piggy back glider launching?
J BRAINer
powerplane and I have some gliders. I want to piggy back launch them. so
anyone out there ever done it? I asked this question on the glider ng, but I
guess those guys are dedicated glider-only people and don't even have an .049
engine somewhere in there tool box. can anyone help? or even tell me where I
can buy one?
thanks for the input,
Joel
Joeheffern
Dno1939
>a
>powerplane and I have some gliders. I want to piggy back launch them. so
You can make the cradle out of lite ply. Keep it upabout 6 inches above the
wing on your power plane to the glider wing to keep the air flow clean. Be
sure to skeletonize it or the power pjlane won't turn. If your plane has
rubber band mounts for the wing you can fasten to that, or make hooks on the
lite-ply frame and just rubber band around the wing on your power plane. Fix
it with a servo to pull wires out of the sides to release the rubber banded on
glider. Good Luck!!
Douglas Kaip
Is there a reason that you don't just tow them like full scale gliders? I
know that on full scale that the release is done from the glider, unless
there is a problem. I would think that you could find some very light and
strong thread that would not hamper the flight of the gliders after they
were released.
CCat151265
>strong thread that would not hamper the flight of the gliders after they
>were released.
why dont the glider release the tow....then theres no flopping wire from the
glider to worry about......just remember to remind the tow pilot not to try any
stall turns, etc......not good for the plane, prop or engine if the wire
becomes tangled tin the engine!!
Piggyback make the CG of the tow plane diffrent...plus the two wings,
elevators,rudders will likely cause trim problems for the tug pilot.....do it
the scale way....tow the glider!!!
pjb...@my-dejanews.com
jbra...@aol.com (J BRAINer) wrote:
> anyone have plans or pictures or can just tell me what to do? my friend has a
> powerplane and I have some gliders. I want to piggy back launch them. so
> guess those guys are dedicated glider-only people and don't even have an .049
> engine somewhere in there tool box. can anyone help? or even tell me where I
> can buy one?
>
> thanks for the input,
> Joel
>
for the task.
The most difficult part is getting a reliable release mechanism. Mine is
diagramed at::: http://www.ptw.com/~pjburke/modelpage4.htm.
The "Mothership" is at http://www.ptw.com/~pjburke/kadetpage.htm
With long-span gliders, I've found it good to have some manner of wing tip
support. The glider can seriously affect the carrier plane's stability if it's
not securely held.
PJB's Seriously Aeronautical Stuff
http://www.ptw.com/~pjburke
-----------== Posted via Deja News, The Discussion Network ==----------
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Michael Brooke
CCat151265 <ccat1...@aol.com> wrote in article
<19990310143708...@ng-fv1.aol.com>...
> Piggyback make the CG of the tow plane diffrent...plus the two wings,
> elevators,rudders will likely cause trim problems for the tug
pilot.....do it
> the scale way....tow the glider!!!
>
Naw, it's easy, I've done it lots of times with a 2 meter poly on the back
of a Senior Telemaster.
Glider pilot just keeps all controls in neutral until the release. I've got
some pictures around here somewhere, if you like I'll dig them out and
email them to you.
Mike
pjb...@my-dejanews.com
ccat1...@aol.com (CCat151265) wrote:
> > I would think that you could find some very light and
> >strong thread that would not hamper the flight of the gliders after they
> >were released.
>
> why dont the glider release the tow....then theres no flopping wire from the
> glider to worry about......just remember to remind the tow pilot not to try
any
> stall turns, etc......not good for the plane, prop or engine if the wire
> becomes tangled tin the engine!!
> elevators,rudders will likely cause trim problems for the tug pilot.....do it
> the scale way....tow the glider!!!
>
Aerotowing is common, and merely requires a lot of flying discipline between
the tow plane pilot and the glider pilot. A good reliable tow-release on the
glider is mandatory! It's very easy to get the glider wrapped up in the tow
line! No abrupt manuvers by either pilot keep things sanitary.
Rich & Bev Moreau
with a ring at the end, and had it hooked to the belly hook of the glider.
NOT GOOD. After making repairs to the glider, I moved the tow hook to the
nose of the glider.
