate it from the Bonanza. The idea was to produce a plane they could sell at a lower price that would be competitive with the Cessna 210 while maintaining higher margins on the latest version of the V-tailed Bonanza. The first Debs were offered with a spartan interior and lacked several "luxury" features of the forked tail sibling. A smaller engine was also standard. The straight tailed Deb/Bo (the Debonair name was eventually dropped) did overtake the V-tail in sales and the concerns over the structural integrity of the original were indeed a factor albeit an subjective one with little basis in fact.
Click to expand...

There was enough basis in fact that the FAA commissioned two studies to determine what was happening: in 1952 (that one lasted 12 years), and 1978, and in the meantime Beech made constant changes/upgrades to the tail surface.

The 78 study conclusion was the V-tail had the worst record when it came to mid-air structural failure. The V-tail was 24 times more likely to have in-flight structural failure than the Straight-tail (such as the Deb). The Beech official reply was that the V-tail was only "8 times more likely than a straight-tail to have an in-flight failure."

I'm an ABS member also, but I can't ignore the fact that there have been a high number of structural failures in the V tail, so I don't fly the 35 IFR (the panel is aged and very basic) and fly it nowhere near the yellow.
 
dmccormack said:
I'm an ABS member also, but I can't ignore the fact that there have been a high number of structural failures in the V tail, so I don't fly the 35 IFR (the panel is aged and very basic) and fly it nowhere near the yellow.
Click to expand...
Almost all of he failure were caused by pilot error and people who couldn't handle the plane. With the ADs, I hear that the V35 is actually stronger than a standard Bonanza now.

-Felix
 
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