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Conference vmszoo::rc

Title:Welcome To The Radio Control Conference
Notice:dir's in 11, who's who in 4, sales in 6, auctions 19
Moderator:VMSSG::FRIEDRICHS
Created:Tue Jan 13 1987
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1706
Total number of notes:27193

337.0. "Sailplane Discussion" by MJOVAX::BENSON () Wed Oct 21 1987 15:22

    I don't think this has been really covered elsewhere in the other
    notes, but I'd like to get a discussion going about various facets
    of sailplaning; favorite sailplanes, techniques, gadgets, etc.
    
    My experience is with a Wanderer 2m with .049 power pod and an
    all-balsa Aquila about to be started. (NO I haven't started that
    one I bought through the notesfile several months ago-- a first
    child right in the middle of flying season put an end to that!!)
    
    PS- Jamie Samantha, July 9, 1987, and she's worth losing half a
    summer of flying for! (She'll be at the field NEXT year though!)
T.RTitleUserPersonal
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337.1BARNUM::WALTERWed Oct 21 1987 17:1822
    Right now I'd most like to hear about methods of getting the sailplane
    up there, and fields in the Eastern Massachusetts area that are
    appropriate for flying. 
    
    I have a Sig Riser (first plane... I'm a beginner) and I've been using
    a hi-start exclusively for launches. The hi-start gets it up 250 ft or
    so, good for about a 3 minute flight, but I want longer flights. I just
    invested in an .049 engine (Tee Dee .051, actually) and I'm building
    the power pod now. I'm hoping the little gas tank will still take
    it up higher than the tow line.
    
    As for fields, the one in Concord near the rotary is great now that
    the corn field was cut down, but it's very popular. Lots of planes
    buzzing around. I'm looking for quieter alternatives. Or, better
    yet, does anyone know of a place around here that has good conditions
    for slope soaring? I've heard of a spot in a town near Sturbridge
    which is ideal, a nice hill with plenty of clear land up-wind of
    it, but it's supposed to be private land, and I didn't get any detailed
    directions.
               
    Dave
    
337.2Let's talk glidersUSRCV1::BLUMJTue Jun 07 1988 11:308
    I thermal fly using a high start and do some slope soaring when
    the wind is right.  My first shipo was an Olympic 650, not a bad
    trainer but penetration in windy conditions was terrible.  currently
    I am flying a Pierce Arrow Paragon. This is a beautriful flying
    sailplane, much easier to fly than a 2-meter ship.  A top flite
    Wristocrat for slope soaring is 50% done.  My next project will
    be a 4-meter ship, possibly a Pierce Aero Paramount or Stan Watsons
    Pegasus
337.4Slope soaring in Upstate N.Y.USRCV1::BLUMJThu Jun 09 1988 11:306
    
    I work in  upstate N.Y.(rochester).  We have many nice hills, however
    most are tree covered.  There are a couple of acceptable sites.
     Good slopes are hard to find, especially facing the prevailing
    winds!
    
337.5Sloping locationsK::FISHERThere's a whale in the groove!Thu Jun 09 1988 15:3013
I was looking at the Quabbin Reservoir a couple of weekends ago.

They have two earthen dams which have great slopes to the south.
Landing would be tricky but to me they seemed ideal.  On the weekends
the place is over run with picnickers tho.  Does anybody know it
flying slope is permitted there?  If somebody knows who to call
it would make an interesting place and maybe we could meet there
some week day that has winds from the south?

Bye          --+--
Kay R. Fisher  |
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337.8Large Gliders Fly BetterUSRCV1::BLUMJTue Jul 05 1988 18:116
    I am fortunate to live in a rural area with many open fields.  I
    usually fly at the local highschool where there is mowed grass.
    This makes high start retrieval easy and doesn't scratch up the
    glider too much.  Spoilers are a good idea on large gliders because
    they seem to glide forever when they are near the ground.  Large
    gliders fly better, cost more, take longer to build, and crash harder!
337.9Help me find my next shipCSC32::M_ANTRYMon Jul 11 1988 22:4546
    I think that I will leave this under this topic for now if some
    one would think it would do better on its own please move it.
    
