Aerotow with Diesel engine?

[Olfert Cleveringa]

Some aero-engine and car manufacturers are working on Diesel engines for
use in small aircraft. There are now quite a lot of aircraft types
flying with these engines.

Is there anyone who can say something useful on recent Diesel engines in
glider-towing operation? Practical information (climb ratio, technical
and financial aspects, reliability etc.) would be very welcome. Or a
club where such a towplane is in use or tested.

Thanks for the info,

Olfert
Hornet A7, Netherlands.

[Bill Daniels]

"Olfert Cleveringa" > wrote in message
bel.com...
> Some aero-engine and car manufacturers are working on Diesel engines for
> use in small aircraft. There are now quite a lot of aircraft types
> flying with these engines.
>
> Is there anyone who can say something useful on recent Diesel engines in
> glider-towing operation? Practical information (climb ratio, technical
> and financial aspects, reliability etc.) would be very welcome. Or a
> club where such a towplane is in use or tested.
>
> Thanks for the info,
>
> Olfert
> Hornet A7, Netherlands.

I've spoken with the good folks at DeltaHawk, a US based manufacturer of
liquid cooled V4 2-stroke diesels in the 200 HP range. See:
http://www.deltahawkengines.com/ They feel their engine would make a near
perfect tug engine. Look carefully at the Specific Fuel Consumption (SFC)
and the altitude performance.

DeltaHawk is busy working with airframe manufacturers to create 'firewall
forward" installation packages. A rumor is that they have a very large
order from the US government for drone engines that will let them work out
the mass production bugs and provide the company with financial stability.

Diesels make power at lower RPM's than a spark ignition engine so they can
use larger, quieter, more efficient propellers. A 200 HP diesel would be
the equivalent of a 260 HP Lycoming O-540 because of the greater propeller
efficiency. An added benefit would be the ability to legally use untaxed
agricultural diesel fuel (red diesel in the US). Even in the US, fuel is a
major expense for tug operators.

Bill Daniels

[Stefan]

Bill Daniels wrote:

> They feel their engine would make a near
> perfect tug engine.

Surprize! :-)

> A rumor is ...

So much for "practical information".

> Diesels make power at lower RPM's than a spark ignition engine so they can
> use larger, quieter, more efficient propellers.

There isn't a requirement anywhere that propellers have to be direct
driven. Actually, the only diesel flying today uses a gearbox.

(Sorry for my unfair quoting, but I couldn't resist.)

Stefan

[Bill Daniels]

"Stefan" > wrote in message
...
> Bill Daniels wrote:
>
> > They feel their engine would make a near
> > perfect tug engine.
>
> Surprize! :-)

Selling an engine for an inappropriate use is a good way to get a bad
reputation. Engine manufacturers who plan to stay in business are very
careful about this. I have good feelings about Doug Doer and his group of
engineers.
>
> > Diesels make power at lower RPM's than a spark ignition engine so they
can
> > use larger, quieter, more efficient propellers.
>
> There isn't a requirement anywhere that propellers have to be direct
> driven. Actually, the only diesel flying today uses a gearbox.

The DeltaHawk is flying with good results. Geared propellers are a good idea
but they seem to work best with a large number of cylinders and in large
aircraft where the weight penalty isn't so great.


Bill Daniels

[Stefan]

Bill Daniels wrote:

> I have good feelings about Doug Doer and his group of
> engineers.

Don't get me wrong: I'm hoping the best for them (und us). But the
original question was about experiences...

Stefan

[Bruce Greeff]

Stefan wrote:
> Bill Daniels wrote:
>
>> They feel their engine would make a near
>> perfect tug engine.
>
>
> Surprize! :-)
>
> > A rumor is ...
>
> So much for "practical information".
>
>> Diesels make power at lower RPM's than a spark ignition engine so they
>> can
>> use larger, quieter, more efficient propellers.
>
>
> There isn't a requirement anywhere that propellers have to be direct
> driven. Actually, the only diesel flying today uses a gearbox.
>
> (Sorry for my unfair quoting, but I couldn't resist.)
>
> Stefan
>
Not entirely accurate.
There is a three cylinder, direct drive two stroke diesel flying in the UK -
WAM120. Look at http://www.wilksch.com/
Mark Wilksch is certainly not following conventional wisdom here.

[Bill Daniels]

"Bruce Greeff" > wrote in message
...
> There is a three cylinder, direct drive two stroke diesel flying in the
UK -
> WAM120. Look at http://www.wilksch.com/
> Mark Wilksch is certainly not following conventional wisdom here.

The UK also has Diesel Air's Dair-100 - a two cylinder, four opposed piston
two stroke diesel that is a near drop in replacement for a Continental
O-200.
See: http://www.dair.co.uk/

They report that they have been running at 135 HP on the dyno which, in an
optimized airframe like a touring motorglider, would make a very nice tug
engine.

Bill Daniels

[John Galloway]

There is also the Zoche radial 2 stroke engine:

http://www.zoche.de/

although I have been mainly watching the progress of
the Wilksch engine because anyone who designs his own
2 stroke cycle has got to be worth a bit of interest:

http://www.wilksch.com/Cycle-1.jpg

John Galloway



At 20:06 21 October 2004, Bill Daniels wrote:
>
>'Bruce Greeff' wrote in message
...
>> There is a three cylinder, direct drive two stroke
>>diesel flying in the
>UK -
>> WAM120. Look at http://www.wilksch.com/
>> Mark Wilksch is certainly not following conventional
>>wisdom here.
>
>The UK also has Diesel Air's Dair-100 - a two cylinder,
>four opposed piston
>two stroke diesel that is a near drop in replacement
>for a Continental
>O-200.
>See: http://www.dair.co.uk/
>
>They report that they have been running at 135 HP on
>the dyno which, in an
>optimized airframe like a touring motorglider, would
>make a very nice tug
>engine.
>
>Bill Daniels
>
>

[Bill Daniels]

"John Galloway" > wrote in message
...
> There is also the Zoche radial 2 stroke engine:
>
> http://www.zoche.de/
>
The Zoche web site has been dormant for several years. I haven't heard
anything new about them since about 1998.

BTW, reading the Diesel Air Ltd. site about the ducted fan dirigible
application, they say that they get 8 pounds of static thrust for each HP.
If 100 HP = 800 pounds of thrust, that stacks up pretty well against a 235
Pawnee that only produces about 390 pounds of thrust. That would be good
for avoiding wing dropping.

Bill Daniels

[Z Goudie]

Bill Daniels wrote:

>Reading the Diesel Air Ltd. site about the ducted fan
>dirigible
>application, they say that they get 8 pounds of static
>thrust for each HP.
>If 100 HP = 800 pounds of thrust, that stacks up pretty
>well against a 235
>Pawnee that only produces about 390 pounds of thrust.
> That would be good
>for avoiding wing dropping.

Jings, crivvens, I can just see the FAA, CAA or JAR
falling all over themselves to approve a ducted fan
for an existing airframe.

A diesel engine of a given horsepower with a propeller
on it will produce the same thrust as similar power
petrol (gas, steam) one.

It will, if turbo charged (another complication), produce
sea level power up to a considerable height but I don't
think that's a major problem for near sea level dwellers.

As far as I can see what's driving the production of
diesel engines in Europe is the low/no tax on diesel
or jet fuel. How long will it take the fiscal authorities
to latch on to that one I wonder?

