Thus, I suggest that not much has changed ... assuming you can buy a set of plans from a previous purchaser who didn't build ... or perhaps a plans owner would agree to run off a copy at Kinkos or a commercial drafting firm. I would suggest running an ad in "Sailplane Builder" for plans. Based on the information I have, 473 sets of drawings were sold. So that is a large pool from which you may find a willing seller.
Please send in the serial number of your drawings if it is higher
than 300. I will post the highest number on this website (see below).
http://www.sailplanehomebuilders.com/ads-misc.htm ... online ads from recent issue (Try www.ebay.com)
Highest Serial Number: In three days, I have received a response to the "contest" for the highest serial number! I guote, "I was lucky enough to buy a set - maybe one of the last - from Maupin LTD in 3/2002. The serial # is 472. Sincerely, Z Mako, Thousand Oaks, Ca."
Application form to join SHA:
Also try the Australian Homebuilt Sailplane Association, they have several Carbon Dragons down there.
Or if you want to miss the fun of building, a Carbon Dragon is for
Once you have plans, I suggest that you contact current builders for questions regarding jigs, materials to use, problems with the drawings, etc. I ceased building due to being too heavy, so I am not a good resource for many questions.
There are several sources to learn about and see what other builders
are doing. At this site:
Scan down for a number of links to Carbon Dragon information. Note that the Manque and Cepheus are Carbon Dragon derivatives. Unfortunately, the Cepheus website is not responding.
Also think about joining SHA and buying the past issues on the Carbon
http://www.sailplanehomebuilders.com ... SHA site
http://www.sailplanehomebuilders.com/application.htm ... application form to join
http://www.sailplanehomebuilders.com/back_issues_sailplane_builder.htm ... listing of back issues
The closest glider to the Carbon Dragon that I have flown is the Schleicher Ka-8. I can circle in thermals where other gliders sink. The Carbon Dragon is yet again much superior in expoiting weak lift.
After giving Steve Osoba an autotow in his Carbon Dragon at Harris Hill, I was towed aloft in a Schweizer 2-33. I was about midway up in a nice thermal. Osoba joined me in the thermal at the bottom. He then made very wide circles in contrast to my coring the thermal. He passed me, topped out, then moved on to the next thermal. At the time he reached the next thermal, I was just reaching the top.
Regarding hanggliding experience.
I am impressed by hangglider pilots. My good friend, Steve Arndt is a hangglider pilot. Steve built a strong Carbon Dragon with a BRS. At a workshop in Elmira New York, USA, I gave a ride to Steve Arndt in an ASK-21. The towplane left us far away from the gaggle of sailplanes circling in a wonderful thermal. I found a weak thermal. Not doing too good at climbing, I turned the K-21 over to Steve. He did a wonderful job of gaining 1000 feet in the weak thermal due to his hanggliding expertise. It was fun to watch other gliders join us in the thermal circle once or twice and leave. At that time, Steve had barely earned his private glider certificate. With an extra 1000 feet, we able to move over to the very large, strong thermal over the field (Harris Hill near Elmira, New York, USA).
Several years ago, I subscribed to a glossy magazine (Hanggliding?). The first issue was the annual safety issue. One writer had quit after breaking his leg twice in one year. A lot of pilots were digging their noses in the dirt. I enjoyed the magazine but did not take up hanggliding and stuck to sailplanes (I'm now a towpilot also). I was very surprised to see that the fatality total per year (about 5 to 9 per year)was similar to sailplane experience as there must be many more people in hanggliding ... and, sailplane flying is generally conducted in a more controlled environment..
It is my understanding that the heaviest of the present builders are in the 175 to 185 pound range. You must change the wing spar caps from carbon tows to carbon rods. Other areas may have to be strengthened. Also, you must fly slower to avoid flutter per the Maupin Builders Manual.
