tricycle undercarriage

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

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

(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

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

"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

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

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

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

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?

"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