[Bill Daniels]

"Z Goudie" > wrote in message
...
> Bill Daniels wrote:
>
> >Reading the Diesel Air Ltd. site about the ducted fan
> >dirigible
> >application, they say that they get 8 pounds of static
> >thrust for each HP.
> >If 100 HP = 800 pounds of thrust, that stacks up pretty
> >well against a 235
> >Pawnee that only produces about 390 pounds of thrust.
> > That would be good
> >for avoiding wing dropping.
>
> Jings, crivvens, I can just see the FAA, CAA or JAR
> falling all over themselves to approve a ducted fan
> for an existing airframe.

The new Sport Light Aircraft regulations (US) have specific language
permitting experimental glider tugs. Nobody said anything about fitting a
ducted fan to an existing airframe.
>
> A diesel engine of a given horsepower with a propeller
> on it will produce the same thrust as similar power
> petrol (gas, steam) one.

Nope. A Bell 47 helicopter rotor turning 300 RPM will produce more than
2450 pounds of static thrust with just 266 HP. The fact that it flies
proves that.

Diesels produce their power at low RPM's. A slower turning propeller that
can absorb the same HP will produce more thrust. A ducted fan will produce
still more thrust per HP at low airspeeds.
>
> It will, if turbo charged (another complication), produce
> sea level power up to a considerable height but I don't
> think that's a major problem for near sea level dwellers.

All 2-stroke diesels are supercharged - else they won't run.

>
> As far as I can see what's driving the production of
> diesel engines in Europe is the low/no tax on diesel
> or jet fuel. How long will it take the fiscal authorities
> to latch on to that one I wonder?
>
Europe has been using diesel fuel for a long time. Raising taxes on
agricultural diesel will be a political hot potato. General Aviation fuel
use is tiny compared to road use.

Bill Daniels

[Mark James Boyd]

The only fuel that I am confident I will be able to find for
aircraft in the coming decades is Jet fuel. If I purchased a
certified aircraft for long term use, it would be powered by this,
or be an experimental (where I could use whatever I want)

In California, the abolishment of MTBE made all the autogas
STCs of aircraft invalid (the new ethanol gas isn't covered by
the STC).

I don't have confidence that 100LL will be available in the near future.
80 has already almost disappeared from general aviation.

Diesel? I'd be surprised to see that in 200 California airports
within the next 10 years.

In article >,
Stefan > wrote:
>Bill Daniels wrote:
>
>> They feel their engine would make a near
>> perfect tug engine.
>
>Surprize! :-)
>
> > A rumor is ...
>
>So much for "practical information".
>
>> Diesels make power at lower RPM's than a spark ignition engine so they can
>> use larger, quieter, more efficient propellers.
>
>There isn't a requirement anywhere that propellers have to be direct
>driven. Actually, the only diesel flying today uses a gearbox.
>
>(Sorry for my unfair quoting, but I couldn't resist.)
>
>Stefan
>


--

------------+
Mark J. Boyd

[Christian Husvik]

Mark James Boyd wrote:
> The only fuel that I am confident I will be able to find for
> aircraft in the coming decades is Jet fuel.ral aviation.
> [...]
> Diesel? I'd be surprised to see that in 200 California airports
> within the next 10 years.

Diesel engines in aircraft run on Jet A1.

Christian 8-)

[Z Goudie]

At 21:48 21 October 2004, Bill Daniels wrote:

>Nope. A Bell 47 helicopter rotor turning 300 RPM will
>produce more than
>2450 pounds of static thrust with just 266 HP. The
>fact that it flies
>proves that.

Ah, so we're going to need very long undercarriage
legs then?

[Bill Daniels]

"Z Goudie" > wrote in message
...
> At 21:48 21 October 2004, Bill Daniels wrote:
>
> >Nope. A Bell 47 helicopter rotor turning 300 RPM will
> >produce more than
> >2450 pounds of static thrust with just 266 HP. The
> >fact that it flies
> >proves that.
>
> Ah, so we're going to need very long undercarriage
> legs then?
>
It wouldn't be hard to design an airframe that could use a 3-4 meter prop.
That would do a lot for low speed thrust and lower noise.

Bill Daniels

[Z Goudie]

At 13:36 22 October 2004, Bill Daniels wrote

>It wouldn't be hard to design an airframe that could
>use a 3-4 meter prop.
>That would do a lot for low speed thrust and lower
>noise

Back to the reduction gearing scenario then?

[[email protected]]

(Mark James Boyd) writes:

> Diesel? I'd be surprised to see that in 200 California airports
> within the next 10 years.

Diesel has a problem with wax precipitation at low temps, so most are
set up to use A1 as the standard fuel.

A diesel recently flew St Johns to Portugal at OVER 27 NM/gal!

--
Paul Repacholi 1 Crescent Rd.,
+61 (08) 9257-1001 Kalamunda.
West Australia 6076
comp.os.vms,- The Older, Grumpier Slashdot
Raw, Cooked or Well-done, it's all half baked.
EPIC, The Architecture of the future, always has been, always will be.

[Steve Hill]

Now that Diesel is hovering in the $2.50 (U.S.) range, what would be the big
savings?? The Diesel engines I've seen on the market for Aircraft use cost
WAY more than gasoline engines...I'd be surprised if we actually settled on
the fuel cost being anywhere near the biggest cost driver in the actual cost
of a tow...

My DG-400 costs two liters of unleaded per launch to 2,500 ft agl....not too
bad when you cost it all out. Acquisition cost of the tug, depreciation of
the asset, Insurance for the tug, annual for the tug, fuel, maintenance,tie
down/hangar, interest if there's a loan Engine reserves...I know for a fact
my Cessna 180 costs WAY more to launch a sailplane on an annual basis than
does the DG...maybe we just need a bunch more self launchers??


( wincing...thinking of the can of worms this comment will open )


Steve.

[Bill Daniels]

"Steve Hill" > wrote in message
...
> Now that Diesel is hovering in the $2.50 (U.S.) range, what would be the
big
> savings?? The Diesel engines I've seen on the market for Aircraft use cost
> WAY more than gasoline engines...I'd be surprised if we actually settled
on
> the fuel cost being anywhere near the biggest cost driver in the actual
cost
> of a tow...
>
> My DG-400 costs two liters of unleaded per launch to 2,500 ft agl....not
too
> bad when you cost it all out. Acquisition cost of the tug, depreciation of
> the asset, Insurance for the tug, annual for the tug, fuel,
maintenance,tie
> down/hangar, interest if there's a loan Engine reserves...I know for a
fact
> my Cessna 180 costs WAY more to launch a sailplane on an annual basis than
> does the DG...maybe we just need a bunch more self launchers??
>
>
> ( wincing...thinking of the can of worms this comment will open )
>
>
> Steve.
>
I don't disagree about motorgliders but there will always be a lot of pure
gliders around that need launching. Diesels will produce the same power on
roughly 1/3 less fuel and that fuel could be un-taxed agri-diesel in the
case of a warm weather glider tug. That would be a large but not
overwhelming savings. If diesels get as popular as most aviation experts
suggest, the availability of avgas and spark ignition engine parts and
repair may eventually be a greater concern.

A typical 180 HP Lycoming O-360 will burn $60,000 worth of avgas to get it
to a 2000 Hr TBO. A 260 HP Lyc O-540 will burn close to $100,000 worth of
avgas in 2000 hours. Engine overhauls are also a big cost but less per hour
than fuel. Any way you look at it, a tow plane is a black hole sucking in
money.