    I have just move to CXO and as before mentioned really enjoying
    the Pikes Peak Soaring Society.  I have flown mostly 1/4 scale power
    planes for about 3+ years.  I have been flying my gentle lady with
    the PPSS club since 2/88 and now at every contest I enter that old
    lady is starting to get me down.  There are people who have only
    been flying anything for 3 weeks and they are flying a 100" very
    good ship.  My delimea about this is that all they have to do is
    stay up 100 seconds longer than I and dont have to worry about a
    landing.  So if I stay up 4 mins and score a 100 out of 100 possible
    landing points (I knew those dead stiks would come in handy).  All
    the other novice has to do is stay up 5 mins and 30 secs and then
    crash. Wallah he just out scored me.
    
    What this all leads up to is, What to build for my next glider kit.
    My criteria:
    	Not overly expensive. ($50-200 dollars).
    	Fairly easy to build.  Hard would be OK if it produces good
    results.
    	At least spoilers (to help my landing) and possibly alierons.
    	Glass Fuse and flying stab (Just because).
    
    I guess what I am looking for is at least a 100+" plane with a glass
    fuse and flying stab.  Something that is below the F3b ships and
    is above the Oly's.
    
    I have been looking at the Larry Jolly Pantera and the Dynaflite
    Sensor 117.  Anyone who has comments on these kits please post your
    oppions.  Everyone else can post their recomendations.  
    

    I am a little scared of the Dynaflite because of past experience
    with a Butteryfly.
    
    I am not sure if Dynaflite kitted the butterfly but whoever did
    should be shot in my mind.  Never before have I paid 40+ dollars
    (mail order) for a kit only to find a box of balsa.  Granted this
    was my first stick kit (fully built up stab etc, Non-Goldberg stlye)
    but I cant believe spending that much for a kit and having the leading
    edge be a square hunk of balsa (for example).
    
    I will be waiting for the public to decide my next glider.
    
    ps.  It should be good for Distance, Thermal, etc.  All around plane.
337.10WindsongK::FISHERThere's a whale in the groove!Tue Jul 12 1988 15:0019
>    good ship.  My delimea about this is that all they have to do is
>    stay up 100 seconds longer than I and dont have to worry about a
>    landing.  So if I stay up 4 mins and score a 100 out of 100 possible
>    landing points (I knew those dead stiks would come in handy).  All
>    the other novice has to do is stay up 5 mins and 30 secs and then
>    crash. Wallah he just out scored me.

Out here in the east I have not seen an advantage in up time taken by the
Standard or Unlimited class gliders over the two meter types.  So I have
been only thinking along the 2 meter line for my next (this winter) sailplane.
    
>    I will be waiting for the public to decide my next glider.

I also will be interested in this feedback.

Bye          --+--
Kay R. Fisher  |
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337.11Cumic PlusIGUANO::WALTERTue Jul 12 1988 17:1314
    Kay,
    I think there is an advantage to the larger span sailplanes, although
    I've never flown one to prove it. However, at the Salisbury contest,
    the scores for the Standard and Unlimited class were generally higher
    than for the 2M class. (Maybe those flying the 2M's were less
    experienced?)
        
    Re: -.2
    As for a choice of 100" ship, you might look at the Cumic Plus.
    I've seen two of them fly, and they definitely stayed up longer
    than my 2M. It does have a fiberglass fuse but I can't remember
    if the elevator is full flying. 
    
    Dave
337.12New Ship ConsiderationsUSRCV1::BLUMJWed Jul 13 1988 14:0216
    When deciding on which kit to build the first question you must
    ask is whether to go with a polyhedral or straight wing ship.  Being
    relatively new to soaring I thought the straight wing ships were
    much better looking, hence that's what I wanted to get.  For a low
    time pilot the straight wing ships are much more difficult to fly
    well and the debate still rages over which type actually flys better.
    A count at the last NATS showed two thirds of the ships were
    polyhedral.  My personal observations at contests in Upsate NY are
    most flyers still have polyhedral ships but there are more straight
    wing ships appearing each year.  The straight wing ships seem to
    handle better in higher winds but you must be an excellent pilot
    to take advantage of this.  Know your skills before spending the
    time and money building a sleek ship only to crash it because you
    haven't acquired the skills to fly it properly.  I would recommend
    flying a hot bent wing ship(ie Sagitta,Pantera,Gemini,etc.) before
    making the jump to straight wing.
337.13Using FlapsUSRCV1::BLUMJMon Aug 22 1988 16:5813
    After attending a contest this weekend held in windy weather(gusts
    to 20mph) I was impressed with the flying techniques permitted when
    flaps are used.  The better pilots were able to come close to the
    spot almost everytime by placing the glider in a steep dive almost
    over the tape and using flaps and spoilers to slow down, rounding
    out at the last minute.  Granted these guys were good, but this
    technique would not be possible without flaps.  Does anyone have
    any experience with flaps which they care to relate?
    
