DG Differences...

Greg Arnold wrote:
g l i d e r s t u d wrote:
Marc in a feild landing you would touch down at 60mph?

I would NOT touch down at 60mph (I must have had one of those special
unflapped gliders that stalled less than 60)? I did say low energy and
nose high. Im not a math guy but isnt energy=velocity squared?

Snip

What speed do you land at in order to stop in 130 feet?

For short, obstructed-approach, field-landings, you can't have too much
disposable drag. The shortest non-abbie-normal landing I ever witnessed
was from the cockpit of my HP-14, on an unpaved, alluvial-fan airfield,
in a 5-knot breeze, at 5300' msl. After nailing the approach (easy to
do with high drag) and a tail-first flare, I paced off the main-wheel
roll at 3 fuselage lengths...accomplished w/o nose-dragging braking.

I have no idea what actual touchdown speed was, though the last part of
final was flown at 40 knots indicated (utterly benign conditions, and,
well above indicated stall speed). Point being, lots of drag and lift
can't be beat for steep, slow approaches, and short landing rolls.
Personally, I find high-drag ships much easier to consistently land than
low-drag ones.

Regards,
Bob W.

P.S. Kinetic Energy = 1/2*Mass*(Velocity*Velocity), so touchdown energy
is proportional to velocity squared. Your wheel brake knows only
velocity-squared in energy dissipation terms (though aerodynamic drag is
its friend early-on in the landing roll).

*sigh*

Well, its all turned out to be moot:

The DG-202 is too far away for me to go look at it this week, and the
DG-300 sold. :-(

--Noel

On 2008-04-19 20:12:21 -0400, "noel.wade" said:

*sigh*

Well, its all turned out to be moot:

The DG-202 is too far away for me to go look at it this week, and the
DG-300 sold. :-(

--Noel

There's a DG-200 listed for sale on wingsandwheels.com

There's a DG-200 listed for sale on wingsandwheels.com

And I'm not interested in it. The DG-200 is a fine machine; but it
doesn't have the automatic hookups that a DG-300 has, and it doesn't
have a one-piece canopy like a 202 or 300. Finally, the price isn't
that different from the going rate for an ASW-20, and the ASW has
somewhat higher performance than the 200.

Thanks, though,

--Noel

noel.wade wrote:
There's a DG-200 listed for sale on wingsandwheels.com

And I'm not interested in it. The DG-200 is a fine machine; but it
doesn't have the automatic hookups that a DG-300 has, and it doesn't
have a one-piece canopy like a 202 or 300. Finally, the price isn't
that different from the going rate for an ASW-20, and the ASW has
somewhat higher performance than the 200.

But not enough to notice unless you are a top racing pilot.


Thanks, though,

--Noel

On Apr 19, 9:44 pm, Greg Arnold wrote:
But not enough to notice unless you are a top racing pilot.


Its not just about what one pilot would notice. Its about market
effects and perception. The DG-200 is not perceived by the market as
being desireable at the same level as the DG-300 or an ASW-20.

I'm looking at this from the standpoint of safety, market-value,
resale speed, trailer quality, finish quality, age of manufacture -
all in addition to pure performance.

I am incredibly thorough in my research about gliders (some might say
I'm obsessed) - and the DG-300 and ASW-20 floated to the top for a
variety of reasons. Some of which are mainstream reasons, and some of
which are personal preferences.

Now if only I'd win the lottery so I could just buy a brand new
glider... *grin*

--Noel

On Apr 18, 12:32*am, Marc Ramsey wrote:
*Try that coming over our tall western trees with most standard
class gliders and you'll float halfway down a 400 ft patch before you
bleed off enough speed to make that nice low energy landing.

Flaps are good for short landings but it's also possible to get high
drag steep approaches with a Standard class glider. My ASW28, and the
ASW19B I used to fly, have a very high sink rate in a full rudder slip
and the speed is easily controlled if the pilot maintains
proficiency. The hard part in practicing the full rudder slip is
getting high enough on final to be able to maintain a stable slip
without undershooting.

