Duo Turbo Climb / Altitude performance

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

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

ok... I have received two lashes with the noodle that the Duo T is a
"sustainer" and not self launch...

but by the same token... of the Duo T can only "sustain" 6500MSL DA... it is
nothing more than a glider out here... I'll admit... I did use that word
"take off" in regards to "sustainer" operations

The POINT is that Density Altitude during standard summer operations will
make the use of the "sustainer engine" worthless. 6500DA is below GROUND
LEVEL in our peak flying season, maybe it will only extend the glide back to
something landable.. but I would not want to count on it to "maintain
altitude".

But then again.. with temps such as these.. we don't need no stinking
engine.

BT

"BTIZ" wrote in message
news:swNhf.4913$pF.4792@fed1read04...
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

Just to clarify just a tad, we shut down the turbo at 6500 ft because we
had final glide back to home, not because we weren't climbing. We still
had about 125-150 FPM up at that point. I've never had a need to fire
it up at any higher altitude and so I'm curious if anyone else has...
I'd love to hear that you could hold altitude at 10k ft.

BTIZ wrote:
ok... I have received two lashes with the noodle that the Duo T is a
"sustainer" and not self launch...

but by the same token... of the Duo T can only "sustain" 6500MSL DA... it is
nothing more than a glider out here... I'll admit... I did use that word
"take off" in regards to "sustainer" operations

The POINT is that Density Altitude during standard summer operations will
make the use of the "sustainer engine" worthless. 6500DA is below GROUND
LEVEL in our peak flying season, maybe it will only extend the glide back to
something landable.. but I would not want to count on it to "maintain
altitude".

But then again.. with temps such as these.. we don't need no stinking
engine.

BT

"BTIZ" wrote in message
news:swNhf.4913$pF.4792@fed1read04...

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

Here's an exercise. Look at the Duo's L/D curve for the value at a useful
speed like 100kts then divide that into the flying weight. That will be the
thrust required to maintain level flight at that speed.

Maybe replacing that balky IC engine & prop with one or two of Bob Carlsons
dinky microjets that burn the Jet-A ballast might work.

Here's how it worked out with the Nimbus 2C. L/D at 100 Kts at 1433 lbs. GW
is 37:1. 1433/37 = 39Lbs thrust. One AMT microjet produces 54 pounds of
thrust at 100 Kats - probably up to the flight levels. That's good cruise
plus a little extra. It gets even better as the fuel weight burns off.

Bill Daniels


"BTIZ" wrote in message
news:kdPhf.4918$pF.3815@fed1read04...
ok... I have received two lashes with the noodle that the Duo T is a
"sustainer" and not self launch...

but by the same token... of the Duo T can only "sustain" 6500MSL DA... it
is
nothing more than a glider out here... I'll admit... I did use that word
"take off" in regards to "sustainer" operations

The POINT is that Density Altitude during standard summer operations will
make the use of the "sustainer engine" worthless. 6500DA is below GROUND
LEVEL in our peak flying season, maybe it will only extend the glide back
to
something landable.. but I would not want to count on it to "maintain
altitude".

But then again.. with temps such as these.. we don't need no stinking
engine.

BT

"BTIZ" wrote in message
news:swNhf.4913$pF.4792@fed1read04...
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

Look at the climb rate/altitude in the graph and time
to climb graph in the Duo T manual? These graphs are
realistic - for example I know that the Discus 2cT
graphs were derived from 11 hours of engine climb testing
time. The Duo T will only be expected to get as much
as 150fpm at low density altitudes.

BTW the advantageous climb rate of a self sustainer
isn't just the rate of climb above level flight but
the rate of climb above the rate of sink at around
max LD - so the Duo T at typical UK flying altitudes
is gaining almost 300fpm over its non turbo twin =
notionally 3000 feet higher after 10 minutes engine
burn and, crucially, about 10 miles closer to an airfield/ridge/th
ermal.

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:-)





At 03:06 26 November 2005, Gary Emerson wrote:
Just to clarify just a tad, we shut down the turbo
at 6500 ft because we
had final glide back to home, not because we weren't
climbing. We still
had about 125-150 FPM up at that point. I've never
had a need to fire
it up at any higher altitude and so I'm curious if
anyone else has...
I'd love to hear that you could hold altitude at 10k
ft.

BTIZ wrote:
ok... I have received two lashes with the noodle that
the Duo T is a
'sustainer' and not self launch...

but by the same token... of the Duo T can only 'sustain'
6500MSL DA... it is
nothing more than a glider out here... I'll admit...
I did use that word
'take off' in regards to 'sustainer' operations

The POINT is that Density Altitude during standard
summer operations will
make the use of the 'sustainer engine' worthless.
6500DA is below GROUND
LEVEL in our peak flying season, maybe it will only
extend the glide back to
something landable.. but I would not want to count
on it to 'maintain
altitude'.

But then again.. with temps such as these.. we don't
need no stinking
engine.

BT

'BTIZ' wrote in message
news:swNhf.4913$pF.4792@fed1read04...

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

John Galloway wrote:
Look at the climb rate/altitude in the graph and time
to climb graph in the Duo T manual? These graphs are
realistic - for example I know that the Discus 2cT
graphs were derived from 11 hours of engine climb testing
time. The Duo T will only be expected to get as much
as 150fpm at low density altitudes.


Do you have a D2CT? What does its manual show as its climb rate at a
density altitude of 6,000' and 10,000' (just marginally above the Nevada
terrain on a hot day)?

At 16:18 26 November 2005, Greg Arnold wrote:

John Galloway wrote:
Look at the climb rate/altitude in the graph and time
to climb graph in the Duo T manual? These graphs
are
realistic - for example I know that the Discus 2cT
graphs were derived from 11 hours of engine climb
testing
time. The Duo T will only be expected to get as much
as 150fpm at low density altitudes.


Do you have a D2CT? What does its manual show as its
climb rate at a
density altitude of 6,000' and 10,000' (just marginally
above the Nevada
terrain on a hot day)?


About 130fpm and 50fpm respectively in 15m unballasted
mode and a slightly better in 18m but not shown graphically.
I have sent you a scan of the manual page.

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!

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!