If you really want to save fuel, think winch launch. That takes about 1/2
liter of diesel to launch a typical glider. That could easily be vegetable
oil. If you are lucky enough to be able to use an electric winch, a launch
will use about 1KW Hr. of energy at about $.05. Add to the fuel savings the
fact that you don't have to deal with the FAA trying to get a Tost hook
installed on a Pawnee.

Bill Daniels

[goneill]

The Australians have an Autotug project that uses a 6 cylinder car engine
,parts available
everywhere overhauls 3-5k US replacement engines available everywhere.
the scuttlebutt was the main problems were making the engine mounts and
ducting
cooling air onto the radiator.I believe it is approaching a 1000hours .
There is a Swedish project using a volvo car engine with similar results ,
The way to go is to get the dollar gobbler(the engine ) changed to a mass
produced
item, that is the car market ,millions of engines instead of hundreds
gary
"Steve Hill" > wrote in message
...
> Now that Diesel is hovering in the $2.50 (U.S.) range, what would be the
> big
> savings?? The Diesel engines I've seen on the market for Aircraft use cost
> WAY more than gasoline engines...I'd be surprised if we actually settled
> on
> the fuel cost being anywhere near the biggest cost driver in the actual
> cost
> of a tow...
>
> My DG-400 costs two liters of unleaded per launch to 2,500 ft agl....not
> too
> bad when you cost it all out. Acquisition cost of the tug, depreciation of
> the asset, Insurance for the tug, annual for the tug, fuel,
> maintenance,tie
> down/hangar, interest if there's a loan Engine reserves...I know for a
> fact
> my Cessna 180 costs WAY more to launch a sailplane on an annual basis than
> does the DG...maybe we just need a bunch more self launchers??
>
>
> ( wincing...thinking of the can of worms this comment will open )
>
>
> Steve.
>
>
>
>

[Steve Hill]

I don't disagree on the issue of winch launching being the cheapest cost
offset for the invested dollar...Even with the argument that Diesel fuel
cost by 1/3 an average tow only uses around 2 gallons of gasoline so we're
talking about a savings of around 2/3rds of a gallon or roughly $ 1.61 if
you're paying at the pump for your diesel maybe a bit more if you're buying
and storing bulk, which isn't figuring in the cost of "Prist" which if any
of you have operated Turbines, know is a necessity for long term storage of
the fuel...the savings from the cost of fuel I'd say is truly almost nil.

This of course isn't again pointing out that in order to save this $1.61 per
tow, we'd have to guy spend presumably a hundred grand...the SMA diesel
which is approved for STC on the 180 is $97,000 installed...

I just don't see any viability to the thought process at this time. I like
the idea of Michael Zoche's radial diesel...but it's been years in
development and doesn't look even cose to certification. Thielert's engine
look great but again, since it doesn't go on a Pawnee or a Super Cub or a
Husky, or anything at this point...what really is the point??

How much does a really nice Winch cost?? And where do you buy one, and how
much real estate do you need to get a 1500 ft agl launch??


I'd really like to see what the actual costs are for a club to purchase a
good winch.



Steve.

[Bill Daniels]

"Steve Hill" > wrote in message
...

> How much does a really nice Winch cost?? And where do you buy one, and how
> much real estate do you need to get a 1500 ft agl launch??
>
>
> I'd really like to see what the actual costs are for a club to purchase a
> good winch.
>
>
>
> Steve.
>
Used Tost winches are going for $3500 in Germany. I have no idea what the
shipping would be.

4000 feet of runway will get you 1500 feet AGL. With lightweight synthetic
cable and a little wind, you can get higher. More runway will get you still
higher.

If you do a spreadsheet of costs and revenue, you find that even an
expensive winch pays for itself in a very short time. Thereafter, it is a
"money printing machine" that will fund a new glider every year or so.
Figure a cost of $2 per launch and charge $6 to $10.

There's a lot of good information at:
http://groups.yahoo.com/group/winchdesign/

Bill Daniels

[F.L. Whiteley]

"Bill Daniels" > wrote in message
news:wD8gd.22588$R05.18302@attbi_s53...
>
> "Steve Hill" > wrote in message
> ...
>
> > How much does a really nice Winch cost?? And where do you buy one, and
how
> > much real estate do you need to get a 1500 ft agl launch??
> >
> >
> > I'd really like to see what the actual costs are for a club to purchase
a
> > good winch.
> >
> >
> >
> > Steve.
> >
> Used Tost winches are going for $3500 in Germany. I have no idea what the
> shipping would be.
>
> 4000 feet of runway will get you 1500 feet AGL. With lightweight
synthetic
> cable and a little wind, you can get higher. More runway will get you
still
> higher.
>
> If you do a spreadsheet of costs and revenue, you find that even an
> expensive winch pays for itself in a very short time. Thereafter, it is a
> "money printing machine" that will fund a new glider every year or so.
> Figure a cost of $2 per launch and charge $6 to $10.
>
> There's a lot of good information at:
> http://groups.yahoo.com/group/winchdesign/
>
> Bill Daniels
>
This, of course, begs certain assumptions on the size of the operation,
available gliders, ability to scale the operation, and soaring conditions
(good soaring may mean many less launches, training is higly encouraged).
There is one case that indicates that the economics will help drive the size
also. ROI may be somewhat unpredictable. With a winch you may be able to
operate in places where aerotowing might be highly objectionable.

Frank Whiteley

[goneill]

Our winch operates off 3000ft uses ordinary polyprop rope and regularly gets
1400-1500ft launches.
gary
"Bill Daniels" > wrote in message
news:wD8gd.22588$R05.18302@attbi_s53...
>
> "Steve Hill" > wrote in message
> ...
>
>> How much does a really nice Winch cost?? And where do you buy one, and
>> how
>> much real estate do you need to get a 1500 ft agl launch??
>>
>>
>> I'd really like to see what the actual costs are for a club to purchase a
>> good winch.
>>
>>
>>
>> Steve.
>>
> Used Tost winches are going for $3500 in Germany. I have no idea what the
> shipping would be.
>
> 4000 feet of runway will get you 1500 feet AGL. With lightweight
> synthetic
> cable and a little wind, you can get higher. More runway will get you
> still
> higher.
>
> If you do a spreadsheet of costs and revenue, you find that even an
> expensive winch pays for itself in a very short time. Thereafter, it is a
> "money printing machine" that will fund a new glider every year or so.
> Figure a cost of $2 per launch and charge $6 to $10.
>
> There's a lot of good information at:
> http://groups.yahoo.com/group/winchdesign/
>
> Bill Daniels
>

[Shawn]

Bill Daniels wrote:

>
> I don't disagree about motorgliders but there will always be a lot of pure
> gliders around that need launching. Diesels will produce the same power on
> roughly 1/3 less fuel and that fuel could be un-taxed agri-diesel in the
> case of a warm weather glider tug. That would be a large but not
> overwhelming savings. If diesels get as popular as most aviation experts
> suggest, the availability of avgas and spark ignition engine parts and
> repair may eventually be a greater concern.
>
> A typical 180 HP Lycoming O-360 will burn $60,000 worth of avgas to get it
> to a 2000 Hr TBO. A 260 HP Lyc O-540 will burn close to $100,000 worth of
> avgas in 2000 hours. Engine overhauls are also a big cost but less per hour
> than fuel. Any way you look at it, a tow plane is a black hole sucking in
> money.
>
> If you really want to save fuel, think winch launch. That takes about 1/2
> liter of diesel to launch a typical glider. That could easily be vegetable
> oil. If you are lucky enough to be able to use an electric winch, a launch
> will use about 1KW Hr. of energy at about $.05. Add to the fuel savings the
> fact that you don't have to deal with the FAA trying to get a Tost hook
> installed on a Pawnee.