Carbon Rods give you more predictable strength in compression as
the rods will be straight but tows (yarn) may be crooked. As you
may know, when pressing on a thin rod, it is very strong until it starts
to bow, then it collapses easily. Resources to check:
http://www.sailplanehomebuilders.com/projectofmonth.htm ... Marske on Carbon Rods
http://www.sailplanehomebuilders.com/arndt_news_posting.htm An 185 pound pilot and builder
I have deduced that Jim Maupin may have used 90,000 pounds per square inch for his strength calculations using carbon tows. Marske indicates that 47,000 would be more appropriate. Fortunately, carbon is so light that one can add enough to be safe without materially changing the weight of the wing. If you are mixing wood and carbon, I believe that Marske suggests using an additional 50% beyond the calculated requirement because carbon has a greater elasticity than wood. If your design is all carbon, he recommends double to avoid excessive deflection on long glider wings. Don't base any changes on this text. Get an experts opinion.
Becertain to test your wing under a static load before flying. Also, the FAA Glider Manual suggests some flutter tests.
Recovery Systems, Inc.
Note: Once the BRS installation has been completed, BRS owners are required (not merely requested) to send photographs depicting the installation directly to the factory. If photos are not returned the limited warranty will not be extended beyond the 30 day base period.
Note: with the feet moved forward, one must recalculate the weight and balance. A forward CG may require one to fly at a lower weight and/or install the horizontal stab at a different angle.
I will share with you some of the things I have learned in regard to
rigging. First, the prototype built by Maupin and now owned by Gary
Osoba had a medium sized Crescent wrench duct taped to the boom
just ahead of the vertical stabilizer. Too much pilot or incorrect
horizontal stabilizer setting????
Graham Betts, from Australia, had heavy nose down problems during initial flights with the stick back about three-quarters. Betts at 198 pounds, changed his seating position towards the rear which required extensions on the rudder pedals.
In an article by Clint Brooks, (Sailplane Builder, December 1997), Graham Betts hung the Carbon Dragon from a tree to check the rigging using a water level. His conclusions:
- The angle of attack for the wing should be 4 degrees
- The angle of attack for the horizontal stab should be 0 degrees
It turns out he had built the horiz stab parallel to the top of the boom rather that the center line of the boom (which is the water line). This error built-in a 2 degree incidence which was corrected with excellent results.
As to the dihedral: dihedral is provided by building the lower spar cap 0.25 inches longer than the top spar cap. The assembly pins are 11 and 5/64th inches apart at the bolt centers. From this, you can calculate how much a wing tip would be raised. I am thinking the center line of the wing tip would be raised nearly 6 inches above the wing root center. One builder mentioned to me he was going to build a flat wing which I discouraged (I wouldn't second guess Irv Culver).
Washout is automatically built into the wing through the excellent design by Irv Culver. He cleverly changed the design for each rib such that washout is built in (careful examination of the plans confirms this). Also, he design the ribs for the horiz stab to provide wash-in which is supposed to provide lighter forces on the control stick.
The builder manual suggests that flight tests should begin with the CG around 30% MAC.
In an old spreadsheet, I have the following entries for range of motion of the flaperons in both the aileron use or flaperon use (don't know the source, may have come from Kitplanes). Notice the significant differential built into the aileron motion. The flap motion will provide cruise settings, thermalling settings and landing settings.
For one thing, many hangglider pilots are not foot launching but are using wheels. Wheels allow one to make a smooth and soft landing without having to accurately predict when the stall will occur flaring to to a tip-toe landing.
In addition to the door for foot launching, the Carbon Dragon has
means of temporarily interconnecting the rudder and aileron for the launch.
But it seems that many builders are building without including doors for
foot launching. Foot launching isn't practical; plus, the pilot pod
will provide better protection and integrity if the doors are omitted.
To foot launch you need about 12 knots wind to hold the tail up and relieve
some of the weight off your shoulders. I worry that one may need
to cross their controls immediately after foot launch which an interlink
would not permit. Once one "retracts" their gear and gets their feet
on the foot pedals, a pin is pulled via a cord which removes the interlock
for the rest of the flight; thus, one won't have interlock for landing
on their feet ... but I suspect all landings will be wheel landings.
