Conventional v tricycle gear

wrote in
:

On Jul 9, 9:26 pm, wrote:
On Jul 9, 1:24 pm, Bertie the Bunyip wrote:

I still don't see it shortening the landing roll. Can't see the
physics that would make a wheel landing shorter. I'll just have to
try it!

Here are the physics:

The trike, to get maximum weight on its mains for braking
traction, has to keep its weight off the nose. We can use full up-
elevator, but the presence of the nosewheel assures us that it will
take some of the weight and that we cannot get the wing's AOA low
enough to stop it lifting. The only advantage we have in the trike is
the elevator's downforce added to the airplane's weight. Electric
flas make it worse, since we can't retract them instantly to dump
their lift.

The taildragger can get its tail way up high. If you sit in the
airplane while its tail is on a jack or some other support so that
the airplane is in level attitude, you will be astounded at how
nose-low it feels. Observe the propeller clearance in this position,
too, and make some allowance for bouncing that might lower the prop
closer to the runway. I used to do this with students who were afraid
to raise the tail to level attitude, and they always amazed at the
picture out the front.
A taildragger with long legs, like a 185, can get its tail even
higher than level. I've seen a shot of a Helio Courier with its tail
up so that the fuselage was pointed downward at 5 or 10 degrees, and
the pilot was braking hard. No lift at all in that scenario, and
manual flaps can be retracted quickly to get even more weight on the
wheels. Most taildraggers will have the main axles 15 degrees ahead
of the airplane's CG, meaning that if you pick up the tail you can
raise it until the airplane is at that 15 degree nose-low attitude
and it will be balanced there. You'd better have lots of skill if
you're going to try this in the rollout. Pilots of another
humanitarian outfit that operated Helios did this all the time, since
the Helio's short-field takeoff capabilities are of no use if you
can't get into that short little strip and get stopped in the first
place.

Dan

You'd better go try a few. It works, believe me.


I will. I have done some very short field stuff and your's wouldn't be a
technique that would appeal! I'm going to try it if I ever get this
damned airplane flying, though..

"Stealth Pilot" wrote in message
...
...
the wings stop an aircraft more effectively than tiny brake pucks.
thats why 3 pointing it achieves the shortest landing.
the actual landing speed is lower and the wing is generating lotsa
induced drag on the backside of the performance curve.

I dont believe that getting rid of flaps shortens the landing.

My _experience_ has been that brakes slow you down faster than floating
along the runway waiting for a three point.

Get to the end of the runway at a reasonably slow speed, plant the mains,
use the brakes, and you will be stopped before you pass the numbers.

I am told, by someone who flew them for a living, that the shortest way to
stop a DC3 is wheel land, yoke FORWARD to put the tail up and generate
negitive lift to drive the mains down against the runway, and use lots of
brakes.

Of course, with tricycle gear, you don't have this sort of option.

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Capt. Geoffrey Thorpe" The Sea Hawk @See My Sig.com wrote in
:

"Stealth Pilot" wrote in message
...
...
the wings stop an aircraft more effectively than tiny brake pucks.
thats why 3 pointing it achieves the shortest landing.
the actual landing speed is lower and the wing is generating lotsa
induced drag on the backside of the performance curve.

I dont believe that getting rid of flaps shortens the landing.

My _experience_ has been that brakes slow you down faster than
floating along the runway waiting for a three point.

True, but you don't float if you want to land wiht little roll. Much of
your flare would have been accomplishded before you cross the fence.

Get to the end of the runway at a reasonably slow speed, plant the
mains, use the brakes, and you will be stopped before you pass the
numbers.

I am told, by someone who flew them for a living, that the shortest
way to stop a DC3 is wheel land, yoke FORWARD to put the tail up and
generate negitive lift to drive the mains down against the runway, and
use lots of brakes.

Of course, with tricycle gear, you don't have this sort of option.

True. I've flown DC 3s for a living and the reason you wheel it on is to
avoid blanking of the stab, though.
There's ample brake available to nose it over from three point, though,
so generating negative lift to plant the mains more firmly would
accompish nothing.


Bertie

On Fri, 11 Jul 2008 00:27:21 +0000 (UTC), Bertie the Bunyip
wrote:

"Capt. Geoffrey Thorpe" The Sea Hawk @See My Sig.com wrote in
:

"Stealth Pilot" wrote in message
...
...
the wings stop an aircraft more effectively than tiny brake pucks.
thats why 3 pointing it achieves the shortest landing.
the actual landing speed is lower and the wing is generating lotsa
induced drag on the backside of the performance curve.

I dont believe that getting rid of flaps shortens the landing.

My _experience_ has been that brakes slow you down faster than
floating along the runway waiting for a three point.

True, but you don't float if you want to land wiht little roll. Much of
your flare would have been accomplishded before you cross the fence.

