tricycle undercarriage

[G. Stewart]

From late WW2 onwards, many aircraft designs started using the
tricycle undercarriage scheme. Prior to this, most used the other one
(you know, two large wheels up in front, with the plane tilted back
onto a small support wheel).

Why the change? Well, good visibility (while taxing/take-off/etc.)
would seem to be a huge advantage of the tricycle undercarraige ... so
I suppose the question really should be - why did most aircraft NOT
use the tricycle undercarriage design until late WW2?

[QDurham]

>why did most aircraft NOT
>use the tricycle undercarriage design until late WW2?
>

Weight, drag, expense. Of course the Wright Flyer had tricycle gear.

Quent

[Steven P. McNicoll]

"G. Stewart" > wrote in message
m...
>
> From late WW2 onwards, many aircraft designs started using the
> tricycle undercarriage scheme. Prior to this, most used the other one
> (you know, two large wheels up in front, with the plane tilted back
> onto a small support wheel).
>
> Why the change? Well, good visibility (while taxing/take-off/etc.)
> would seem to be a huge advantage of the tricycle undercarraige ... so
> I suppose the question really should be - why did most aircraft NOT
> use the tricycle undercarriage design until late WW2?
>

The tricycle gear has more drag and weight, but the primary reason was
generally poor runways prior to 1950 or so.

[Steven P. McNicoll]

"QDurham" > wrote in message
...
>
> Weight, drag, expense. Of course the Wright Flyer had tricycle gear.
>

The Wright Flyer had skids.

[Tex Houston]

"G. Stewart" > wrote in message
m...
> From late WW2 onwards, many aircraft designs started using the
> tricycle undercarriage scheme. Prior to this, most used the other one
> (you know, two large wheels up in front, with the plane tilted back
> onto a small support wheel).
>
> Why the change? Well, good visibility (while taxing/take-off/etc.)
> would seem to be a huge advantage of the tricycle undercarraige ... so
> I suppose the question really should be - why did most aircraft NOT
> use the tricycle undercarriage design until late WW2?

Are you referring to those 'late' designs such as

Bell P-39, Production 1939

Douglas A-20, Production 1939

Douglas C-54, Production 1942

Martin B-26, Production 1940

North American B-25, Production 1940

Consolidated PBY-5, Production 1939

Consolidated B-24, Production 1941

ERCO Ercoupe, Production 1937

Fairchild AT-13, AT-14, At-21 Production ??? but early

I really do not think they were as rare as you say and I only included USA
aircraft.

Regards,

Tex Houston

[QDurham]

> Of course the Wright Flyer had tricycle gear.
>>
>
>The Wright Flyer had skids.

I stand corrected. But I think the first wheeled Wright plane was tricycle.

Q

[WDA]

Tail draggers are prone to ground loop whereas the trike configuration makes
for less destructive landings by tyro pilots.

WDA

end


"G. Stewart" > wrote in message
m...
> From late WW2 onwards, many aircraft designs started using the
> tricycle undercarriage scheme. Prior to this, most used the other one
> (you know, two large wheels up in front, with the plane tilted back
> onto a small support wheel).
>
> Why the change? Well, good visibility (while taxing/take-off/etc.)
> would seem to be a huge advantage of the tricycle undercarraige ... so
> I suppose the question really should be - why did most aircraft NOT
> use the tricycle undercarriage design until late WW2?

[killfile]

Early landing gear was heavy, because materials technology dictated that it
had to be big, and thick to solid. In addition to this it was, of course,
another thing to fail. One of the other big, big factors was that the nose
gear needs to go into the nose - which on on piston engined fighters, was
usally full of ... engine. (Bar the P-39, which was rear-engined.)

One of the best illustrations of why the switch was made was the Me-262,
which originally had a tail-dragger configuration. On the initial test
flight, they found that the jet wash headed straight for the tailplanes and
pinned the aircraft to the ground - to get it airbourne, the pilot had to
take the horrendously dangerous manouver of tapping the brakes to bring up
the tail.