    Thanks,
    
    Jim
    
337.14Full scale flapsLEDS::JENSENMon Aug 22 1988 18:3934
    This experience with flaps is not with gliders but I think it's
    kinda applicable and I certainly plan on putting flaps on any glider I
    might make.
    
    I won a spot landing contest in a full scale Cessna 150 by putting
    the flaps all the way down and pointing the nose of the beast at
    a point about 10 feet in front of the spot at a very steep angle of
    approach.  The 150 wouldn't do over 70 with full flaps (40 degrees),
    even pointed straight down!
    
    Since not much speed was picked up in the landing approach (dive?),
    one simply flared out about 2 feet off the ground, the speed
    immediately bled off, and the 150 just sat down on the spot.
    This is a very safe approach since you are well above
    stall and you always have the runway made even in the event of an
    engine out.  Just pull off a little of the flaps and the glide can
    be greatly stretched, allowing easy compensation for misjudgements.
    
    The two ways to hit a spot without flaps are either to make a very
    precise approach so the airspeed is just above stall as you come
    over the fence or slip it in.  Both of these are much more difficult
    and dangerous.  In the case of the precise approach the craft
    is barely above stall.  For the slip, the moment to kick the plane
    straight must be precisely judged or you could land sideways.  On
    the other hand, the slip is very pretty to watch and is much
    appreciated by the troops on the flight line!
    
    I learned to fly on a plane with a tailwheel and no flaps and was
    very pleased when I got my second plane (the 150) and found the
    wind just seemed to go away.  You can talk about the golden age,
    but if flying's what you want, get flaps.
    
    Ed          
    
337.15SPKALI::THOMASTue Aug 23 1988 11:379
    What I suspect you saw was a "Windsong". A dodgson design . Great
    ship. Mechanically adds down elevator when flaps are deployed. Also
    reflexes the flap area to change the airfoil of the wing. Great
    design,big ship. 
    
    
    						Tom
    
    P.S. If your serious about competition I'd but one for unlimited.
337.16Your Right!USRCV1::BLUMJTue Aug 23 1988 13:1911
Your right, several of the ships I described using this kamikazee landing
    technique were Windsongs which are far and away the most popular
    open class contest ship in Upstate New York.  Many local flyers
    are building their Sagitta 900's with flaps now.  The most interesting
    design was flown by Pete Carr, it had a single spoiler acrooss the
    center span of the wing, flaps, ailerons, and Schempp-Hirth double
    swept back Discus Wings.  This ship flew beautifully and penetrated
    like nothing I've ever seen before.
    
    Jim
    
337.17The Flap about Flaps!MJBOOT::BENSON__Frank Benson, DTN 348-2244__Tue Aug 23 1988 14:0314
    Jim or anyone else who's seen flaps on a sailplane:
    
    Are the flaps essentially ailerons that move together or is there
    more to the design/placement?
    
    Also, are the "fowler-type" hinges an advantage or is standard hinging
    just as good?
    
    Thanks in advance for the comments...
    
                             |                      
   \	       	         ____|____                      /   Regards,
    \________________________O_________________________/    Frank.
    
337.18Real flapsMURPHY::ANKERAnker Berg-SonneTue Aug 23 1988 14:4211
        Re:< Note 337.17 by MJBOOT::BENSON "__Frank Benson, DTN 348-2244__" >

        Frank,
        
                The flaps  I  saw  are  proper  flaps  set inboard of the
        ailerons.  The  spoilers are at the normal position.  The idea is
        that the combination of  flaps  and spoilers create both drag and
        reduced  lift, which enables the  planeto  descend  at  about  15
        degrees without picking up speed.   
        
        Anker
337.19Flaps, slats, spoilers and speed brakes...30399::FISHERThere's a whale in the groove!Tue Aug 23 1988 15:5137
>                The flaps  I  saw  are  proper  flaps  set inboard of the
>        ailerons.  The  spoilers are at the normal position.  The idea is
>        that the combination of  flaps  and spoilers create both drag and
>        reduced  lift, which enables the  planeto  descend  at  about  15
>        degrees without picking up speed.   

