R/C Cross Country Soaring

[steelhead]

Let's discuss all general aspects of R/C CROSS COUNTRY SOARING here.


The main website for the XC SOARING COMMUNITY is www.xcsoaring.com


R/C CROSS COUNTRY SOARING combines RC THERMAL DURATION FLYING with FULL SCALE RC CROSS COUNTRY FLYING and mixes it all up with a team on the ground in a chase vehicle. For a good overall description of a contest and the duties of the team members, I wrote an article for RCSOARINGDIGEST.COM covering the 2006 contest starting on page 32 here-

http://www.rcsoaringdigest.com/pdfs/RCSD-2006/RCSD-2006-08.pdf


Many of us hope this thread will increase interest and answer the many questions people have about XC Soaring and the gear needed to participate.



To subscribe to this thread to make sure you are notified when someone posts a reply, either make a post yourself to this thread, or click on "THREAD TOOLS" above and to the right and then follow the instructions.



Dean

[Lance Prior]

Why has the RnR SBXC dominated cross country RC soaring for so long?

I see some planes around that have about the same span but it seams that RnR has the secret formula or something.

[jtlsf5]

Why has the RnR SBXC dominated cross country RC soaring for so long? I see some planes around that have about the same span but it seams that RnR has the secret formula or something.

In one word, availability. RnR has made hollow molded planes for around 20 years. I think the SBXC is their most enduring design because XC doesn't go through the continual reinvention that TD/F3J ships seem to experience. Having molds for all the parts makes the production of kits commercially possible, hence the availability of a well-developed, successful design.

The other successful ships flown over the last 20 or so years that XC has been popular were mostly one-off creations of their pilots, built to the task. Usually the designer/builder made a fuse mold. That was generally all that you would start with to build an XC ship, everything else was up to the builder.

There are some big European planes that seem like they would be good for XC, but there is more than size that has to be taken into account for a good XC ship. Visibility at altitude is a key factor, along with being able to land almost anywhere without damage, and the ability to save a flight by taking a low small thermal. When these are factored in, many planes that at first look usable aren't a good choice.

JT

[Lance Prior]

Land almost anywhere without damage?

How is the SBXC designed to accomplish that?

[FrogChief]

Land almost anywhere without damage?

How is the SBXC designed to accomplish that?

Mass and fuse/wing skin thickness.

[ShredAir]

Why has the RnR SBXC dominated cross country RC soaring for so long?

I see some planes around that have about the same span but it seams that RnR has the secret formula or something.
The 5kg (11lbs) FAI rule applies to XC soaring, and the SBXC and MXC are designed to meet that weight including vario, GPS, etc. There are many higher-performance large gliders available, but many exceed 5 kg flying weight.
Also, a good XC glider sacrifices some performance for visibility at altitude, which is why XC gliders have a relatively deep chord and hence lower aspect ratio than higher-performance gliders.
They're relatively easy to land because of the relatively low wing loading, and good XC pilots find suitable LZs... : )

Dieter Mahlein, ShredAir

[jtlsf5]

Land almost anywhere without damage?

How is the SBXC designed to accomplish that?

Multi-function control with flaps. An experienced pilot can land an 11 lb SBXC with remarkable precision. Don't get the idea that they are bullet proof, but try to land a 4M Euro ship at something below Mach 2 sometime.

JT

[Lance Prior]

Have any of you guys flown the new MXC?

[jtlsf5]

Have any of you guys flown the new MXC?

Yes. Think big Millennium. More chord than an SBXC so a bit easier to see at altitude. I find it a bit loggy close to the ground, but I have only flown a friends very early example of the MXC. The ship has evolved a bit through the first 5-10 that are in use. Of the 10 teams that flew California Valley, I believe 3 were flying the MXC, three flew home brews, the rest SBXCs.

JT

[bigjohn]

I have a 5m plane I bought a few years ago. Actually, WS is 15 or 17 depending on the tips. it's called a Condor. Seller said it was one of a kind.

http://www.rcgroups.com/forums/attachment.php?attachmentid=512028

Still don't have a good way to launch it. Nearest winch club is about an hour away. Does anyone have any tips about auto-towing one of these things?

[jtlsf5]

I have a 5m plane I bought a few years ago. Actually, WS is 15 or 17 depending on the tips. it's called a Condor. Seller said it was one of a kind.

http://www.rcgroups.com/forums/attachment.php?attachmentid=512028

Still don't have a good way to launch it. Nearest winch club is about an hour away. Does anyone have any tips about auto-towing one of these things?


We have successfully car launched while participating in the Soaring Safari. The appratus was a glorified hi-start (geez, I hate saying that anywhere on RCG). We worked out the vehicle speed and tested the gizmo at our club field. Launches were a bit higher than normal winch launch, based on Alti-2 altitude data.

25' of ~1/2" ID heavy wall tubing tied into a loop (use a Carrick Bend, a sailing knot) to form the loop so it can't pull out under tension, with a metal ring strung on the rubber before looping. 500' of winch line and a chute onto the ring. The rubber loop is mainly a shock absorber, though it will store a little energy for a zoom. We don't push the rubber too hard.

We lash the rubber around a trailer hitch, then the truck drives out until the line is deployed. Helper and driver are in communication, cell phones work fine, or FRS radios. On command the driver accelerates to 21-23 mph (no more) and helper throws the plane. At the top of the launch, helper tells driver to stop, pilot uses the stored energy in the line/rubber for a reasonable zoom (for an XC plane). Reel in the line and hit the road.

JT

[Thermaler]

Check this one out

http://www.rcgroups.com/forums/showthread.php?t=873174

Joe

[dhauch]

how do you guys normally launch the SBXC's ?

dh

[rdwoebke]

how do you guys normally launch the SBXC's ?


I have seen some guys hand launch them (sometimes with two hands) and I have assisted Don Richmond ROG his SBXC.