While I have not seen a foot launch, I have driven the tow vehicle while launching the prototype Carbon Dragon (Gary Osoba the pilot, Harris Hill the airport) and found that Gary could fly all day on a 200 foot tow! In his home area, he gets off tow at 300 feet if he finds lift ... otherwise he waits to 600 feet to release.
Gary Osoba reports having made a number of foot launches in 12 mph winds, and at least one launch in winds as light as 8 mph. It is usually landed on a wheel.
I haven't been releasing the remainder of the spreadsheet. If there is interest, I am will to redo the spreadsheet by removing engineering information (which is not trustworthy) while retaining the various indices and cross-references.
Brian Davis, Edmonton, Canada, created a Word version of the builders manual. My copy was lost in a hard crash. If anyone knows how to contact Brian, please let me know. I have one hard copy which could be re-scanned and organized back into a Word version, but that is a lengthy process. It was handy for electronic-searches to locate a particular step in the building process.
Some builders are considering adding an engine to the Carbon Dragon ... even two! The Carbon Dragon consists of a very light structure with a low maximum gross load. Any such addition will need careful analysis by an experience aircraft designer. You are on your own in this regard. I take issue with the narrower pod ... proper aerodynmic design for minimum drag calls for constantly increasing width or decreasing width (like an airfoil).
Here are some comments by one builder regarding twin engines:
- The engines are very light but they will be both aft of the CG thus allowing a much more reclined pilot with feet further forward. I think I will be able to reduce the overall height of the pod by at least three inches. I'm also shooting for a narrower pod and a retractable gear. All these things should impact both sink rate and glide.
- I just finished making a mock-up like yours. I like the way it sits and I think I may be able to significantly reduce the frontal area (profile) drag by putting the pilot in a more reclined position. This also happens to be much more comfortable and possible if you throw out the foot launch requirement. I'm going to sit in it for a few days and make some adjustments. I think the longeron realignment will accommodate the engine retraction. Right now I have the sight lines the way I want them and I'm real excited about the possibilities.
-Imagine this, Steve. You fill the fuel tank with enough fuel to attain 2000' or first thermal. This should be about 1/2 pint of regular gas! Wheel the glider out of the hanger, fire it up and launch from the airstrip in the back yard. A gentle bank while climbing out over the pond to center on south side of Diamond Hill farm(my neighbors). You find the first sign of lift at 600' so you throttle back, center on the lift, and climb to 4500'. As you climb past 3000', you idle the engines to cool down, then shut them down after cooling is complete as you continue to climb through 4000'. Once cooled, you retract the engines, climb to cloud base and go on course. If you land out at an airport, another 1/2 pint of regular gas and you're back at it again. I bet I could fly 20 days per month with a rig like this.
Or try Ultralight_Soaring discussion group:
Post message: Ultralight_Soaring@yahoogroups.com
List owner: Ultralight_Soaringemail@example.com
This group is for the discussion of all aspects of ultralight sailplanes/gliders.
With the development of sailplanes such as the AC-4, Sparrowhawk, Monarch, Esprit, Piuma, TST Alpin, Carbon Dragon, Windrose, Cepheus, Tempest, Windancer, and Silent there is a new and growing interest in a cost-effective and enjoyable area of silent flight.
Also don't forget the primary newsgroup for soaring. Either
subscribe to the newsgroup or access through google.com by clicking on:
This group is concerned primarily with the high performance glass gliders and contest activity. But still a good source. This group is responsive to requests for places to glide and questions about techniques and equipment.
Write me if you have more questions. If you find plans and start to build ... write!
Click here to Contact Steve (Be sure to delete the word "REMOVE" from the email address before sending.)
S. Steve Adkins ... Minnesota
http://www.isd.net/sadkins/steve_webmaster.htm ... bio - Glider Pilot, Tow Pilot
http://www.sailplanehomebuilders.com ... Webmaster SHA
http://www.isd.net/sadkins/ ... Carbon Dragon Technical Website