Sailplane flaps are in the normal position BUT unlike real flaps they
usually can deploy 90 degrees negative thereby acting more like speed 
breaks.  Windsongs do not have spoilers.  They instead have spoilerOns.
Not sure how to spell that.  They have extra linkage to move the ailerons
both up for a spoiler like effect - again more like a speed break than
a true spoiler.  In combination (usually with the help of an Airtronics
Module SP radio you can set the plane up for a Crow configuration landing
where the flaps drop 90 degrees and the ailerons go up.  There were two
windsongs that I watched at the CRRC event and neither of those did
crow landings BUT with just flaps they did some impressive approaches
at steep angles.

Confused - sure.

Spoilers (and flaps) have an additional use in sailplanes.  Getting
out of a thermal.  Sometimes they can be so strong that you really
need to deconfigure the wing to get out.  You can usually do loops and
rolls and inverted flight but that is harder to time precisely when
your in a contest and want to be down in one minute exactly.  Some
planes can spin down - but some can't.  My Drifter used to be able
to spin out of thermals but after adding weight - it can't do that
anymore.

In Sudbury one guy was still going up with his spoilers deployed.
But he wasn't trying hard to shake it until after he lifted the
spoilers.

Bye          --+--
Kay R. Fisher  |
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337.20Confused? Sure.MJBOOT::BENSON__Frank Benson, DTN 348-2244__Tue Aug 23 1988 16:377
    Kay, why would somebody launch with spoilers deployed?  Am I missing
    something here?
    
                             |                      
   \	       	         ____|____                      /   Regards,
    \________________________O_________________________/    Frank.
   
337.21Spoiled my launch...K::FISHERThere's a whale in the groove!Tue Aug 23 1988 19:2522
>< Note 337.20 by MJBOOT::BENSON "__Frank Benson, DTN 348-2244__" >
>                              -< Confused? Sure. >-
>
>    Kay, why would somebody launch with spoilers deployed?  Am I missing
>    something here?

Now I'm confused also Frank.  I reread my last note and didn't see where
you saw anything that would imply launching with spoilers deployed.

The closest I could find was that I said in Sudbury a guy was still going
up with his spoilers deployed.  

If that's where I mislead you let me add that he had launched 6 minutes
earlier and was in a good thermal.  When he wanted to come down he deployed
his spoilers and it kept going up.  The thermal was so good that he
had to do more than disturb the lift on the wing with the thermal.

Bye          --+--
Kay R. Fisher  |
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337.22Stretched Gemini with Selig 4061USRCV1::BLUMJMon Aug 29 1988 13:2330
    My father flew his scratch built stretched Gemini for the first
    time this weekend.  This ship is based on the popular Ed Slobod
    design(100") and has been kitted for years by Pierce Aero.  A plan
    for a 122" version of this ship using the Selig 4061 airfoil was
    presented in a past issue of Radio Control Soaring Digest.  The
    finished weight of this glider including Schempp-Hirth type spoilers
    came out at 80 ounces(heavy by my father's conservative standards).
    This is the most gentle ship I have ever seen fly in my life!  When
    trimmed nose high it floated just like his 39 ounce Mirage.  The
    stall was very gentle with no tip stall tendancy at all!  The designer
    Bob Champine claimed that it could be flown like a Gentle Lady but
    still have excellent penetration ability, boy he wasn't kidding!
    Bob has achieved LSF Level V with this ship and won tons of contests.
    This ship is a WINNER, I have never seen a Glider with such a wide
    speed range.  My father is legally blind and has a difficult time
    flying fast gliders, which atests to the magnificent handling of
    this bird.  Michael Selig has defintely come up with a great airfoil
    in the 4061, I only hope the Algebra I am building which employs
    the Selig 3021 flys half as well.  The airfoil is a little tricky
    to build because it is undercambered and uses a 1/64" of plywood
    on the trailing edge to achieve the razor sharp trailing edge. 
    Mr Champine is very helpful and enthusiastic if you call him with
    any problems, indeed he will talk longer than you might
    wish(considering its a long distance call).  If you have sctratch
    building ability this ship will not disappoint you.
    
    Regards,
    
    Jim
    
337.24Stretched Gemini Info.USRCV1::BLUMJWed Aug 31 1988 13:1220
    Building the Stretched Gemini requires one to have the original
    100" Gemini fuselage plan and be able to scale it up.  The wing
    is totally different.  I do not know if the Gemini plan was ever
    offered separately, however this is a very popular ship that has
    been around for years so you might be able to find someone who would
    let you borrow the plan.  The ribs were presented in an article
    in a past issue of Radio Control Soaring Digest along with the
    designer's name and address.  I could provide all this information
    if you were serious about building the ship.  A scratch building
    project is a big undertaking, I have met few people with the time
    or interest in these type of projects.  If you are seriously interested
    in soaring I would recommend that you subscribe to Radio Control
    Soaring Digest.  This is a pamphlet type monthly magazine not available
    on the news stand.  It is exclusively dedicated to RC Soaring and
    has more useful information than all the glossies combined.  I will
    obtain the address of RCSD and post it.
    
