US Dollar sinks to new low against Euro

Bob Korves wrote:

After being around self launchers for many years, however, I mostly
remember watching the owners fiddle with them, and then send the prop
in for an AD, wait 3 months, then fiddle some more, and then send the
engine in for an AD, wait another 3 months, and then fiddle some
more.

Was that a Stemme you were around?

Well, maybe I am exaggerating at little.

THey do require more maintenance than an unpowered sailplane because of
the motor. Most of the time, it can be deferred to the winter or other
times you can't fly anyway. The other side of the coin is an entire club
shut down because of a towplane problem, which I've experienced more
often than a problem with my motor.

The other issue is that for the extra cost of the engine I could buy
a Pawnee and have enough left over to hire a cute tow pilot on the
interest it earned.

Maybe a bit more exaggeration.

IF you fly a lot (40+ flights a year), you can save more on tow and
retrieve fees than the extra cost of interest, insurance, and
maintenance. That's also an exaggeration, but not much. And the engine
does hold it's value, so you can get your money back when you sell it.

I suppose if you are antisocial or live in a part of the country
where there are no tow planes, have time only during the week when
the club is closed, or whatever, and have lots of money, and time for
fiddling, then a self launcher would be dandy.

It's also dandy for other purposes, and dandy even if most of those
things aren't true. You quoted Steve Hill's posting, now you should read
it more carefully!


I happen to like the people in this sport at least as well as I like
the flying. I sometimes actually enjoy waiting in a tow line telling
war stories with my buddies. Nothing beats the Saturday night
barbecue at the gliderport. Not that having a self launcher excludes
you from any of this, of course.

Another reason I don't seek self launchers is that I am not really
good at complexity. I have enough trouble with the few levers and
knobs is a pure glider. While learning to use flaps I did just about
every dumb thing one can do with that single additional handle. A
little voice in my head tells me that the complexity of a self
launcher is not a good thing for me, personally.

This is an excellent reason for sticking with unpowered gliders. Safely
flying a motorglider does take more discipline and care than an
unpowered glider. You are no longer just a glider pilot, but also the
"tow" pilot.

I think I am usually immune to peer pressure and my perceived
standing in the gliding community. Somehow, though, after I
completed a long and difficult flight in trying conditions, and
somebody said "But you have an engine" -- I might have a problem with
that!

This used annoy me, but I don't hear it anymore. Pilots are much more
aware of motorgliders now, so mostly, they ask thoughtful questions
about how my flying differs, now that I have an engine. They can see I'm
flying farther and in more interesting conditions than comparable
gliders/pilots, yet I usually come back with a cold engine. It whets
their curiosity.

I am having a lot of fun with this post and I'm sure I have raised
Eric Greenwell's blood pressure by now. I guess I need to tell the
other side of the story. Last summer I met a pilot from Denmark,
Francis, several times who was in the U.S. flying his DG-400 all
around the western part of the country. And I mean all around. He
started in Texas, worked his way up to Washington state, and was on
his way back to Texas. He had done this sort of thing many times, in
Europe, Morocco, etc. He does this every year. He lives out of a
plastic grocery sack stuffed into the tiny luggage shelf of the
glider. We took him to motels and to dinner since we had cars. This
guy was living my daydream!

And then there are the two Germans that flew their ASH 26 Es from
Houston to Alaska, and back!

Eric is also a pilot that really uses his self launcher well and
often. He is a great guy, sociable, and fun to fly with.

Why, thanks, Bob!

I'm sure that there are many others out there, too. So a self
launcher can be a wonderful thing.

I would rather spend my meager gliding money buying more L/D with
several wonderful partners in really nice ships than buying a stinky,
noisy engine and propeller to fiddle with. If I won that lottery
today, I don't think I would change what I am doing now. As always,
YMMV.

They aren't for everyone, but there are plenty of people that don't
realize how much they would enjoy one, because they don't know very much
about them and how they can improve their soaring experience. Generally,
the $premium$ for the engine stops them thinking about the good things
that make it worthwhile.

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

Eric Greenwell
Washington State
USA

(Ruud) wrote in message . com...
(Tom Seim) wrote in message om...
(Mike Stringfellow) wrote in message . com...
The US dollar is now valued close to 0.75 Euro, down from its peak of
1.25 a couple of years ago. Analysts say it may go even lower, with
some projecting exchange rates of 0.7 (1.4 dollar to the Euro).

This has pretty much put the kibosh on my goals of buying a new
European sailplane. A model at, say, Euro 85,000 cost around $70,000
a couple of years ago, is now around $110,000 and may soon be at
$120,000.