Ryan

[rocketman47]

how do you guys normally launch the SBXC's ?

dhhttp://youtube.com/watch?v=thpfXz_h92Q

[ShredAir]

how do you guys normally launch the SBXC's ?

dh
see http://xcsoaring.com/contests/mccc/2006/photo2.htm : )

Dieter Mahlein, ShredAir

[bigjohn]

We lash the rubber around a trailer hitch, then the truck drives out until the line is deployed. Helper and driver are in communication, cell phones work fine, or FRS radios. On command the driver accelerates to 21-23 mph (no more) and helper throws the plane. At the top of the launch, helper tells driver to stop, pilot uses the stored energy in the line/rubber for a reasonable zoom (for an XC plane). Reel in the line and hit the road.

JT

OK, that's pretty much the setup I was thinking. I was wondering what the target tow speed would be. So, your numbers are helpful. Is that basically a hard acceleration right to 20 mph?

[jtlsf5]

OK, that's pretty much the setup I was thinking. I was wondering what the target tow speed would be. So, your numbers are helpful. Is that basically a hard acceleration right to 20 mph?

I wouldn't suggest laying rubber, but definately up to speed ASAP. We picked the speed by driving alongside a streamer-marked ground line during a few tows. Turned out to be perfect for the car tow.

JT

[bigjohn]

Any idea who much linear space you need to do this. Our flying field has a straight run of about 1300 feet. Wondering if it would fit in there.

[jtlsf5]

Any idea who much linear space you need to do this. Our flying field has a straight run of about 1300 feet. Wondering if it would fit in there.

Should be enough. We have winch runs north and south about 700' each side of center. We did trials within this space, and didn't have to start very far from center. I'd be surprised if the whole launch lasts more than 10 seconds, more likely 6-8 seconds on tow.

A quick calculation: 22 mph = 32.2 ft/sec. Assuming vehicle instantly hits 22 mph and stops instantly, you need 320 ft of run for a 10 second launch. 500' line + 320' = 820'. You have plenty of room.

JT

[bigjohn]

About competitve CC rules: Is there any limit to gadgetry? Seems telemetry is OK, does that include video? Seems one way to recover a plane you lost sight of would be to center your ground location in a cockpit view camera and fly back.

Also, what about stabilizing systems? Seems an FMA style auto pilot would keep things pretty calm at altitude. within the rules?

How about visibility enhancement? small strobe system?

[jtlsf5]

About competitve CC rules: Is there any limit to gadgetry? Seems telemetry is OK, does that include video? Seems one way to recover a plane you lost sight of would be to center your ground location in a cockpit view camera and fly back.

Also, what about stabilizing systems? Seems an FMA style auto pilot would keep things pretty calm at altitude. within the rules?

How about visibility enhancement? small strobe system?


Competitive XC allows telemetry, and no reason why video wouldn't be allowable (but it hasn't been done, to my knoweldge). Might not be useful because once you lose visual, you might be out of range of the small equipment that would fit in a plane (and still stay under 11 lb all up weight to stay legal).

We already use laser tape to help visibility, different color schemes, etc. A strobe would be no issue, but probably not much help against a blue or hazy sky at serious altitude (we're talking 3500'+ agl). It would be great for nocturnal XC, but not many thermals at night. Best place would be fuse bottom and wingtips, but fuse bottom would be at risk during every landing.

My personal opinion on stabilizers is no, but thats my opinion. XC is still an RC pursuit, and the idea is pilot controls airplane. If pilot can't see plane, pilot can't control it any more. Part of the challenge is knowing and staying within your limits, and completing the task. As I said, my opinion. Others may differ.

JT

[dhauch]

see http://xcsoaring.com/contests/mccc/2006/photo2.htm : )

Dieter Mahlein, ShredAir

thx Dieter.

didn't think a standard winch would launch one of these monsters.
does it take huge throw ?

curious if my self launching trailer would launch one of these.
i can set it to release any any tension i want, but there's no throw getting it moving.

i'm guessing it wouldn't do it, unless it doesn't take that much to launch these.

dh

[ShredAir]

Dave, I wouldn't yank them off some raised platform (if that's what you're saying, I don't know), but people ROG them no problem.
I don't know winches from Adam, but I consider the launch heights I'm witnessing in Montague as mediocre. I'm always amazed how well the pilots are able to connect to thermals after launch.

Dieter Mahlein, ShredAir

[Lance Prior]

What about a dolly with big wheels on it so it rolls on the grass?

I think I saw pictures of one around here somewhere not to long ago.

[danstrider]

We've aero-towed an SBXC using a small dolly, don't see a reason it couldn't be done off a winch the same way... two videos for you, same day:

Aerotow with the dolly:
http://www.rcgroups.com/forums/showatt.php?attachmentid=1898670

Winch launch:
http://www.rcgroups.com/forums/showatt.php?attachmentid=1900154

Dan

[Lance Prior]

Are there any guys that do cross country with big scale sailplanes or is the wing loading to high on them too?

[ShredAir]

Are there any guys that do cross country with big scale sailplanes or is the wing loading to high on them too?

Yes, it's been done and it certainly can be done. The wing-loading is not "too high." Most large scale gliders weigh over 5kg, but that's no big deal, it's just not an FAI contest.

Dieter Mahlein, ShredAir

[Lance Prior]

What is the story behind the FAI weight limit, why is it 5kg?

[DEAN GRADWELL]

ROG is the easiest and safest way to launch the SBXC or MXC if you are flying from asphalt or a somewhat even grass strip. Dollies are not needed.

Modern scale gliders if 1/4 or larger should out perform a legal XC glider. Weight and aspect ratio will do them in for a glide angle. However those skinny wings are hard to see at altitude.

Scale glider pilots are content to watch their glider fly around until they need another tow. Nothing wrong with that, after all they have built a perfect specimen of the real thing.

