Aerotow with Diesel engine?

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

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

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
illspam
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...

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."

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.

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.

(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

"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

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.

"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