Get to the end of the runway at a reasonably slow speed, plant the
mains, use the brakes, and you will be stopped before you pass the
numbers.

I am told, by someone who flew them for a living, that the shortest
way to stop a DC3 is wheel land, yoke FORWARD to put the tail up and
generate negitive lift to drive the mains down against the runway, and
use lots of brakes.

Of course, with tricycle gear, you don't have this sort of option.

True. I've flown DC 3s for a living and the reason you wheel it on is to
avoid blanking of the stab, though.
There's ample brake available to nose it over from three point, though,
so generating negative lift to plant the mains more firmly would
accompish nothing.


Bertie

what were they like to fly? the dak I mean.
it is one aircraft I'd really love to fly just to see what they were
like, having read Gann's masterpieces.
I had an old airline dak pilot as a customer once. he reckoned that
they were a really sweet aircraft to fly and lifting the tail on
takeoff was a non event.
Stealth Pilot

Stealth Pilot wrote in
:

On Fri, 11 Jul 2008 00:27:21 +0000 (UTC), Bertie the Bunyip
wrote:

"Capt. Geoffrey Thorpe" The Sea Hawk @See My Sig.com wrote in
m:

"Stealth Pilot" wrote in message
...
...
the wings stop an aircraft more effectively than tiny brake pucks.
thats why 3 pointing it achieves the shortest landing.
the actual landing speed is lower and the wing is generating lotsa
induced drag on the backside of the performance curve.

I dont believe that getting rid of flaps shortens the landing.

My _experience_ has been that brakes slow you down faster than
floating along the runway waiting for a three point.

True, but you don't float if you want to land wiht little roll. Much
of
your flare would have been accomplishded before you cross the fence.

Get to the end of the runway at a reasonably slow speed, plant the
mains, use the brakes, and you will be stopped before you pass the
numbers.

I am told, by someone who flew them for a living, that the shortest
way to stop a DC3 is wheel land, yoke FORWARD to put the tail up and
generate negitive lift to drive the mains down against the runway,
and
use lots of brakes.

Of course, with tricycle gear, you don't have this sort of option.

True. I've flown DC 3s for a living and the reason you wheel it on is
to
avoid blanking of the stab, though.
There's ample brake available to nose it over from three point,
though,
so generating negative lift to plant the mains more firmly would
accompish nothing.


Bertie

what were they like to fly? the dak I mean.

Aaargh! Only Brits call it a Dak.

It flies just lke a Cub. Really.
That's why it was such a success in WW2. You could take a 200 pilot and
stick him in it and he had a reasonable chance of surviving.
It's big and sluggish, but it does what it's told if you told it firmly.

it is one aircraft I'd really love to fly just to see what they were
like, having read Gann's masterpieces.
I had an old airline dak pilot as a customer once. he reckoned that
they were a really sweet aircraft to fly and lifting the tail on
takeoff was a non event.

Yeah, it realy did fly just like a cub. Very slow in spite of what the
published figures say. About 120 knots or so.
You could three point it, but it had a problem in that the wing would
blank the stab near the stall causing a pitch down that would shove the
mains into the ground pretty firmly and a rather exciting bounce. You
could do it, but you had to have the mains about 1/4 inch or less above
the runway as you reached that point. That's why you see most of them
wheeling on. The Twin Beech was the same as were a lot of low wing
taildraggers. The three really was docile. Stall was low. About 60 IIRC
so it was approach category A. It was difficult to taxi in high winds
snce it tended to weathervane.
Single engine handlig was a piece of cake. It even climbed on one! It
had an interesting quirk if you got too much rudder in, though. The
balance are ahead of the hinge could be caught by the prop slipstream
and push the rudder against the stop. Not a huge problem since it's only
a bit more rudder than you'd have in anyway. The only way out was to
reduce power a bit and have both guys stick both feet on the high rudder
and push. The only other real gotcha was a runaway prop. It was a
problem common to all airplanes of the period. If you lost all oil it
wouldn't autofeather like a modern twin would. It would go into fine
pitch and rendered the airplane almost impossible to steer in a straight
line. I know someone who had this in a B-25 in the Med and they tried to
shoot the prop off. He ended up ditching and spent the duration in a POW
camp. It had hydraulic everything. Gear, flaps, boosted brakes, cowl
flaps, windshield wipers! There was a great big accumulator behind the
FO that looked like an old toilet header float and the system ran about
1200 psi. The flaps were split and only lowered the stall speed by 4
knots, but did increase the drag considerably so the approach could be
made more steeply. The gear was locked down by a spade that went through
the knee of the gear leg. There was a sepearte lock lover next to the
capatins seat on the floor for this known as the "dog's dick" The up and
down handle was just behind the FO on the bulkhead as was the flap
handle. One of the reasons the FAA won't certify turbine versions is
ecause you can't se the flap and gear handles without looking behind
you. The consider the turbine version to be a new type, ya see.
I realy likd flying it. At the time is was the biggest thing I'd ever
flown. It was impressive to watch a wing that long go up and down at my
whim. I much preferred flying thr Twin Beech though. Crisper to fly and
also much more demanding.