My choice would be to have a less than perfect scale glider that I wouldn't be afraid of an unknown landout, just like the real thing.

There will be another Montague Scale Cross Country Event.

Who knows when 5k came about, it's the way it is.

Regards Dean

[steelhead]

Dieter made a cart for E-version-
Dieter hat ein E-modell frachtwagen gemacht-

Post #106

http://www.rcgroups.com/forums/showthread.php?t=215645&page=8


Very Nice!
Sehr schone!

Dean

[jtlsf5]

Dieter wasn't the only one. I did an electrified SBXC for a gentleman in Alabama. It too was cart launched, and worked well. This project was published in S&E Modeler.

JT

[tkallev]

The FAI set R/C Saiplane weight limits at 5 Kg back before my time (1966-67). I did a lot of XC with Jack Hiner in the SOAR club, and he built to the 11.023 lb limit and always wished to go heavier. It would take a lot to change FAI limits, but it might be done. Lots of lobbying, but FAI has a lot of inertia like any other staid, well-established firm. You would have to prove the need for the increased weight limit and/or establish a different weight limit based on the class ...

A few years ago, LSF tried a closed-course aerotow Scale XC event at the Nats. It was a real hoot, and those scalies at 4, 5, 6+ meters can really haul. We didn't run the goal and return course used for the winch XC event because much of that course is extremely unfriendly to wings wider than the road you drive on.

In order to do the scale aerotow, I worked with AMA to classify these planes as "Giant Scale" that allowed the weight limit to increase to 50 pounds. There were some people who wanted to add weight to their SBXCs and call them SB-10's ... we required a 3 view for scale fidelity. There were some talking about building special aerotow non-scale planes for the event, but that wasn't the spirit or intent of the event, we just wanted to go "down the road" with the scale planes.

Skip Miller towed behind Johnny Berlin's Pegasus to 3,000 feet under a high, gray overcast and did a bunch of laps without ever working lift, that HKM Nimbus 4 (6.6 meters) is a real XC queen. Skip's always zipping around the XC course at the JR Aerotow.

tk

[bobthenuke]

This may sound like a dumb question, but is anyone today using woodie ships for cross country, i.e., Sagitta XC or anything along those lines?

-bob

[jtlsf5]

Not in recent west coast competition. The problem with wooden ships is that they aren't strong enough to withstand the sometimes violent maneuvers that occur at altitute. This could be from thermal activity or from losing sight of the plane momentarily and pulling out of an unintended dive. Either way, a failure was usually catastrophic.

There were only a couple of somewhat succesful wooden XC planes that I know of. The Astro Jeff and Sagitta XC. Neither one would stand XC racing speeds for long without some kind of failure, but could be flown in pure distance events if careful about watching speeds. The Jeff had a glass fuse, the Sagitta all wood, though the fuse would generally be glassed if to be used in XC. The weak point of the Sagitta was its stab.

JT

[Lance Prior]

Does any one in your group race full scale sailplanes?

How does full scale racing compare to RC cross country?

[jtlsf5]

Dean Gradwell owns full size sailplanes, and is the host/originator of the Montague XC event (which is next weekend, BTW). The RC XC event is modeled after full scale, though with differences. Many other XC flyers do or have flown full scale.

In full scale, turnpoints are photographed from the plane, or GPS is used to confirm. Neither is practical for RC, though some pilots do have GPS capability (but it isn't mandatory due to cost). For RC, the pilot and plane cross or round the turnpoint, verified by the honor system. Other than that its not much different. A course is laid out, you launch and thermal to altitude, then enter the course.

In a distance event, time is immaterial, you take as long as you need/like. Pilots will tend to maximize thermals before moving on down course.

In a speed event, there will be a proscribed course (or an open course), and the pilot will generally not max a thermal on course, he's just burning time. This is more of a decision making event, when to stay and when to go.

JT

[bobthenuke]

Not in recent west coast competition. The problem with wooden ships is that they aren't strong enough to withstand the sometimes violent maneuvers that occur at altitute. This could be from thermal activity or from losing sight of the plane momentarily and pulling out of an unintended dive. Either way, a failure was usually catastrophic.

There were only a couple of somewhat succesful wooden XC planes that I know of. The Astro Jeff and Sagitta XC. Neither one would stand XC racing speeds for long without some kind of failure, but could be flown in pure distance events if careful about watching speeds. The Jeff had a glass fuse, the Sagitta all wood, though the fuse would generally be glassed if to be used in XC. The weak point of the Sagitta was its stab.

JT


Thank you, JT

I ask because I have a Sagitta XC NIB and would find it tough to justify the purchase of a new machine at this time. I have to imagine that systematic addressing of the stress points by means of some modern materials and techniques may make it feasible to get into this gig using what I have. If you believe this would be a waste of time and materials please let me know; it won't break my heart. :)

-bob

[ShredAir]

Regarding how-to of an RC cross country event, see also http://xcsoaring.com/organize.html

Dieter Mahlein, ShredAir

EDIT: Bob, you just posted... In my opinion, it's always worthwhile to try "this gig." Check out the link above (and the rest of this XC site) for an idea on what to expect. Maybe even make the trek to Montague next weekend and see for yourself...

[Lance Prior]

GPS is used to confirm. Neither is practical for RC, though some pilots do have GPS capability (but it isn't mandatory due to cost).
What do you think of the new low cost GPS loger system that has become available?

Do you think that with such devices available at low cost that using them will become popular for verifying RC XC races?

[Lance Prior]

http://www.magtechinc.net/purchase.htm

[jtlsf5]

What do you think of the new low cost GPS loger system that has become available?

Do you think that with such devices available at low cost that using them will become popular for verifying RC XC races?


No. Technology doesn't need to replace personal integrity in XC. This form of competition is not the same as most TD contests, where winning seems more important than participating. XC is still a participatory, gentleman's facet of the hobby.