Oh now, you had to rub that in didn't you.
;-)

Shawn

[Mark James Boyd]

Steve Hill > wrote:
>
>I'd really like to see what the actual costs are for a club to purchase a
>good winch.

The "street" has spoken. There are NO winches in California.
And the ones I researched that were closest were in Arizona or
Washington, and aren't getting anywhere even remotely close to
50 launches a day.

I haven't been to Washington yet, but I have talked to the club there
and they were closed for a good part of last winter (0 launches).

Would a winch in CA do well? I dunno. At Avenal, there are
days when it would be fine, but then again there are
a lot of days or times of the day when a higher tow or further
away is better. And of course I've had 4 aero-retrieves.
Try that with a winch ;)
--

------------+
Mark J. Boyd

[Bill Daniels]

"Mark James Boyd" > wrote in message
news:41818652$1@darkstar...
> Steve Hill > wrote:
> >
> >I'd really like to see what the actual costs are for a club to purchase a
> >good winch.
>
> The "street" has spoken. There are NO winches in California.

I think you overlooked AGCSC who operates their winch at Torry Pines and
Warner Springs.

> And the ones I researched that were closest were in Arizona or
> Washington, and aren't getting anywhere even remotely close to
> 50 launches a day.

I've done many 50+ launch days. If our European friends check in, I'll bet
they report a lot more than that.

>
> I haven't been to Washington yet, but I have talked to the club there
> and they were closed for a good part of last winter (0 launches).
>
> Would a winch in CA do well? I dunno. At Avenal, there are
> days when it would be fine, but then again there are
> a lot of days or times of the day when a higher tow or further
> away is better. And of course I've had 4 aero-retrieves.
> Try that with a winch ;)
> --
Four aero retrieves! What you flyin' boy, a 1-26?

Bill Daniels

[Mark James Boyd]

In article <rLfgd.540846$8_6.36371@attbi_s04>,
Bill Daniels > wrote:
>
>"Mark James Boyd" > wrote in message
>news:41818652$1@darkstar...
>> Steve Hill > wrote:
>>
>> The "street" has spoken. There are NO winches in California.
>
>I think you overlooked AGCSC who operates their winch at Torry Pines and
>Warner Springs.

I had thought AGCSC was only auto-tow for ground launch.
I will look into the winch there; thanks for the correction, Bill.

>> And the ones I researched that were closest were in Arizona or
>> Washington, and aren't getting anywhere even remotely close to
>> 50 launches a day.
>
>I've done many 50+ launch days. If our European friends check in, I'll bet
>they report a lot more than that.

I suspect the density of population in Europe and the relatively
prohibitive comparable cost of aerotow make winches what they are
in Europe. A U.S. winch (esp. a very expensive/nice one) would likely
do best near a very large population and regular ridge/wave lift.

I'm not aware of something like this which is away from (and not under)
"B" and "C" airspace. A winch right in LA, Reno, or SF would be great,
but I'd bet the Federales would notam out the operation pronto.

Such an operation would likely need to be a private club, too.
I just can't see a club buying up the $$$$s worth of acres to
get this working near a major CA city...

>> I haven't been to Washington yet, but I have talked to the club there
>> and they were closed for a good part of last winter (0 launches).
>>
>> Would a winch in CA do well? I dunno. At Avenal, there are
>> days when it would be fine, but then again there are
>> a lot of days or times of the day when a higher tow or further
>> away is better. And of course I've had 4 aero-retrieves.
>> Try that with a winch ;)
>> --

>Four aero retrieves! What you flyin' boy, a 1-26?
That's right, sonny. ;P

>Bill Daniels
--

------------+
Mark J. Boyd

[Bill Daniels]

"Mark James Boyd" > wrote in message
news:41818c33$1@darkstar...
> In article <rLfgd.540846$8_6.36371@attbi_s04>,

> I suspect the density of population in Europe and the relatively
> prohibitive comparable cost of aerotow make winches what they are
> in Europe. A U.S. winch (esp. a very expensive/nice one) would likely
> do best near a very large population and regular ridge/wave lift.

The European population density makes it harder to find the room for glider
strips. We, on the other hand, still have lots of open space by comparison.
A local ridge is nice but there are lots of places where thermal lift can be
contacted well under 1000 feet AGL.
>
> I'm not aware of something like this which is away from (and not under)
> "B" and "C" airspace. A winch right in LA, Reno, or SF would be great,
> but I'd bet the Federales would notam out the operation pronto.

I'm not aware of one either but I'm working on it.

>
> Such an operation would likely need to be a private club, too.
> I just can't see a club buying up the $$$$s worth of acres to
> get this working near a major CA city...
>
Not near a city but dry land in the desert isn't too bad. There are lots of
lonely, low traffic county airports that woud be great for winch launchng

Bill Daniels

[Jim Vincent]

>And the ones I researched that were closest were in Arizona or
>Washington, and aren't getting anywhere even remotely close to
>50 launches a day.

Well, a friend and I got about 25 launches in four hours. Take off, fly the
pattern, land on the cross wind, rotate the glider 90 degrees, and then off
again.

Of course, then you also have the esteemed contingent at my club who take off,
do a complete pattern landing back into the wind, and then have to push back to
the take off spot again. About half the efficiciency.

Best line ever after dropping off the 'chute and driving back to the winch for
the next go. "We're still figuring out who is going to fly next."

All depends on the efficiency of the operation. Slow cycle time is zero fun.

Jim Vincent
N483SZ

[Eric Greenwell]

Bill Daniels wrote:

> Four aero retrieves! What you flyin' boy, a 1-26?

Come on, now: landing out is caused by the pilot, not the glider. If you
don't know when to turn back, even a 60:1 glider isn't going help.

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

Eric Greenwell
Washington State
USA

[F.L. Whiteley]

Winching.

1. You may be able to secure a long term lease for land much cheaper than
buying it. If use is weekends only, the land may be used for grazing or
some other activity in the interim. In the case of my club, we could
conceivably lease enough dry land a few miles east for what we pay in
property taxes annually. Site selection is important. Multiple sites may
be needed to cover then changing seasons.

2. At Avenal, are there roads at either end of the runway? If not, perhaps
the neighboring property owners could be convinced to allow the winch to be
put 2000-2500 off the end of the airport a couple of days a week. This
should give you a land back area and provide for great launches. We have
days when pilots tow 20 miles away to 11,500ft and still land back. Wait
for the convergence to come to you.

3. Launch rate is important. With our single drum winch, I can drive a
launch, drag the wire, return to the winch, and launch again with an 8
minute cycle time on a 5000ft run. If the headwind is good, I can have both
CG equipped two-seaters in the air at the same time. When there's lift, we
launch about every 15 minutes, giving each training sorty about 20-25
minutes. I will chastise anyone who is not ready to launch when the wire
arrives. Do your ground school after hours or week nights, not at the
launch point.

