Real stall speed of Discus CS

[Hans Hallder]

Hi,

i just made my first flights with my new glider: Discus CS.
I've never flown a Discus before.
One thing i recognized was the hight stall speed.
I wonder if this could be normal, so i'm interested in your
experiences with this ship.

I flew the glider without water.

With 45 knots i got some warning and with 40 knots i stalled.
(In the manual they talk about 35 knots).

In thermals i have to fly at min.48 better 51 knots.

Even on landing i had to be real fast for my feelings.

Any suggestions ?

Thanks
Hans

[Charles Yeates]

Check your airspeed indicator for accuracy.

Hans Hallder wrote:
> Hi,
>
> i just made my first flights with my new glider: Discus CS.
> I've never flown a Discus before.
> One thing i recognized was the hight stall speed.
> I wonder if this could be normal, so i'm interested in your
> experiences with this ship.
>
> I flew the glider without water.
>
> With 45 knots i got some warning and with 40 knots i stalled.
> (In the manual they talk about 35 knots).
>
> In thermals i have to fly at min.48 better 51 knots.
>
> Even on landing i had to be real fast for my feelings.
>
> Any suggestions ?
>
> Thanks
> Hans

[Don Johnstone]

Better yet, check your weight. The stall 'speed' depends
on many factors and will vary with weight, configuration,
and g loading. The best way is to stall the glider
in every cofiguration to see what happens, what warning
you get. The speed at which it stalls with you in the
seat is the stall speed. I always recommend to anyone
flying a glider new to them that they carry out a stall
in the landing configuration, wheel down, flaps down
and spoilers/brakes extended so that they recognise
the signs of the approaching stall before it happens
for real.

Thermalling at 48kts in a Discus does not sound that
far out to me but I am on the heavy side.

When you say fast approach what do you call fast? 55kts
is normally enough except in very stong winds or turbulence.


At 11:18 19 April 2004, Charles Yeates wrote:
>Check your airspeed indicator for accuracy.
>
>Hans Hallder wrote:
>> Hi,
>>
>> i just made my first flights with my new glider: Discus
>>CS.
>> I've never flown a Discus before.
>> One thing i recognized was the hight stall speed.
>> I wonder if this could be normal, so i'm interested
>>in your
>> experiences with this ship.
>>
>> I flew the glider without water.
>>
>> With 45 knots i got some warning and with 40 knots
>>i stalled.
>> (In the manual they talk about 35 knots).
>>
>> In thermals i have to fly at min.48 better 51 knots.
>>
>> Even on landing i had to be real fast for my feelings.
>>
>> Any suggestions ?
>>
>> Thanks
>> Hans
>
>

[Alan Irving]

Depending on centre of gravity position, 48-50 knots
is ideal for thermalling the Discus. For heavy pilots,
a (removeable) lead weight can be fitted to the top
of the fin - this would help to move the CG backwards
and slightly lowers the circling speed. Your local
Schempp-Hirth rep should be able to supply one.

When landing, the glider has quite a nose-up attitude,
so it is better to approach slightly faster and/or
steeper than normal to have a good view of the landing
area. The airbrakes are very effective so this is
never a problem.

At 10:48 19 April 2004, Hans Hallder wrote:
>Hi,
>
>i just made my first flights with my new glider: Discus
>CS.
>I've never flown a Discus before.
>One thing i recognized was the hight stall speed.
>I wonder if this could be normal, so i'm interested
>in your
>experiences with this ship.
>
>I flew the glider without water.
>
>With 45 knots i got some warning and with 40 knots
>i stalled.
>(In the manual they talk about 35 knots).
>
>In thermals i have to fly at min.48 better 51 knots.
>
>Even on landing i had to be real fast for my feelings.
>
>Any suggestions ?
>
>Thanks
>Hans
>

[Kevin Neave]

Hi,

My Discus Bwl weighs about 235kg empty (515lbs)
With my weight of 75kg plus a 'chute (Approx 5kg)
I have a cockpit weight of 80kg (176lbs)

At this load (Dry) I have a stall speed of 36kts and
can thermal reasonably easily in the low 40s

With 100kg water (220 lbs) stall speed goes up to around
40kts and I need to thermal in the high 40s

So unless you're 100kgs heavier than me - And I'm assuming
that if you can actually get in the glider this is
not the case - I'd get your ASI checked.

The Discus (dry) will happily approach & round out
at 50-55kts, but, as someone said earlier it's pretty
nose high at these speeds, so if you're not used to
it, and are maintaining what looks like a 'normal'
approach attitude to you, then your speed will build
up.

Regards

Kevin

At 13:00 19 April 2004, Alan Irving wrote:
>At 10:48 19 April 2004, Hans Hallder wrote:
>>Hi,
>>
>>i just made my first flights with my new glider: Discus
>>CS.
>>I've never flown a Discus before.
>>One thing i recognized was the hight stall speed.
>>I wonder if this could be normal, so i'm interested
>>in your
>>experiences with this ship.
>>
>>I flew the glider without water.
>>
>>With 45 knots i got some warning and with 40 knots
>>i stalled.
>>(In the manual they talk about 35 knots).
>>
>>In thermals i have to fly at min.48 better 51 knots.
>>
>>Even on landing i had to be real fast for my feelings.
>>
>>Any suggestions ?
>>
>>Thanks
>>Hans
>>