Conference vmszoo::rc

        Re:< Note 1025.0 by BRNIN::SOUTIERE >

                Ken I have a bit of experience.  Flaps have the effect of
        greatly increasing the  lift  and  drag  of the main wing.  It is
        surprising how much a  little flap affects the lift and drag.  If
        you have flaps totally uncoupled with elevator you will fund that
        the  plane  balloons  when  you  apply    the   flaps  and,  more
        dangerously, dips the nose when you retract them.  To avoind this
        effect you have to couple the elevator so  that  down elevator is
        fed in as the flaps are lowered.  If this is done right the plane
        will  remain  level,  may  rise  a  bit,  and  will  slow    down
        beautifully.
        
                The biggest  problem  with  flaps is caused by retracting
        flaps with insufficient  airspeed.  This causes the plane to drop
        like a brick.
        
                Flaps are enormous fun.    Try  them at altitude and make
        sure you are completely confortable before you use them too close
        to mother earth.  A bit  of  advice:  start with only about 10-15
        degrees.
        
                      _ 
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        |  _====____/==|
        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

Good subject, Ken,

What are flaps?  Quite simply, flaps are a device designed to increase lift
(and/or drag) at low speeds when stability is critical, i.e. taking off and 
landing.

The first application for flaps was, most likely, to shorten landing distance
while slowing landing speed.  By lowering the flap, the air passing over the top
surface of the wing is forced to travel further before rejoining the air passing
under the wing.  This accelerates the air, further decreasing pressure on top of
the wing, thereby increasing lift.  In addition, the lowered flap produces drag
which helps reduce airspeed.

There are other applications, e.g. Fowler-type flaps which extend back as well 
as down, increasing effective wing area in addition to their flap-function, and
speed brakes wich provide drag only with no appreciable effect on lift.

But, we're primarily interested in the first application so let's discuss their
use.  In a full scale aircraft, the increase in lift resulting from deploymant
of flaps will raise the nose of the aircraft and decrease the airspeed.  There-
fore, down elevator-trim is fed in to lower the nose and raise the airspeed to
the recommended approach speed.  Failure to do this can result in a stall/snap/
spin which is not particularly desireable at the low altitude of a landing 
approach.  Your cockpit procedure, normally, is to dial in the predetermined 
amount of down-trim _before_ deploying flaps; this prevents the ballooning 
effect as you simply relax your back-pressure on the elevator as flaps are fed
in.

What results is a steeper, shorter approach angle while retaining the same air-
speed but lower ground speed.  Voila, you can land slower, in a shorter distance
over higher obstacles.

In model application, generally, we don't use flaps for takeoff.  (I _did_ find
that using about 15-degrees of flap at Colorado Springs last year effectively
shortened my takeoff run to what I was used to at my [lower] home field ele-
vation.)  Unless the model is quite overweight, flaps simply aren't necessary 
for takeoff.  On landing, however, they're more than a novelty, even on lightly
loaded aircraft that wouldn't require their use.  The use of flaps will allow
for a nice slow touchdown under full control and will lower the stall speed by
[perhaps] 10-15% adding an extra margin of safety.

So, how do we use them?  First, I would suggest getting familiar with how flaps
affect the model's pitch attitude by experimenting with them at a comfortable
altitude.  As with a full-scale, don't deploy flaps at full throttle; this is
not only potentially harmful to the flaps, it will aggravate any ballooning
tendencies as well.  Slow the model to a comfortable medium speed like that used
for a landing approach and smoothly drop the flaps watching the pitch angle.  If
there's no change in attitude, yer' home free.  If the nose rises, dial-in
down-elevator trim to establish a slight nose-down attitude.  Note this amount
of trim and use it as part of your pre-landing checklist, setting elevator trim 
just before dropping flaps...you'll hold the nose level with back-stick when the
trim is dialed in, then release it as the flaps are fed in.

I always drop flaps during the crosswind portions of the landing pattern while 
the aircraft is banked in the turn...this dampens any ballooning and maintains
a constant rate of descent.  All you can see is a reduction in groundspeed.
Once flaps are deployed, fly the pattern just as you normally would, though 
you'll probably find that the pattern must be flown shorter than usual.  Keep an
eye on the pitch attitude, keeping the nose slightly down all through the ap-
proach.  DON'T let the nose come up without adding power; you're already plenty
slow and the plane'll decelerate to stall speed rapidly if you don't keep the 
nose down.  Flatten the glide at about 1-foot up (right over the numbers, of 
course ;b^}) and simply hold it off without ballooning until the wheels kiss
onto the runway.  Simple. right?

But be careful if you overshoot or have to go around for any reason.  Add full
power and keep banks gentle while you milk the flaps back up.  DO NOT raise the
flaps rapidly as you'll drop the bottom out from under the ship with results
that don't require explanation.  Just be smooth and gentle with the flaps
whether raising or lowering them and you won't get into any trouble.

This may sound a little more daunting than it should.  Flaps are not at all 
dangerous, in fact, they're just the opposite as long as they're USED PROPERLY
AND NOT ABUSED.  Flaps add a new dimension to R/C flying and I highly recommend
them to anyone who wants to experience a bit more challenge and realism in his
R/C flying.

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    Really good stuff, everything I really wanted to know about flaps,
    but was afraid to ask !
    
    Help clear this up a little further for me please.
    I intend to use flaps on my Bird Dog, and have carefully selected
    a radio that offers a nice proportional motion on that particular
    channel.  Now, I have assumed all along that it is indeed imperative
    to have this kind of proportional control so that the degree of
    flap deployment is infinitely controllable.  Am I correct ?
    
    Does anyone use a simple on-off, bang-bang switch.  If so, is it
    successful ?, and further, if so, how do you select the optimum
    angle ?
    
    One more question, if you were to pick a "Best" angle, what would
    it be ?
    