4. When there's lift, at least 75 percent of the launches commit soaring.
My average aero tow release height is less than I normally get from a winch
launch. Sometimes you just need to be patient and work it for a while. If
you get impatient, you'll land back more often. However, the price of a
re-light is okay too! When I did primarily winch launching in the UK, I
could count on one hand the number of re-lights I took in an entire season.
Depending on the year, I averaged more than 3 or 4 hours per flight (with
long wings admittedly).

5. My club has actually done a retrieve with a winch. It's on a licensed
trailer chassis and portable. Our tow plane is not covered for off airport
tows.

6. If you get a ground launch endorsement in six launches, you've been
cheated. Don't expect to exercise your privileges at my club. There are
some insidious things about ground launching that could bite you, and you
will practice and understand avoiding them. They can't be exercised in six
launches. No matter how many winch launches we've flown or driven, we're
still learning. I, for one, haven't seen it all, nor do I care to.

Frank Whiteley

[Bruce Greeff]

Jim Vincent wrote:
>>And the ones I researched that were closest were in Arizona or
>>Washington, and aren't getting anywhere even remotely close to
>>50 launches a day.
>
>
> Well, a friend and I got about 25 launches in four hours. Take off, fly the
> pattern, land on the cross wind, rotate the glider 90 degrees, and then off
> again.
>
> Of course, then you also have the esteemed contingent at my club who take off,
> do a complete pattern landing back into the wind, and then have to push back to
> the take off spot again. About half the efficiciency.
>
> Best line ever after dropping off the 'chute and driving back to the winch for
> the next go. "We're still figuring out who is going to fly next."
>
> All depends on the efficiency of the operation. Slow cycle time is zero fun.
>
> Jim Vincent
> N483SZ
>
You don't need any magic number of launches a day to make a winch viable. You
need to have enough to cover the overheads, but that is a very modest number.

Our vintage (30years +) winch is a good example of how a winch can make a
gliding club viable with few members and resources.

Built originally for a small club, we have stayed in business with less than 10
active members. Our average is around 30 launches per day. Worst case 12 minute
cycle time with 2km of cable - shorter retrieve is quicker turn around.

There is no substitute for experience if you want it slick, when we have a bunch
of experienced guys doing the winch driving and retrieving and radio control it
can come down to <8 minutes per launch. This is typical of a weak day when we
have 3 to 5 gliders on the line and folk are managing to stay up long enough to
allow us to launch before they land. Record day this way was 46 launches. Launch
marshal makes sure someone is ready to go when the wire comes back. If you
appear lees than keen to get in the air you might get sent to drive the winch
for a bit. Tends to focus minds.

Works well for a club that does proportionally high amount of training. Early
and late part of the day focus is on teaching flights, the private guys and more
experienced club pilots get to use the better part of the day for longer
flights. Everyone gets to fly, as long as everyone contributes. It is cheap and
sociable. Club membership getting back over 30 again.

We charge ~$4 per launch, and keep the maintenance on the winch at an acceptable
level. Means we have some guys flying at our club who could not afford it
anywhere else. ALso means that in the depths of winter there are queues waiting
for the trainer, with students banging out cheap instruction circuits. SOmetimes
they get lucky and come back an hour later...

[Marian Aldenhövel]

Hi,

> And of course I've had 4 aero-retrieves. Try that with a winch ;)

I read about a place in Namibia where they take the winch to the
landout site.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn.
Fon +49 228 624013, Fax +49 228 624031.
http://www.marian-aldenhoevel.de
"I know you believe you understand what you think I said, but I'm
not sure you realize that what you heard is not what I meant."

[Chris Reed]

My club (Rattlesden in Suffolk, England) operates both winch and aerotow
simultaneously. From 8 years flying there I'd say that the most important
factor for winching is the layout of the site. If it is possible for
aircraft to land without interrupting winch launching then it's very
satisfactory as a launch method, and you might consider moving to winch
only.

Our site is more difficult - an ex WW2 USAF airfield with a main 3,000 ft
runway and a shorter 1,600 ft cross runway. We can only winch from the main
runway, which means a crosswind component on the majority of days. In a
typical (!) single-seater like a Grob Astir you could expect 800-1,000 ft on
a 90 degree crosswind day, and 1,400 ft plus with a 20kt headwind. A
reasonable soaring day with, say, a 30 degree crosswind at 10kt should give
you around 1,300 ft. From this, if you are a reasonably competent soaring
pilot, I estimate you have a 50/50 chance of soaring. This increases if you
can delay the launch until "your" cloud arrives over the winch.

Frank Whiteley makes some highly relevant points:

> 3. Launch rate is important. With our single drum winch, I can drive a
> launch, drag the wire, return to the winch, and launch again with an 8
> minute cycle time on a 5000ft run. If the headwind is good, I can have
both
> CG equipped two-seaters in the air at the same time. When there's lift,
we
> launch about every 15 minutes, giving each training sorty about 20-25
> minutes. I will chastise anyone who is not ready to launch when the wire
> arrives. Do your ground school after hours or week nights, not at the
> launch point.
>
All this is very true, but on a restricted site the launch rate also suffers
from aircraft landing on the main run, used for winching. Trainees and early
solo pilots will use the main runway most of the time, as will the tug
aircraft. Practice winch failures at low hight will land straight ahead. The
sudden appearance of three gliders will require at least one to use the main
runway. All this means you need to be well organised, so as to clear the
gliders waiting to launch if necessary.

Given these potential frustrations of the winch launch, unnecessary delays
by pilots waiting to launch are to be avoided at all costs.

We use a Skylaunch twin drum winch with braided wire cable, and on a good
summer day might achieve 50 launches, 35 winch and 15 aerotow. On an evening
when instructors fly introductory flights, using two two-seater gliders
launching from the main runway and landing on the cross we have achieved 16
launches per hour (6 min flights), winching only.

> 6. If you get a ground launch endorsement in six launches, you've been
> cheated. Don't expect to exercise your privileges at my club. There are
> some insidious things about ground launching that could bite you, and you
> will practice and understand avoiding them. They can't be exercised in
six
> launches. No matter how many winch launches we've flown or driven, we're
> still learning. I, for one, haven't seen it all, nor do I care to.
>
Absolutely! From memory from the BGA instructor's manual you need to learn
at least:

1. The ground run (quite different from aerotow);

2. A safe transition to the climb, so that a 50ft cable break doesn't leave
you with insufficient energy to push over, regain flying speed and round
out. Correct use of the airbrakes in this situation is critical.

3. Recovery from a low cable break with a straight ahead landing.

4. Recovery from an "awkward" height cable break, where you can't land ahead
but have too little height for a normal circuit.

5. Recovery from a mechanical failure of the winch (usually a gradual loss
of power).

6. Signalling too fast and too slow, and what to do if the winch doesn't
respond.

7. Laying off for crosswinds to prevent the cable falling off the runway on
release.

8. Avoiding over-speeding and under-speeding. This includes understanding
the changes in stresses on the glider throughout the launch and the symptoms
of an impending stall on the wire (very nasty!).

9. Stalling and spinning from launch failures - these will be simulated at
height, e.g. dive to 70kt, pull up into 45 degree climb, as speed falls to
around 50kts instructor announces cable break. It takes a second or two to
react and push over, by which time speed will be down to 30 kt or so. If you
stop the pushover at the normal gliding attitude and turn immediately most
gliders will roll smoothly into a spin with no warning signs - don't try
this on your own if you haven't been well trained on spin recovery!

