4-seater

Bill Daniels wrote:

With retractable gear, flaps and winglets that would suggest ~45:1 L/D and a
min sink of about .55 M/Sec. If flown with a cockpit load of 300 Kg the min
sink would be less.

I bet you'd sell a lot more at 1/4 the price with fixed gear,
no flaps, 30:1 glide and higher wing loading.

In my experience, non-pilots are happier with glider rides,
and pilots want soaring rides. The 2-32 rides that succeed seem
to be in places with no lift or ridge lift, and are high tows
of short duration with little turbulence or "excitement."

The best part of these flights for the pax seem to be the great
visibility, smooth ride, and quiet sightseeing, for a reasonable price.
This isn't quite in line with the specs you suggest.

This is easily within the state-of-the-art.
At what price? $200,000 each? $100,000 each? $50,000 each?
The venerable 2-32s sell briskly at $40-$50k.

Every commercial ride operator
in the world would want one and so would some wealthy individuals and clubs.
Say, maybe a market for 300+ gliders?

At $50k yes, at $100k maybe, at $200k no.
--

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

In article ,
Ralph Jones wrote:
On Thu, 25 Nov 2004 14:54:52 GMT, "Bill Daniels"
wrote:

Just some 'back of the envelope' calculations for a '2+2' seating glider.
(No controls in the back seats.)

Interesting...how did the ride operators who bought up the 2-32s do?
Haven't heard about them in years.



--

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

"Andreas Maurer" wrote in message
...
On Thu, 25 Nov 2004 14:54:52 GMT, "Bill Daniels"
wrote:

Start with the need for 600 Kg cockpit payload.

600?
Aren't 400 more appropriate?

Nope, it needs 600 Kg to allow for three 'super sized' customers.


Assume that the best
composite materials and construction techniques are used. That would
suggest a GW of 1000 Kg. Further assume a 25 meter span and 30 Kg/sq. M
wing loading. That yields a wing area of 33.3 Sq. Meters and an aspect
ratio of 18.75. That gives good spar depth to carry the weight.

With retractable gear, flaps and winglets that would suggest ~45:1 L/D
and a
min sink of about .55 M/Sec. If flown with a cockpit load of 300 Kg the
min
sink would be less.

L/D of 45:1 with such a low aspect ratio? Hardly...

Well, AR isn't everything. Sheer span contributes a lot to L/D. To get a
good ratio between GW and payload, the spar depth has to be larger so the
chord has to be larger. So, maybe 40:1.


What are you going to use to tow this monster? A P-51 or an F4U?

What do you tow a fully ballasted ASH-25 with?

Bill Daniels

"Ralph Jones" wrote in message
...
On Thu, 25 Nov 2004 14:54:52 GMT, "Bill Daniels"
wrote:

Just some 'back of the envelope' calculations for a '2+2' seating glider.
(No controls in the back seats.)

Interesting...how did the ride operators who bought up the 2-32s do?
Haven't heard about them in years.

rj

They're still working day in, day out.

Bill Daniels

On Thu, 25 Nov 2004 14:54:52 UTC, "Bill Daniels"
wrote:

: Every commercial ride operator
: in the world would want one and so would some wealthy individuals and clubs.

How many commercial ride operators are there in the world? I'll take a
guess at "none" for Europe.

Ian

--

On Thu, 25 Nov 2004 18:41:43 UTC, "Bill Daniels"
wrote:

: What do you tow a fully ballasted ASH-25 with?

Odd gliding fact number 1: The ASH-25 uses a brown weak link on the
winch, not, as most people expect, the stronger black one.

Odd gliding fact number 2: ASH-25 pilots often get very, very cross if
you try to winch them on a brown weak link and not a black one

Ian

--

Earlier, "Bill Daniels" wrote:

Start with the need for 600 Kg cockpit payload...

A few random thoughts on this concept, which seems to pop up every few
years:

That averages 150 kg per seat, which is about 330 lbs. I'd think that
300 kg would be a more realistic maximum cockpit load. That would
average 75 kg (165 lbs) per seat, which I think would be more than
adequate for a typical group of 4 people. Remember that many flights
would be families that include relatively light children.

Since the intent of the aircraft would be commercial operation, I'd
think that the aircraft must be engineered and validated to the
certification standards of at least JAR 22/FAR 23. Amortizing the
development and validation and certification costs over the relatively
few aircraft you could expect to sell would make each very expensive.

Also, I think that it would be somewhat difficult to arrange the seats
and the wings and the fuselage so that everybody has a good view and
feels like they've had a glider ride. Adopting the sort of low-wing or
high-wing layout you see on a Cezzna or Piper Cherokee could be made
to work, but I think it impairs the visibility and makes it too much
like just another automobile ride. Clustering all four seats ahead of
the wing as if making a wide-body training glider would require either
lots of forward wing sweep (which is hard on laminar flow) or a very
long aft fuselage. I suppose you could put two seats ahead of the wing
and two behind, but I think that separating the passengers detracts
from the experience.

What suggests itself to me is sort of a parasol arrangement with the
wing on a short pylon over the cabin. That plus some forward sweep and
generous transparency area should give the sort of view and exposure
that riders would appreciate.