    Regards,
    
    Jim
337.25design the wing ?BZERKR::DUFRESNEVAXKLR - You make'em, I break'emWed Aug 31 1988 13:4715
    re Address: there is a note (real early one) used for that purpose..
    pls put there..
    
    Asfor scaling up: Nema probleme.. I have a friend who has a machine
    that you can use to blow plans. You just give him the scale factor
    and presto !! One set of plans..
    
    As far as the wing is concerned, do I undertand that will have to
    basically deisgn my own or is the info on the newsletter sufficient..
    I can work from a set of plans. I can cut wood.. I don't think I
    would want to tackle the design at the same time..
    
    md
    
    
337.26Additional Gemini Info.USRCV1::BLUMJWed Aug 31 1988 20:5318
    You do not have to design the wing, basically you use the same
    construction techniques shown on the original Gemini plan(sheeted
    D tube, spar webbing, etc.) but use the rib drawings(Selig 4061)
    provided in the construction article in Radio Control Soaring 
    Digest instead of the standard Gemini ribs.  Building this model
    requires that you have some previous building experience because
    not everything is totally documented and relies on your previous
    modeling experience.  My father is retired and has a lot of time
    to build.  He is pretty fussy(tends to take a lot of time) but
    has scratch built at least 15 models previously, he knows what 
    he's doing.  It took him 3+ months to build this ship, so that
    might be some gauge of the time frame.  Hope this information is
    helpful.
    
    Regards,
    
    Jim
    
337.27That is nit so badBZERKR::DUFRESNEVAXKLR - You make'em, I break'emThu Sep 01 1988 13:4312
    sounds like something I could handle.. The instructions on the AQUILLA
    (my current project) also expect you to know what you are doing.
    
    The only difference here is that I got a box full of pre-cut parts,
    so I save time in that dept..
    
    BTW, did your father get thicker wood due to blow up or did he use
    the same thickness as on the original??
    
    tx
    
    md
337.28More Stretched Gemini info.USRCV1::BLUMJThu Sep 01 1988 20:299
    I am not sure if the dimensions of the balsa were changed or not.
    I will be seeing him this weekend and will try to get a copy of
    the construction article.  I will mail this to you if I get it.
    Good luck on the Aquilla!
    
    Regards,
    
    Jim
    
337.29RC Soaring Digest AddressUSRCV1::BLUMJTue Sep 06 1988 13:0713
    Anyone seriously interested in RC Sailplanes should subscribe to
    Radio Control Soaring Digest.  The cost is $16 per year.  The address
    is:  RC Soaring Digest
         P.O. Box 1079
         Payson, AZ. 85547
    
    This magazine is exclusively dedicated to Sailplanes, unlike the
    glossies where it is rare to have more than a few pages about
    anything related to Sailplanes.
    
    Regards,
    
    Jim
337.30I'm all AMIX'ed up in a Sailplane RadioCSC32::M_ANTRYWed Oct 05 1988 19:5241
    
    
    I need to ask a sail plane related question.  What is the best thing
    to do with your spoilers on a ship.  I know that as you come in
    for a landing if you need to loose altitude you open the spoilers
    and then to correct the nose down atitude you feed in up elevator.
    
    The soulution to the two thumb approach is to automatically mix
    those two channels so that as you open the spoilers it feeds in
    the up elevator.
    
    Now for the questions:
    
    What are the standard notations on a radio as far as channel numbers:
      1 - Rudder
      2 - Elevator
      3 - Aileron (usualy working the rudder on a non-aileron plane)
      4 - Throttle (Spoilers/Flaps on a Glider)
    
    Is this correct????????
    
    So assuming that you have the Spoilers hooked up to the Throttle.
    I want to mix the Elevator with the Throttle.
    
    What type of radio does this take??????
    
    I have normaly seen most plane radios mix Rudder/Aileron,
    Aileron/Elevator.
    
    I am looking for a Futaba radio that is hopefully not more that
    $200.00 that will do this.
    
    Are the Heli radios set up to do this by default?????
    
    Would a Cristi-mixer do that same thing for cheaper.  I read the
    info in Tower and I didnt really gather that it would do what I
    want.  You know is the mix adjustable in proportions????
    