    Oh !, one more - is it advisable to try "Full" flap (90 deg) for
    any reason !!
    
    Keep 'em comin'
    
    Thanks, John N.

        Re:< Note 1025.3 by RUTLND::JNATALONI >

                The flaps  on my Robinhood were of the two position type.
        Either full on  or  full  off.  From trial and error I found that
        about 30 degrees was  optimal.    The flaps were about 1/3 of the
        trailing edge, the rest (outer  part)  were ailerons.  The effect
        was amazing.
        
                The Robinhood died from an accident  which  clearly shows
        where flaps can be tricky.  I had just made a slow, low pass down
        the runway and gunned the engine, rised the  nose  and  retracted
        the  flaps  when the engine died, just like that.    The  instant
        change  from flying machine to falling object was amazing.   Much
        more severe than your typical stall.
        
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        |    |        o \
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                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

    John,
    
    Anker's already adressed most of yer' questions plus verifying what
    I'd said about "dropping the bottom out from under the plane." 
    Again, let me say that flaps, of themselves, are not dangerous but
    they must be handled carefully, preferably always "milked" down
    and ESPECIALLY up.
    
    For this reason, I've never entertained anything but proportional
    flaps where I can select the desired deflection and speed of deployment
    myself.  Anker's experience with dumping the flaps on a go-around
    is one good reason for this.  I know many scale fliers who _do_
    use non-proportional flaps, "bang bang," as you called them and
    get away with it just fine.  Problem is that there's always the
    chance for events to gang up on you as they did to Anker...I'll
    stick to proportional, thanx just the same.
    
    As to optimum degree of deflection, that depends a lot on the
    individual airplane and must be determined through experimentation.
    At some point around 30-45 degrees, flaps cease increasing lift
    and become merely drag-brakes.  This _can_ be desireable in some
    applications but be aware that no augmentation of lift is realized
    and yer' flirting with a stall.
       

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    
    Great stuff guys, sure helps me sort things out.
    
    I can relate one type of experience I've had with flap use in
    full scale aircraft; As a back seat passenger in an L-19 in
    Korea, with one "Very good" pilot who could spot land just about
    anywhere:
    
             Nose down (Way down), deploy flaps, (My eyeball guess
    says about 35-45 d.) - and I'd be looking, over his shoulder,
    through the windshield, at GROUND...Comin' up!
    
             Then a perfect flare about 2 feet up, a quick yank up on
    the flap handle...and we were planted...flying done, period!
    
    I'd love to be able to duplicate that maneuver with my model !!
    
    
    Thanks again, I'm impressed.
    
    John N.

    
    	I'm still a bit concerned about the "mixing" aspect.  My radio
    is a Futaba 6NLK AM and does not have a mixing switch/dial.  I've
    got my flaps connected to channel 6 which is a OFF, 3/4 ON and FULL
    ON.   What I am hearing is to dial in down trim on the elevator
    first then hit the flap switch to the first setting (3/4 ON).  When
    I turn on approach hit the flap switch to FULL ON and cut power
    some more.  Is this right?  Again remember, I don't have a mixing
    switch.
    
    Ken

    Ken,
    
    That'll probably work fine.  They key is to slow the aircraft before
    deploying flaps, then observe pitch and compensate with the elevator
    stick; set elevator trim to get stick back to neutral with the nose
    slightly down..._this_ amount of trim is what you'd preset from
    now on when setting up a flap-assisted landing.    

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    Dan,
    
    Did I misunderstand the flap-function on the panic.  I thought the
    flaps were coupled with the elevator to function like the wing-flaps
    on a U-control stunt ship and had no particular function as landing
    flaps.  What'sa skinny....??   

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

RE:< Note 1025.12 by PNO::CASEYA "THE DESERT RAT (I-RC-AV8)" >
>                             -< PANIC FLAPS...... >-

    Eric had his set up like a U-control stunt ship - coupled to the
    elevator all the time.  In fact, Eric was using only one servo to
    drive both elevator and flap - thus, they were always coupled.  Now,
    however, with a new and fancy radio, he has a separate servo for
    each and with a flick of a switch, he can get the origional way he
    had it (flap moves with elevator all the time), or just the "normal"
    landing flap function.

    Dan Snow set his up to be just a landing flap.  (Moving the elevator
    never moves the flap.  Although he can dial in down elevator trim
    with the flap down.)

                       _____
                      |     \
                      |      \                          Silent POWER!
      _        ___________    _________   |            Happy Landings!
     | \      |           |  |         |  |
     |--------|-  SANYO  + ]-|  ASTRO  |--|              - Dan Miner
     |_/      |___________|  |_________|  |
                      |       /           |     " The Earth needs more OZONE,
                      |      /                       not Caster Oil!! "    
                      |_____/

    
    	I just had a thought!  (sorry)
    
    	Correct me if I'm wrong, but when I fly, I normally have to
    set trim at the speed I plan on flying.  So lets say I'm flying
    at 3/4 throttle and set my trim for level flight.  When I'm ready
    to make my landing approach, I usually cut speed which in turn will
    drop the nose.  If I apply flaps which in turn raises the nose,
    they should basically even out.....shouldn't they?  I just can't
    wait to fly my Chipmunk with flaps!!!
    
    Ken
    
    
    P.S.  I've been hunting for over 20 years, and I've never seen a
    Chipmunk with flaps!

    Re: .-1, Ken,
    
    Well, almost...you still may need to feed in some extra down-trim
    depending upon how the Monk behaves with flaps down.
    
