Tailwheel

Originally Posted by Ventus_a

...and starting with stick full back to keep the glider straight at the beginning of a crosswind take off will unlock the wheel and negate its benefits

Colin

How about a steerable castering tail wheel?...a la HP series.

One of Eric's points earlier was the added drag most full castering tailwheels would present. On his ASH26E, the steerable tailwheel is limited in it's steering range to about 30 degrees to each side. Thus the tailwheel fairing can have a reasonably small opening and the extended part of the tailwheel presents minimal drag.

In order to fully caster, the tailwheel structure would either have to extend out far enough, or the boom would have to be fat to accomodate complete rotation.

Course the tailwheel could be retractable . . . more complex and expensive. Cost/ benefit?

bumper

On Wednesday, December 12, 2012 7:41:20 PM UTC-7, bumper wrote:
One of Eric's points earlier was the added drag most full castering tailwheels would present. On his ASH26E, the steerable tailwheel is limited in it's steering range to about 30 degrees to each side. Thus the tailwheel fairing can have a reasonably small opening and the extended part of the tailwheel presents minimal drag.



In order to fully caster, the tailwheel structure would either have to extend out far enough, or the boom would have to be fat to accomodate complete rotation.



Course the tailwheel could be retractable . . . more complex and expensive. Cost/ benefit?



bumper

Well, that's a point. As I imagine it, the tailwheel would extend only 5mm further than one of those breakaway rubber things with a skate wheel. That far back, the boundary layer is pretty thick so not much extra drag - probably less than an open air scoop.

This is not one of those things for retrofit - the 337 field approval hassle wouldn't be worth it but it would be a nice feature on a new glider or an experimental. The idea isn't for taxiing, it's just to make it easier to push the glider off the runway without running to get a tail dolly. Of course, nothing in the idea would prevent using a tail dolly for really rough ground.

On 12/12/2012 9:02 PM, Bill D wrote:

Course the tailwheel could be retractable . . . more complex and
expensive. Cost/ benefit?
bumper

Well, that's a point. As I imagine it, the tailwheel would extend
only 5mm further than one of those breakaway rubber things with a
skate wheel. That far back, the boundary layer is pretty thick so not
much extra drag - probably less than an open air scoop.

This is not one of those things for retrofit - the 337 field approval
hassle wouldn't be worth it but it would be a nice feature on a new
glider or an experimental. The idea isn't for taxiing, it's just to
make it easier to push the glider off the runway without running to
get a tail dolly. Of course, nothing in the idea would prevent using
a tail dolly for really rough ground.

The Grob tail wheel that plugs in always seemed like a good idea: full
dolly size wheel for moving it around, drops off during launch if you
forget it, small and light enough to carry in the glider, seemingly
minor weight addition to the glider to use it.

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

Walking to get the dolly after a long flight might reduce the chance of
blood clots in the legs and will certainly aid in preventing weight gain.
Or do youse guys just walk to the cooler for that "beverage"?

Ah... Off season...


"Eric Greenwell" wrote in message
...
On 12/12/2012 9:02 PM, Bill D wrote:

Course the tailwheel could be retractable . . . more complex and
expensive. Cost/ benefit?
bumper

Well, that's a point. As I imagine it, the tailwheel would extend
only 5mm further than one of those breakaway rubber things with a
skate wheel. That far back, the boundary layer is pretty thick so not
much extra drag - probably less than an open air scoop.

This is not one of those things for retrofit - the 337 field approval
hassle wouldn't be worth it but it would be a nice feature on a new
glider or an experimental. The idea isn't for taxiing, it's just to
make it easier to push the glider off the runway without running to
get a tail dolly. Of course, nothing in the idea would prevent using
a tail dolly for really rough ground.

The Grob tail wheel that plugs in always seemed like a good idea: full
dolly size wheel for moving it around, drops off during launch if you
forget it, small and light enough to carry in the glider, seemingly minor
weight addition to the glider to use it.

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

On Thursday, December 13, 2012 10:09:01 AM UTC-5, Dan Marotta wrote:
Walking to get the dolly after a long flight might reduce the chance of
blood clots in the legs and will certainly aid in preventing weight gain.
Or do youse guys just walk to the cooler for that "beverage"?

Cool dudes do NOT push the glider about.
We taxi back to the trailer and the cool beverage ;-)

See ya, Dave "YO electric"

On Thursday, December 13, 2012 4:20:33 PM UTC+1, Dave Nadler wrote:

Cool dudes do NOT push the glider about.

We taxi back to the trailer and the cool beverage ;-)



See ya, Dave "YO electric"


Really cool dudes taxi back to the trailer without an engine... ;^)

66

On Thu, 13 Dec 2012 06:57:27 -0800, Eric Greenwell
wrote:


The Grob tail wheel that plugs in always seemed like a good idea: full
dolly size wheel for moving it around, drops off during launch if you
forget it, small and light enough to carry in the glider, seemingly
minor weight addition to the glider to use it.

My partner and I used to have an Astir-CS, and I wouldn't have wanted
the factory tail dolly in the cockpit: it was several pounds of
ironmongery and could have done some damage in a bad outlanding. We
did make a small, lightweight one to carry aboard, but used the much
larger factory wheel for most ground handling.

The dolly hole made a whining noise that was ground-audible at 1000
AGL...don't know how much drag that really produced, but we habitually
taped it over before a contest launch. And that produced a memorable
event: I positioned my partner on the grid, removed the dolly, and he
said "Tape up my a$$hole!", unaware that he was on a hot mike.

Sounds like a jet! I can't make a direct link, but if you check out
"UF Low Level" from hehttp://www.youtube.com/my_videos?feature=mhum
it's clearly audible.
Eric: While that 'wheel on a post' dolly COULD be made fairly
lightweight, the OEM unit isn't. But it DOES fall away if you forget
to remove it. ;-)


On Dec 13, 7:56*am, Ralph Jones wrote:
On Thu, 13 Dec 2012 06:57:27 -0800, Eric Greenwell

wrote:

The Grob tail wheel that plugs in always seemed like a good idea: full
dolly size wheel for moving it around, drops off during launch if you
forget it, small and light enough to carry in the glider, seemingly
minor weight addition to the glider to use it.

My partner and I used to have an Astir-CS, and I wouldn't have wanted
the factory tail dolly in the cockpit: it was several pounds of
ironmongery and could have done some damage in a bad outlanding. We
did make a small, lightweight one to carry aboard, but used the much
larger factory wheel for most ground handling.

The dolly hole made a whining noise that was ground-audible at 1000
AGL...don't know how much drag that really produced, but we habitually
taped it over before a contest launch. And that produced a memorable
event: I positioned my partner on the grid, removed the dolly, and he
said "Tape up my a$$hole!", unaware that he was on a hot mike.

On 12/13/2012 7:56 AM, Ralph Jones wrote:

The Grob tail wheel that plugs in always seemed like a good idea: full
dolly size wheel for moving it around, drops off during launch if you
forget it, small and light enough to carry in the glider, seemingly
minor weight addition to the glider to use it.

My partner and I used to have an Astir-CS, and I wouldn't have wanted
the factory tail dolly in the cockpit: it was several pounds of
ironmongery and could have done some damage in a bad outlanding.

These days it would light weight carbon fiber and stow safely behind the
seat.

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