That said, I think there is a place for such GPS devices to help pilots analyze and learn from their recorded performance. I already use an altitude logger, know where I have flown, and can correlate the two. I have seen the output from GPS loggers and it is interesting, but I'm not sure it would have caused me to do anything I do in real time much differently.

JT

[rdwoebke]

I ask because I have a Sagitta XC NIB and would find it tough to justify the purchase of a new machine at this time.

Bob,

I have been working on a Sagitta XC for like 5 years now. I'm far from an expert on XC, but I'd suggest fully sheeting the center section (I'm told that one problem with the Sagitta XC was flutter) and probably wrapping the spar. That is what I did on my wings.

I'm also told either use the glass Sagitta XC fuselage or extend the wooden one. And then perhaps beef up or enlarge the horizontal stab.

I'd say with a Sagitta, you might be at a disadvantage in a race. But like Jim says, the participation is just as fun as the winning. For me, I'm not really interested in the racing, just interested in doing the XC Nats some day, working on the LSF tasks, etc.

I did my 2K goal and return with my Paragon.

Ryan

[bobthenuke]

Ryan,

Thanks for that info. Actually, I don't care much about being at a disadvantage only because I involve myself in some competitions only to better myself as a flier, not to win anything.

-bob

[Robglover]

I managed my level 4 goal and return with a Syneryg 91. It was the fastest XC trip I ever took. It would outrun the car we were in. Not the best plane for the task, but really fast.

[zenoid]

some kind of hijacking to drive you to my website and an experimantation I'am having : it's a real time telemetry system to ppc, glider oriented. Goal is to make a flight computer like for real birds. Website is only in french for now, sorry, but the little movie show you what it can do on a PDA. Still in alpha. Was using 433Mhz but plan to also use 2.4GHz.
Movie show you a flight recorded in the FAI igc standard that you can replay.
I'll appreciate any comments, thx

link to the movie (http://glidebywire.free.fr/index.php?view=article&catid=10%3Awm5&id=6%3Aintro-gbw-wm5&option=com_content&Itemid=6)

[big jer]

Car tow is a fine way to launch a X/C model. Add 50' of line between the rubber tube and the car. At some point, the line or the rubber is going to break. If the rubber hits you it will break the skin and hurt like hell.

Astro Jeff's and Sagitta's don't go. Not high enough wing loading. Buy or build a glass wing.

I've got a pod mold for a pod and Boom fuse. Never pulled a pod from it. I think it is 7" high, 4" wide and aabout 36" long. Takes a 1.75" boom i think.

You can probably see the side of a white fuse longer than you can see the bottom of a Stab.

Bravo Juliet

[jtlsf5]

Car tow is a fine way to launch a X/C model. Add 50' of line between the rubber tube and the car. At some point, the line or the rubber is going to break. If the rubber hits you it will break the skin and hurt like hell.

Astro Jeff's and Sagitta's don't go. Not high enough wing loading. Buy or build a glass wing.

I've got a pod mold for a pod and Boom fuse. Never pulled a pod from it. I think it is 7" high, 4" wide and aabout 36" long. Takes a 1.75" boom i think.

You can probably see the side of a white fuse longer than you can see the bottom of a Stab.

Bravo Juliet


Not quite accurate.

Added line between the car and rubber loop just makes things more complex. I highly doubt the rubber (connected to vehicle) as we use it could/would travel 500+' with the type of normal tension used for a car tow. Please review post 11 in this thread for a description of what we use now.

Sagitta XC and Astro Jeff will go up just fine to high altitude, its been done countless times by many pilots over the last 20+ years. Wing loading is also not an issue, they can be ballasted to FAI max, and wing area can be reduced to increase loading during construction if desired. The problem is that they just aren't robust enough to stand the stresses generated by high altitude turbulence, violent pullouts from unintended dives, or serious, sustained XC racing speeds. The stock wing joiner system and wooden tail feathers need significant strengthening to survive.

Lots of fuse molds are floating around. Most are suitable to mate a wing and tail feathers that will produce a workable XC. Whats the benefit of an added joint (between pod and boom), and why do you think boom mounted tailfeathers would be stiffer (more torque resistant) than a conventional/single piece fuselage?

JT

[big jer]

I suppose that wasn/t blood gushing from my arm when I was struck by broken Hi-start. Ask Bill Nibley or Thunder Throat what it feels like to be hit in the balls by 1/2" broken Hi-start rubber.
OK, have it your way, but keep it too your self when you get hit by the rubber.
I never said you couldn't climb an Astro Jeff or Sagitta X/C to altitude. If you reduce the area of the Astro Jeff or the Sagitta for that matter, you are making my point. They don't go. A little carbon will fix the fact that are weak.
A glass pod with a carbon boom is pretty versitile. You can cut to the correct length as needed. And by the way, I also have a 1/4 size LS-1c mold that was used for 3 or 4 X/C models.
The last X/C model I designed was built by Buddy Fox. The 150" E-374 wing had a spar and was white foam and glass. Up to that time, I was sceptical of Wurtz's claims of 90 MPH final glides. After I did one, I was convinced.

Bravo Juliet

[bigjohn]

Since I asked about the car-tow method, lemme see if I can broker a truce on this discussion before we are whipping each other with old hi-starts.

Rubber will hurt if it breaks under tension and hits you. If you are, say, riding in a pickup bed while towing - you might want a buffer between you and the rubber. I would. If you are in an enclosed towing car, there's not much need. Perhaps that is the difference in points of view.. Definitely use a buffer if you try this with a motorbike :D


I suppose that wasn/t blood gushing from my arm when I was struck by broken Hi-start. Ask Bill Nibley or Thunder Throat what it feels like to be hit in the balls by 1/2" broken Hi-start rubber.
OK, have it your way, but keep it too your self when you get hit by the rubber.
I never said you couldn't climb an Astro Jeff or Sagitta X/C to altitude. If you reduce the area of the Astro Jeff or the Sagitta for that matter, you are making my point. They don't go. A little carbon will fix the fact that are weak.
A glass pod with a carbon boom is pretty versitile. You can cut to the correct length as needed. And by the way, I also have a 1/4 size LS-1c mold that was used for 3 or 4 X/C models.
The last X/C model I designed was built by Buddy Fox. The 150" E-374 wing had a spar and was white foam and glass. Up to that time, I was sceptical of Wurtz's claims of 90 MPH final glides. After I did one, I was convinced.