    You might get lucky and not need to retrim anything; my MiG-3's
    that way...I can dump the flaps and experience no pitch change
    whatever.  And, since I like to fly with a little nose-down trim
    anyway, I'm all set to just let the ship come downhill on final
    all on its own, just maintaining bank, yaw and throttle 'til time to 
    flatten the glide at a foot or so and hold 'er off 'til touchdown.
    BTW, it's a kinda' hard thing to teach yourself but, once you're on
    final, you should use throttle, not elevator, to control your rate 
    of descent...believe it or not, elevator is used to control airspeed
    via the angle of attack it establishes.     

      |
      | |      00	 Adios,      Al
    |_|_|      ( >o
      |    Z__(O_\_	(The Desert Rat)

    
    	Al, I guess thats going to take some getting used to.  What
    I do when I'm ready to land, is on the down leg of the circuit
    I cut power to an idle, then I make my turn upwind (this gives 
    me plenty of decent time), I then use elevator to either get me
    up or down depending on the distance to the runway.  If I know
    I'm going to be too short, I give it a little gas and cut back
    when I've reached the correct distance.  I know this is not the
    proper way, but I taught myself, and became accustomed to this
    non-realistic method.  
    
    	I promise I will try to change my habits, but I am not flying
    with any experienced RC'ers who can OJT me.  One of these days
    I will join a club and become an official RC'er.
            
    Ken

    
    Another flap-related question...  what is the best way to handle
    dead-stick situations (such as Anker's)?  My first guess would be that
    if flaps are down, keep them down unless you have enough altitude
    to raise them safely.  My second guess would be that if you do have
    to dead-stick with flaps down, you must keep pushing the nose down
    or risk a stall (from what I'm reading in here).  Will a typical ship
    handle as well dead-stick with flaps down?  Would you intentionally
    use flaps to land dead-stick, if you thought you were going to run
    out of runway but didn't have enough altitude to swing around again?
    Might Anker have had a chance if he had kicked the flaps down and
    pointed his nose down quickly?  Thanks for the topic and replies, this
    has a lot of interesting stuff.
    
    Bill

    
     
    Bill,
    
     Answers, (Based on my full scale experience)
    
         1. YES
    
         2. YES, or preferably add down trim.
    
         3. NO
    
         4. YES
    
         5. Don't recall the circumstance.
    
    
                              Dan 
    

    'Scale Aircraft Quarterly' Summer 89 Issue has a very interesting
    article on Fowler Flaps. The article includes drawings of both Fowler
    flaps and 'drooping' leading edge mechanisms for model aircraft.  The
    mechanism uses a single servo for deployment with a differential on the
    push & angle of flap rods. Whereas the drooping leading edge is just a
    bottom hinged leading edge pushed out (in conjunction with the flaps)
    at the top revealing the extra top surface. 

    I don't know much about the idea of a drooping leading edge so who
    would like to explain that one. My guess, as per the principle of
    flaps, you are further increasing the distance over the top of the wing
    that the air has to travel. 

    Is it normal to use just one servo for operating a set of flaps ? Or do
    you use one for the push and one for the angle. I can see that a single
    servo could do it but controlling the lowering of the flap would be a
    little limited. Any comments ? 

    If anyone is interested I will forward a copy. I don't know if you get
    the magazine in the US. 


    Regards, 

    Eric(); 
    

>    I don't know much about the idea of a drooping leading edge so who
>    would like to explain that one. My guess, as per the principle of
>    flaps, you are further increasing the distance over the top of the wing
>    that the air has to travel. 

    If I'm correct, I believe that this is the system employed  on early
    F-86's.  The leading edge wasn't mechanically operated by the pilot. It
    was essentially spring loaded.  When airspeed fell low enough, the force
    actuating the leading edge could overcome the frictional forces of the
    airstream, and the leading edge slat would deploy (or pop out, so to
    speak). At higher speeds, the forces created by friction with the
    airstream were enough to push the leading edge in.

    The idea is of course, similar to the idea of flaps.  You increase the
    chord and camber of the airfoil, and this gives you greater lift at the
    expense of increased drag.  You then have the advantage of a thin, low
    drag airfoil for high speed flight, where the reduction of drag is
    important, and a thicker, draggier airfoil for when your flying slow,
    and need the extra lift and don't care about the extra drag.  Leading
    edge slats complement trailing edge flaps. 

As I understand the principle of the leading edge slat from my
sailing days, it acts differently than in -2.  The slat narrows
the space for air coming into the leading edge of the wing and
thereby accelerates it, giving increased lift for the lower
forward speed.  In a sailboat, the slat is the jib and the
wing is the mainsail. 

A recent issue of, I think, Model Builder, had a diagram for the
fowler mechanism, and possibly the leading edge slat too.  It was
in the soaring column if memory serves right.

        Re:     <<< Note 1025.23 by CLOSUS::TAVARES "John -- Stay low, keep moving" >>>

                The way  the  slat  works  is  exactly  like the jib of a
        sailboat.  It reroutes some of the airstream that otherwise would
        have gone under the  wing  to  the  top.   This causes two highly
        desirable effects:  higher angles  of  attack without a stall and
        greater lift.
        
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        |    |        o \
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         Hang in there! o_|_
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             Anker      \_|_/

    OK, I am changing a plane from strip ailerons to flaps and ailerons.
    I am going to use the 1/3 outboard length for the aileron, and the
    rest for the flaps (as recommended in the note about the C-45 and
    adding flaps).
    
    Obviously, if I use the same pieces, then I need to substantially
    increase the throw.
    
    But what about using a wider surface??  I have material enough to
    double the current width.  Or will increased throw be sufficient??
    
    Thanks,
    jeff
    

        Re:        <<< Note 1025.26 by WRASSE::FRIEDRICHS "Never trust a premi!" >>>

        Jeff,
        
                You didn't  read  my  lips.  Your flaps will be much more
        effective than you  imagine.  The 1/3 inboard end of uour aierons
        weren't  doing anything anyway,  but  as  flaps  they  will  work
        incredibly well.  I would  say no need to change the width of the
        pieces or increase the throw.   I  would  also advise you to make
        the rations 2/3 aileron and 1/3 flaps.
       