    Oh well,  thanks for all the help in advance......
    

337.31Christi-mixer should workRICKS::MINERElectric = No more glow-glopThu Oct 06 1988 01:2725
RE: < Note 337.30 by CSC32::M_ANTRY >

>    Would a Cristi-mixer do that same thing for cheaper. 

    I think the Christi-mixer would work fine for this.  I base this
    comment only on having read the Ace R/C description (more detailed
    than Tower's).  The way I understand it, you can mix any amount of
    either channel to the other one.  In your example, any amount of
    spoiler to elevator _AND_ any amount (including none) of elevator to
    spoiler.

    However, since I have never seen one in person, maybe someone else
    out there can correct this possibly mis-understood idea.  Another
    idea may be to call Ace R/C and ask them specifically.

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/
337.32NOT HELI RADIOSSALEM::COLBYKENThu Oct 06 1988 16:5712
    Heli radios do not have the type of mixing that you are looking
    for.  They mix the throttle and usually an aux. channel that is
    used for collective pitch.  They also couple this to the
    tail rotor (rudder) channel to compensate for torque.

		________
	 /	  __|__  
	=========[_____\>
	/	__|___|__/  BREAK A BLADE,
			    Ken    	

337.33Do what they did before fancy radiosK::FISHERThere's a whale in the groove!Thu Oct 06 1988 17:076
Buy a cheaper radio and mix it mechanically.

Bye          --+--
Kay R. Fisher  |
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337.34Airtronics MD7SP 53 mhz????CSC32::M_ANTRYThu Oct 06 1988 20:5530
    It looks like the radio of prefrance in our club, for a no holds
    barded, spare no expense radio is the Airtronics MD7SP which has
    all the mixing you would ever want.
    
    This infor was obtained from some of the F3b'ers in our Club (Pikes
    Peak Soaring Society)
    
    I guess this radio wsa intended for the Giant/Pattern flyers and
    now Tower even has them on sale for $249 or about 1.5 pager shifts.
    
    
    Now for the next questions:
    
    If I buy one of these I would like to take advantage of having a
    Ham Radio licence and get one on either 51 or 53 mhz.  Just what
    is the status on those frequencies now and in the 1991 future.
    
    Also,
    
    Has anyone heard of a Flying wing slope ship that is made by a young
    fellow out in San Dieago called I believe the Slope Master.  I seen
    it and talked with the fellow about 2 years ago out at Torrey Pines
    before I knew I was interested in Gliders.  I am looking for
    fun/cheap/easy to build slope ship and I thought this would be one.
     It comes with foam core wings and a mechanical mixer for the elevons.
    
    Also there are about 12 of us in our club that has gotten together
    to build the MARIAH slope plane that was in MAN about 2 issues ago.
     It should be fun, we hope to have a 1 plane class contest on the
    slope here soon.
337.35SP = Sail PlaneK::FISHERThere's a whale in the groove!Fri Oct 07 1988 11:3026
>    barded, spare no expense radio is the Airtronics MD7SP which has
...    
>    I guess this radio wsa intended for the Giant/Pattern flyers and
>    now Tower even has them on sale for $249 or about 1.5 pager shifts.

MD is for Modular, 7 is for 7 channel, SP is for Sail Plane.  So even
tho it is (was) the preferred Airtronics radio for pattern that is just a
side effect - the mixing setups were designed with Sail Planes in mind.

Also in the issue before last the AMA magazine credited only one company
with certifying radios for 1991 - Airtronics and they listed the models
certified and the Modular series was one of them (includes MD7SP) so
if anyone orders one from Tower or anybody else make sure you get the
newest version (gold sticker transmitter and double tuned receiver).

Also Tower has been selling this radio for $250 for a few years.  Their
last few flyers try to make this look like a reduced price - but it is
normal.  You could argue that it is a good price in that JR prices have
increased 25% in the last year.

P.S.  I give up - what is a pager shift?

Bye          --+--
Kay R. Fisher  |
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337.42Check the balanceCURIE::ANKERAnker Berg-SonneMon May 15 1989 14:5737
        Re:< Note 998.1 by CLOSUS::TAVARES "John -- Stay low, keep moving" >

                Gliders are extremely  sensitive to balance and typically
        balance problems are aggravated  on  landings because of the slow
        speeds and sharp turns.   With  my latest glider that is properly
        balanced I have not had a very hard landing yet.
        
