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aeajr
09-30-2003, 05:30 AM
I am making this post because I could not find tips or advice anywhere on the internet on how
a person, working alone, could learn to use a hi-start. I invite more
experienced sailplane pilots to add their tips, comments and advice to mine.

These links may be helpful for background.

http://www.mrcss.org/pdf/articles/a_beginners_guide.pdf

http://www.labyrinth.net.au/~learmont/HiStart

Hi-start launching.

First, let's be clear, I am NOT talking about competition launches here I am
talking about safe sport launches. I am sure someone will post about maximum
altitude and such. I just want to help you get in the air safely.

Second, get a coach/instructor if one is available and ignore all of this.
This is ONLY intended for someone who is unable to get help.

Third, your plane must already be well trimmed and flying straight and even
from a hand launch. Fail to this and the hi-start will turn your plane to
junk!

Fourth and very important, make sure your tow hook is in the forward most hole
that your plane has. It should be a little in front of the CG of your plane.
This will give you a more controlled launch than the more rear, competition
positions.

OK? We understand the goal here? Safe and gradual build up. Control, not
height!


Always launch into the wind. Launching is easier with a mild breeze than it
is in dead calm air. For learning purposes I would say you want at least 2-3
MPH and no more than 6-7 MPH of head wind.

I was taught to launch with all controls at neutral. In fact my initial
launches were with a little down elevator to help reduce the chance of a
pop-off. But I started with a full size hi-start and an instructor who made
the first 4-5 launches for me so I could watch and he could see how the plane
would behave. Then he released the plane on the next three while I held the
radio to control the plane. Then I released while he flew the plane. Then I
did both. But we were working with the BIG hi-start in a huge field and he
was there to guide me. If your plane is properly trimmed, all controls should
be at neutral for your launches.

You should only need rudder to control the launch. You may use a little up
elevator at the very very end to help release the ring from the tow hook, but
mostly I just let it fly off. If you get your angle off a little left or
right the plane will tend to go that way, just like a bad hand throw. Use the
rudder to get it back to center.

Build up to it slowly. Think of a hi-start as an assisted hand throw. Do
exactly what you would do on a hand throw. Basically flat firm throw.

I don't know what hi-start you have or how big it is, but if it is a "full
size" hi-start it probably has 30 meters/100 feet of elastic and 100-120
meters/300-400 feet of line. That is an awful big thing to handle on initial
launches without a coach.

You can either get an up-start which is 5-15 meters/15-50' feet of elastic
plus 15-50 meters/50-150 feet of line which can be used in a smaller space
and, in my opinion be a little less scary. Or, take your big hi-start,
replace the big length of line with a smalle length. You can cut a 50-100
foot length to use for your initial launches You can reattach it later with
snap swivels or just tie a knot.

Get a metal ring, 1.5-3 inches, that will allow you to loop the elastic onto
the ring in some fashion to secure it so that you are only using part of the
elastic you have to make the shorter launcher. Make sure the stake that you
put into the ground has a washer on it that will not pull through the ring.
Don't cut the elastic.

If you start small, say 10' of elastic and 30' of line it will be a lot easier
to control, and the launch will be lower and the energy smaller. Again, just
an assisted hand throw. We will use this length combination for this
discussion.

Pull back 5-10 feet, or about 1/2 the length of the elastic, for the first
launch.

Check to make sure all of your controls are working.

Stand firm and just give it a straight. firm, flat throw, controls at neutral.
You should only need rudder to control direction.

It should go out just like a hand launch, only with a little more speed and it
should naturally climb a little. It should just fly off the end of the line.
Don't go for height, go for control.

Build up the strength of the pull over several launches. 1/2 the length of
the elastic. Then 3/4, then the full length. Then 1.5 times the length of
the elastic. Build till you are comfortable. Then just slide the metal ring
further down the elastic and add more line. Use roughly 1 foot of elastic to
3-5 feet of line.

