Speeds to fly for Two-Up cross country in ASK21?

Am going to fly a club K21 in the upcoming contest at CCSC and have
been trying to find some basic speed to fly data.

What I have so far is Schleicher says( in an on-line brochure) that
the L/D flown two up is 34 at 90 KMH...so I interpret that to be about
49 Kts.

They also say that the stall speed flown two up is 35 Kts

I find no mention anyplace of Minimum Sink Speed. From the polar in
the brochure it looks to be about 42 to 44Kts.

I have a some cross country time in the K21 and these speeds look
reasonable to me but I'm not sure.

Anyone have any suggestions regarding speeds to fly the ASK21 ?

From the above data on a weak day I might fly 55 kts or so. On a good
day with cu's maybe 60 or even 65 kts. Any rules of thumb you would
like to share ?

Thanks,

Jim

On Apr 2, 11:34*am, 77 wrote:
Am going to fly a club K21 in the upcoming contest at CCSC and have
been trying to find some basic speed to fly data.

What I have so far is Schleicher says( in an on-line brochure) that
the L/D flown two up is 34 at 90 KMH...so I interpret that to be about
49 Kts.

They also say that the stall speed flown two up is 35 Kts

I find no mention anyplace of Minimum Sink Speed. From the polar in
the brochure it looks to be about 42 to 44Kts.

I have a some cross country time in the K21 and these speeds look
reasonable to me but I'm not sure.

Anyone have any suggestions regarding speeds to fly the ASK21 ?

From the above data on a weak day I might *fly 55 kts or so. On a good
day with *cu's maybe 60 or even 65 kts. Any rules of thumb you would
like to share ?

Thanks,

Jim

Jim,

Pull out Reichmann and start building a speed to fly chart. It
should have speed to fly based on each 0.5 to 1 knot of thermal
average based on what your conditions are. That will give you a
target speed to fly.

If you would like, send me note and I can send you several of the
programs I use. Below is the chart I use for a Ventus. It is all
based off the polar of the glider you are flying.



MC MPH knots Avg Cruise Speed (MPH)
0 63 55 0
1 75 65 28
2 85 73 41
3 93 81 50
4 101 88 57
5 109 95 63
6 116 101 68
7 122 106 72
8 129 112 76
9 135 117 80
10 140 122 83

Just keep it at 80kts all day long-


devin

On Apr 2, 10:38*pm, Devin Bargainnier wrote:
Just keep it at 80kts all day long-

devin


Isn't that what I did at Sports Nats last year ;-)

On Apr 3, 5:34*am, 77 wrote:
Am going to fly a club K21 in the upcoming contest at CCSC and have
been trying to find some basic speed to fly data.

What I have so far is Schleicher says( in an on-line brochure) that
the L/D flown two up is 34 at 90 KMH...so I interpret that to be about
49 Kts.

They also say that the stall speed flown two up is 35 Kts

I find no mention anyplace of Minimum Sink Speed. From the polar in
the brochure it looks to be about 42 to 44Kts.

I have a some cross country time in the K21 and these speeds look
reasonable to me but I'm not sure.

Anyone have any suggestions regarding speeds to fly the ASK21 ?

From the above data on a weak day I might *fly 55 kts or so. On a good
day with *cu's maybe 60 or even 65 kts. Any rules of thumb you would
like to share ?

That sounds close enough. Those are about the speeds I fly in a PW5,
which is very similar performance.

Err on the slower side unless you're having trouble staying below
cloudbase -- in which case remember to fly fast between the streets
and slow when under them, not vice versa!

If you can fly around the course at even 50 - 55 knots with no
circling then you'll probably win the day.

If you can get a CAI 302 coupled with a 303 and Seeyou mobile running, with
the ASK 21 polar installed, then its a no brainer on the speed to fly. Set
the Mc Cready to the conditions and the computer will tell you how fast to
fly and you may well be surprised at how fast that number is. Get some good
advice from a successful competition pilot on the Mc settings. I feel
having a good computer setup is very important to any XC flying and the
302/ Seeyou mobile combination is rock solid and very easy to use.
With all due respect, at over 1300 lbs gross Wt and 17 meter span the ASK
21 will blow the doors off a PW 5. Weight and span is what you need to
get after it and the PW 5 lacks both. And at max Gross the ASK 21 still
climbs very well. I flew one for 8 years and it was super fun. I miss
that plane, she was sweet.