Matt

[Cub Driver]

> why did most aircraft NOT
>use the tricycle undercarriage design until late WW2?

Cost, weight, and the fact that "conventional" (tailwheel) landing
gear was a matter of pride with the Old Pilots.

(Still is. There's a sign at Hampton Airport: "Real Men Fly
Taildraggers".)

Actually, trikes came in a bit earlier than you suggest. The Bell P-39
Airacobra and the Douglas A-20 (DB-9) were two examples of trikes
designed and put into service at the end of the 1930s.

Weight was a fairly significant matter. The Douglas AD / A-1 "Spad"
was designed toward the end of World War II and served through the
Vietnam War. It was a taildragger because Douglas had to meet a
stringent weight requirement from the navy. I forget how many hundred
ponds a trike would have added, but it was significant.

For a while there, also, taildraggers were considered a requirement
for carrier landings, since they could be caught by the tail and
slammed down onto the deck in their normal landing position.

Personally, I like to fly a taildragger. A two-wheel landing, well
performed, is a very satisfying act. I'm always amused at the thought
that I fly a taildragger but fly the plane right onto the ground,
while the guys in the trikes have to make a stall-down landing.


all the best -- Dan Ford
email: (put CUB in subject line)

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

[QDurham]

Dan wrotre in part:
>Personally, I like to fly a taildragger. A two-wheel landing, well performed,
is a very satisfying act. I'm always amused at the thought that I fly a
taildragger but fly the plane right onto the ground, while the guys in the
trikes have to make a stall-down landing.

Well said. Couldn't agree more. A good wheels landing is a total delight --
particularly in that miserable (in landing) Twin Beech.

Quent


>
>

[Steven P. McNicoll]

"QDurham" > wrote in message
...
>
> I stand corrected. But I think the first wheeled Wright plane was
> tricycle.
>

I believe you're thinking of a Curtiss machine. The first Wright airplane
with wheels was the Model B of 1910. It still had skids, but added two
bicycle-type wheels on each skid near the center of gravity. You can see an
image of one here:

http://www.fi.edu/press/aviation/BFlyer_front_view.jpg

[Pat Carpenter]

Tail draggers help when you have a very large diameter prop circle
i.e. stops the prop hitting the runway. Of course not a problem with
multi-engine or jet propulsion.

Mustang
Spitfire
Hurricane
Tempest
Typhoon

to name a few.

On Wed, 26 Nov 2003 20:43:34 -0000, "killfile" >
wrote:

>Early landing gear was heavy, because materials technology dictated that it
>had to be big, and thick to solid. In addition to this it was, of course,
>another thing to fail. One of the other big, big factors was that the nose
>gear needs to go into the nose - which on on piston engined fighters, was
>usally full of ... engine. (Bar the P-39, which was rear-engined.)
>
>One of the best illustrations of why the switch was made was the Me-262,
>which originally had a tail-dragger configuration. On the initial test
>flight, they found that the jet wash headed straight for the tailplanes and
>pinned the aircraft to the ground - to get it airbourne, the pilot had to
>take the horrendously dangerous manouver of tapping the brakes to bring up
>the tail.
>
>Matt
>
>

[G. Stewart]

Thanks for the answers.

I was off on the dates for the shift to tricycle undercarriage
dominance ... sorry.

I guess what I was asking was - when the designers of the Spitfire, or
the FW-190, or the Mustang, etc. sat down to consider the
undercarriage part, why did they go with the taildragger design
instead of the tricycle design, when the latter offered so much more
visibility on the ground, and which seems to be the design of most
modern aircraft today?

From the answers, weight and strength seem to be the primary
considerations. I suppose the tricycle design requires 3 large wheels,
while the tailhanger design can get away with 2, so there is a 1/3
savings in weight. I am not sure about strength, though ... why should
the tailhanger undercarriage design be inherently stronger than the
tricycle?

Do take-off/landing characteristics have anything to do with it? With
propeller aircraft, does the tailhanger design lend itself to easier
takeoffs and landings?

[Kirk Stant]

(QDurham) wrote in message >...