Bravo Juliet

[jtlsf5]

Since I asked about the car-tow method, lemme see if I can broker a truce on this discussion before we are whipping each other with old hi-starts.

Rubber will hurt if it breaks under tension and hits you. If you are, say, riding in a pickup bed while towing - you might want a buffer between you and the rubber. I would. If you are in an enclosed towing car, there's not much need. Perhaps that is the difference in points of view.. Definitely use a buffer if you try this with a motorbike :D


I don't get the problem here. There is no one in the truck, just the driver, and he has a tailgate between him and the rubber lashed to the towhitch. Pilot and helper are 500' away with the airplane. In 30 years I have yet to see a piece of rubber travel that far, but I try to design things so I won't get hit in the nuts; don't want my brains or sensibilities rattled!

Big Jer, you should bring what you got to one of the current XC events and show all the new kids what you can do. Cal Valley was a few weeks ago, Montague is this weekend, Cal Valley or Davis in early fall. I'd be glad to show you how we car launch, without anyone's nuts at risk.

JT

[Mark Miller]

I'd be glad to show you how we car launch, without anyone's nuts at risk.


This has to be one of the best out of context quotes of the year

[big jer]

I see, you don't have an observer in the tow car watching the model. Whatever floats your boat I guess.
I don't have a X/C model, or the telemetry, or the cash to build or buy one or to go to 2 day comps. Just the way it is.
I did lead a team from Cal St LA/U Ok. Stillwater last year to a W/R out and return record flight for multiple energy source models. Around 120KM I think.
I can still fly if someone else is paying.
I'll tell ya what, if we are going to issue challanges here, How about taking the telemetry out of your models and making a 38 + mile flight. I've done it.
Barstow Dagget apt to Ludlow. With a 100" model.
Bravo Juliet

[jtlsf5]

I see, you don't have an observer in the tow car watching the model. Whatever floats your boat I guess.
I don't have a X/C model, or the telemetry, or the cash to build or buy one or to go to 2 day comps. Just the way it is.
I did lead a team from Cal St LA/U Ok. Stillwater last year to a W/R out and return record flight for multiple energy source models. Around 120KM I think.
I can still fly if someone else is paying.
I'll tell ya what, if we are going to issue challanges here, How about taking the telemetry out of your models and making a 38 + mile flight. I've done it.
Barstow Dagget apt to Ludlow. With a 100" model.
Bravo Juliet


Whatever...

[steelhead]

Some photos and such from Montague 2008 are starting to show up here-

http://www.rcgroups.com/forums/showthread.php?t=872648

Some people have been interested in the vehicles and seating used in XC flights, and some of the photos show a good cross reference of how most of the teams do it in California.

There should be some more photos and writeups soon.

Dean

[aeajr]

OK, let me make sure I understand this car launch technique.

Sounds like you tie a hi-start to the car ... somehow. You lay it out to full length, relaxed.

Now, do you stretch back first, then start the car moving or let the car stretch the hi-start?

I presume this is all to get more speed into the launch.

I think I read the car is doing about 20 mph. How long does the tow typically last? 100 yards? A mile?

Once it is launched, I presume you work the local air while you gather up the hi-start so you can pursue the plane and the course.

Do I have this right?


And mainly this is a substitute for a winch launch. Right?

[Lance Prior]

Where I live the law prohibits riding in the back of a pickup truck. Do you guys ever have problems with the police stopping you for riding in the back of a pickup truck?

[jtlsf5]

OK, let me make sure I understand this car launch technique.

Sounds like you tie a hi-start to the car ... somehow. You lay it out to full length, relaxed.

Now, do you stretch back first, then start the car moving or let the car stretch the hi-start?

I presume this is all to get more speed into the launch.

I think I read the car is doing about 20 mph. How long does the tow typically last? 100 yards? A mile?

Once it is launched, I presume you work the local air while you gather up the hi-start so you can pursue the plane and the course.

Do I have this right?


And mainly this is a substitute for a winch launch. Right?



Wrong. One more time this is NOT a histart launch, its a car tow. Short loop of very heavy rubber that is a shock absorber, not the power. Car moves ahead to lay out the line. Hook up plane, signal car to go, when car goes and tension comes up, launch. At top, car stops, short zoom to use the slight amount of stored energy in the line and rubber. Again, this is not a histart launch.

JT

[jtlsf5]

Where I live the law prohibits riding in the back of a pickup truck. Do you guys ever have problems with the police stopping you for riding in the back of a pickup truck?


Not sure of the exact wording of the California laws, but the local cops that stop any of the teams are more than satisfied to see that the fliers are seat belted. None have demanded that the flying stop and fliers be under the cab. Seems like seat belts are the issue and we make sure we are belted. Most are just curious what the heck we are doing.

JT

[aeajr]

Wrong. One more time this is NOT a histart launch, its a car tow. Short loop of very heavy rubber that is a shock absorber, not the power. Car moves ahead to lay out the line. Hook up plane, signal car to go, when car goes and tension comes up, launch. At top, car stops, short zoom to use the slight amount of stored energy in the line and rubber. Again, this is not a histart launch.

JT

Thanks for the clarification.

How far does the to go? 100 yards? Mile? Typically? Just curious.