10. Inadvertent launching into cloud.

This list may sound alarming, but we regularly solo students on the winch
with, say, 7 hrs flying time. However, there's no way these matters can be
covered in a handful of launches.

The UK consensus seems to be that winch launching is as safe as aerotow but
*only* if pilots are well trained.

So why do we aerotow as well? Obviously, some aspects of pilot training
require more height than a winch launch will give. More important, for
pilots setting off on a task an aerotow takes you to the lift at a height
where it's easier to work. Less mental energy used to get started means more
left over to complete the task.

[[email protected]]

Mark James Boyd wrote:
> In article <rLfgd.540846$8_6.36371@attbi_s04>,
> Bill Daniels > wrote:
> >
> >"Mark James Boyd" > wrote in message
> >news:41818652$1@darkstar...
> >> Steve Hill > wrote:
> >>
> >> The "street" has spoken. There are NO winches in California.
> >
> >I think you overlooked AGCSC who operates their winch at Torry Pines
and
> >Warner Springs.
>

Almost forgot, Antelope Valley Soaring at Krey Field is supposed to
have a winch they use on occasion. So with AGCSC, 29 Palms and Los
Alamitos that makes 4 winches in southern cal. The place is
practically a winch paradise.

[Kirk Stant]

(Mark James Boyd) wrote in message news:<41818652$1@darkstar>...
> Steve Hill > wrote:
> >
> >I'd really like to see what the actual costs are for a club to purchase a
> >good winch.
>
> The "street" has spoken. There are NO winches in California.
> And the ones I researched that were closest were in Arizona or
> Washington, and aren't getting anywhere even remotely close to
> 50 launches a day.
>
> I haven't been to Washington yet, but I have talked to the club there
> and they were closed for a good part of last winter (0 launches).
>
> Would a winch in CA do well? I dunno. At Avenal, there are
> days when it would be fine, but then again there are
> a lot of days or times of the day when a higher tow or further
> away is better. And of course I've had 4 aero-retrieves.
> Try that with a winch ;)


The Prescott (AZ) Soaring Club does well with their winch, apparently.
Down here where I usually fly at Turf (just west of Phoenix), we
rarely aerotow higher than 1500', I think my usual release altitude is
about 1200' just off the end of the runway into the house thermal -
ideal for a winch! Of course, this makes for a pretty quick cycle
time with a couple of Pawnees, and we would really need a double or
triple drum setup to get a race grid off rapidly, but it sure would be
fun to watch!

Kirk
66

[Bill Daniels]

"Kirk Stant" > wrote in message
om...
> (Mark James Boyd) wrote in message
news:<41818652$1@darkstar>...
> > Steve Hill > wrote:
> > >
> > >I'd really like to see what the actual costs are for a club to purchase
a
> > >good winch.
> >
> > The "street" has spoken. There are NO winches in California.
> > And the ones I researched that were closest were in Arizona or
> > Washington, and aren't getting anywhere even remotely close to
> > 50 launches a day.
> >
> > I haven't been to Washington yet, but I have talked to the club there
> > and they were closed for a good part of last winter (0 launches).
> >
> > Would a winch in CA do well? I dunno. At Avenal, there are
> > days when it would be fine, but then again there are
> > a lot of days or times of the day when a higher tow or further
> > away is better. And of course I've had 4 aero-retrieves.
> > Try that with a winch ;)
>
>
> The Prescott (AZ) Soaring Club does well with their winch, apparently.
> Down here where I usually fly at Turf (just west of Phoenix), we
> rarely aerotow higher than 1500', I think my usual release altitude is
> about 1200' just off the end of the runway into the house thermal -
> ideal for a winch! Of course, this makes for a pretty quick cycle
> time with a couple of Pawnees, and we would really need a double or
> triple drum setup to get a race grid off rapidly, but it sure would be
> fun to watch!
>
> Kirk
> 66

If Babblefish translated it right, the Dutch Nationals launched 60 gliders
in 45 minutes with two of their 6-drum winches. That's a LOT cheaper than a
fleet of Pawnees.

Bill Daniels

[F.L. Whiteley]

Did they ever remove the broken up concrete or resurface the runway? It was
in a state 25 years ago. Would have been lethal to aerotow there then.

Are you still using that old piano wire winch with the big 'drum'?

Frank

"Chris Reed" > wrote in message
...
> My club (Rattlesden in Suffolk, England) operates both winch and aerotow
> simultaneously. From 8 years flying there I'd say that the most important
> factor for winching is the layout of the site. If it is possible for
> aircraft to land without interrupting winch launching then it's very
> satisfactory as a launch method, and you might consider moving to winch
> only.
>
> Our site is more difficult - an ex WW2 USAF airfield with a main 3,000 ft
> runway and a shorter 1,600 ft cross runway. We can only winch from the
main
> runway, which means a crosswind component on the majority of days. In a
> typical (!) single-seater like a Grob Astir you could expect 800-1,000 ft
on
> a 90 degree crosswind day, and 1,400 ft plus with a 20kt headwind. A
> reasonable soaring day with, say, a 30 degree crosswind at 10kt should
give
> you around 1,300 ft. From this, if you are a reasonably competent soaring
> pilot, I estimate you have a 50/50 chance of soaring. This increases if
you
> can delay the launch until "your" cloud arrives over the winch.
>
> Frank Whiteley makes some highly relevant points:
>
> > 3. Launch rate is important. With our single drum winch, I can drive a
> > launch, drag the wire, return to the winch, and launch again with an 8
> > minute cycle time on a 5000ft run. If the headwind is good, I can have
> both
> > CG equipped two-seaters in the air at the same time. When there's lift,
> we
> > launch about every 15 minutes, giving each training sorty about 20-25
> > minutes. I will chastise anyone who is not ready to launch when the
wire
> > arrives. Do your ground school after hours or week nights, not at the
> > launch point.
> >
> All this is very true, but on a restricted site the launch rate also
suffers
> from aircraft landing on the main run, used for winching. Trainees and
early
> solo pilots will use the main runway most of the time, as will the tug
> aircraft. Practice winch failures at low hight will land straight ahead.
The
> sudden appearance of three gliders will require at least one to use the
main
> runway. All this means you need to be well organised, so as to clear the
> gliders waiting to launch if necessary.
>
> Given these potential frustrations of the winch launch, unnecessary delays
> by pilots waiting to launch are to be avoided at all costs.
>
> We use a Skylaunch twin drum winch with braided wire cable, and on a good
> summer day might achieve 50 launches, 35 winch and 15 aerotow. On an
evening
> when instructors fly introductory flights, using two two-seater gliders
> launching from the main runway and landing on the cross we have achieved
16
> launches per hour (6 min flights), winching only.
>
> > 6. If you get a ground launch endorsement in six launches, you've been
> > cheated. Don't expect to exercise your privileges at my club. There
are
> > some insidious things about ground launching that could bite you, and
you
> > will practice and understand avoiding them. They can't be exercised in
> six
> > launches. No matter how many winch launches we've flown or driven,
we're
> > still learning. I, for one, haven't seen it all, nor do I care to.
> >
> Absolutely! From memory from the BGA instructor's manual you need to learn
> at least:
>
> 1. The ground run (quite different from aerotow);
>
> 2. A safe transition to the climb, so that a 50ft cable break doesn't
leave
> you with insufficient energy to push over, regain flying speed and round
> out. Correct use of the airbrakes in this situation is critical.
>
> 3. Recovery from a low cable break with a straight ahead landing.
>
> 4. Recovery from an "awkward" height cable break, where you can't land
ahead
> but have too little height for a normal circuit.
>
> 5. Recovery from a mechanical failure of the winch (usually a gradual loss
> of power).
>
> 6. Signalling too fast and too slow, and what to do if the winch doesn't
> respond.
>
> 7. Laying off for crosswinds to prevent the cable falling off the runway
on
> release.
>
> 8. Avoiding over-speeding and under-speeding. This includes understanding
> the changes in stresses on the glider throughout the launch and the
symptoms
> of an impending stall on the wire (very nasty!).
>
> 9. Stalling and spinning from launch failures - these will be simulated at
> height, e.g. dive to 70kt, pull up into 45 degree climb, as speed falls to
> around 50kts instructor announces cable break. It takes a second or two to
> react and push over, by which time speed will be down to 30 kt or so. If
you
> stop the pushover at the normal gliding attitude and turn immediately most
> gliders will roll smoothly into a spin with no warning signs - don't try
> this on your own if you haven't been well trained on spin recovery!
>
> 10. Inadvertent launching into cloud.
>
> This list may sound alarming, but we regularly solo students on the winch
> with, say, 7 hrs flying time. However, there's no way these matters can be
> covered in a handful of launches.
>
> The UK consensus seems to be that winch launching is as safe as aerotow
but
> *only* if pilots are well trained.
>
> So why do we aerotow as well? Obviously, some aspects of pilot training
> require more height than a winch launch will give. More important, for
> pilots setting off on a task an aerotow takes you to the lift at a height
> where it's easier to work. Less mental energy used to get started means
more
> left over to complete the task.
>
>