BETTER....but still not good enough.... The trainer 60 was too fast to tow
the glider without inducing sever wallow of the glider, and the tow plane
was changed to a 40 size Cub.
STILL BETTER, but still had a problem. No way to get 100% proper take offs
from a standing start off the grass runway.
MY SOLUTION: I built a Senior Telemaster with cradles to piggy back the
glider, with a servo in the top of the tow plane to hook on the belly hook
ofthe glider. Like flying a biplane..... and by splitting the fins and
rudders--never damaged either plane at launch.
Hook the glider on top of the tow plane, climb to altitude, slow to idle,
count to three, an drelease the glider. A nice, gentle separation, and could
launch up to 5 gliders before the first one was back to the runway.
Needs two pilots, and remember to turn the radio on in the glider, and don't
make any imputs to the glider until after separation.
pjb...@my-dejanews.com wrote in message
<7c92dv$f8n$1...@nnrp1.dejanews.com>...
Pé Reivers
You need a saddle for the High winged aircraft on which to fasten the
gliders wings with rubber bands. Incidence of this saddle is negative, so
the glider wing generates hardly any lift. I would suggest 2 degrees.
Centre of gravity of the glider should be about over the piggy aircraft
centre. In my practice, I never encountered large trim differences with the
glider positioned about 5 inches above the fuselage, because a brisk climb
is required anyway. Rudder experience is required and should be a natural in
assisting turns.
We call it Huckepack over here. The piggy back airplane should be able to
fly slow and very powerful, in order to gain height without much speed. To
much speed, and the glider will try to fly off the saddle, straining in the
rubber bands. That is wat the negative angle is for!. When it is time to
release the glider, reduce power, stay in a slight climbing angle. When
ready to drop a wing, call "NOW", hit the release switch, let the nose drop,
so the piggy plane falls away from the glider, preferably slightly to the
left, while the glider slightly banks right, without dropping the nose below
horizontal.
Land quickly, to pick up the next glider. No need to worry about tow cables,
makes for a great show that visitors enjoy.
Great fun, need a strong large plane. Mine is 2.4 meter span 0.34 meter
chord, weighs 16 pounds (lbs.) and is powered by a 2.5 hp engine at 6600 rpm
18x10 or 20x8 prop. Any good gas engine or low-rev glow can do. Need plenty
of prop wash to "fly on the prop" and descend on the wing.
Happy landings, Pé
Juha Kettunen
<snip>
>MY SOLUTION: I built a Senior Telemaster with cradles to piggy back the
>glider, with a servo in the top of the tow plane to hook on the belly hook
>ofthe glider. Like flying a biplane..... and by splitting the fins and
>rudders--never damaged either plane at launch.
>Hook the glider on top of the tow plane, climb to altitude, slow to idle,
>count to three, an drelease the glider. A nice, gentle separation, and could
>launch up to 5 gliders before the first one was back to the runway.
>
>Needs two pilots, and remember to turn the radio on in the glider, and don't
>make any imputs to the glider until after separation.
Yes, that´s the way to go. Reminds me of a time when I was to test
fly a newbie's glider and decided to take it up this way. So I strap
it on and test that tail feathers move when stick is wiggled - they
do, so it´s up, up and away. The release was at slightly too high
speed, so the glider zooms up. I push gently, but the glider is now
near inverted on top of a very sloppy loop. Strange - it wasn't that
much overspeed. Oh well, let´s make a loop then. I pull slightly and
the glider stabilizes into vertical dive. I pull harder and it begins
to do an outside loop. Soo... did I check the *direction* of control
movements? Nope, just that they move... time to learn to fly with
reversed elevator...
pjb...@my-dejanews.com
attached!
MEpst22487
glider" (imported by Dale Willoughby) on a Smog Hog. The Hog was designed by
Howard Bonner...if I'm not mistaken. It was quite similar to today's
Telemasters. Mitch
Ntelekt (in-tel-ekt)
simple aileron/elevator aerobatic glider behind a Stik 60 using a
stall/fly-by release method...and even worked our way to the other side of
the spectrum by towing a 7lb, scale Discus, all-fiberglass glider with full
function controls, behind an ARF Stik 40. We also piggy-backed with a Stik
60 carrying Goldberg Gentle Ladies.