                It took me a long time  to  learn how to balance a glider
        correctly.  On a power plane you  want  to  have  the CG at or in
        front of the CG marked on the plans.    On gliders I have several
        times found that the correct GC is BEHIND the  one  marked on the
        plans.
        
                To balance a glider put the CG EXACTLY as marked  on  the
        plans.  Then hand launch it a few times to tim  it  out  and then
        put it on a hi-start.  One its trimmed out for horizontal  height
        put  it  into  a  shallow  dive and release the controls.  If the
        glider pulls  out of the glide, stalls, dives, pulls out, stalls,
        etc.    then    your   CG  is  too  far  FORWARD  (which  I  find
        counterintuitive).  If it  stays in the dive or dives steeper and
        steeper, then your CG is  too  far  back.   You want the glier to
        pull gradually out of the dive without porpoising.
        
                I don't know whether this is  a  problem for you, but its
        worth repeating because a poorly balanced glider  is  a  bitch to
        control.
        
                      _ 
                     / |
        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/
337.43Prophet 941 sailplaneIGUANO::WALTERThu Nov 16 1989 16:1324
Now that I've finished the Scooter, I can move onto my real winter project, a
Davey Systems Prophet 941 sailplane. Up to now I have only flown 2 meter
gliders. This plane has polyhedral wings of 100 inch wingspan that may be
separated into two pieces (which is the only way it will fit in my car). I 
plan to also include spoilers.

Why choose the Prophet? This is the plane that Tommy Keisling flies. Tom 
became an Expert sailplane pilot in the Eastern Soaring League last year,
accumulating a record number of points for a single year. Now, I'm not 
suggesting that I'll start flying like that once I get the plane in the 
air. However, I've watched his style intently, trying to pick up pointers, 
and I've noticed that the Prophet turns into a thermal very nicely. It's 
able to make tight, flat turns without loosing much altitude, something
I've found very tough to do with my 2 meter Metric. And the extra wingspan
makes it much more visible, especially useful when riding a thermal way
down wind. It also has a very strong wing for those hard winch launches.
I figure it'll take me well into February to complete it.

I also promised to build a cheap and quick glider for a guy in the CRRC 
club (Paul Desorcy in case you know him). I figured a Gentle Lady would
be fine, but I've never built one. Any comments?

Dave

337.40review of R/C Soaring DigestABACUS::RYDERperpetually the bewildered beginnerWed Dec 20 1989 03:2625
    I received my first issue of R/C Soaring Digest today.  It seems to
    be worth the $17 for 12 issues.  It is a black and white pamphlet
    from a garage shop, 5.5 x 8.5 x 32 pages, not a glossy.  It has
    ads, brief articles, press releases, letters, and product reviews.
    ( 9 pages,    6 + 3        4            4           2     plus 4 misc)

    The articles in this issue:
    
      Jerry Slates: one page on carbon [shielding] effect on radio & fix    
    
      Gordon Jones: one page on several uses of carbon fiber
    
      B&B Kuhlman: two pages on sweep angle of flying wings
    
      Pancho Morris: 2/3 page on dive testing CG positioning
    
    I noticed that the drawings of the Competition Products Phoenix
    show the ailerons in the outer wing sections are driven by servos
    just over the border in the inner/main wing sections.  Is that common?

    Jim Blum recommendation this little magazine and gave its address
    in 337.29.  He referred to the magazine in notes 337.6, 337.22, 337.24,
    and 687.1  I now second his recommendation.

    Alton
337.41Aileron Servo positionsK::FISHERStop and Smell the Balsa!Wed Dec 20 1989 15:4431
>    I noticed that the drawings of the Competition Products Phoenix
>    show the ailerons in the outer wing sections are driven by servos
>    just over the border in the inner/main wing sections.  Is that common?

Yes.

If you put the servos in towards the center you have more linkage slop.
If you put them out further you have your mass too far from the center
line of the aircraft.

Ideally you want the servo(s) in the center with no linkage slop and the
control horn in the exact center of the aileron.  That way you keep the
mass in the center (remember when gliders land how a wing tip touches 
the ground and the plane just spins around with seemingly no mass).
You want the horn in the center of the aileron so that if there is minimal
flex to the aileron.  When you have the horn at the inside edge (like
they typically do) then the aileron must be stiff so it doesn't flex
which means it is fiberglassed or covered or harder wood or... all of
which adds weight.  The reason they want two servos is because they want
the fancy radios to give aileron differential and optionally flaperons
or spoilerons.  In scale power planes they want the redundancy of the
extra servo and the increased power of two aileron servos in giant scale.
You will almost never see a 1/4 scale Cub with only one standard servo
for ailerons.  In the tournament of champion planes they have the servo
horns very close to the control horns to minimize control linkage slop.
They also use very expensive accurate servos.

