Twin Tailed Fighters
smharding
fighter aircraft?
The F-14 was the first such US aircraft as far as I know
and now of course the F-22 and F-35 have them as well as
corresponding Russian/Soviet Sukhois and MiGs. The latest
images of the Chinese J-20 show similar twin tails.
Given so many fighter aircraft with twin tails, I presume
there must be very good aerodynamic reasons for having them
over a single tail. Increased rudder control surface area
is about the only thing that comes to mind as an advantage.
Is such an advantage worth the added complexity? Apparently
it is, if there aren't other reasons.
And who produced twin tailed jet fighters first? Did the
F-14 start the trend or was it part of a Eureka moment that
came upon Americans and Russians at the same time? My
suspicions are that someone copied someone but perhaps it
was independently derived at about the same time.
SMH
Walt
wrote:
Not new. The F7U comes to mind. Even earlier the twin boom-twin tail
Venom/Vampire/Sea Vixen from the UK and the the SAAB J-21 jet version.
Jim Wilkins
> On Sun, 16 Jan 2011 12:19:05 -0500, smharding <smhard...@verizon.net>
Do they improve engine-out control?
jsw
Dan
In the case of the U.S. Navy twin tails solved the problem of tall
tails. Hangar ceilings would have been a tad more expensive to raise.
Dan, U.S. Air Force, retired
Eunometic
> So what's the deal with the trend towards twin tails in
> fighter aircraft?
The new twin engined designs were relatively "flat" with little
fueselage side area for stabillity. The choice of getting sufficient
fin area got down to
a/ One very large vertical fin, obviously structurally challenging.
b/ Ventral fins, which although in nice 'clean air' can only be small
or need to be paird or folding (eg MiG 23 and MiG 27)
c/ twin fins. These can be canted out so that they can be in cleaner
air.
> And who produced twin tailed jet fighters first? Did the
> F-14 start the trend or was it part of a Eureka moment that
> came upon Americans and Russians at the same time?
Using twin fins to get more area, clean air (or place the rudder in
the prop flow) is not a new idea. AFAIKT the Soviets started the
trend with the MiG 25 Foxbat though you can see the beginings of the
problem and its solution in the SR-71/YF-12
Daryl Hunt
I think someone mentioned that the twin tail enabled it to have a
lower profile for a carrier. Makes sense after looking at that
one. It would make sense on a slower jet as the F-7U. But with
the Mig-25 I think it was done to keep the streamlining as low as
possible. Same goes for the F-14. Rather than one big single
vertical stab, use 2 smaller ones and get the same affect with
less drag and a smaller profile. Of course, the Mig-25 and the
F-14 needed all the help they could get to minimize the
visibility as both were rather large.
hcobb
LEX works best with twin tails. Yes the F-16 has LEX and a single
tail, but it also has those dorsal fins so you could call it triple
tailed.
Stealth designs favor not having vertical slabs, so twin leaning tails
are used on every stealth design that has "vertical" tail surfaces.
-HJC
bod43
> Additionally:
>
> LEX works best with twin tails. Yes the F-16 has LEX and a single
> tail, but it also has those dorsal fins so you could call it triple
> tailed.
LEX?
> Stealth designs favor not having vertical slabs, so twin leaning tails
> are used on every stealth design that has "vertical" tail surfaces.
I would think that the removal of the "corner reflector"
effect by leaning the tails might be quite a bit part of it
but I have no insight into the actual design process.
T
"smharding" <smha...@verizon.net> wrote in message
news:igv9at$9f2$1...@news.eternal-september.org...
Look at the Tornado, and you'll see the alternative.
Scott M. Kozel
Daryl Hunt
I think we are talking about function over looks. The P-38 had a
reason for twin tails or booms. What do you do with the
Turbosupercharger of that size? you put it behind the engine in
a boom and tie the booms together.
The F-14, Mig-25 both did it to have less drag and get the same
controls. Others have followed this example.
Most of the early designs were just because it looked neat.