[F.L. Whiteley]

"Kirk Stant" > wrote in message
om...
> (Mark James Boyd) wrote in message
news:<41818652$1@darkstar>...
> > Steve Hill > wrote:
> > >
> > >I'd really like to see what the actual costs are for a club to purchase
a
> > >good winch.
> >
> > The "street" has spoken. There are NO winches in California.
> > And the ones I researched that were closest were in Arizona or
> > Washington, and aren't getting anywhere even remotely close to
> > 50 launches a day.
> >
> > I haven't been to Washington yet, but I have talked to the club there
> > and they were closed for a good part of last winter (0 launches).
> >
> > Would a winch in CA do well? I dunno. At Avenal, there are
> > days when it would be fine, but then again there are
> > a lot of days or times of the day when a higher tow or further
> > away is better. And of course I've had 4 aero-retrieves.
> > Try that with a winch ;)
>
>
> The Prescott (AZ) Soaring Club does well with their winch, apparently.
> Down here where I usually fly at Turf (just west of Phoenix), we
> rarely aerotow higher than 1500', I think my usual release altitude is
> about 1200' just off the end of the runway into the house thermal -
> ideal for a winch! Of course, this makes for a pretty quick cycle
> time with a couple of Pawnees, and we would really need a double or
> triple drum setup to get a race grid off rapidly, but it sure would be
> fun to watch!
>
> Kirk
> 66
A single drum winch is the poorest of compromises in effeciency with only
cost being the overriding factor. There is simply no reason to drag one
rope at a time and doing so can make the entire process more tedious and
dampen enthusiasm. Only one thing matters to private owners on the ground,
and that's launch rate. For wide adoption, a two drum winch works well.
For a large operation, two two-drum winches provide high availability and
redundancy, portability is off-site operations are anticipated.

Frank

[Bob Salvo]

Why not two winches; one to launch with and the other to retrieve the cable?
I think I remember this being done years ago. If the drag chute is big
enough, the retrieve winch should be able to return the entire cable. I
wonder how fast two setups (4 winches) could launch a fleet?

"F.L. Whiteley" > wrote in message
...
>
> "Kirk Stant" > wrote in message
> om...
> > (Mark James Boyd) wrote in message
> news:<41818652$1@darkstar>...
> > > Steve Hill > wrote:
> > > >
> > > >I'd really like to see what the actual costs are for a club to
purchase
> a
> > > >good winch.
> > >
> > > The "street" has spoken. There are NO winches in California.
> > > And the ones I researched that were closest were in Arizona or
> > > Washington, and aren't getting anywhere even remotely close to
> > > 50 launches a day.
> > >
> > > I haven't been to Washington yet, but I have talked to the club there
> > > and they were closed for a good part of last winter (0 launches).
> > >
> > > Would a winch in CA do well? I dunno. At Avenal, there are
> > > days when it would be fine, but then again there are
> > > a lot of days or times of the day when a higher tow or further
> > > away is better. And of course I've had 4 aero-retrieves.
> > > Try that with a winch ;)
> >
> >
> > The Prescott (AZ) Soaring Club does well with their winch, apparently.
> > Down here where I usually fly at Turf (just west of Phoenix), we
> > rarely aerotow higher than 1500', I think my usual release altitude is
> > about 1200' just off the end of the runway into the house thermal -
> > ideal for a winch! Of course, this makes for a pretty quick cycle
> > time with a couple of Pawnees, and we would really need a double or
> > triple drum setup to get a race grid off rapidly, but it sure would be
> > fun to watch!
> >
> > Kirk
> > 66
> A single drum winch is the poorest of compromises in effeciency with only
> cost being the overriding factor. There is simply no reason to drag one
> rope at a time and doing so can make the entire process more tedious and
> dampen enthusiasm. Only one thing matters to private owners on the
ground,
> and that's launch rate. For wide adoption, a two drum winch works well.
> For a large operation, two two-drum winches provide high availability and
> redundancy, portability is off-site operations are anticipated.
>
> Frank
>
>

[F.L. Whiteley]

It's doable and is done at the Long Mynd, Midland GC,
http://www.longmynd.com/ along with bungee launching.

Spectra's 'float' might make work pretty well on a long run.

Frank Whiteley

"Bob Salvo" > wrote in message
...
> Why not two winches; one to launch with and the other to retrieve the
cable?
> I think I remember this being done years ago. If the drag chute is big
> enough, the retrieve winch should be able to return the entire cable. I
> wonder how fast two setups (4 winches) could launch a fleet?
>
> "F.L. Whiteley" > wrote in message
> ...
> >
> > "Kirk Stant" > wrote in message
> > om...
> > > (Mark James Boyd) wrote in message
> > news:<41818652$1@darkstar>...
> > > > Steve Hill > wrote:
> > > > >
> > > > >I'd really like to see what the actual costs are for a club to
> purchase
> > a
> > > > >good winch.
> > > >
> > > > The "street" has spoken. There are NO winches in California.
> > > > And the ones I researched that were closest were in Arizona or
> > > > Washington, and aren't getting anywhere even remotely close to
> > > > 50 launches a day.
> > > >
> > > > I haven't been to Washington yet, but I have talked to the club
there
> > > > and they were closed for a good part of last winter (0 launches).
> > > >
> > > > Would a winch in CA do well? I dunno. At Avenal, there are
> > > > days when it would be fine, but then again there are
> > > > a lot of days or times of the day when a higher tow or further
> > > > away is better. And of course I've had 4 aero-retrieves.
> > > > Try that with a winch ;)
> > >
> > >
> > > The Prescott (AZ) Soaring Club does well with their winch, apparently.
> > > Down here where I usually fly at Turf (just west of Phoenix), we
> > > rarely aerotow higher than 1500', I think my usual release altitude is
> > > about 1200' just off the end of the runway into the house thermal -
> > > ideal for a winch! Of course, this makes for a pretty quick cycle
> > > time with a couple of Pawnees, and we would really need a double or
> > > triple drum setup to get a race grid off rapidly, but it sure would be
> > > fun to watch!
> > >
> > > Kirk
> > > 66
> > A single drum winch is the poorest of compromises in effeciency with
only
> > cost being the overriding factor. There is simply no reason to drag one
> > rope at a time and doing so can make the entire process more tedious and
> > dampen enthusiasm. Only one thing matters to private owners on the
> ground,
> > and that's launch rate. For wide adoption, a two drum winch works well.
> > For a large operation, two two-drum winches provide high availability
and
> > redundancy, portability is off-site operations are anticipated.
> >
> > Frank
> >
> >
>
>

[Derrick Steed]

For experience with retrieve winches see the Long Mynd site, they use one all the time - Bill Dean should be able to tell you more.