Bye          --+--
Kay R. Fisher  |
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337.44The Prophet flies7983::WALTERMon Apr 02 1990 21:5833
I finally got my winter project, a Prophet 941 sailplane, finished to the point
where it was flyable this weekend. (If you're interested in a description of
the model, see note 1079.8).  It looked like the weather wasn't going to
cooperate, but Sunday afternoon it cleared up, the sun came out, and I set out
for my favorite field.

I have to say I've never had a plane perform so well right off the building
bench. My first test throw was to check out the elevator trim, and I ended up
having to walk about 300 feet to retrieve the plane. It seemed to slice 
through the air like a scimitar.
 
It felt so good, I didn't bother with more hand throws, so I strung out the
high start. With the adjustable towhook placed where the instructions
suggested, it went up solid as a rock, a nice high arc with no weaving. I 
intended to concentrate on setting the trim, but it immediately went up in a 
thermal, so I decided to ride it up. Damn, it flies nice! I can stand it on a
wingtip in a turn with only minimal loss of lift. It floats very nicely, but
has a pretty wide speed range. I haven't weighed it yet, but guessing around
42 ounces, and 941 sq. in. area, that's around 6.5 oz/sq.ft. Stalls are very
gentle and there's plenty of time to react to them.

I also did the dynamic trim test for CG (put it in a dive, let controls go
to neutral, see if it continues in a straight line), and I got it pretty much
right in one try. I have about 2 oz. of lead in the nose, but I'm using
a 270ma battery until I can figure out how to fit a 500ma in. When I put in the
500ma battery, most of the lead can be taken out.

It DEFINITELY outperforms my 2 meter models, but I'm not sure if that's due
to the design, or the increase in wing area. But who cares? I love flying
this thing! 

Dave

337.3gliders come down, sailplanes are reluctantK::FISHERStop and smell the balsa.Wed Apr 25 1990 21:0565
>                     <<< Note 539.3001 by CSC32::M_ANTRY >>>
>                               -< WEll......... >-
>
>    A glider is plane that was designed as a power plane but has no engine. 
>    A sailplane is designed as a sailplane from the very beginning.
>    
>    Glider's are like all the army/navy/airforce stuff.
>    
>    Sailplanes are like GROB's and the such.

I don't agree with your first line but you're certainly close to our
definition so I'll give it to you.

Here's what the old buzzard has to say about the matter.
============================================================================
Glider, Sailplane.

   Interchangeable words, to most folk.  A few cranks insist that a glider
glider downward after release, a sailplane soars upward.  This would seem
to make the definition largely dependent on the weather.  In the 1920's the
British formally declared a sailplane to be "a glider having a sinking
speed of less than .8 meters (2.6 feet) per second."  Conclusion: the
Brits had long winters, with little to occupy their minds, back before
the BBC.
============================================================================

The following is taken from the August 1981 issue of AOPA Pilot.

============================================================================
One way to be given the cold shoulder is to walk up to the proud owner of
a 20-meter Schleicher ASW-17 and say, "Gee, what a beautiful glider."
Such a remark has the same insulting effect as referring to a Stradivarius 
as a fiddle.

Technically speaking, all fixed-wing, powerless aircraft belong in the 
glider category; but soaring purists reserve this generic term for aircraft 
that usually are not expected to gain altitude in free flight and that have
glide ratios (or lift-to-drag ratios) of less than 20:1.  A glider
designed to gain altitude after tow release is called a sailplane.  In other
words, gliders glide and sailplanes soar.

The term sailplane seems to have originated from the German, segelflugzeug,
and was introduced in the United States during the late 1920s by pioneer
designer Holly Bowlus.

Since virtually all modern gliders have glide ratios better than 20:1, it is
appropriate to refer to all of them as sailplanes.  Those with glide ratios
exceeding 30:1 are called high-performance sailplanes.  A design topping
40:1 is a very high-performance sailplane, and those rarities exceeding
50:1 are known as extremely high-performance sailplanes.

The Schleicher sailplane mentioned earlier has a glide ratio of 48.5:1 and
can glide 7.98 nautical miles in still air from a pattern altitude of only
1,000 feet.  It definitely is not a glider.

                                           -- Barry Schiff
============================================================================


Bye          --+--
Kay R. Fisher  |
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