With all of this behind us, and several absolutely spectacular aircraft
dissembowlments, we have learned a few things...the hard way !!
#1: The only way to get a wingless glider (without a tow release mechanism)
off of a tow line, is by high altitude, full-stall maneuvers in which the
powered plane literally falls out from under the towed wreckage and releases
the tow line.
#2: The only way to entangle a tow line around a prop shaft is by
attempting the maneuvers described in Lesson #1
#3: A glider in tow behind a larger aircraft can be made to shed its wings
in mid flight if the powered aircraft is not throttled back to a suitable
airspeed.
#4: A large glider has the ability to lift smaller tow planes from the
runway during takeoff if the glider pilot does not maintain control over his
altitude.
#5: Piggy-backing delicate gliders on the backs of power-house, acrobatic
planes is a surefire way to seperate wings from gliders, unless the
appropriate climb attitude is maintained at all times while at full-power.
#6: Large gliders can sometimes have the ability to overfly smaller,
powered aircraft, even while in tow.
#7: "Intertubing" or slingshotting the glider in high-bank turns is not
well advised.
#8: Do not engage spoilers while in tow....unless a high rate of descent is
required for some stupid reason.
#9: Inverted fly-bys by hotshot tow pilots.......need I say more?
And the most important thing we learned from our trials and errors of glider
towing:
#10: Do not attempt it if you or the tow pilot have a propensity toward
violence when a prized aircraft "buys the farm!"
*LOL*
Honestly....I loved every minute of it....even the
inverted-overhead-immelman-wing-snapping-shit-now-what maneuver!!!
TRY AT LEAST ONCE !!!!!
(I really do have some good ideas to make it a reasonably very safe
adventure...e:mail me if you would like to here them)
Michael A Stephens
result of a piggy back launch. I love it!.
The piggy back aircraft that we used was a Birdi Loadstar with an os 120
four stroke (I believe)........The platform was made of music wire
instead of plywood. They tried a plywood one, similar to what Hobyloby
used to offer, but it acted to much like a giant rudder.
The glider was attached using 2 rubberbands, one over each wing. the
front of the band went over a pin that could be retracted via a servo.
The K.I.S.S. method works best here. The simpler the better.
Mike Stephens
Ntelekt (in-tel-ekt)
steady hand on the parts of both pilots.
I too live in Georgia.....Southwesterly....and our town is a site for an
anual Mid-Georgia Soaring competition by the big-boys.....(full scale
sailplanes, single and dual seaters)
I'm a private pilot, and I have gone up with these guys and was even allowed
to fly the Grob 103 Sailplane while we were on the tow...you guys wouldn't
believe how touchy the real thing is as compared to a Cessna...*eg*
Anyway....since we see real gliders under tow every year....we had to try it
with our models. And yes, we did loose a couple of nice gliders and one tow
plane, but we learned how to do it, and now I wouldn't do it any other way.
Most importantly....you HAVE to have a dependable release mechanism...one on
the glider and one on the tow plane....if either guy has to bail from the
tow, he can at the flip of a switch or even the throw of a control surface.
And if one can't get off the line, the other can cut him loose.
You can start learning how to fly the tow by working on the take off run.
Hook them up and pull the tow line tight behind the tug plane. The tug
pilot has to ease into the throttle to get the two moving, but once
everything is up and going, he has to go full throttle. The worst part
about the take off is the fact that the glider can catch a wing on the grass
or runway while it's still too slow to get airborn. This can toss the
glider around for a bit and can damage it. You can eliminate this by adding
some small wire-outriggers to the glider wing that remain in contact with
the ground at all times until the glider gets airborn....that evens up the
resistance on both wings.
Once you get a smooth takeoff, make a straight climb out until you have to
turn....on your first flights, the glider should release before the tug
makes the first turn...then everyone get back to the ground and try it again
until you are confident about making the turn.
Before you try the turn under tow....make sure that both pilots know what
pattern you are going to fly. You have to avoid bringing the two planes in
too close. It's best if you can position yourself on the flying field so
you fly a large circle around you instead of having to make full 180 degree
turns and coming back across the field....at least not at first.