Rob Arndt
>
> - Show quoted text -
The OP was talking twin-tails for fighters with same fuselage- not
twin boom a/c which have been around for a long time.
During WW2 the Germans experimented with a Bf 109G-0 V-tail:
http://i18.photobucket.com/albums/b142/apollyonsun/Luftwaffe%20Reviews/Bf_109_G-0_VJWC_bl-1.jpg
One of three known photos of Messerschmitt Bf 109 G-0, VJ+WC,
Werknummer 14003, as featured as part of report no. 109 08 E 43,
issued by Messerschmitt AG's flight test department, dated May 5,
1943.
This early Bf 109 G-0, Werknummer 14003, VJ+WC, was used for
Messerschmitt trials of a V-tail empennage on January 21, 25, 26, and
27, 1943. The extensive technical description and flight test reports,
issued by Messerschmitt AG in Augsburg and dated from early 1943,
survive and have been reproduced in their entirety in Luftfahrt - Band
5 (Germany, 1978, ISBN 3 87547 182 2). Only three pictures of this
aircraft are know to exist (all originally included in the
aforementioned technical description), but none of them show the
entire Bf 109.
There are a number of features which distinguish this Bf 109. Based on
its Werkummer, it was part of the first three Bf 109 G-0s produced at
Messerschmitt's Regensburg plant in October of 1941. According to the
technical description, the aircraft was powered by a Daimler-Benz DB
605 A (Werknummer 76172), driving a VDM airscrew. The aircraft's wings
incorporated early (i.e., small) G-type wing bulges, implicating that
the corresponding wider wheels had possibly been fitted. One of the
photos of this Bf 109 shows that this aircraft had a Bf 109 F-4 type
canopy, but it seems to have lacked any head armour. Also visible in
the photos is a Bf 109 F type tail wheel. Werknummer 14003 had no
antenna mast, but an antenna wire ran from each butterfly fin towards
the canopy (the exact location where the wires entered the fuselage
cannot be discerned from the existing photos).
An F-style external fuselage strengthening strip ran from the fuselage
to the converted tail cone. This strip seems to have been riveted to
the fuselage. There was also an apparent actuating rod on the bottom
of the new tail fins, near the hinge point. The new fins were faired
into the fuselage by means of (aluminium) slip-over gloves. On the
outside of the fins, very noticeable external strips apparently
signify the mounts of the hinges for the rudders. These strips are not
present on the upper side of the fins.
The camouflage of Werknummer 14003 appears to have been standard for
the time, i.e., 76/74/75. The converted tail cone had been left
natural metal, and the two butterfly fins were painted in a dark
color, possibly 66 or 70, or even 22. The aircraft Werknummer was hand-
painted in white above the last letter of the call sign on both sides
of the fuselage, right before the demarcation line from the
camouflaged fuselage to the natural metal tail cone. The small number
"8" denoting the fuselage frame was uniquely applied over the bottom
part of the call sign letter "C" on the port side, on a small patch of
what appears to be 76.
~ http://luftwaffereviews.blogspot.com/2009/05/notes-on-messerschmitt-bf-109-g-0.html
Many German fighter projeckt a/c featured twin tails for a single
fuselage.
F-14, F-15, F/A-18, F-22, F-35, MiG-25 and 31, MiG-29, and Sukhoi
Flaker/Su-47 series are large fighter/interceptors. Seems logical to
have twin vertical tails for stability and manoeuverability.
Rob
Daryl Hunt
We are talking about operational AC, not evolutionary dead ends.
Your Whatifs don't apply nor does anyone elses. The 109 had no
reason to use the V tail and Messie figured it out pretty quick.
It looked neat but wasn't as good as the tail the 109 already
had. And the V tail was much more complicated.
>
> F-14, F-15, F/A-18, F-22, F-35, MiG-25 and 31, MiG-29, and Sukhoi
> Flaker/Su-47 series are large fighter/interceptors. Seems logical to
> have twin vertical tails for stability and manoeuverability.