Please try your first full rudder slips in Standard glass at high
altitude. If you are not proficient, the rapid loss of altitude can
be quite alarming. All gliders may not be as benign as the 19 and 28
in full rudder slip. Also do not be surprised if the airspeed
indicates zero as it will with some pitot systems. Ignor the ASI and
just keep the pitch attitude the same as before slip entry.

Andy

Andy wrote:
On Apr 18, 12:32 am, Marc Ramsey wrote:
Try that coming over our tall western trees with most standard
class gliders and you'll float halfway down a 400 ft patch before you
bleed off enough speed to make that nice low energy landing.

Flaps are good for short landings but it's also possible to get high
drag steep approaches with a Standard class glider. My ASW28, and the
ASW19B I used to fly, have a very high sink rate in a full rudder slip
and the speed is easily controlled if the pilot maintains
proficiency. The hard part in practicing the full rudder slip is
getting high enough on final to be able to maintain a stable slip
without undershooting.

Been there, done that, in both standard class ships and Duos. It's a
whole lot easier to come down steep with decent flaps. Just shove the
stick forward, pull on full flaps, and point the nose at where you want
to touch down...

Marc

You make it sound easy Marc, but try that in a cross wind (slipping to
maintain correct heading) and you will find an undershoot situation
rushes up really quickly! I have over 1400 hrs up in PIK 20Bs and am
still learning the fine balance between flap settings and slipping on
finals. Remember, it's generally better to land long than short.

Regards,

Geoff Vincent

On Mon, 21 Apr 2008 00:50:02 GMT, Marc Ramsey
wrote:

Andy wrote:
On Apr 18, 12:32 am, Marc Ramsey wrote:
Try that coming over our tall western trees with most standard
class gliders and you'll float halfway down a 400 ft patch before you
bleed off enough speed to make that nice low energy landing.

Flaps are good for short landings but it's also possible to get high
drag steep approaches with a Standard class glider. My ASW28, and the
ASW19B I used to fly, have a very high sink rate in a full rudder slip
and the speed is easily controlled if the pilot maintains
proficiency. The hard part in practicing the full rudder slip is
getting high enough on final to be able to maintain a stable slip
without undershooting.

Been there, done that, in both standard class ships and Duos. It's a
whole lot easier to come down steep with decent flaps. Just shove the
stick forward, pull on full flaps, and point the nose at where you want
to touch down...

Marc

On Mon, 21 Apr 2008 00:50:02 GMT, Marc Ramsey
wrote:

Andy wrote:
On Apr 18, 12:32 am, Marc Ramsey wrote:
Try that coming over our tall western trees with most standard
class gliders and you'll float halfway down a 400 ft patch
before you bleed off enough speed to make that nice low energy
landing.
Flaps are good for short landings but it's also possible to get
high drag steep approaches with a Standard class glider. My
ASW28, and the ASW19B I used to fly, have a very high sink rate
in a full rudder slip and the speed is easily controlled if the
pilot maintains proficiency. The hard part in practicing the
full rudder slip is getting high enough on final to be able to
maintain a stable slip without undershooting.
Been there, done that, in both standard class ships and Duos. It's
a whole lot easier to come down steep with decent flaps. Just
shove the stick forward, pull on full flaps, and point the nose at
where you want to touch down...

Geoff Vincent wrote:
You make it sound easy Marc, but try that in a cross wind (slipping
to maintain correct heading) and you will find an undershoot
situation rushes up really quickly! I have over 1400 hrs up in PIK
20Bs and am still learning the fine balance between flap settings and
slipping on finals. Remember, it's generally better to land long than
short.

What makes it easy in the ASW 20 is you also have spoilers, which allow
you to easily adjust the glideslope without changing the flaps.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org