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        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

    Hmmmm, I just looked back at my note 807, "Flaperons vs Ailerons and
    Flaps" because I thought I read in there the 1/3 for ailerons and 2/3
    for flaps, but it didn't.  
    
    Using the same stock will make this task trivial.  I used gapless 
    iron on hinges so all I have to to is cut the aileron and add control
    horns...
    
    Hopefully, I will be giving this a try this weekend, I'll report next
    week on how it all went..
    
    Thanks all (especially anker for correcting what could have been a
    grave error!)
    jeff
    

    Well, the flaps have been added to my SS-40.  I strongly recommend
    this modification.  I have only had 2 flights with them so far, and
    they really change things a lot!!  
    
    See note 813.144 (The super sportster note) for details on how I
    implemented the flaps...
    
    Thanks Anker, the 1/3 flap, 2/3 aileron seems to be working well.
    I will post the amount of deflection that I have after I play with
    it some more and measure it.  (I need to increase it just a bit...)
    
    cheers,
    jeff
    

    Well, I guess I just couldn't learn from what I read here!!
    
    Last night I was flying the SG-40 and after a long flight the engine
    went dead (you just can't trust and engine that runs outa fuel!).  I
    had plenty of altitude, so I deployed the flaps, gave some down trim
    and set her up for the landing..  Well, being a rookie at these flap
    things, I came in much too high.  The field that I was flying at is
    very restricted, with trees at both ends, so I *had* to put it down in
    the field...
    
    All of the sudden, for some reason, I reacted to my height by breaking
    rule #1, "Don't dump the flaps when you get into trouble".  
    
    Well, I proved just how quickly things without lift fall out of the
    sky.  Luckily, I was over some tall grass and I made a 3 point (main
    gear and spinner) landing and the only damage appears to be a bent gear
    and a bruised ego.
    
    I fell asleep last night saying to myself "Don't dump the flaps!"
    
    cheers,
    jeff
    

        Re:        <<< Note 1025.30 by WRASSE::FRIEDRICHS "Never trust a premi!" >>>

        Jeff,
        
                It sounds  like  you  are  like me.  I have to make every
        mistake at least once.
        
                Last night Fritz  Bien  told me about a real novel way of
        building flaps.  It  came up in a conversation about the SongBird
        100  glider kit that I  bought  recently  from  Bob  Page.    The
        instructions  don't  include  flaps  or spoilers,  which  are  an
        absolute necessity for competition soaring.  His  suggestion  was
        to  build  the  flaps  conventionally by conversion the  inner  8
        inches  of  ailerons  to  flaps,  but  here  comes  the    really
        interesting bit.  By putting a piece of plywood on the top of the
        flap  which  extends  over  the trailing edge of the wing and  is
        flush  with  it  when  the  flaps are raised I get both flap  and
        spoilers when the  flaps  deploy!   Since the flaps increase lift
        and increase drag and the spilers decrease lift and increase drag
        the net effect becomes increased  drag  with  the  resultant lift
        change  customizable.   For gliders you  want  to  increase  drag
        dramatically without altering lift, so this setup is ideal. Neat!
        
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        |    |        o \
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         Hang in there! o_|_
                          |
             Anker      \_|_/

>                Last night Fritz  Bien  told me about a real novel way of
>        building flaps.  It  came up in a conversation about the SongBird

I had to read this a few times before I figured out what you said.
Here is a side view for the benefit of others:


                                  \  <- Spoiler
                                   \
-----------------------------------o\
Front          Wing           Aft / |\
---------------------------------/  | \
                                    \  \
                                     \  \
                                       \ \  <- Flap
                                         \\
                                           \

Seems like a neat idea but slightly dangerous - if flying fast and you pulled
the flaps/spoilers the wind could rip it right off.

>        100  glider kit that I  bought  recently  from  Bob  Page.    The
>        instructions  don't  include  flaps  or spoilers,  which  are  an
>        absolute necessity for competition soaring.  His  suggestion  was

Tho I am surely enjoying my Sagitta Spoilers and it makes getting points
on landing much easier and I also agree that the larger a plane is the
harder it is to his the same small circle I would disagree that flaps
and spoilers are absolute necessities for competition soaring.  I have
seen too many 1st prizes go to flyers without flaps and spoilers.

Bottom line is thanks for passing on this really neat idea to all of us.
Now if only there was a simple way I could zap on some plywood to my spoilers
and get free flaps!

Bye          --+--
Kay R. Fisher  |
---------------O---------------
================================================================================

    
    
        I am in the process of adding flaps to my Ace 4-40. They will
    initially be coupled via a Y - connector to the elevator. When I get
    something more than a 4 channel radio, I will possibly convert to
    independant operation.
         I am looking for some advice on how to set up the flap deflection
    when the flaps are coupled to the elevator ( as in U-control stunt ).
    I know basically it is set up so the flap deflects down (towards the
    ground) as the elevator is deflected up (Towards the sky). 
       My questions are:
    
          
       1.   What are the best ratio's to set up the deflections ?
    
       2.   Does the flap ever exceed neutral, and deflect upward (Towards
            the sky)when the elevator is deflected down (towards the
            ground), or does this create too much dive capability since 
            gravity is added to the equation.
    
        * any reference to the ground or sky assumes normal (not inverted
          operation) and is only coincidental to the comments made regarding
          Jim R's panic flap questions.
   
      I assume this set up will give slightly increased take off performance
    due to the extra lift created, and slightly slower, although maybe
    trickier landing approaches, and squarer loops.
    
      Any help, especialy from the veteran Panic pilots, will be
    appreciated
    
                                               Thanks,
    
                                               Dan W.
      