Nope, has nothing to do with it. The twin vertical stabs can be
made smaller, less drag, lower visibility and have a lower (for
Carriers) ceilings in the bays. the Twin Vertical Stabs like
that really wasn't needed on slower AC as they would not have the
speed to enjoy the benefits.
Keith Willshaw
"Daryl Hunt" <dh...@nospami70west.com> wrote in message
news:ih0odv$is1$1...@speranza.aioe.org...
There were LOTS of WW2 aircraft with twin tails for the reasons
you already mentioned. Most of them were bombers of course.
The requirement to keep the overall height down was a critical
factor for most RAF aircraft as the Air Ministry wanted to
be able to fit them into existing hangars. The Avto Manchester
actually had a triple tail IRC.
One additional advantage of th twin tail is resistance to battle
damage which I believe was a factor in the choice of the twin
tail layout for the A-10.
Keith
Rob Arndt
Yes, the bombers were huge a/c and there really was no need for twin
tails on WW2 fighters. But the 1970s-present fighters are huge
compared to WW2. They probably work better under multiple redundancy
computers with two tails vs a large delta with a single tail...
... and if you lose one to cannon or missile fire, then you still have
the other one.
BTW, the Me P.1106 and 1110 would have had twin tails as would the
Arado E.581.5.
Messerschmitt investigated the V-tail for both fighters and bombers.
The He-162 had a version with propsed V-tail too.
Why do I even mention this as the US in WW2 also investigated V-tails?
Rob
Dweezil Dwarftosser
>
> So what's the deal with the trend towards twin tails in
> fighter aircraft?
In my mind, there were two types of 'twin tails', which had
nothing to do with each other.
The first type was the sort of thing we found mass-produced
beginning around WW II: some need for strength in the fuselage
may have demanded it, or other design goal (as others have
mentioned concerning lower rudder 'height', on aircraft
carriers). In any case, all of these involved an application
where two smaller 'tails' (instead of one large one) were a
valid design alternative to better 'distribute' stresses or
some other integrity goal.
The second type (the 'all-moving, independent' tails - which
often included stabilators, or non-hinged horizontal tail
surfaces) addressed a completely different problem in very
high-speed aircraft. The A-11/YF-12/SR-71 series was clearly
the first operationally-employed aircraft of this type - and
the ability to independently tilt those 'vertical' tails toward
each other (away from vertical) even provided a bit of realized
stealthiness it could utilize as a bonus under certain conditions.
> The F-14 was the first such US aircraft as far as I know
I'm not sure if the F-14's equipment falls in that same "all-moving'
design goal, more than being a strength and controlability
accomodation for the wide separation between the two in-fuselage
engines. A single-engine landing, for example, might have been
extremely dicey with the resultant assymetrical thrust so far from
the aircraft centerline, using a single 'tail'.
While the Russian's Mig-25 was an early entry with twin tails, it
clearly did not include any of the 'all-moving' features. It used
conventional rudders and tail planes.
The F-15's twin tails did, however, have a wide range of 'all-moving'
independent tail surfaces.
> and now of course the F-22 and F-35 have them as well as
> corresponding Russian/Soviet Sukhois and MiGs. The latest
> images of the Chinese J-20 show similar twin tails.
>
> Given so many fighter aircraft with twin tails, I presume
> there must be very good aerodynamic reasons for having them
> over a single tail. Increased rudder control surface area
> is about the only thing that comes to mind as an advantage.
If that were the only advantage, they could have stuck with
conventional designs, like the Mig-25.
> Is such an advantage worth the added complexity? Apparently
> it is, if there aren't other reasons.
>
> And who produced twin tailed jet fighters first? Did the
> F-14 start the trend or was it part of a Eureka moment that
> came upon Americans and Russians at the same time?
I'm just guessing, but I imagine the cat was let out of the bag
for the rest of the world, the first time an F-15's range of
tailplane movement was filmed. Then the lightbulbs illuminated
over heads all over the world. (Film of SR-71s were rare - and
classified - until late in its operational lifetime. I gotta' say
it: I was blown away, watching an SR-71 doing a pre-flight check
of control-surface authority. It was amazing; and huge, compared
to what I had imagined from still photos.)