> Well said. Couldn't agree more. A good wheels landing is a total delight --
> particularly in that miserable (in landing) Twin Beech.
>
> Quent

Learning wheel landings were so much fun - having to push the stick
forward to pin the wheels right after touchdown is definitely an
unnatural act at first!

Here is a bit of a anomaly. Most taildraggers (my power tailwheel
experience is limited to Cubs, Citabrias, Cap-10s, and one fabulous
wheel landing in a 450 Stearman) are a bit squirrely after touchdown
due to the CG being aft of the main gear. Theoretically, the narrower
the gear, the more they will tend to want to groundloop - the P-47
with a really wide gear was much less groundloop prone than a Wildcat,
for example. Nowadays I fly high performance gliders, most of which
have the ultimate narrow taildragger gear - one main wheel on the
centerline. And in my experience, unless you get really sideways (or
snag a wingtip, which is the usual cause of a glider groundloop), they
have absolutely no tendency to switch ends on landing. My theory it
that the stability is due to the relatively long wheelbase (in
relation to gross weight), low CG, and (usually) a fixed tailwheel or
skid. Any ideas from you aero majors out there?


Happy Thanksgiving to all!

Kirk

[Keith Willshaw]

"G. Stewart" > wrote in message
om...
> Thanks for the answers.
>
> I was off on the dates for the shift to tricycle undercarriage
> dominance ... sorry.
>
> I guess what I was asking was - when the designers of the Spitfire, or
> the FW-190, or the Mustang, etc. sat down to consider the
> undercarriage part, why did they go with the taildragger design
> instead of the tricycle design, when the latter offered so much more
> visibility on the ground, and which seems to be the design of most
> modern aircraft today?
>

One factor would be that the Spitfire, Hurricane and Me-109 were
lightweight aircraft with heavy engines, you'd probably need to prop
the rear when you removed an engine

> From the answers, weight and strength seem to be the primary
> considerations. I suppose the tricycle design requires 3 large wheels,
> while the tailhanger design can get away with 2, so there is a 1/3
> savings in weight. I am not sure about strength, though ... why should
> the tailhanger undercarriage design be inherently stronger than the
> tricycle?
>
> Do take-off/landing characteristics have anything to do with it? With
> propeller aircraft, does the tailhanger design lend itself to easier
> takeoffs and landings?

I seem to recall that tail draggers cope better with rough field
conditions and since most of the RAF fighter bases in the 1930's
had grass runways I suspect this was a major factor.


Keith

[Ken Duffey]

"G. Stewart" wrote:

> Thanks for the answers.
>
> I was off on the dates for the shift to tricycle undercarriage
> dominance ... sorry.
>
> I guess what I was asking was - when the designers of the Spitfire, or
> the FW-190, or the Mustang, etc. sat down to consider the
> undercarriage part, why did they go with the taildragger design
> instead of the tricycle design, when the latter offered so much more
> visibility on the ground, and which seems to be the design of most
> modern aircraft today?

Just think about it for a second..........

Taking each of those 3 types you mention - where would you put the
nosewheel ??

You would have to provide space underneath the engine.

Then, raising the tail would cause the prop to touch the ground.

So you would then have to lengthen the main gear legs to raise the whole
a/c (and move them back to maintain cg).

I suppose one solution would be to put the 'nosewheel' BEHIND the
mainwheels - into the lower fuselage behind the wing (or radiator in the
case of the P-51!).

You would still have to lengthen the mainlegs - but you could then make
the fuselage datum parallel to the ground.

Would such a scheme work - a 'reverse' tricycle undercarriage ??

I have a mental picture of just such an arrangement - but I can't think of
the a/c it was on ??

And would a reverse-tricycle undercarriage have the same effect as a
'normal' one - in terms of flared landing, ground-looping etc ?