Economic models would suggest a strong incentive for sailplane
manufacture in North America, but I wonder if the numbers of potential
sales would justify this.

Any thoughts?

Yes, invest your money and wait. For instance, if you put your money
in a high quality mutual fund you will begin accumulating principal.
Take your $70,000 and put in a Morningstar 5-star fund (i.e. Fidelity
Contrafund). If you average 15% return the numbers a
Year Amount
0 $70000
1 80500
2 92575
3 106461
4 122430
5 140795
6 161914
etc.

At some point the price of the glider, converted from euros, is going
to be less than your investment. BUY THE GLIDER! This is, simply, the
power of compounded interest.

Don't agree with my numbers? Then put your damn money into a mattress
and see what happens!

The moral of the story is that patience is on the side of the buyer.

Interesting story.
The only trouble with it is that an average return of 15% on your
investment is not enough to keep up with the free fall of the US
dollar.

Your grasp of international money markets is truly awesome! Have you
considered running for Alan Greenspan's job?

You might bother to check out what has happened historically to
international exchange rates: they oscillate. This is merely one more
cycle in the oscillation. Otherwise, by your logic, the dollar will be
worthless in 5-7 years. Invest and wait, that's my advice. Of course,
if you're loaded with dough, go for it!

In article 419ab2d8$1@darkstar,
(Mark James Boyd) wrote:

I'm still interested in the idea of a turbine powered sailplane
without a propeller. Sure, very inefficient (it looks like
about 3-4 times as much fuel consumed), but gliders seem about the
ONLY place where this may be a good tradeoff, since the time of
engine running is so short.

A low weight, fuel inefficient engine with no prop, a low weight glider,
and a medium performance L/D (meaning a low stall speed so
reasonable acceleration to takeoff). Must be a single engine,
otherwise it would likely be uninsurable (as if
insuring a glider with ONE turbine wasn't bad enough

A low stall speed isn't what you want. By far the most important thing
is a high Vne. The best way to climb in a jet is to accelerate in level
flight (in ground effect if you can) to Vne and then climb at Vne.



Other than a lightweight, inefficient turbine, I don't see
any other "revolutionary" powerplants for gliders which might
bring the cost down and create more widespread interest.

There are also rockets. Lighter, simpler, less fuel efficient, and
(probably) cheaper than jets.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

In article ,
Bruce Hoult wrote:

A low stall speed isn't what you want. By far the most important thing
is a high Vne. The best way to climb in a jet is to accelerate in level
flight (in ground effect if you can) to Vne and then climb at Vne.

This may be the best way in terms of efficiency and power, but
I'm not sure it is as practical as the alternative.

I'm thinking of a situation where acceleration to a speed where
climbing out of ground effect is possible. If we assume a
glider weighing 400 lbs total, it takes a certain amount of thrust
to accelerate it to above stall speed, and then Vx and Vy. It then takes
a lot more thrust to get it to Vne.

Will a turbine produce 4 times as much thrust at 120 knots compared to
50 knots? I don't know. I do know that if the stall speed is pushed
way up, you need a lot more runway or a lot bigger engine.

So look at the Sparrowhawk polar, and assume 400 lbs. What is the
minimum thrust turbine engine that can launch this thing from a
2000ft long runway with 30 feet of clearance over the far end
and thereafter at least 200 fpm climb per NM (no wind)?

Assuming the same turbine is used, I'm guessing moving the polar to
the right (with a new wing) doesn't help, even if the weight remains
the same. The issue is acceleration to flying speed, and this is
helped by lowering the flying speed (Vy or Vx) and lowering the weight.

So any of you math/aerodynamics guys out there got a guess?
I guessed 45 pounds of continuous thrust would do it, but
this was a SWAG, and I have no idea what a turbine rated at 45lbs
really puts out at 0 airspeed. I also didn't account for any drag
during the acceleration, and used interpolation for climb.

How much more thrust is needed to do the same thing, but with 500 fpm
climb per NM after launch?

I really don't know, but I'd love to see a java program where
you put in the weight numbers, polar data, and thrust at different
speeds, and get the results...

Other than a lightweight, inefficient turbine, I don't see
any other "revolutionary" powerplants for gliders which might
bring the cost down and create more widespread interest.

There are also rockets. Lighter, simpler, less fuel efficient, and
(probably) cheaper than jets.