> My suspicions are that someone copied someone but perhaps it
> was independently derived at about the same time.
All we really have is our suspicions and opinions (except, of course,
the 1890s German cocktail-napkin designs for spacecraft with massive
independent control surfaces made necessary by the thinness of the air
they would encounter . . . as 'documented' in modern artworks on
specialized websites). ;-)
Daryl Hunt
> "Daryl Hunt"<dh...@nospami70west.com> wrote in message
> news:ih0odv$is1$1...@speranza.aioe.org...
>> On 1/16/2011 11:15 PM, Rob Arndt wrote:
> And the V tail was much more complicated.
>>
>>>
>>> F-14, F-15, F/A-18, F-22, F-35, MiG-25 and 31, MiG-29, and Sukhoi
>>> Flaker/Su-47 series are large fighter/interceptors. Seems logical to
>>> have twin vertical tails for stability and manoeuverability.
>>
>> Nope, has nothing to do with it. The twin vertical stabs can be made
>> smaller, less drag, lower visibility and have a lower (for Carriers)
>> ceilings in the bays. the Twin Vertical Stabs like that really wasn't
>> needed on slower AC as they would not have the speed to enjoy the
>> benefits.
>>
>
> There were LOTS of WW2 aircraft with twin tails for the reasons
> you already mentioned. Most of them were bombers of course.
The only fighter that was needed to be twin tailed was the P-38.
All the others were just, "Hey, that looks neat". the bombers
were taller, yes. And that is probably the only reason other
than taking battle damage better like the Avro and the B-24.
>
> The requirement to keep the overall height down was a critical
> factor for most RAF aircraft as the Air Ministry wanted to
> be able to fit them into existing hangars. The Avto Manchester
> actually had a triple tail IRC.
For the Avro, that is what I would call, "Doesn't that look sexy"
to have a triple.
>
> One additional advantage of th twin tail is resistance to battle
> damage which I believe was a factor in the choice of the twin
> tail layout for the A-10.
Which I don't think has been proven up to this point as being
needed. If the A-10 gets into that kind of jam, I doubt if it's
going to make it back since it will also be taking hits elsewhere
on the tail including engines. Of course, the original idea was
for the A-10 to engage Armor which it would take that kind of
damage and an A-10 was cheaper than a MBT. Now we find that
there are better methods to be used to engage MBTs that we might
or might not encounter from the enemy. The whole thing stems
from the US taking control of the skies. So far, this has worked
well and air supremacy has been accomplished. That releases an
even more terrifying weapon platform to engage the Armor; the
Buff. And our M-1 Abrams have done a remarkable job with Tank
on Tank as well. And don't forget the F-16 with it's real big
bombs. And the Ground troops, etc.. It's not real safe to be
sitting in a tin can going against the US these days. In fact,
outside of Roadside Bombs and sniper fire, it's just not safe to
be close to any US forces. But the enemy has learned this as
well and uses extraordinary means.
Daryl Hunt
Wow, Rob, you mean the US was experimenting with something that
the Germans were experimenting? Glad you mention this. And both
learned that the V tail was inferior to the straight tail for
fighters and abandoned it for about 35 years.
it's not the size of the modern fighter. it's the speed they
travel at. Twin Tails are still used for height, control,
redundancy and something new called Stealth. If they were still
flying near Mach the twin tails would not be necessary except for
stealth. Unless there is a height problem for a hangar. Tall
landing gear went by the way as well so the height probably isn't
the reason.
guy
Me-110?
Guy
Daryl Hunt
The Germans had a bad habit of trying out new things. The 110
tail was one of those "Sure looks Neat" where a single Vertical
Stab would have worked at least as well, been cheaper, stronger,
etc.. The Tail looked neat. Too bad the rest of it looked like
a nightmare as did many of the German WWII and earlier designs
But they learned, just not soon enough for their war efforts.