++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++
Ken Duffey - Flanker Freak & Russian Aviation Enthusiast
Flankers Website - http://www.flankers.co.uk/
++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++

[Rick]

Kirk Stant wrote:

> Nowadays I fly high performance gliders, most of which
> have the ultimate narrow taildragger gear - one main wheel on the
> centerline. And in my experience, unless you get really sideways (or
> snag a wingtip, which is the usual cause of a glider groundloop), they
> have absolutely no tendency to switch ends on landing. My theory it
> that the stability is due to the relatively long wheelbase (in
> relation to gross weight), low CG, and (usually) a fixed tailwheel or
> skid. Any ideas from you aero majors out there?


Consider that the wheel is usually very close to the CG, the arm between
the CG and the very effective rudder is long giving a great deal of
rudder authority at low speeds and that the tail skid or wheel does not
touch the ground until the glider is all but stopped, and sometimes not
even then 8-)


Rick

[Kyle Boatright]

"Rick" > wrote in message
hlink.net...
> Kirk Stant wrote:
>
> > Nowadays I fly high performance gliders, most of which
> > have the ultimate narrow taildragger gear - one main wheel on the
> > centerline. And in my experience, unless you get really sideways (or
> > snag a wingtip, which is the usual cause of a glider groundloop), they
> > have absolutely no tendency to switch ends on landing. My theory it
> > that the stability is due to the relatively long wheelbase (in
> > relation to gross weight), low CG, and (usually) a fixed tailwheel or
> > skid. Any ideas from you aero majors out there?
>
>
> Consider that the wheel is usually very close to the CG, the arm between
> the CG and the very effective rudder is long giving a great deal of
> rudder authority at low speeds and that the tail skid or wheel does not
> touch the ground until the glider is all but stopped, and sometimes not
> even then 8-)
>
>
> Rick
>

Don't forget that a glider has LONG wings out there. Those long wings have
a fair amount of mass, and if mass is distributed farther from the CG, it
will result in a a more stable aircraft. One extremely unstable aircraft
that comes to mind is the Sopwith Camel.. All the heavy parts (fuel tank,
engine, pilot, gun) were located in about a 7' or 8' secton very near the
CG..

KB

[William Hughes]

On Thu, 27 Nov 2003 17:24:00 +0000, in rec.aviation.military Ken Duffey
> wrote:

> So you would then have to lengthen the main gear legs to raise the whole
> a/c (and move them back to maintain cg).

Gull wings, a.k.a. F4U Corsair series.

[Cub Driver]

> when the designers of the Spitfire, or
>the FW-190, or the Mustang, etc. sat down to consider the
>undercarriage part, why did they go with the taildragger design
>instead of the tricycle design,

In addition to weight and cost, a very important factor in the first
two aircraft was the absence of any tradition of retractable tricycle
landing gear. By the time the Mustang came along, it had been proved
out in the P-39. But the P-39 was pretty much a dead end in aircraft
design (as someone pointed out, one reason there was room for a front
retractable landing gear was that the engine was in back, with all
sorts of consequences for the pilot cockpit, balance, etc.). So the
Mustang stayed true to the P-40 tradition, big liquid-cooled engine up
front, two retractable mains, and a small tail wheel.

all the best -- Dan Ford
email: (put CUB in subject line)

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

[Cub Driver]

> why should
>the tailhanger undercarriage design be inherently stronger than the
>tricycle?

For the mains, no real difference. You do take some of the shock off
the mains with a taildragger if you make a stall-down landing, where a
bit of the weight is borne by the tail wheel. In a trike, you never
put weight on the nose wheel until the plane is rolling on the ground.

But it is certainly more difficult to build a strong nose gear than a
strong tail gear.

>
>Do take-off/landing characteristics have anything to do with it? With
>propeller aircraft, does the tailhanger design lend itself to easier
>takeoffs and landings?

Quite the contrary. A trike is easier to taxi, easier and safer in the
takeoff, and very much easier and safer on landing. The major
exception would be rough-field landings, where a wheelie in a
taildragger is more likely to have a happy outcome. It is not
generally recognized that the tires on a J-3 Cub are low-rent "tundra
tires" -- they're soft, to absorb rocks and ruts in the fields that
were common when the plane was built.