It looks like $20 for 4lbs of thrust for 8 seconds. Each launch looks like
at least hundreds of dollars (worth of commercial rockets sold
by Public Missiles, Ltd and the like).

Perhaps these can be constructed as reusable and experimental,
for much less cost, but I'm just not familiar with this.

If you can give us some estimates on costs and thrust and burn time,
that would be great Perhaps the largest barrier to this
is unfamiliarity and not knowing how such a burn is controlled.
How does one perform an aborted takeoff?

--

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

In article 419af6e1$1@darkstar,
(Mark James Boyd) wrote:

In article ,
Bruce Hoult wrote:

A low stall speed isn't what you want. By far the most important thing
is a high Vne. The best way to climb in a jet is to accelerate in level
flight (in ground effect if you can) to Vne and then climb at Vne.

This may be the best way in terms of efficiency and power, but
I'm not sure it is as practical as the alternative.

I'm thinking of a situation where acceleration to a speed where
climbing out of ground effect is possible. If we assume a
glider weighing 400 lbs total, it takes a certain amount of thrust
to accelerate it to above stall speed, and then Vx and Vy. It then takes
a lot more thrust to get it to Vne.

Thrust is cheap. The amount of fuel used is to a first approximation
independent of the thrust of the engine (in fact to a certain point more
powerful engines result in less fuel used). But an engine that will
give you only 200 fpm of climb will take *forever* to get you to any
reasonable flying speed.


There are also rockets. Lighter, simpler, less fuel efficient, and
(probably) cheaper than jets.

It looks like $20 for 4lbs of thrust for 8 seconds. Each launch looks like
at least hundreds of dollars (worth of commercial rockets sold
by Public Missiles, Ltd and the like).

Perhaps these can be constructed as reusable and experimental,
for much less cost, but I'm just not familiar with this.

If you can give us some estimates on costs and thrust and burn time,
that would be great Perhaps the largest barrier to this
is unfamiliarity and not knowing how such a burn is controlled.
How does one perform an aborted takeoff?

You seem to be assuming solid rockets. That would be a *very* bad idea.
Liquid rockets are reusable and use cheap fuels. Have a look at the
videos etc on XCor's web site (http://www.xcor.com/). They've built
liquid/gas fuelled rocket engines with thrust levels ranging from 15 lb
to 1800 lb. One of their 400 lb thrust alcohol/oxygen engines would
launch a typical glider with performance similar to a winch launch using
about 45 lb of fuel.

I've done calculations on takeoff performance several times over the
years, and posted the results on this newsgroup.

http://groups.google.com/groups?selm...12003%40copper
..ipg.tsnz.net

http://groups.google.com/groups?selm=an_595515430

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

In article ,
Bruce Hoult wrote:
In article 419af6e1$1@darkstar,
(Mark James Boyd) wrote:

Thrust is cheap. The amount of fuel used is to a first approximation
independent of the thrust of the engine (in fact to a certain point more
powerful engines result in less fuel used). But an engine that will
give you only 200 fpm of climb will take *forever* to get you to any
reasonable flying speed.

http://groups.google.com/groups?selm=an_595515430

I looked at your previous calculations, thanks for the reference to
the earlier post.

I wonder if you could redo the numbers for the limiting (minimum)
case for launching a human. Lets say a 50kg launch. Then also
do the numbers for a 150kg launch. I'd love to see what this looks like for
10kg and 20kg of thrust.

I also looked at some of the other numbers in the post,
and they seemed a little off.
20kg of drag until liftoff speed seems a bit of an overestimate.
The Sparrowhawk would seem to have at most 5kg of drag
while accelerating to best L/D, assuming no
wheel friction, and this drag should increase as airspeed increases.
If a turbine is used, perhaps this isn't so bad, if it helps
compensate for turbine inefficiencies at low airspeeds? I dunno.
Also, maybe this was to compensate for rough ground?

You also stated that "exact L/D doesn't matter much at all while in
powered mode." For the numbers you ran, this looks true (5000fpm
climb!). But at very low thrust and the minimal thrust case,
the best L/D and speed at that L/D would seem to be quite important.
Speeds much faster than this should require significantly more thrust.

Here were some of the calculations, which you did and I found enlightening:

thrust 50kg 100kg
Ground run 204m 76m
Dist at low level 945m 420m
climb angle 8deg 17deg
powered time 104s 45s
climb rate? 1000 fpm?

I'd be intereted to see what thrust is needed if the weight is reduced to
150kg, and the ground run is about 600m, using a Sparrowhawk polar.
Then I'd like to see how this changes if the ground run is allowed
to be 1200m. By ground run I'm assuming we mean accelerating
to something between Vs and Vy. I'd love to see what the climb angle
and climb rate then become.