Dean
The twin tails on A-10s have one further design advantage: They help
mask the exhaust from IR seeking missiles.
Keith Willshaw
"Daryl Hunt" <dh...@i70westnospam.com> wrote in message
news:_UUYo.1931$ma6....@newsfe20.iad...
Not it was a case of it wont fit in the bloody hangar with
a single tail.
With only two engines you needed a LOT of rudder
authority for single engined flying.
>
>>
>> One additional advantage of th twin tail is resistance to battle
>> damage which I believe was a factor in the choice of the twin
>> tail layout for the A-10.
>
> Which I don't think has been proven up to this point as being needed. If
> the A-10 gets into that kind of jam, I doubt if it's going to make it back
> since it will also be taking hits elsewhere on the tail including engines.
Which is why the engines are widely separated too. I seem to
recall at least on picture of an A-10 that had eaten an IR SAM
coming back missing an engine and most of its tail.
Keith
Rob Arndt
>
> - Show quoted text -
Back to the P-38 again??? WTF??? That is a TWIN-BOOM a/c and not
unique at all. The P-61 was twin-boom. So was the Fokker D.XXIII and
Saab J.21. Italy had the SM.91 & 92. Germany had the Fw-189 and Skoda-
Kauba V6. Etc, etc, etc...
Twin-boom is not the same as V-tail nor twin tail (on a single
fuselage) as the OP inquired about.
Stop bringing up the P-38 twin-boom. Germany had a twin-boom in WW1.
The US tried the V-tail on a variant of the P-63:
http://www.olive-drab.com/images/id_fighters_p63_02_700.jpg
Postwar Thunderceptor V-tail:
http://q-zon-fighterplanes.com/wp-content/uploads/2010/07/Republic-XF-91-Thunderceptor-V-tail.jpg
Rob
Rob Arndt
>
> - Show quoted text -
Bf 110/210/310/410
Ar-240/440
He-219/280/162
Bf 161/162/Me-261
Rob
guy
>
> - Show quoted text -
Halberstadt CLIIIa? ok the twin tails were horizontal not vertical
but....
Guy
Keith Willshaw
"guy" <guyswe...@googlemail.com> wrote in message
news:e46d7064-7d0e-46bd...@r19g2000prm.googlegroups.com...
= Halberstadt CLIIIa? ok the twin tails were horizontal not vertical
= but....
= Guy
For real oddities look no further than the Blackburn Scout AD
a high wing biplane with the fuselage attached to the UPPER
wing and twil tails below the horizontal stabilizer
http://en.wikipedia.org/wiki/AD_Scout
Just in case that wasnt ugly enough they then tried a triplane version
http://en.valka.cz/viewtopic.php/t/54869
Keith
Keith
Ken S. Tucker
> So what's the deal with the trend towards twin tails in
> fighter aircraft?
Sad but interesting story, check out the development of the
F-100, basically aerodynamists grossly underestimated the
area of the vert fin required near and over supersonic speeds.
('grossly' means men died).
So lots of vert fin is needed.
A 2nd reason is suction lift at high AoA's, the twin verts make
a suction between them, in consort with the fuselage, that's
less well known but is being improved by canting the verts
outward, noteworthy on the F-18.
Ken
frank
Its as much aerodynamics as it is other reasons that may be built into
the airplane. Getting cargo in and out, stealth, fitting into a hangar
deck, lots of reasons. Less material to add to put the tail on. Think
of how massive some of the vertical stabilizers were post WWII.
Remember there are a lot of people who come together to engineer an
airplane. Sometimes you need the stability of two tails. Usually wind
tunnel studies work all this out, but not always. A few aircraft have
had single tail and twin tail variants. Some aircraft were just dogs,
but that's another fight for another day.
hcobb
> On Jan 17, 12:11 am, hcobb <henry.c...@gmail.com> wrote:
>
> > Additionally:
>
> > LEX works best with twin tails. Yes the F-16 has LEX and a single
> > tail, but it also has those dorsal fins so you could call it triple
> > tailed.