[Ercoupe Ed]

Not sure of the exact wording of the California laws, but the local cops that stop any of the teams are more than satisfied to see that the fliers are seat belted. None have demanded that the flying stop and fliers be under the cab. Seems like seat belts are the issue and we make sure we are belted. Most are just curious what the heck we are doing.

JT

Hee hee hee, I remember when we got stopped by an Illinois State Trooper
during the SOAR Great Race back in the late 80's.
His main concern was our 70 mph speed on a 50 mph highway.
He gave us a warning and also was concerned no one in the pickup bed ( two people) flyer and spotter had no restraints.
(Hence another warning).
But the funniest part was when he asked us what we were doing.
"Flying a model airplane officer"
Hmmm, okay the sailplane is almost 3,000 feet plus overhead, just a speck in the sky, and TOTALLY SILENT, since the officer expected to hear some kind of model airplane engine noise! LOL!
We finally pointed it out to him, while some of our competitors sped on by doing the same thing. He chased a few of them down after letting us go with just a warning.
Later two Troopers showed up at the flying field and looked around, then spoke with the contest directors.
Result was we had to STAY AT or UNDER the speed limit while on Illinois roads.
So that put a little more competition into it.
Really didn't bother one sailplane pilot though.
He easily won the Great Race.
His name?
Joe Wurts.
Joe is a great guy and so was his X-Country team!
Haven't really flown any competitive X-Country since then, but did upscale a Bird of Time to 156 inch wingspan and flew it on a few practice flights before it got hooked in a REALLY STRONG thermal under a HUGE Thunderhead one day, and it went bye -bye until about 15 minutes later it reappeared coming out of the cloud in pieces, and I was able to retrieve the fuselage, rudder, and part of one wing, but th rest of it went up, up, and away into the cloud, never to be seen again!!!

But hey it was fun anyay!!!

Ed

[steelhead]

Great video except the lack of seatbelts......... :)

So, the end of 2008's XC soaring contests- Whats the plan for 2009?

Dean

[Wing-span]

What video steelhead? Have i missed the link?

[Mark Miller]

Follow the links in post 55

[Wing-span]

Ah! Thank you Mark.

[steelhead]

Actually, I mistook the video in post #15 for something new :) Sorry guys- I think it was late that night.

Dean

[Libelle201B]

Thank you, JT

I ask because I have a Sagitta XC NIB and would find it tough to justify the purchase of a new machine at this time. I have to imagine that systematic addressing of the stress points by means of some modern materials and techniques may make it feasible to get into this gig using what I have. If you believe this would be a waste of time and materials please let me know; it won't break my heart. :)

-bobBob ,there is no reason I could think of why you shouldn't get into the "gig". You have to start somewhere, right? I would really hope that there isn't a mindset that suggests that you need a $2000 XC sailplane to enjoy the XC experience. Yes, you will have to be very careful at altitude to not overstress the wings and or stab in your case. One poster, big jer, seems to be quite happy and succesful with a 100" model. :)

[steelhead]

Winter time, time to build.
I pulled out an XC fuse mold today and had a look. I'm getting the materials together, and making some space to work. I have a friend who is interested in the layup process, so that might help speed things along.


Also, I found this link today-

http://www.rcgliderandsailplane.com/forum/topics/2309125:Topic:1881

It's the Kuhlman REDWING XC forward swept XC wing. Neet stuff- I've read lots about it for a while. I still think a standard planform plane will be easier to fly XC.

Dean

[Cort]

Dean,

I have been thinking of building a Redwing XC for several months now. I first came across it in RCSD. Thanks for the link that you provided. I see that you are in the Eureka area. I am outside of Blue Lake up near Titlow Hill. Maybe we should do a dual XC build this winter. Interested?

[steelhead]

Cort- Sent you a PM.

Dean

[DT56]

Winter time, time to build.
I pulled out an XC fuse mold today and had a look. I'm getting the materials together, and making some space to work. I have a friend who is interested in the layup process, so that might help speed things along.


Also, I found this link today-

http://www.rcgliderandsailplane.com/forum/topics/2309125:Topic:1881

It's the Kuhlman REDWING XC forward swept XC wing. Neet stuff- I've read lots about it for a while. I still think a standard planform plane will be easier to fly XC.

Dean

Thanks Dean for the link to the Redwing XC! :) I've been interested in the 2 meter version for some time now.

All we need are some wing cores. ;)

[steelhead]

Hey Cort-

Got any time coming up for a couple of fuse builds?

Dean

[scaflock]

Hey guys I've got a question for you that I've been wondering about. What is the maximum distance for a XC race/event or is there one? I've been thinking of trying to get some of the people in my area interested in giving XC a try and have an idea for a 3 leg course layout but it seems to be quite long to my mind. Best estimate from Google Earth is 98.13 miles as the crow flies. Is this excessive?

Jeff

Edit: I can upload a screen shot from google earth if that would help.

[jtlsf5]

Hey guys I've got a question for you that I've been wondering about. What is the maximum distance for a XC race/event or is there one? I've been thinking of trying to get some of the people in my area interested in giving XC a try and have an idea for a 3 leg course layout but it seems to be quite long to my mind. Best estimate from Google Earth is 98.13 miles as the crow flies. Is this excessive?

Jeff

Edit: I can upload a screen shot from google earth if that would help.


Jeff,
There is no limit for a course. The longer courses can be quite challenging. Usually the limiting factors are terrain, roads and civilization. The things to keep in mind when laying out a course are pilot visibility (no tree tunnels or underpasses), lightly traveled roads (lots of stop, start and parking on the side of the road), and no heavily populated areas (in case of landouts).

You should also consider the event you want to hold. Free distance (no time limit), speed over a specific part of the course, or open speed (for instance a 2 hour limit for any part of the course). A triangular course as you suggest really only allows distance and speed over a designated portion of the course (no real turn points to drive strategic decisions).

