Duo Turbo Climb / Altitude performance

I fly a Ventus CM which uses the same basic SOLO engine block. The
major problem I have with higher flights is the progressive over rich
mixture at altitude ( there is no mechanism for leaning.) I have
climbed to 12,000 but started with marginally lean carburator jet
settings. I think John Lubon (who also flys a CM) told me he was able
to get to the 14,000 ft. published service ceiling by setting the
mixture so lean on the ground that the engine would only run with
partial choke! One technique I don't recommend is to try to lean by
partially closing the fuel shut of valve. I managed to burn a cylinder
trying this trick.
BTIZ wrote:
Thanx Walter.. I take it you are referring to the DuoT

"Walter Kronester" wrote in message
...
To supply some real world data:
At density altitudes from around 3500 ft to 7000 ft I got
between 250 and 300 fpm with 170 lbs pilot weight
and 180 - 230 fpm with (2 persons) 380 lbs (no additional water).
(VSI-Output, no precise measurement, but in correlation with altimeter
data).
Theese values were very similar in two different airplanes.
I think this climb rate is really acceptable for a sustainer only engine,
but please do never expect to escape from a downwash with a sustainer
engine.
A glide ratio of 16 seems realistic for me with the engine extended but
not
running.
So before extending the engine look out for an emergency field near by.
I hope this helps
Walter Kronester

PS: I love this bird!

At Boulder we had a DG808B & my DG500M this past Summer. The DG808B
seems to outperform the Pawnee by most everyone's estimation probably
regularly beating 500fpm on the 8500 DA typicall day as quoted below,
thats without water but still very impressive to watch and very quiet.

My DG500M doesn't do as well as the 808 but has less power and much
more weight. Looking through my notes where I actually recorded data I
see on July 10 at Boulder (1V5) approx 5300MSL, 88F, Baro 30.01, 9
minutes to shutdown at 8300 ft. Probably a minute of that was with the
engine idling before shutdown. So about 375fpm actual but I was solo.
A few weeks before that flying dual with my buddy Rolf at Gallup NM
dual climb rates at DA of about 10k looked to be about 300fpm. From
the logger traces no averages below 250fpm nor any above 400fpm dual
over a week with typicall DA 10k.

Without checking all the data (aren't loggers cool ?) it feels like the
DG500M gets better climb performance on its own then when behind the
180HP Super Cup but not as good as the 235HP Pawnee. It also feels
that weight makes more of a difference then DA. I have never self
launched my DG below Boulder's field elev nor fly in cooler weather so
can't really comment on the other side of the spectrum. Though I read
(maybe on the Aux Sailplane Assc news group or the DG owner site) that
the flapped ships do much better. It is interesting that DG had
problems certifying the new non-flapped DG-1000 as a self launcher and
for now its only available as a "turbo" like the Duo Discus. I follow
the manual and climb at flaps +10degrees at Vy 49kts.

Graham Beasley DG-500M Hotel Golf
home.comcast.net/~grahambeasley/dg4sale


BTIZ wrote:
Now that is an interesting data point... I'd be interested in others also..

If that DuoT can't climb above 6500ft MSL at better than 150fpm, then I
would not even attempt a takeoff out here in the summer time. Airport Elev,
2833MSL, Baro 30.00, Temp 100F, puts the DA at 6000ft. Granted there can be
found a thermal right on the runway to assist, but there is also strong down
near strong up.

Another favorite launch site, at 5500MSL, Baro 30.00 and 90F puts the DA at
8500, even if the temp is still only 80F, the DA is 7940.

I've noticed a DG500M on the market that flies regularly out of Colorado,
would the seller care to offer some data points?

Maybe the DG808B?

BT
"Gary Emerson" wrote in message
news
Greetings,

Looking for some real world data on what the max altitude that a Duo T can
sustain level flight. Would also be nice to know what sort of climb
performance people have seen at lower altitudes. I know it'll climb to
6500ft MSL and average around 150 FPM, but hoping to get more data points.

Gary

At 00:54 27 November 2005, Walter Kronester wrote:
To supply some real world data:
At density altitudes from around 3500 ft to 7000 ft
I got
between 250 and 300 fpm with 170 lbs pilot weight
and 180 - 230 fpm with (2 persons) 380 lbs (no additional
water).
(VSI-Output, no precise measurement, but in correlation
with altimeter
data).
Theese values were very similar in two different airplanes.
I think this climb rate is really acceptable for a
sustainer only engine,
but please do never expect to escape from a downwash
with a sustainer



engine.
A glide ratio of 16 seems realistic for me with the
engine extended but not
running.
So before extending the engine look out for an emergency
field near by.
I hope this helps
Walter Kronester

PS: I love this bird!