    I am planning to add flaps to my Eagle2 trainer to get some experience
    flying with flaps.  I will be using one of the standard techniques for
    building the flaps as covered elsewhere in these notes.  My question
    involves the issue of how this is done with the transmitter.
    I am using an Airtronics Vanguard 6-channel Tx.  There is a
    three-position ,center-off switch labled "flaps" that I assume is what
    I will be using to deploy the flaps.  My vision of this is that when
    the switch is thrown, it will very rapidly move the flaps from neutral
    to full down.  Won't this rapid movement of the flaps cause problems? 
    I would think that moving the flaps down more slowly would be much
    better, and I'm thinking that a control like the throttle stick, where
    you can move it at the speed you want, is much better.
    
    This leads me to think that if I replaced the toggle switch with a
    small pot of the correct resistance, I could in essence have the same
    capability as a throttle stick, thereby allowing the flaps to be moved
    down slowly, as well as adjusted for the exact amount of down
    deflection desired.
    
    Does anyone have experience with flaps deployed by a toggle switch, and
    if so, is there any problem with this?  Also, what about the idea of
    taking out the toggle switch and using a pot?  All comments/suggestions
    are welcome.
    
    Thanks,
    Joe

    Joe,
    
    
    	Are you sure the toggle switch is "center off". I have the Vanguard
    6 Ch. PCM and it's a 3 position switch with full throw one way (forget
    which way that is) is off, and then 2 flap positions. In this
    configuration, the first position would give you X degrees of flap, and
    the second, full flap deflection.
    
    	Flaps on an Eagle2 huh..........That must mean you never want to
    come down. 8^)
    
    Steve

    Re: -.1
    
    As far as I can tell, it is a center-off switch, and I had the same
    reaction you had.  However, I will examine it more carefully to make
    sure.  Your scenario is more like what I would expect.
    
    The eagle2 lands pretty well as it is, but the field where I land has
    high trees at one end, and numerous hazards at the other end, so I want
    to start coming in a little faster to avoid the problems, but still get
    on the ground quickly as the field is not that long.
    
    Thanks,
    Joe

    Hi Joe,
    
    I know, we still haven't had our phone call...  Try me tonight!
    
    Anyways, I have used the "gear" switch for flaps (binary - deployed or
    retracted) and never had a problem with the speed of deployment being
    too fast...  I usually had either already fed in down trim or had my
    finger on it when I deployed the flaps, otherwise it would baloon.
    
    You also want to be careful of when you deploy them as if you are going 
    too fast, you could rip both (or worse, one) off.
    
    I have also used the 6th channel on a Futaba (ie a trim lever
    controlling the channel).  I found that I usually just deployed them
    completely as it is difficult to accurately control this, while still
    using both sticks...
    
    I think that a 3 or 4 position switch would be the best.  (this is what
    I have in my 1:1 Cessna!).  You can then always have the same amount of
    flap at each position, but you don't have to remember anything more
    than was that 1 click or 2..
    
    cheers,
    jeff
    

    My JR Max6 has a center off flap switch. Up is mixed with elevator and
    down is landing position (which I can mix down elevator with to prevent
    ballooning).
    
    
    Ummmm, what's your manual say?? ;^)

    Chuck Colliers JR Galaxy-8 transmitter is arranged as Joe decribes,
    which doesn't make a lot of sense to me, ergonomically.  I guess it's
    because one position is for flap/elev mixing?  No matter, Chuck uses
    only full flap anyway.
    
    Chuck switches directly to full flap on his Baker Jug and the airplane
    does NOTHING, no ballooning, no nothing.  But, understand we're talking
    a 27-lb., low wing warbird here, not a lightly loaded, high wing
    trainer with a flat-bottom/high lift wing.  No matter how the flaps
    are initiated, proportionally or non-proportionally, I'd expect
    ballooning out'a the Eagle...it just wan't intended for flaps.  I
    suppose it'd work OK just for practice but I'd expect to have to dial
    in lots'a down trim when using flaps to keep the nose down and the
    airspeed above stall.  A trick you can use is to deploy the flaps while
    in a turn...this dampens the ballooning effect quite a bit.
    
    BTW, I'm dead set against home brew radio mods as the problems you can
    create far outweigh whatever advantage you might be seeking.  Also, if
    the radio is still in warranty, be advised that such modification
    (called tampering by the mfgr.) will void the warranty.  Oh, and I
    should mention that most contemporary radios use a toggle switch for
    flaps.  Unless it was a slide-type pot, I'd prefer the toggle to a
    rotary pot like my FP7UAP has...it's a pain to have to reach up and
    twist the flap knob several turns to dial in full flaps.
						 __
				|      |        / |\	   	       
      	         \|/		|______|__(o/--/  | \	   	       
      | |        00	       <|  ~~~  ____ 04 ---- | --------------------
    |_|_|        (O>o		|\)____/___|\_____|_/	   Adios amigos, Al
      |     \__(O_\_	        |	  |___/	 o	   (The Desert Rat)

    Joe.....I'll check the Vanguard when I go home. I could be wrong. At
    any rate, you should be able to mix flap and elevator which (after
    several attempts) should eliminate the balooning.
    
    BTW.....it's not so much a FASTER approach you should be looking for, 
    but rather a STEEPER one. Come in high over the trees, dump the flaps,
    and go into a fairly steep dive without gaining airspeed.
    
    Steve

    Re: Mixing flap with elevator
    
    Is this done thru some automatic method, or are you referring to
    manually giving it down elevator as the flap switch is flipped?
    
    If it's automatic, I sure didn't see anything in the Vanguard manual
    that talked about this.
    
    Still more questions than answers.
     