Thanks, and best regards to all

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

I only reported what DG had said on the return email .
The ASH25 was only projected to be a product run
of 25-30 gliders and they still proceeded.
A dedicated ride machine at a reasonable price was
the concept tossed around ,that is why a tube and fabric
fuse was touted attached to a production set of wings
that are able to carry the load, the DG 500/505 being used
for the Stemme and others was a natural suggestion.
I don't think the market is huge but I can think of 3 tourist spots
here in NZ that would make use of such an aircraft.
A self launching version would be an ideal but I have often
looked at tourist spots where I could do this with the idea of
an operation but back of the envelope calcs show ride price
would be too high.
Motor durability and lifespan is a big issue for a commercial
operation
The only economic way would be to winch launch but with its
problems of more staff plus land required plus difficulty with
other aviation operators re the dropping cables.

gary

"Bill Daniels" wrote in message
news:%mmpd.459727$D%.420868@attbi_s51...
Just some 'back of the envelope' calculations for a '2+2' seating glider.
(No controls in the back seats.)

Start with the need for 600 Kg cockpit payload. Assume that the best
composite materials and construction techniques are used. That would
suggest a GW of 1000 Kg. Further assume a 25 meter span and 30 Kg/sq. M
wing loading. That yields a wing area of 33.3 Sq. Meters and an aspect
ratio of 18.75. That gives good spar depth to carry the weight.

With retractable gear, flaps and winglets that would suggest ~45:1 L/D and
a
min sink of about .55 M/Sec. If flown with a cockpit load of 300 Kg the
min
sink would be less.

This is easily within the state-of-the-art. Every commercial ride
operator
in the world would want one and so would some wealthy individuals and
clubs.
Say, maybe a market for 300+ gliders?

Bill Daniels

"goneill" wrote in message
...
The idea of a joyride machine with multiple places was discussed
at our club a year back and some design ideas tossed around ,
the concensus was something like the DG505 wings attached to a
light tube and fabric fuse with either a triangle seat pattern or a
4 seater star pattern.
This concept was emailed to the owner of DG and the answer came back
that DG had discussed this very idea for a limited production run
but the engineering loads on the fuselage wing junction were very
high and would take a lot of redesigning to get it to work and secondly
the DG505 wingset were simply not strong enough to take those loads.
A Nimbus4D or an ASH25 wingset maybe?
gary
"Bill Daniels" wrote in message
news:wy0pd.141192$HA.53129@attbi_s01...
I recall a recent discussion about the desirability of a 4-place glider
for
the ride business. The subject came up after stuffing two not so
smallish
people into the back seat of a 2-32 and sending them on a ride over the
Rockies.

The majority view was that the probability of one of the three paying
passengers getting airsick and ruining it for the other two was just
too
high. I'm not too sure about that. A 4-place, 25 meter span ride
glider
might be a money maker.

Bill Daniels

"Bert Willing" wrote in
message ...
Urban legend ?

--
Bert Willing

ASW20 "TW"


"cernauta" a écrit dans le message
de
news: ...
(Nyal Williams) wrote:

A friend keeps insisting that a 4-place glider was built at one
time.
Can anyone verify, identify, or point to a picture?

Somebody built a 4 place glider with twin fuselages. It was based on
Blanik parts. A center section, two outside wings, two fuselages and
tails.
I believe it was built by a German Blanik repair station.

Aldo Cernezzi

On Thu, 25 Nov 2004 18:41:43 GMT, "Bill Daniels"
wrote:

Nope, it needs 600 Kg to allow for three 'super sized' customers.

These are really super sized customers...
170 kg per customer... wow. hard to find people that heavy here in
Germany I have to admit.


What are you going to use to tow this monster? A P-51 or an F4U?

What do you tow a fully ballasted ASH-25 with?

I somehow have the impression that your 400 kg dry weight of the
glider are about factor 2 too small, considering the fact that my
club's DG-505 weighs already 426 kg.


Bye
Andreas

Andreas Maurer wrote in message . ..
On Thu, 25 Nov 2004 14:54:52 GMT, "Bill Daniels"
wrote:

Start with the need for 600 Kg cockpit payload.

600?
Aren't 400 more appropriate?

Assume that the best
composite materials and construction techniques are used. That would
suggest a GW of 1000 Kg. Further assume a 25 meter span and 30 Kg/sq. M
wing loading. That yields a wing area of 33.3 Sq. Meters and an aspect
ratio of 18.75. That gives good spar depth to carry the weight.

With retractable gear, flaps and winglets that would suggest ~45:1 L/D and a
min sink of about .55 M/Sec. If flown with a cockpit load of 300 Kg the min
sink would be less.

L/D of 45:1 with such a low aspect ratio? Hardly...

This is easily within the state-of-the-art. Every commercial ride operator
in the world would want one and so would some wealthy individuals and clubs.
Say, maybe a market for 300+ gliders?



Cool idea. I like your 300+ number.
What are you going to use to tow this monster? A P-51 or an F4U?


I have another idea.
Take a proven self-launching glider with sufficient L/D (25 should be
sufficient for a glide) that already has a type-certificate and proven
to be able to perform a halfways safe landing with engine shut down
(Boeing 767, Airbus A 310, Airbus A 330, Space Shuttle), equip it with
a final glide computer (the Shuttle already has one), go to an
airfield with a runway of sufficient length, and you are able to give
several hundred passengers a glider ride. Not to forget the
stewardesses and the presence of a toilet.






Bye
Andreas

Possibly Bill meant 600 Lbs? for the cockpit. some additional for
usefull load...

There are some fuselages around that would lend themselves for your
project.

I would use the Stemme concept first, make the cab a little longer,
stick the new Diesel in front, right behind Stemme's Prop, they have a
23 m wing already, beef it up with the secondary spars, Retract
landing gear is there.

Diamond has 4 place Fuselages, several, even the new jet. is that a 6
seater? make everything lighter, leave all the junk out for high
altitude flight pressure,... and stick a great wing on it. Maybe use
the jet. There ARE possibilities.