I'm interested in the minimum case because this is a natural starting
point. I've done these calculations and it seemed that 15kg of thrust
gave a ground run less than 600m, and a climb rate of more than 200fpm
(might have been 500fpm, but I don't recall).



There are also rockets. Lighter, simpler, less fuel efficient, and
(probably) cheaper than jets.

It looks like $20 for 4lbs of thrust for 8 seconds. Each launch looks like
at least hundreds of dollars (worth of commercial rockets sold
by Public Missiles, Ltd and the like).

Perhaps these can be constructed as reusable and experimental,
for much less cost, but I'm just not familiar with this.

If you can give us some estimates on costs and thrust and burn time,
that would be great Perhaps the largest barrier to this
is unfamiliarity and not knowing how such a burn is controlled.
How does one perform an aborted takeoff?

You seem to be assuming solid rockets. That would be a *very* bad idea.
Liquid rockets are reusable and use cheap fuels. Have a look at the
videos etc on XCor's web site (http://www.xcor.com/). They've built
liquid/gas fuelled rocket engines with thrust levels ranging from 15 lb
to 1800 lb. One of their 400 lb thrust alcohol/oxygen engines would
launch a typical glider with performance similar to a winch launch using
about 45 lb of fuel.

Interesting stuff. Maybe for the moment we look at the thrust
calculations, and decide later what makes the thrust


I've done calculations on takeoff performance several times over the
years, and posted the results on this newsgroup.

http://groups.google.com/groups?selm...12003%40copper
.ipg.tsnz.net

http://groups.google.com/groups?selm=an_595515430

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------


--

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

In article ,
Bruce Hoult wrote:
In article 419b8d27$1@darkstar,
(Mark James Boyd) wrote:

I wonder if you could redo the numbers for the limiting (minimum)
case for launching a human. Lets say a 50kg launch. Then also
do the numbers for a 150kg launch. I'd love to see what this looks like for
10kg and 20kg of thrust.

Well, if you scale the weight, thrust and drag by the same amount then
all the speeds and times are the same.

So with half the thrust, half the drag, and half the weight,
the rest is the same? Hmmm...ok. If this is right then 25kg of
thrust will get the Sparrowhawk accelerated and aloft smartly.
20kg of thrust (45# of the AMT turbine) will do nearly as well.

I don't know how much is the right amount, but I was trying to guess for
a heavily loaded (full of water) single seater or light two seater on
grass on ground that isn't rock hard. Imagine putting 20 kg of weights
on a rope over a pulley, with the rope attached to a glider. Would it
move it? I don't think so. Would it keep it going if it was already
moving? Maybe, just.

I've considered the idea of using fishing line with a 50# rating attached
to a bicycle. We've used a 14-year old to pull an (empty) 2-33
this way (with stronger rope). I'd like to try this "bicycle launch"
with a very light glider (maybe a Russia) to see what happens. I'd
really love to see a glider break ground pulled by a guy on a bicycle!
I'm only just half joking here...

I'm interested in the minimum case because this is a natural starting
point. I've done these calculations and it seemed that 15kg of thrust
gave a ground run less than 600m, and a climb rate of more than 200fpm
(might have been 500fpm, but I don't recall).

Good God. I don't know where you fly, but most glider pilots don't have
that sort of takoff space available to them!

All of the places I've launched have at least 3000ft of takeoff
space available, mainly because this is a pretty minimum runway length
for aerotow of the heavier ships on warmer days.

I, for one, do *not* want to be stooging off the end of the runway and
overflying the houses at best L/D speed with 200 fpm of climb in still
air!

Depends on the price. If it costs me an additional $5,000 a year
for anything over 200fpm, and my runway is 6000 feet long,
I'd be happy at 200 feet crossing the end of the runway with consistent
200fpm climb, then a downwind turn. Is this safe? That seems clear.
Is it cost effective? Well, what's the price for more climb?
Everybody *wants* 1,000,000 fpm climb. Nobody *wants* to pay for it.
I choose 30 feet over the end of the runway and 200ft per NM specifically
because I don't know anyone who would accept less performance. So this
is a natural starting point for calculations. A very light glider with
a very low stall speed with moderate performance on a runway
that is of fairly common US length. What is the thrust needed?

It doesn't mean everyone will *want* this combination, just that
nobody wants anything less. Ergo it is the starting point.