The last thing you need to know is to release from the tow while you can
still tell the two planes' relation to each other.....you find out that the
aero-tow is really quite easy, but you cannot get the same height from the
aero-tow as you can from the piggy-back simply because you loose aircraft
orientation.
A piggy-back can go as high as the tug pilot wants before he releases the
glider....all the two pilots can see is one airplane anyway.....until
seperation.
Coming from a true sailplane fan.....if you like scale flying, then the
aero-tow is the only way to go.
Les Rispens
tutor powered by a K&B 65.
1) Neg incidence on the glider is REQUIRED. Does 2 things for you. I makes
the whole thing flyable (I think I know why but that's another thread) adn it
keeps the load off of the glider wing during the lift, which means it takes
less to keep the glider on the tug. As mentioned earlier, 2 deg is about
right.
2) There may be trim changes. With the glider in place I need some down trim.
3) Don't risk a stall. With mine a stall results in a nose up position and the
more power you apply the more up the nose goes. With the glider on I have to
power down and nose down, then recovery is instant. My trainer climbs under
power anyway and the glider on top makes it more noticable.
4) You ailereons may respond differently. My alierons are almost usless with
the glider in place. The plane is very stable with the glider. Almopst too
stable to control. It takes coordinated turns, then is handles very well. I
have even landed with the tug and glider together, it was actually uneventful.
5) Glider CG equal to or ahead of tug.
6) At least 6 inches between the tug and glider wings. The one accident I
have had was when the tips of the tug and glider wing sort of sucked (I know)
together in flight. I could kep the thing in the air just fine, which really
surprised me, but I could not get the glider to release until I put the whole
mess into a deep stall way up there. As soon as they stalled they tried to
seperate but the glider antenna got cuaaght on the tail of the tug. I towed
the glider sideways until, almost simultaneously, the wing left the glider
and the antenna broke. Glider flew again the next week. No damage to the tug.
It is a ball. A real show stopper.
>
Les Rispens
lj...@yahoo.com for fun and personal stuff
les.r...@bbs.fsa.usda.gov for work stuff
Ntelekt (in-tel-ekt)
J BRAINer wrote in message <19990313205713...@ng128.aol.com>...
>Ok, to make this more spacific, I have a Gentle Lady and my friend has a
Tower
>Trainer .40. If I did aero tow, where does the hook go? On the front? Or
on
>the top? Or on the bottom where the tow hook for hi starts is? And for
piggy
>back, is it possible to release by a servo in the glider? He only has 4ch
and
>is using all of them. I have 4ch, but am only using 2. Any comments?
>
>thanks,
>joel
From my experience, this would be a good combination.
The tow plane should have the tow-line attachment screwed into the top of
the wing, at the main spar. You can use something simple such as a "screw
eye" that you can pick up at Walmart in the housewares section...pack of
about 4 or 8 should be less than a buck or so.
While you're at Walmart, go into the toys and pick up a spool of kite
string, then go to sporting goods and by a pack of the largest fishing
swivels they have. Check the crafts section for a key-ring or maybe
automotive. You don't want a large key ring (like an inch or so) but the
key chain might have a small ring on it (like a 1/4 inch ring). If you
can't find something exactly like that, you can use a wire coat hanger and a
wire bender to make a small ring.
By the time you get out of Walmart, your total towing package investment
should be less than five bucks.
-------------------------------------------------
Tie the small (1/4 inch) ring onto the kite string.
Screw a screw eye into the top of the tow plane's wing at the main spar, a
little drop of 5-min epoxy on the threads might help in the long run.
Now you need a tow hook on the glider....you can use something simple that
would not require a mechanical release at all, or you can use my idea for a
mechanical release (below) But the hooking point must be in the nose of the
glider. If it is on the bottom of the glider, the glider will constantly
try to climb above the tow plane....and this can over-stress the glider.
A non-mechanical release:
Screw a screw eye into the nose of the glider.
Using pliers or other suitable tool, open up the screw eye to form a
hook.
Set the glider on a flat surface like a work table or such.
String out the kite string about 5 feet or so in front of the glider and
hook the small tow ring on the nose hook of the glider.