One other thing you might consider to help your event is to lay out LSF 1, 2, and 10 Km goal and return courses along the first leg of the course. This can help increase participation by getting those needing these tasks out, and they can help man teams if they don't want to try the open course.

JT

[scaflock]

Hummm The terrain might be a problem along the course. Lots of pine tree groves etc. and the roads would also be a challenge.

I am trying to get people around here interested in sailplanes and the LSF but haven't had any takers so far. I've been wanting to start getting my levels but don't have anyone that will witness the tasks. I am getting a couple of the guys at the "local" field weaned off the glow juice slowly but surely so maybe soon we can all start our tasks together.

Sailplane pilots around here seem to be few and far between as most of them in Georgia are up in the Atlanta area. Those that are in my area are very spread out. Maybe I should rethink this and make it a smaller course to start with to give them a chance to get used to the ways a XC course is flown.

Jeff

[aeajr]

Getting people to try electric gliders is a LOT easier than pure gliders. More stick time, easier launching and a safety net if they get in trouble.

Like training wheels, electric gliders is the easiest path to pure glider soaring.

[scaflock]

LOL I've been flying slope and thermal for years but have actually started to get into electrics for their ease of launching. When I want to get a quick flight in it is a lot easier to use electric that to have to set up a highstart. It has also opened up a lot more flying sites for me. I've built up a modified Paragon fuselage and can swap the wing between it and the stock fuselage. Best of both worlds.

One of the guys from the local field wants me to build him up a Gentle Lady with an electric system. With luck when the other guys see how much fun we're having they'll want to jump in as well. I'll wean them off the glow juice one way or another. ;)

Most of the glider pilots at the local field are just getting into Hl and DLGs. I keep trying to show them that "bigger IS better". When Ray releases the Merlyn kit I think they're going to have their jaws dropped to about knee cap level when I show up at the field with that "Portable Eclipse".

Jeff

[jtlsf5]

Getting people to try electric gliders is a LOT easier than pure gliders. More stick time, easier launching and a safety net if they get in trouble.

Like training wheels, electric gliders is the easiest path to pure glider soaring.


Ed, be careful. Training wheels are a crutch regardless of the ease, access, and all the other arguments. Its very hard to get users to throw away their crutches and move upward and onward once they get used to the instant save that electric offers. They never learn the necessary decision skills of when to go for it and when to abandon and move on when there is no risk. Two edged sword.

JT

[nuevo]

scaflock, Until level 5, your witnesses don't have to be LSF members. Any unrelated adult will do.

I know you prefer the larger planes, and so do I. But, why not try DLG's and join the crowd already using them? You said you wanted to get them into sailplanes. Sounds like some already are there.

[scaflock]

I've got one HLG (so far) but I've got a really bad shoulder so I'm having to relearn how to throw smoothly with the other arm. DLG might be less stress on the shoulder but right now I've got too many other building projects in line to be able to get to one any time soon. I do have a bunch of parts that I'm going to use one of these days to make my own design DLG. It's just a matter of time is all.

My sole HL is a "Thermal Thing" designed by Rol Klingberg. It's a 72" span little floater and looks huge next to the Gamblers and other HL/DLGs at the field.

Jeff

[aeajr]

Ed, be careful. Training wheels are a crutch regardless of the ease, access, and all the other arguments. Its very hard to get users to throw away their crutches and move upward and onward once they get used to the instant save that electric offers. They never learn the necessary decision skills of when to go for it and when to abandon and move on when there is no risk. Two edged sword.

JT

JT,

There is no doubt that you are right. But I did not learn to thermal soar on a glider, I learned on a parkflyer. So I know this approach works and perhaps that has influenced my approach.

However, when I first started to teach soaring to electric pilots using a pure glider, they became frustrated. Flights were too short, they were not finding lift and so they gave up. Mission not accomplished. Maybe I was not a good enough teacher or maybe they were too impatient with the whole glider process.

When I switched over to the Easy Star ( a pretty good parkflyer/glider trainer) the Easy Glider Electric and now the Radian, I had a lot more success. They could spent more time hunting for thermals and less time hunting for the hi-start or trying to avoid breaking the plane on the winch.

In five years of teaching flying to new pilots I think I had one pilot show up saying they wanted to learn to fly pure gliders. That as opposed to dozens I have helped learn to fly. That is what has taken me to this approach. So far it has been working fine.


But this thread is supposed to be about RC Cross Country Soaring. Let's get back on topic.

[Libelle201B]

I see, you don't have an observer in the tow car watching the model. Whatever floats your boat I guess.
I don't have a X/C model, or the telemetry, or the cash to build or buy one or to go to 2 day comps. Just the way it is.
I did lead a team from Cal St LA/U Ok. Stillwater last year to a W/R out and return record flight for multiple energy source models. Around 120KM I think.
I can still fly if someone else is paying.
I'll tell ya what, if we are going to issue challanges here, How about taking the telemetry out of your models and making a 38 + mile flight. I've done it.
Barstow Dagget apt to Ludlow. With a 100" model.
Bravo Juliet What was your 100" model ? I once had a friend here in S FLA that designed his own XC poly ship with the E374 airfoil. The span was about 140" or so. It climbed fairly well and would run well. I have always been of the thought that for basic XC fun one doesn't have to buy a $2K sailplane with all the bells and whistles. :)

[big jer]

The Model Was Eddie Slobod's Geminii MTS. I think it was the one we called Rent-a-wreck. Alex Bower used the same model to qualify for the 83 US Soaring Team finals. Pretty good model.

JDK

[scaflock]

I don't think I've ever seen an Ed Slobod design that wasn't a good model. All of them did what he designed them for and did it well.

Jeff

[steelhead]

Scaflock- a 100 mile course would seem too large of a course, especially if your expected participants were pretty new to XC. This has exceptions though. If you wanted to fly the whole course, you stand to be out all day. Also,on a course that size, you probably wouldnt be around of any of the other teams. A smaller course to start a fresh crowd with would seem better to me.