Rgds,

Derrick Steed

[Mike Lindsay]

In article >, Bob Salvo
> writes
>Why not two winches; one to launch with and the other to retrieve the cable?
>I think I remember this being done years ago. If the drag chute is big
>enough, the retrieve winch should be able to return the entire cable. I
>wonder how fast two setups (4 winches) could launch a fleet?

This is the set up the Midland Gliding Club has used for at least 30
years, the two cables join in a device that used to be an iron triangle,
but the present gizmo is a lot lighter.

It gives a very good launch rate with an experienced driver on each
winch.

But its not universally suitable...
--
Mike Lindsay.

[Chris Reed]

Each end of the runway has been resurfaced but the middle is the original
concrete, patched where necessary. Aerotow is no problem, though I think one
landout pilot (with a brand new glider) decided against an aerotow retrieve
because of possible stone chip damage.

Piano wire is a distant memory - our nearly new Skylaunch winch gives very
smooth and consistent launches.

"F.L. Whiteley" > wrote in message
...
> Did they ever remove the broken up concrete or resurface the runway? It
was
> in a state 25 years ago. Would have been lethal to aerotow there then.
>
> Are you still using that old piano wire winch with the big 'drum'?
>
> Frank
>
> "Chris Reed" > wrote in message
> ...
> > My club (Rattlesden in Suffolk, England) operates both winch and aerotow
> > simultaneously. From 8 years flying there I'd say that the most
important
> > factor for winching is the layout of the site. If it is possible for
> > aircraft to land without interrupting winch launching then it's very
> > satisfactory as a launch method, and you might consider moving to winch
> > only.
> >
> > Our site is more difficult - an ex WW2 USAF airfield with a main 3,000
ft
> > runway and a shorter 1,600 ft cross runway. We can only winch from the
> main
> > runway, which means a crosswind component on the majority of days. In a
> > typical (!) single-seater like a Grob Astir you could expect 800-1,000
ft
> on
> > a 90 degree crosswind day, and 1,400 ft plus with a 20kt headwind. A
> > reasonable soaring day with, say, a 30 degree crosswind at 10kt should
> give
> > you around 1,300 ft. From this, if you are a reasonably competent
soaring
> > pilot, I estimate you have a 50/50 chance of soaring. This increases if
> you
> > can delay the launch until "your" cloud arrives over the winch.
> >
> > Frank Whiteley makes some highly relevant points:
> >
> > > 3. Launch rate is important. With our single drum winch, I can drive
a
> > > launch, drag the wire, return to the winch, and launch again with an 8
> > > minute cycle time on a 5000ft run. If the headwind is good, I can
have
> > both
> > > CG equipped two-seaters in the air at the same time. When there's
lift,
> > we
> > > launch about every 15 minutes, giving each training sorty about 20-25
> > > minutes. I will chastise anyone who is not ready to launch when the
> wire
> > > arrives. Do your ground school after hours or week nights, not at the
> > > launch point.
> > >
> > All this is very true, but on a restricted site the launch rate also
> suffers
> > from aircraft landing on the main run, used for winching. Trainees and
> early
> > solo pilots will use the main runway most of the time, as will the tug
> > aircraft. Practice winch failures at low hight will land straight ahead.
> The
> > sudden appearance of three gliders will require at least one to use the
> main
> > runway. All this means you need to be well organised, so as to clear the
> > gliders waiting to launch if necessary.
> >
> > Given these potential frustrations of the winch launch, unnecessary
delays
> > by pilots waiting to launch are to be avoided at all costs.
> >
> > We use a Skylaunch twin drum winch with braided wire cable, and on a
good
> > summer day might achieve 50 launches, 35 winch and 15 aerotow. On an
> evening
> > when instructors fly introductory flights, using two two-seater gliders
> > launching from the main runway and landing on the cross we have achieved
> 16
> > launches per hour (6 min flights), winching only.
> >
> > > 6. If you get a ground launch endorsement in six launches, you've
been
> > > cheated. Don't expect to exercise your privileges at my club. There
> are
> > > some insidious things about ground launching that could bite you, and
> you
> > > will practice and understand avoiding them. They can't be exercised
in
> > six
> > > launches. No matter how many winch launches we've flown or driven,
> we're
> > > still learning. I, for one, haven't seen it all, nor do I care to.
> > >
> > Absolutely! From memory from the BGA instructor's manual you need to
learn
> > at least:
> >
> > 1. The ground run (quite different from aerotow);
> >
> > 2. A safe transition to the climb, so that a 50ft cable break doesn't
> leave
> > you with insufficient energy to push over, regain flying speed and round
> > out. Correct use of the airbrakes in this situation is critical.
> >
> > 3. Recovery from a low cable break with a straight ahead landing.
> >
> > 4. Recovery from an "awkward" height cable break, where you can't land
> ahead
> > but have too little height for a normal circuit.
> >
> > 5. Recovery from a mechanical failure of the winch (usually a gradual
loss
> > of power).
> >
> > 6. Signalling too fast and too slow, and what to do if the winch doesn't
> > respond.
> >
> > 7. Laying off for crosswinds to prevent the cable falling off the runway
> on
> > release.
> >
> > 8. Avoiding over-speeding and under-speeding. This includes
understanding
> > the changes in stresses on the glider throughout the launch and the
> symptoms
> > of an impending stall on the wire (very nasty!).
> >
> > 9. Stalling and spinning from launch failures - these will be simulated
at
> > height, e.g. dive to 70kt, pull up into 45 degree climb, as speed falls
to
> > around 50kts instructor announces cable break. It takes a second or two
to
> > react and push over, by which time speed will be down to 30 kt or so. If
> you
> > stop the pushover at the normal gliding attitude and turn immediately
most
> > gliders will roll smoothly into a spin with no warning signs - don't try
> > this on your own if you haven't been well trained on spin recovery!
> >
> > 10. Inadvertent launching into cloud.
> >
> > This list may sound alarming, but we regularly solo students on the
winch
> > with, say, 7 hrs flying time. However, there's no way these matters can
be
> > covered in a handful of launches.
> >
> > The UK consensus seems to be that winch launching is as safe as aerotow
> but
> > *only* if pilots are well trained.
> >
> > So why do we aerotow as well? Obviously, some aspects of pilot training
> > require more height than a winch launch will give. More important, for
> > pilots setting off on a task an aerotow takes you to the lift at a
height
> > where it's easier to work. Less mental energy used to get started means
> more
> > left over to complete the task.
> >
> >
>
>