Tailwheel

At 21:22 12 December 2012, Eric Greenwell wrote:
On 12/12/2012 12:08 PM, Bill D wrote:

One imagines a variation of this could work with gliders. If the
cockpit is empty, weight on the tailwheel would make it caster.
With a pilot in the cockpit, the lighter weight on the tailwheel
locks it straight ahead. The castering shaft would just have a
axial spring pushing the tail wheel down 5mm or so to lock it
straight ahead. Basically it would be automatic with no input
from the pilot.



And the first bump it unlocks ?

Complicated and not smart.

Geez, more negative experts!

A large enough bump might unlock it for a few milliseconds, but it
would re-lock instantly. Note that Blanik's are taildraggers and
many have permanently castering tail wheels so it can't be a big
deal.

Blaniks have a huge rudder that becomes effective even before the wing
runner lets go. Not so for high performance gliders.

Another likely reason: the tailwheel is large but carefully faired in.
Enabling it to swivel would involve tradeoffs in cost, weight, and drag.

And possibly: people tow the gliders around with vehicles attached to
the tail dolly. Attaching a tow bar to just the might be a problem.

But I agree it would be nice; personally, I'd rather have a steerable
tail wheel. No more directional control problems at low speeds. I love
the one on my ASH 26 E even when I take a tow, and, of course, every
time I land.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)


Question: How much download can you apply when pulling the stick full back
right after touchdown?

Experience: I forgot to lock the tailwheel on a Stearman once before I
took off. Boy was that exciting!

FR

On 12/12/2012 1:59 PM, Roger Fowler wrote:
At 21:22 12 December 2012, Eric Greenwell wrote:

And the first bump it unlocks ?

Complicated and not smart.

Geez, more negative experts!

A large enough bump might unlock it for a few milliseconds, but it
would re-lock instantly. Note that Blanik's are taildraggers and
many have permanently castering tail wheels so it can't be a big
deal.

Blaniks have a huge rudder that becomes effective even before the wing
runner lets go. Not so for high performance gliders.

Another likely reason: the tailwheel is large but carefully faired in.
Enabling it to swivel would involve tradeoffs in cost, weight, and drag.

And possibly: people tow the gliders around with vehicles attached to
the tail dolly. Attaching a tow bar to just the might be a problem.

But I agree it would be nice; personally, I'd rather have a steerable
tail wheel. No more directional control problems at low speeds. I love
the one on my ASH 26 E even when I take a tow, and, of course, every
time I land.

Question: How much download can you apply when pulling the stick full back
right after touchdown?

Experience: I forgot to lock the tailwheel on a Stearman once before I
took off. Boy was that exciting!

Or just touching down tail first, and having it unlock in a cross wind.
Probably not as exciting as your Stearman ride, but disturbing enough.


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)