Bertie

"Bertie the Bunyip" wrote in message
...

Major bull**** snip -


Bertie


I don't know what book you are reading, but you just proved you have never
flown one, to anyone that really has.

What a crock.

"Stealth Pilot" wrote in message
the wings stop an aircraft more effectively than tiny brake pucks.
thats why 3 pointing it achieves the shortest landing.
the actual landing speed is lower and the wing is generating lotsa
induced drag on the backside of the performance curve.

I dont believe that getting rid of flaps shortens the landing.

On Jul 10, 4:28 pm, "Capt. Geoffrey Thorpe" The Sea Hawk @See My
Sig.com wrote:
My _experience_ has been that brakes slow you down faster than floating
along the runway waiting for a three point.

Exactly. The problem, Geoff, as many don't see it, is that a
three-point rollout has the wing at a high AOA. The wing does not stop
lifting just because the wheels are on the ground so that traction is
minimal, and aerodynamic braking diminishes by the square of the
airspeed---half the speed, one-quarter of the drag. So a three-point
touchdown does not allow immediate heavy braking, and since the speed
is still high the airplane covers lots of runway before the lift has
dropped to the point that the tires have enough traction for heavy
braking. If we wait for the drag to slow us down, that's what we'll
do: wait. And use up runway.
Raising the tail gets rid of lift and places weight on the
mains. Modulating brakes and elevator slows the airplane quickly right
from the touchdown point, noseover tendency being controlled with the
elevator. Once the airplane is slowed the tail is planted and braking
increased further if necessary, though the loss of elevator
effectiveness determines just how much brake one can use.
Until one tries it he has no idea what it feels like. There was
no way I could stop the 185 in anywhere near the same distance three-
point as I was able to do with the tail-high braking. I'm not talking
the normal wheel landing here; that requires a higher airspeed to
reduce AOA so that the tail is high to start with at touchdown. That
eats up runway. I'm talking minimum speed touchdown, which will be
close to the three-point attitude, if not tailwheel-first, and then
the tail is raised after touchdown to dump the lift.

Dan

"Maxwell" luv2^fly99@cox.^net wrote in
:


"Bertie the Bunyip" wrote in message
...

Major bull**** snip -


Bertie


I don't know what book you are reading, but you just proved you have
never flown one, to anyone that really has.

Have I now?


Bertie

wrote in news:85199077-5301-44e1-b3a7-
:


"Stealth Pilot" wrote in message
the wings stop an aircraft more effectively than tiny brake pucks.
thats why 3 pointing it achieves the shortest landing.
the actual landing speed is lower and the wing is generating lotsa
induced drag on the backside of the performance curve.

I dont believe that getting rid of flaps shortens the landing.

On Jul 10, 4:28 pm, "Capt. Geoffrey Thorpe" The Sea Hawk @See My
Sig.com wrote:
My _experience_ has been that brakes slow you down faster than
floating
along the runway waiting for a three point.

Exactly. The problem, Geoff, as many don't see it, is that a
three-point rollout has the wing at a high AOA. The wing does not stop
lifting just because the wheels are on the ground so that traction is
minimal, and aerodynamic braking diminishes by the square of the
airspeed---half the speed, one-quarter of the drag. So a three-point
touchdown does not allow immediate heavy braking, and since the speed
is still high the airplane covers lots of runway before the lift has
dropped to the point that the tires have enough traction for heavy
braking. If we wait for the drag to slow us down, that's what we'll
do: wait. And use up runway.
Raising the tail gets rid of lift and places weight on the
mains. Modulating brakes and elevator slows the airplane quickly right
from the touchdown point, noseover tendency being controlled with the
elevator. Once the airplane is slowed the tail is planted and braking
increased further if necessary, though the loss of elevator
effectiveness determines just how much brake one can use.
Until one tries it he has no idea what it feels like. There was
no way I could stop the 185 in anywhere near the same distance three-
point as I was able to do with the tail-high braking. I'm not talking
the normal wheel landing here; that requires a higher airspeed to
reduce AOA so that the tail is high to start with at touchdown. That
eats up runway. I'm talking minimum speed touchdown, which will be
close to the three-point attitude, if not tailwheel-first, and then
the tail is raised after touchdown to dump the lift.

I'm still beting that with no float and max braking you;d still stop a
lot faster three point.


Bertie

"Bertie the Bunyip" wrote in message
...

I'm still beting that with no float and max braking you;d still stop a
lot faster three point.


Bertie


No you're not, you're just trolling, or attempting it.