If your Duo T is giving those climb rates you should
be very happy:-)

wrote in
ups.com:

Without checking all the data (aren't loggers cool ?) it feels like the
DG500M gets better climb performance on its own then when behind the
180HP Super Cup but not as good as the 235HP Pawnee. It also feels
that weight makes more of a difference then DA. I have never self
launched my DG below Boulder's field elev nor fly in cooler weather so
can't really comment on the other side of the spectrum. Though I read
(maybe on the Aux Sailplane Assc news group or the DG owner site) that
the flapped ships do much better. It is interesting that DG had
problems certifying the new non-flapped DG-1000 as a self launcher and
for now its only available as a "turbo" like the Duo Discus. I follow
the manual and climb at flaps +10degrees at Vy 49kts.

Graham Beasley DG-500M Hotel Golf
home.comcast.net/~grahambeasley/dg4sale


Years ago we had a DG-500M at Soar Truckee. On high density altitude days
his self launch climb rate was dangerously low. The glider was also heavy
enough that the Cessna 182 tow planes that we had at that time gave a
dangerously low climb rate. His solution was to aerotow with the engine
running. Takeoff roll was shorter, initial climb rate was much better, and
rope break options were much better. He was able to release at 1000' AGL
or lower to go find a thermal.

IIRC he had to use reduced throttle on tow to prevent engine overspeed at
typical towing speeds.

My only worries about this method are the chance of slack line or broken
rope tangling in the prop, and the extra drag if the glider engine quits
early in the launch.

Does anyone else out there have much experience with this "towplane plus
self launch engine" method?
-Bob Korves

Though I read
(maybe on the Aux Sailplane Assc news group or the DG owner site) that
the flapped ships do much better. It is interesting that DG had
problems certifying the new non-flapped DG-1000 as a self launcher and
for now its only available as a "turbo" like the Duo Discus. I follow
the manual and climb at flaps +10degrees at Vy 49kts.

Graham Beasley DG-500M Hotel Golf
home.comcast.net/~grahambeasley/dg4sale

DG have always intended to produce a selflaunch DG 1000. It is going to have
the flapped wing for the reason above. They are just searching for the right
engine. I think they prefer to go a four stroke at the 60 to 80 hp mark. (
If you know of one that would suit let them know :-) The turbo version is a
result of asking customers what they would prefer/buy.
Paul

John Galloway wrote:

Even with zero rate of climb in the US midwest then
if the Duo T engine is started at a safe altitude then
the likelyhood of an off-airfield landing will be considerably
reduced - it just might not be the home airfield:-)

With my self-launcher, I usually (but not always) consider 1000' agl a
safe altitude to start the engine . In the situation you describe, what
would you consider a "safe altitude"? High enough to fly level to the
airport, or would you count on some climb along way, or ?

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

Have a look at the real DDT data from IGC files.
I have a few available via these links:
http://www2.onlinecontest.org/olcphp...&ein_name=1355
and
http://www.onlinecontest.de/olcphp/2...&ein_name=1355

In SeeYou you can put markers at the begin and at the end of the climb
on engine power and SeeYou will calculate the average rate of climb.
At lower altitudes the avarage rate of climb is about 0.9 meter/second
when you maintain the speed at the blue mark (95 kph).

The best thing is to fly a DDT as a pure glider, always within gliding
distance from an outlanding field or airfield.
When getting lower I usually configure the glider for landing,
position it on a downwind position with the gear down.
I start the engine at that position.
If the engine does not start I continue the landing.
Also after engine start you have to be able to be able to survive an
engine failure. This means that at low altitude with the engine
running you have to stay within gliding distance (engine out) of a
landing field.

Ruud.






On Fri, 25 Nov 2005 23:18:44 GMT, Gary Emerson
wrote:

Greetings,

Looking for some real world data on what the max altitude that a Duo T
can sustain level flight. Would also be nice to know what sort of climb
performance people have seen at lower altitudes. I know it'll climb to
6500ft MSL and average around 150 FPM, but hoping to get more data points.

Gary