    Yes, the idea of coming in over a high tree line is as you pointed
    out...come in high, lower flaps, then get a steeper angle of descent to
    bring it to the runway in a shorter distance.  That's what I really was
    trying to say earlier.  I also like the idea of deploying flaps in a
    turn to avoid the balooning problem.
    
    Thanks for the replys so far.
    
    -Joe

    Remember, Angle of Attack determines speed and throttle controls
    distance.  
    
    I also suggest that you never add flaps on final (after making the
    trees).  You should add flaps (in a turn or whatever) in the pattern.
    Then use the throttle to make it over the trees.  You don't want to 
    be changing the AOA that much on short final..
    
    chers,
    jeff
    

Joe - this is a bit off the subject but...

If the radio doesn't allow you to have automatic mixing of down elevator
when you deploy the flaps then I would:

Put a bomb drop on the Eagle and use the extra channel for that.
It will be more fun.  Or:

How about a camera pod?  Or:

To really make life interesting have an extra servo set up to move
a mass of weight aft so that you can flip a switch and change your
CG, then when ever your friends want to take the sticks and show
you how real RC men fly - just flip the switch and watch them sweat!

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

Joe - I spoke too soon.  If the radio doesn't have flap/elevator mix
you can still do it mechanically.  It is really easy to implement.
A bit time consuming to adjust I'm sure the quite easy if the flap
servo and elevator servo are both in the fuselage.

But please don't ask me to draw the linkage picture with ASCII characters.
Only Tom Tenerowicz (our ASCII picture expert) can do that.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    Joe,
    
    On the PCM version of the Vanguard there is a FLAP/ELEVATOR mixing pot. 
    I would be suprized in the FM does not have one also.
    
    I had considered doing the same thing on my Sky Tiger.  Since the wings
    are almost identical with the Eagle it will be interesting to see how 
    you do it.
    
    Loren

    Kay:
    
    I got great news.  I can do the flaps AND one of the nice things you
    suggest.  You see, this is a 6 channel job, so in addition to the
    switch I've been talking about, there's another one marked "Retracts". 
    So I can have my flaps as well as a Bomb drop, or a shifting weight (I
    love that one), or whatever else I want, but I'm not sure of the camera
    as this baby is pretty underpowered with an OS .40 FP as it is.
    
    But you really did give some very creative ideas ;-)
    
    Great stuff.
    
    Joe

						 __
				|      |        / |\	   	       
      	         \|/		|______|__(o/--/  | \	   	       
      | |        00	       <|  ~~~  ____ 04 ---- | --------------------
    |_|_|        (O>o		|\)____/___|\_____|_/	   Adios amigos, Al
      |     \__(O_\_	        |	  |___/	 o	   (The Desert Rat)

    Loren:
    
    No such luck...the FM version does NOT have a pot, only a switch.  
    
    BTW: The reason I'm doing this on the Eagle 2 is to get the experience
    so I can eventually do it on the Sky Tiger.  I had the Sky Tiger out
    two weeks ago for its maiden flights, and it flies like a dream.  The
    only thing I can compare it to is the Eagle2, which is probably not an
    entirely fair comparison, but the difference in flight characteristics
    is enormous, and I was extremely pleased at the way it handled, and the
    ease with which it performed basic maneuvers.  The best way I can say
    it is that the Eagle2 is klutzy and the Sky Tiger is smoothe.  Now that
    I've flown it, its going to be hard going back to the Eagle2.
    
    Getting back to the flaps for the Eagle2, I have to build a new wing
    due to a bad crash which destroyed the original wing, so I am planning
    to do some experimentation, like flaps, also putting in less dihedral,
    and that way flying it again won't be so boring.  You see, the old
    Eagle has 140 flights on it this past season so I'm looking for a new
    challange.
    
    Re: a few back:
    
    Al, I respect what you are saying about the dangers of tampering with a
    radio design.  If there was some strong reason to have a proportional
    flap control, I was going to contact Airtronics to ask them for one of
    two things; 1) a schematic and parts list for the mod, or 2) a quote
    for them to do it.  I recognize that there is a temptation to believe
    it is so easy to do, then end up screwing things up, or worse, creating
    a safety hazzard, simply because of not knowing enough about the things
    that can go wrong.  Thanks for the reminded, however.
    
    -Joe

    Joe,
    
    
    	I rechecked the Vanguard PCM and you were right. The flap switch is
    center off. Forward is flap/elevator mix, and back is flaps. As has
    already been stated, there is a pot under the front panel where the
    servo reverse switches are that allows you to control the amount of
    down elevator that gets added when you activate the flaps. For the flap
    elevator mix function, it could verywell be a set value with no
    adjustments. Meaning that everytime you feed in up elevator, the flaps
    will deflect downward a set amount to also lift the wing. This has the
    effect of giving you a much higher degree of elevator control.
    
    All of this stuff should be alot of fun to play with. Just make sure
    you try everything out up high until you get used to how the plane
    responds with the new toys.
    
    Steve

I have flaps installed on a Royal 20H Trainer and Ace Seamaster 40. I used the
"1/3 of the aileron" guideline for the flap size on both.  The Conquest 6ch
transmitter has a 3 position switch, (UP, partial down, full down), I have set
to 0 degree, 20 degree and 40 degree.

Taking-off:   On the Royal I use the 20 degree position for take-off.  Its
effect seems to  "stabilize the plane", giving me more time to react (Or is
this just me?).  The Seamaster is under powered and has difficulty breaking the
water surface tension without the flaps. Yet with 20 degree flaps it lifts
quite nicely. Full flaps is too much drag as it would break the water tension,
gain about 3 feet and settle back into the water. Lesson 1) Don't use too much
of a good thing (thanks to Al in an earlier note referencing lift vs. drag of
flaps.)