If it is a race, my favorite task so far has been one circuit of (trying to remember) 18 miles. I think there are 4 or 5 turnpoints in the circuit, and with this kind of course, you encounter other teams during the race.

At Montague, with 10 to 12 teams flying, it is really fun to leap frog over other team vehicles as you go on the course. Lowest time to finish the course wins, multiple attempts OK.

The other task that I like is a minimum 2 hour flight with distance divided by time to find the fastest average speed for the day. Most teams will fly for less than 3 hours, and the course can be set or open (between recognized turnpoints) If you land before the 2 hours minimum, you still get divided by 2 hours, so the goal is to fly at least 2 hours as far as possible. If you are having a great lift day, you can fly for longer than 2 hours, with your distance divided by how long you were in the air- do this only if you think you can best your average speed for the previous 2 hours)

My least favorite task is open distance- winches open at 10 am, be back at the starting field before 6pm. On this task, you encounter the other teams very little, and the driver gets bored. This is a great task for getting your distance pins.

If I was going to start up a contest with teams who were new to XC, just to to get people started, here's how I would do it-

I would probably find a 20 mile course with 3 or 4 turnpoints. (SEE SAMPLE COURSE DRAWING) I'd require teams to fly one lap, timed. Best time for one lap wins. Allow multiple starts, and unlimited launches at home field. Also allow unlimited time from launch to starting the course. Clock starts when you pass turnpoint 1. In case no one finishes course, furthest distance completed that day wins. Team vehicle must be parked at turnpoint 1, and plane must be directly overhead of turnpoint 1 when clock starts. On sample map I drew, The lap direction would go 1, 2, 3, 4, 1. The Clock stops when both plane and vehicle are at or passes turnpoint 1.

The best way to decide when to log the turnpoint on the flight log would be to park the vehicle at the turnpoint, then fly the plane on the outside of the turnpoint (make the plane fly further) or circle the turnpoint. When the plane and the vehicle have logged the turnpoint, head to the next turnpoint.

If I wanted to have a second day task, to see how many miles a team can rack up in a 2 hour minimum flight, or open distance, I would add turnpoint 5 to the mix as an available turnpoint. Make it so you cant do laps between 2 turnpoints, in other words, you cant go 1, 2, 5, 2, 5. Instead of doing the 2 to 5 path repeatedly, you would have to go 1, 2, 5, 2, 3. You could even change direction while on course to suit the weather.

The distance logged would be the actual straight line distance between turnpoints using GPS data. Road miles are used only if you land out on course. If you do land out, Reset odometer, then drive from landing point to last logged turnpoint and add those road miles with the logged turnpoint miles. If a timed event, clock starts at turnpoint 1, and ends when the plane touches something connected to the ground (or passes the required finish line)

These are basically the rules used at Montague. The Montague course has 9 turnpoints, with a square in the middle and two spurs (one long, one short) at opposite sides. I cant remember the distance between the two furthest turnpoints- I cant find my turnpoint book, but I'm sure someone else here remembers.

A 100 mile course would be great to have, and give teams something to see their progress advance over the years, but I'd rather have people on a smaller course for the leapfrogging, and the smaller distance to drive to get back to the home field after a landout.

It's late, so I hope this makes sense. I've gotten a few emails asking how I would run a contest, and I think that's what I would do- A single lap, timed race or a 2 hour minimum max average speed like we do at Montague.

Hope this also explains a little to help some others new to XC understand how the Montague Races work.

Dean

[danstrider]

I dug out the Montague turnpoints since Dean didn't have them handy. Northmost to Southmost point is 28mi the way the crow flies. It's more in the range of 30-35mi road distance.

The file attached is a Google Earth KML inside a zip so RC Groups is happy with it.

Dan

[scaflock]

I can understand how a 100 mile course would be rough on a newbie. With the added problems we'd have here with trees and roads it would be next to impossible to pull off. I thought of the course because the turn points are all at "local" flying fields. There would also be several small towns that due to roads you would have to go through. Then there's a lake that you'd have to cross as one field is on the west side of it and the other two fields are on the east side of it.

I can see that it's not going to be easy to get a XC event setup here in Georgia. There are just too many things that would get in the way. I'd imagine that it's pretty much the same all over the southeast portion of the country. I may have to wait until I move back out to the western part of the country. I am bound and determined to do some XC flying though.

Jeff

[aeajr]

Curious,

Are there ever XC courses that would allow relaunches from mid point field? Jeff's comment that his turn points were at club fields. So, could there be a relaunch at turn points?

It would present some interesting strategy. If you are coming down, do you land out, turn back for the start point, or do you try and run to the turn around where you could relaunch.

Not suggesting a new format, just asking a question.

Edit:

If this is not a typicaly format, maybe this would be called a XCountry Relay, or perhaps one would take a penalty if you had to relaunch from one of the intermediate points. Could be interesting.

[DEAN GRADWELL]

xcsoaring.com has a section on setting up a cross country contest.
SVSS the Davis, Ca. has an event called "Soaring Safari". We try to fly as far as possible but are allowed to relaunch if needed. Go to their website for pictures.
Regards Dean

[steelhead]

There's been a lot of discussion lately on new XC designs. Seems like people are getting more and more excited about big ships lately.

A cross country task would be pretty easy for someone to set up as a simple club contest. We've discussed some of the contest formats that are currently held, but it all comes down to just having a couple waypoints and some open country to fly in.

Rent a Jeep or borrow a convertable and give it a shot. Once that 2 or three teams start up in an area, the excitement will breed more participants. Keep it simple and let enthusiasm grow!

One question that comes up regualarly to me is "what special changes do you need to make to the Transmitter to get it to work at those distances?"

I've used a stock Futaba 72 mhz, 4 channel radio with no changes. Most full powered, hobby class radios will do this range just fine.

Dean