But I think all the calculations and even the Alisport Silent
implementation on a 150%-200% scale point to this as a fully viable
solution with a lighter glider and one engine and still 500fpm climb
from an acceptable ground roll. I know a (creative) Russia motorglider
owner/A&P who is almost disgusted enough with his unreliable
engine that he's almost ready to try out an AMT450. I've seen that
twinkle in his eye and know he's an avid experimenter. Hmmm...
winter is upon us and he may need somethin' to tinker with, even
if it just ends up as a turbo
--

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

In article 419b8d27$1@darkstar,
(Mark James Boyd) wrote:

In article ,
Bruce Hoult wrote:
In article 419af6e1$1@darkstar,
(Mark James Boyd) wrote:

Thrust is cheap. The amount of fuel used is to a first approximation
independent of the thrust of the engine (in fact to a certain point more
powerful engines result in less fuel used). But an engine that will
give you only 200 fpm of climb will take *forever* to get you to any
reasonable flying speed.

http://groups.google.com/groups?selm=an_595515430

I looked at your previous calculations, thanks for the reference to
the earlier post.

I wonder if you could redo the numbers for the limiting (minimum)
case for launching a human. Lets say a 50kg launch. Then also
do the numbers for a 150kg launch. I'd love to see what this looks like for
10kg and 20kg of thrust.

Well, if you scale the weight, thrust and drag by the same amount then
all the speeds and times are the same.


I also looked at some of the other numbers in the post,
and they seemed a little off.
20kg of drag until liftoff speed seems a bit of an overestimate.
The Sparrowhawk would seem to have at most 5kg of drag
while accelerating to best L/D, assuming no
wheel friction

I don't know how much is the right amount, but I was trying to guess for
a heavily loaded (full of water) single seater or light two seater on
grass on ground that isn't rock hard. Imagine putting 20 kg of weights
on a rope over a pulley, with the rope attached to a glider. Would it
move it? I don't think so. Would it keep it going if it was already
moving? Maybe, just.


Here were some of the calculations, which you did and I found enlightening:

thrust 50kg 100kg
Ground run 204m 76m
Dist at low level 945m 420m
climb angle 8deg 17deg
powered time 104s 45s
climb rate? 1000 fpm?

I'd be intereted to see what thrust is needed if the weight is reduced to
150kg, and the ground run is about 600m, using a Sparrowhawk polar.
Then I'd like to see how this changes if the ground run is allowed
to be 1200m. By ground run I'm assuming we mean accelerating
to something between Vs and Vy. I'd love to see what the climb angle
and climb rate then become.

I'm interested in the minimum case because this is a natural starting
point. I've done these calculations and it seemed that 15kg of thrust
gave a ground run less than 600m, and a climb rate of more than 200fpm
(might have been 500fpm, but I don't recall).

Good God. I don't know where you fly, but most glider pilots don't have
that sort of takoff space available to them!

I, for one, do *not* want to be stooging off the end of the runway and
overflying the houses at best L/D speed with 200 fpm of climb in still
air!

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

The business types seem to be saying that the US dollar has only begun to
fall and that it could fall much faster now that it is at record lows vs the
Euro.

That aside... what gliders are being produced in the US? I believe the
Peregrine is very close, there's the SparrowHawk. What else? And will anyone
Stateside be able to come up with a (different thread) moderate performance,
moderate price, self-launcher?

Wad.


"Mike Stringfellow" wrote in message
om...
The US dollar is now valued close to 0.75 Euro, down from its peak of
1.25 a couple of years ago. Analysts say it may go even lower, with
some projecting exchange rates of 0.7 (1.4 dollar to the Euro).

This has pretty much put the kibosh on my goals of buying a new
European sailplane. A model at, say, Euro 85,000 cost around $70,000
a couple of years ago, is now around $110,000 and may soon be at
$120,000.

Economic models would suggest a strong incentive for sailplane
manufacture in North America, but I wonder if the numbers of potential
sales would justify this.

Any thoughts?

Earlier, "Waduino" wrote:

...What else? And will anyone Stateside
be able to come up with a (different
thread) moderate performance,
moderate price, self-launcher?

We're working on it. Update number 100 shows some drawings that Brad
Hill did for fitting a sustainer-sized motor into the basic HP-24:

http://www.hpaircraft.com/hp-24/upda...ovember_04.htm

We're also looking at what it will take to fit a larger self-launch
sized motor in back there. We're working on it as fast as we can
afford to.

Thanks, and best regards to all

Bob K.
http://www.hpaircraft.com