Flying:   Flaps are fun while flying. I would say the effect of flaps tends to
slow the plane down and allows more time to react and learn.  The Seamaster
will barely perform a loop without flaps, with 20 degree flaps its much easier.
Flaps allowed me to better see the effect of using rudder in coordinated turns.
I recently attempted "backward" flying (in relation to the ground, not tail
first!) into a mild headwind, full flaps, and jocking the throttle around
to keep from stalling. I only managed about 50 yards before it stalled.
Recovering from the stall was easy with flaps and so much lift! Lesson 2) Too
much of a good thing can be fun.

Landing:   With flaps, the angle of descent is much steeper, and the visual
angle of the plane is deceivingly "nose down".   That is to say, while the
plane "looks" to be following a nice shallow descent angle into the field, it
will really land before the field (not where you are trying to land).
Fortunately I was flying over water the first few times this occured and have
since adjusted to the diffent angle of descent.  Another thing I like about
flaps is the speed of landing is much slower and it gives you more time to
react. Lesson 3) The slower the plane, the better I land.

Other notes of interest:  The Royal 20H started with a OS 20FP and was
underpowered for grass field take-offs. With the addition of 2 servo's, one for
each aileron (old aileron servo now being used for flaps) the weight was not
overcome by the lift provided by the 20 degree flaps (sigh). I changed the .20
for a .35 and now have plenty of power. Lesson 4) It takes a lot of lift to
overcome a little weight.

My latest challenge was a super-sportster 40 with flaps. Its first flight a few
weeks ago went very well. The only short fall was in landing where I clipped the
tops of the weeds at the end of the runway - too much flap, too much descent,
not quite enough throttle(See lesson 3) but it came in nice and slow!

More flapp'in later.
Lawton

    I may be accused of nit-picking, but...
    
    >>>Lesson 4) It takes a lot of lift to overcome a little weight.
    
    is incorrect...  It will always takes the same amount of increase in
    lift to overcome an increase in weight...  deploying flaps, increasing
    airspeed, or increasing angle of attack may be used to induce more
    lift.  However, flaps and AOA also have the negative effects of
    increasing drag, thus most people will go to a larger engine to offset
    increases in weight...
    
    cheers,
    jeff
    
    

>    lift to overcome an increase in weight...  deploying flaps, increasing
>    airspeed, or increasing angle of attack may be used to induce more
>    lift.  However, flaps and AOA also have the negative effects of
>    increasing drag, thus most people will go to a larger engine to offset

    Jeff,

    I may be accused of nit-picking, but...

    Although an airplane's Coefficient of Drag remains constant (provided
    the AOA remains the same), the Aerodynamic Drag itself increases with
    the cube of velocity (or some such silliness).  So, increasing speed
    also increases drag.


    Randy
    

    Not that anybody cares, and not that it makes a whole lot of
    difference, but in the event someone might be considering the
    Airtronics Vanguard 6 channel PCM, I rechecked the flap switch last
    night and it is, in fact, what I had originally thought it to be. It's
    a three position switch with the forward position being the off
    position. first position (center) gives X degree of flaps, and position
    2 gives X degrees more (full flaps). It also automatically mixes in the
    elevator, the amount of which is goverened by an adjustable pot under
    the front cover.
    
    Steve

    Randy,
    
    Yes, you are correct..  However, that drag is equally offset by the
    increase in thrust, thus you get more airspeed while the drag and the
    thrust balance out, which, at constant AOA, increases lift...
    
    Cheers!
    jeff
    

Re: -.51,-.52
Lets see if I understand this correctly. I wanted to make the Royal a little
easier to take-off - I thought adding flaps would do the trick! I was wrong.

Is this explaination correct?:

The Royal was originally difficult to get airborn with the .20.  I added flaps
and 2 servo's thus I increased the weight and increased the drag (using 20
degree flaps to take off). However the increase in weight (requiring a linear
increase in lift) and the increase in drag (resulting in an exponential loss of
speed, resulting in loss of lift) was greater than the increase in lift
provided by the flaps (at the reduced speed).

Changing the engine from the .20 to the .35 overcame the issue by adding speed
to the equation. (I assume Angle of Attack (AOA) would remain constant when
taking off.)

Lesson 4) should read - Don't add flaps expecting to make a "marginal take-off
plane" any better for taking off, unless you add speed!

Re:-.53 Unfortunately my Futaba Conquest 6 ch PCM doesn't have the ability to
mix in down elevator like the Airtronics Vanguard 6 channel PCM! I wish it did,
as I end up using 4 down-clicks on the trim for partial flaps and full down
trim for full flaps.

Lawton

I like this explanation better:

When you have a plane that is under-powered, adding flaps does not add power
and therefore does not make things any better. In fact, deploying flaps makes 
things worse. The L/D of the plane with flaps down is worse than with flaps 
up (that's why the glide is nice and steep on landing). So, you need that much 
more power with the flaps down. The flaps increase the CL (cooef of lift) so 
the plane takes off at a lower airspeed but you need _more_ power to do this, 
not _less_. It seems to me that the only cure for being under-powered is a 
bigger engine.

Glenn Schrader

    After a near fatal accident with my Eagle 2 last fall, when I put it in
    a tree and the tree kept the wing ( it's still up there) but gave me
    back the fuse in two pieces, I decided to rekit as follows.  First, I
    did a simple reconnection of the fuse using plywood doublers all around
    the inside, and it came out great.  Since I was missing the wing, I
    ordered a new wing kit from Tower, but instead of building the stock
    wing, I decided to make things a little more interesting by building it
    with flaps.  After some lengthy consultation with Jeff Friedrichs on
    the various ways to do this, I built it with flaps that are 1/3 the
    length of the stock ailerons, and actuated them with the servo that is
    normally used for the ailerons.  Then I mounted the extra servo further
    forward in the wing and drove the ailerons from this using a
    combination of nyrods out to bell cranks, followed by straignt wire
    from the bell cranks to the aileron horns.  All in all, a lot of extra
    work was involved, but I learned some new things, and felt it was a
    rewarding project.  BTW, I forgot to mention that the flap servo is
    actuated by a two position switch, giving two flap positions that by
    eye are about 30 and 45 degrees respectively.
    