Adjust the hook so that it can just hold the tow ring on it while
sitting on the work table.
The alignment should be such that if the glider pitches above the
tow-plane, the ring will slide off the hook.
MOST IMPORTANT: This has to be fool-proof...if this does not work as
needed, you are going to loose a plane!!!!
A mechanical release:
Cut the outside sleeve of a "ni-rod" to roughly 4 inches. Then cut it
again into a 1inch piece and a 3 inch piece.
Inside your glider fuse, as far to the nose as you can get, you need to
glue the 1 inch piece to the floor of the fuse.
Make sure it is in the center-line of the fuse and aligned with the
long-axis of the glider.
Butt the 3 inch piece of "ni-rod" tubing up against the first piece.
Slide it backwards from the first piece about a 1/4 inch and glue it
in place.
Use a razor knife to cut a hole in the bottom of the glider fuse that is
centered on the gap between the "ni-rods"
IMPORTANT: The hole should not expose any of the 1 inch piece of
"ni-rod" and should be larger than the tow-ring
(you can mount a new servo into the glider or link up to your elevator
servo)
Fashion a solid wire pushrod to run from your servo, through the 3 inch
sleeve and into the 1 inch sleeve.
The length must be cut so that at full-throw of the servo, the wire
slides out of the 1 inch sleeve and is completely pulled into the 3 inch
piece.
IMPORTANT: If you use your elevator servo, the wire must be able to
slide back into the 1 inch piece without binding or you will loose elevator
effectiveness. Also, I suggest using full-up elevator as the release
command if you use the elevator servo.
When you reload your electronics and batteries, ensure that the wire
release mechanism is not put into a bind....your glider may depend on
it....use some balsa blocks glued into place to keep your radio gear from
binding onto the wire.
If all is hooked up correctly, you should be able to move the controls into
the release position to hook up the tow-ring, then move them into normal
flight position to hold onto the ring. When you move the controls into the
release position, the ring should fall from the bottom of the glider even if
pulled tight as if under tow.
If you need a better desciption, I can put down some paint to a drawing and
send you a picture.
I used this mechanical release method in my scale, fiberglass glider to
great effectiveness. One note though, you need the hooking location to be
as far forward as possible....and the ring must be able to be pulled from
the hole in the fuse. A better idea might be to use a rubber band to hook
through the ring and then onto the "hook" inside the fuse. There is no
sicker feeling than to throw the release switch and nothing happen.....if
that glider can't get off the hook....you're going to loose a plane...or
two....!!!!
That's it!!!
Happy flying !!!!
J BRAINer
pjb...@my-dejanews.com
Aero-tow with the tow line at the nose of the glider, and at the top of the
tow plane, near the c.g. A release in the glider is mandatory. Simple
releases are detailed frequently in R/C Soaring Digest. Piggy back, the
release servo should be in the carrier. No need to add a single-use servo and
its weight to the glider, unavoidable with aero-tow.
PJB's Seriously Aeronautical Stuff
http://www.ptw.com/~pjburke
-----------== Posted via Deja News, The Discussion Network ==----------
Pé Reivers
some more considerations:
1) I do not use the trim, instead I handle the sticks very actively to keep
the nose up the right amount. Yes the glider does change the plane's
behaviour.
2) I use a plywood saddle, which makes the tail end go low in a turn
requiring lots of rudder to counteract. I practice a lot without glider, and
piggy back installed.
3) I use 4 rubber bands each wing laid over flexible pressure pieces
foldingly attached to rubber sheet on the saddle to avoid glider wing
damage.
4) Just before release, I chop the throttle. As the speed is gone and the
nose starts to drop in the stall, I shout GO!, andhit the release switch.
The glider either goes straight ahead or recovers from the stall by lifting
off the saddle while my plane continues straight down a little while. Becaus
of near zero air speed, no interference (sucking action) between the wings
has been observed
some words on towing:
In a nearby club a lot of towing is accomplished, but only on gliders with
ailerons!!! They often loose the tow line in the corn field. In the time
they up one glider, I can handle two! and I do not care for rudder only or
aileron on the glider part. Try to tow a rudder only glider, and it ends up
acting like a tail rotor of the tow plane. 'nuf said