>
> LEX?
http://en.wikipedia.org/wiki/McDonnell_Douglas_F/A-18_Hornet
During flight testing, the snag on the leading edge of the stabilators
was filled in, and the gap between the Leading edge extensions (LEX)
and the fuselage mostly filled in. The gaps, called the boundary layer
air discharge (BLAD) slots, controlled the vortices generated by the
LEX and presented clean air to the vertical stabilizers at high angles
of attack, but they also generated a great deal of parasitic drag,
worsening the problem of the F/A-18's inadequate range.
-HJC
Rob Arndt
Fokker K.I (M.9):
http://www.schofields-flying-club.com.au/newsletter/images/nov08/FKI.jpg
Schwade Kampfeinsitzer II:
http://static.rcgroups.net/forums/attachments/4/3/9/8/7/t3684985-223-thumb-Schwade%202.jpg?d=1293408260
Rob
Rob Arndt
http://static.rcgroups.net/forums/attachments/4/3/9/8/7/t3684984-254-thumb-Schwade%201.jpg?d=1293408260
Rob
Daryl Hunt
Okay, Rob. That's enough. You say that I am not allowed to
include the P-38 yet you include AC that have the same setup.
the difference is, that your AC are "Sure looks Nice" designs.
your Fokker KI, only one was built and the tails flexed too much
and it was abondandoned. Failure to the first order. Another
"Looks Sexy" but didn't work out. There is no rhyme nor reason
for this tail layout or this AC.
Your Schwade was a disaster. Another failure and not really in
quantity to call operational. But the reason it was a twin boom
(again, you already discounted these by throwing your girlie
tantum over the mention of the P-38) was that it was a pusher and
that's the only way to get a tail on it.
Jeff Crowell
>> A 2nd reason is suction lift at high AoA's, the twin verts make
>> a suction between them, in consort with the fuselage, that's
>> less well known but is being improved by canting the verts
>> outward, noteworthy on the F-18.
"Suction lift"?
And here I was, thinking that the Hornet's vertical tails were
canted outboard to improve controllability (both stability and
rudder authority) at high AOA...
Jeff
--
A people that values its privileges above its principles will
soon lose both.
Ken S. Tucker
> Ken S. Tucker wrote:
> >> A 2nd reason is suction lift at high AoA's, the twin verts make
> >> a suction between them, in consort with the fuselage, that's
> >> less well known but is being improved by canting the verts
> >> outward, noteworthy on the F-18.
>
> "Suction lift"?
> And here I was, thinking that the Hornet's vertical tails were
> canted outboard to improve controllability (both stability and
> rudder authority) at high AOA...
The F-18 is one strange bird, but it works really well, ingenious,
reality speaks.
As you know the original F-15 didn't cant verts but it's intended for
the
newer version, obviously because the effects are better understood,
and regarded as important enough to redo the verts.
Jeff, there are issues with an outboard vert cant for stability at
high
cruise speeds, it has inferior properties but at those speeds the AoA
is low, and those fighters rarely operate (maneuver) near transonic,
so it doesn't matter.
Here's a nice photo of F-18,
http://www.richard-seaman.com/Aircraft/AirShows/Indianapolis2002/F18/F18Banking3oClock.jpg
the SOBs put the verts 'between' the main and the tail, taking
airflow
from the space between them I suppose, that is effective at high
AoA's.
Ken
Typhoon502
> So what's the deal with the trend towards twin tails in
> fighter aircraft?
>
> The F-14 was the first such US aircraft as far as I know
> and now of course the F-22 and F-35 have them as well as
> corresponding Russian/Soviet Sukhois and MiGs. The latest
> images of the Chinese J-20 show similar twin tails.
I read once that twin tails were implemented in part to add stability
for missile launching, which is why the F-14 and F-15 interceptors
have them but the F-16, which wasn't designed (initially) to be a real
missileer platform, did not. Take it for what it's worth. One could
extrapolate that the F-4 was a learning experience...