    Now on to the flying.  
    
    Takeoffs with flaps deflected are like an elevator ride.  Since the
    vertical performance of the somewhat-heavy Eagle2 with an OS 40 FP is
    considerably less than stunning, I was really taken by the very fast
    climb-out possible with flaps deployed.  With very little up
    elevator, it climbs our very quickly, something Glen Schrader could
    probably explain by the change in L/D ratio brought about by the
    extended flaps.   I love take-offs with flaps.
    
    Landings have been more of a problem, however.  Deploying flaps prior
    to final approach causes balooning, and either I have to manually push
    it down with down elevator, or put in some down trim.  It just won't
    come down by itself.  I'm still in the learning process with this and
    have had a few hairy landing attempts.  But, it does come in SLOW, and
    I love the way the flaps steepen the angle of descent without changing
    airspeed.
    
    Slow speed flight with flaps down is also a real blast.  In a good wind
    it doesn't take much effort to hover at zero ground speed.  I'm really
    having a lot of fun with my "new" plane, and even though it's had 150
    flights, the experience now is totally new, and its given this
    well-worn, dull, and uninteresting aircraft a new lease on life, plus
    some new fun for its owner/operator.
    
    Anyone interested in getting into yet another aspect of our hobby would
    do well to try building flaps into one of your planes.  I feel it was a
    worthwhile endeavor and has been an excellent learning tool as well.
    
    What can I say...flaps are FUN!
    
    -Joe 
    

    Joe,
    
    	What radio are you using. If it has a 2 position flap switch, does
    it also have flap/elevator mixing? If it does, you can automatically
    add in down elevator when you deploy the flaps.
    
    Steve

    
    
       Joe,
    
          If your radio does not have mixing like Steve talked about, an
     alternative is to reduce the flap deflection. I also had a 2 position
     flap on my modified ace 4-40. In the first position, it was about
     10 - 15 degrees deflection, and the second position was about 35 - 40.
         I found the first setting just about right, it allowed slower
    landings without a major pitch change. I found the second setting 
    almost uncontrollable, especially on landing approaches. It simply
    required too much elevator compensation to fly it comfortably. To
    comfortably use the higher deflections, you may need a radio with the
    mixing that Steve specified.
    
                                                        DW2

    Re: .58
    
    Steve, I'm using Airtronics Vanguard 6 channel FM (I think the official
    designation is VG6DR) which to my knowledge has NO mixing capability,
    at least I can't find it anywhere in the instruction booklet.  
    
    However, it's a good thought, and I only wish it was possible with my
    present radio.
    
    Thanks,
    Joe

>    However, it's a good thought, and I only wish it was possible with my
>    present radio.

Nothing is impossible to the man who doesn't have to do it himself.
(famous managers quotation).

Anyway - in Dodgson's newsletter (Second Wind) and along with the
Lovesong instructions there is a section on how to modify radios to
have a Reflex/Launch switch.  I Think this gives you exactly what
you want if you are willing to void your Transmitter warranty and
do a bit of hacking.  If so let me know and I can mail you a copy
of the article.

Bye          --+--
Kay R. Fisher  |
---------------O---------------
################################################################################

    After reading the notes in 1025, 1024 and 807, I would like your
    response to the following queston:
    
    Would it be a good idea to link the flaps to the engine servo in order
    to have full flaps at idle and full up flaps when the engine is at full
    throtle?
    
    Your comments will be appreciated.
    
    Regards,
    
    Ollie 

    I have used the offset option on the JR X-347 flap switch coupled to the
    throttle with great success.
    
    The way it is set up is that the flaps will only come down if the flap
    switch is engaged and the throttle is below a 2/3 power.
    
    It works great on overshoots and prevents servo strain if the flaps are
    deployed by accident at full throttle.
    
    I would not make it proportional due to the timing of power and flap
    changing all of the time.
    
    Regards,
    
    E.

    
    I speak from the depths of ignorance. (Again).
    
    I would have thought that a simple linking of throttle and flaps would
    not be a good idea. You don't want flaps to deploy at the top of a loop
    for example. Eric's scheme sounds a bit more sophisticated than the one
    suggested in .62
    
    OK folks, shoot me down!
    
    Nigel.
    

    It is a standard feature of the JR X-347 and is part of the Land/flap
    program options. (It does not use a Free mix).
    
    It is basically using the throttle as a switch. The switches operate in
    "AND" mode.
    
    If a plain mix is used with the thottle the result can be deferred in
    a similar manner but not overidden by the Land switch..
    
    There was some debate that suddenly raising the flaps at low speed
    could cause a disaster. Practical tests proved this not to be the case. 
    
    I used the set up with the Panic and had fun leaving it in all the time. 
    I had it set to raise the flaps at half throttle. Boy was it fun to fly
    the thing slow and then just gun it!. You could see the plane rise while 
    flying level at just below half throttle. Inside loops did not care about 
    the flap coming in and out but outside loops did not like the throttle to 
    be killed at the bottom!.  :-)
    
    Much height was lost until the throttle was opened above half.
    
    Please note that automatic elevator trim was also used to compensate
    for the effect of the flap. Even then there was always a dip as the
    flaps were deployed due to the elevator down-trim kicking in faster
    than the flaps could deploy.
    
    On the Dalotel I always drop the flaps in the base turn. The plane is
    banked over and the nose drop does not show up.
    
    With the MC-20 I can control the speeds of the flap and the flap trim
    deployment so that they match. Oops - turn of ramble key, Bye!.
    
    E.