On Apr 2, 1:34*pm, 77 wrote:
Am going to fly a club K21 in the upcoming contest at CCSC and have
been trying to find some basic speed to fly data.

What I have so far is Schleicher says( in an on-line brochure) that
the L/D flown two up is 34 at 90 KMH...so I interpret that to be about
49 Kts.

They also say that the stall speed flown two up is 35 Kts

I find no mention anyplace of Minimum Sink Speed. From the polar in
the brochure it looks to be about 42 to 44Kts.

I have a some cross country time in the K21 and these speeds look
reasonable to me but I'm not sure.

Anyone have any suggestions regarding speeds to fly the ASK21 ?

From the above data on a weak day I might *fly 55 kts or so. On a good
day with *cu's maybe 60 or even 65 kts. Any rules of thumb you would
like to share ?

Thanks,

Jim

General speeds I use fwiw
Survival-about 55 kt.
Moderate lift- to say 300 ft/min- about 70 kt
Above 300 ft/min, gradually move range up to about 80kt.
Polar ain't that great, so it almost never pays to put speed range
above about 80, at least in the East with usual
working band.
Plan on max L/D of about 32.
The good news is that where you will land is in sight of old eyes.
The bad news is the same.
The glide amoeba on Clearnav is quite useful in the '21 where "what
can I get to or over" is a bigger deal
than the higher performance ships we usually fly.
You will have fun taking friends on contest flights. I'm doing 2
contests this year with riders.
UH/K21

On Apr 6, 5:57*am, wrote:
On Apr 2, 1:34*pm, 77 wrote:





Am going to fly a club K21 in the upcoming contest at CCSC and have
been trying to find some basic speed to fly data.

What I have so far is Schleicher says( in an on-line brochure) that
the L/D flown two up is 34 at 90 KMH...so I interpret that to be about
49 Kts.

They also say that the stall speed flown two up is 35 Kts

I find no mention anyplace of Minimum Sink Speed. From the polar in
the brochure it looks to be about 42 to 44Kts.

I have a some cross country time in the K21 and these speeds look
reasonable to me but I'm not sure.

Anyone have any suggestions regarding speeds to fly the ASK21 ?

From the above data on a weak day I might *fly 55 kts or so. On a good
day with *cu's maybe 60 or even 65 kts. Any rules of thumb you would
like to share ?

Thanks,

Jim

General speeds I use fwiw
Survival-about 55 kt.
Moderate lift- to say 300 ft/min- about 70 kt
Above 300 ft/min, gradually move range up to about 80kt.
Polar ain't that great, so it almost never pays to put speed range
above about 80, at least in the East with usual
working band.
Plan on max L/D of about 32.
The good news is that where you will land is in sight of old eyes.
The bad news is the same.
The glide amoeba on Clearnav is quite useful in the '21 where "what
can I get to or over" is a bigger deal
than the higher performance ships we usually fly.
You will have fun taking friends on contest flights. I'm doing 2
contests this year with riders.
UH/K21

Do what Hank says.

9B

On Sat, 02 Apr 2011 10:34:48 -0700, 77 wrote:

Am going to fly a club K21 in the upcoming contest at CCSC and have been
trying to find some basic speed to fly data.

Both LK8000 and XCSoar have the ASK-21 polar built in: I just checked
LK8000 2.00c and XCSoar 6.0.6, so an obvious solution is to take a PNA
along that runs one of these programs. The advantage of a PNA is that its
a self-contained solution (built-in GPS), with the program and its data
files on an SD card. Plus, they're fairly cheap if you have to buy one.

Anything that runs WinMobile 5 or 6 is OK for either program. I use a
Binatone B.350. The Mio M400 seems to be popular too.

However, if your task exceeds a couple of hours, you'll need an external
power supply. Getting a 3000 mAh Li-Poly external USB power pack is
easiest since then you won't have to tap into the K-21's wiring. Most PNAs
have 800 mAh internal batteries, so using a 3000 mAh pack will more than
quadruple its run time to over 8 hours, which should be plenty. Adding in
a USB extension cable will let you put the external battery in a sensible
place away from the PNA.

PNAs are light, so at a pinch you'd probably get away with using its
standard suction cup mount to put it onto the canopy. Last week this
worked well for a fellow pilot flying a club Junior. Failing that, the
PNA's mounting clip detaches from the suction mount and can be screwed to
a suitably shaped piece of softwood which can be mounted on the K-21's
glare shield with Velcro (or duct tape if you must). Make a nice job of
the set-up and its likely to be used more than once.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
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