The Hurricanes of RAF 17 Sq retreated from Rangoon in March 1942 to a
rough field some miles north of the city. Several had their tail
wheels torn off by rocks; they were replaced by bamboo skids.


all the best -- Dan Ford
email: (put CUB in subject line)

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

[vincent p. norris]

> I'm always amused at the thought that I fly a taildragger but fly the plane right onto the ground,

Were you originally taught to land that way? I first learned in a J-3
and was taught to three-point it.

vince norris

[Rick]

vincent p. norris wrote:

> Were you originally taught to land that way? I first learned in a J-3
> and was taught to three-point it.

I used to do a lot of taildragger conversion instruction and always
started my students with full stall landings. They would not learn wheel
landings until they were comfortable and competent with full stall
landings under nearly all conditions on paved and dirt strips.

Wheel landings tend to become a habit for some, a bad habit in my
opinion. Regular "wheel landers" tend to get a bit lazy, land a bit too
fast and long, and lose the skills of low speed handling that landing a
tail dragger requires.

Rick

[Peter Stickney]

In article >,
William Hughes > writes:
> On Thu, 27 Nov 2003 17:24:00 +0000, in rec.aviation.military Ken Duffey
> > wrote:
>
>> So you would then have to lengthen the main gear legs to raise the whole
>> a/c (and move them back to maintain cg).
>
> Gull wings, a.k.a. F4U Corsair series.

A couple of points, here:
1) A conventional gear isn't necessary for prop clearance. All
taildraggers have long enough landing gear that the prop will be some
acceptable distance from the ground when the tail is raised on
takeoff. I've yet to see a Mustang or Corsair take off in a 3-point
attitude. (You wouldn't be able to see the runway, and the rudder
would be blanketed, just when you need it to keep the pointy part
forward.

2) If the Corsair needed Gull Wings to get adequate prop clearance,
than howcomzit that the F6F Hellcat, with an identical propeller, (the
prope wer interchangable. F4Us flew with F6F props and vice versa) was
able to make do with a flat center-sectioned mid wing and landing gear
retracting into the wings? And, in the process, provide better takeoff
an landing behavior? I think that if you really look into it, the
reason for the Corsair's wing design was a desire to reduce
interference drag at teh wing/fuselage junction by making sure that
the wing met the fuselage at a right angle. The inverted gull shape
allowed this to be done without having to add a lot of fairings to the
joint.

--
Pete Stickney
A strong conviction that something must be done is the parent of many
bad measures. -- Daniel Webster

[Cub Driver]

>> I'm always amused at the thought that I fly a taildragger but fly the plane right onto the ground,
>
>Were you originally taught to land that way? I first learned in a J-3
>and was taught to three-point it.

No, the wheelies were very hard to learn.

Come to think of it, everything was hard to learn. I guess that's why
most training is in trikes.

all the best -- Dan Ford
email:

see the Warbird's Forum at www.warbirdforum.com
and the Piper Cub Forum at www.pipercubforum.com

[Rick]

Cub Driver wrote:

> The major exception would be rough-field landings, where a
> wheelie in a taildragger is more likely to have a happy outcome.

????

Having spent a few thousand hours flying in the Idaho and Montana
backcountry in both taildraggers and trikes including 206's and 210's, I
have to call BS on that one.

I will take a 210 into nearly any field that I would not think of wheel
landing a taildragger. For one thing, a wheel landing requires a higher
touchdown speed, imposes greater loads on the gear and airframe, and
burns up runway that may not be there to begin with on a rough field.

Try wheel-landing that cub on a field that is rough and sloped a few
degrees and you will trash it in a hurry.

A trike can be full stalled as well as a taildragger and in the case you
mentioned would nearly always come out the winner in that game over a
wheel landing. The ability to stand on the brakes without worrying about
a noseover also leads to a shorter rollout than a wheel-landing taildragger.

Rick

[Ron]

>The Hurricanes of RAF 17 Sq retreated from Rangoon in March 1942 to a
>rough field some miles north of the city. Several had their tail
>wheels torn off by rocks; they were replaced by bamboo skids.

in which case, they became true taildraggers....

Ron
Pilot/Wildland Firefighter