As the pull gets stronger, the plane will fly out faster and the lift of the
wings will take it higher naturally. No need to throw it up, it will go up on
its own. You can reserve aggressive angles and the more rear tow hook
positions for competition.

I have about 60 launches with my Spirit 2 meter. I launch flat with neutral
controls and the forward tow hook position. Using my smaller launcher (25'
tubing and 100' line) I get 100-150 foot launches depending on the wind.
With the larger one (100' elastic and 400' line) I estimate I go up 400-550
feet and can zoom off of the end if I want.

These links may provide some additional, useful info. Like you I was afraid
of the hi-start. If you had someone to coach you through the first few you
would be fine. If you don't, try this method.

That plane was made to fly. Fly it! :cool:

aeajr
08-29-2004, 12:15 PM
This is a more complete article on using a hi-start for anyone who is starting out in sailplanes.

http://www.rcezine.com/cms/article.php?cat=&id=52

aeajr
10-29-2005, 04:56 AM
In the past I had only used hi-starts for flat field Thermal Duration flying. Recently we found a slope site that lies on the other side of some trees. We now use a hi-start to launch the plane over the trees to get to the lift. So hi-starts can be helpful for slope soaring too.

aeajr
01-16-2007, 09:29 PM
Anyone have a different approach to learning to use a hi-start?

cosmicpossum
01-17-2007, 11:20 AM
I learned exactly the same way. Later moved on to winches, that was a whole different learning curve for me since I was in control of the winch speed...it took a bit to transfer what I was seeing into my foot in addition to controlling the plane with my hands.

aeajr
01-18-2007, 08:52 AM
I had a heck of a time learning to use a winch. If you have a strong plane that can handle a full pedal launch, it is much easier, but I was using a Spirit 2M and a Sagitta 600. Neither could handle a full power launch. 3 broken wings and 2 broken fuselages later I finally got it under control.

Never broke a plane on a hi-start, and I have a BEAR of a hi-start!

cosmicpossum
01-18-2007, 09:20 AM
Ah, yes, the dreaded power launch! I watched a brand new Sailaire snap into several pieces on a launch. That was enough to teach me. After that it was launch, tap tap tap, and I was okay. I watched an old friend launch a 4M on my winch. It was terrific. Although the winch didn't have enough power to really get him altitude, he'd launch as high as possible, turn around and tow the winch line back downwind, turn back into the wind and stomp on the pedal again. After about four passes doing this, he'd get tremendous altitude on his launch. I've not had any planes that large so I've not had any problems, although now I'm looking for releasale towhooks so I can try it with a 3M I'm building.

azmotorhead
01-24-2007, 06:45 PM
Excellent write up on learning how to begin with a Hi start.
I never had a instructor or friend to help me. First time I used one my plane wasn't trimmed quite right. Sailplane veered HARD right on launch,I tried to correct but by the time Inputed the rudder correction. the wings snapped in half and the remaining portion on the model was hurtled downrange.
My second aircraft(Aspire 2M) lauched beautifullly and straight from its first flight. Unfortunately on about my 10th launch from the hi start the plane had too great of a launch angle,maybee too much tension from the bungee :confused: The wingspars snapped at the center joint,thus turning the fuselage and tail section into a unguided missile at about 300ft AGL.
Cant wait till it warms up a bit so I can see what happens on the next launch :D

aeajr
01-25-2007, 06:09 AM
That must be one heck of a strong hi-start. I have never broken a plane on a hi-start launch. I have broken some wings on the winch, but not a hi-start.

Maybe you are applying too much force.

I believe the Aspire has a 2 part wing. With wings like that, it is best to tape them togehter at the field. I use clear packing tape on my Spirit. This makes for a strong wing and takes all the stress of the joiner.

I think you will find that this will make a huge difference.

azmotorhead
01-25-2007, 06:56 PM
My Hi Start has approx 100ft of tubing and approx 300ft(cut down from 500ft) of Nylon cord.
I had only stretched the tubing to about 1.5 times its length before I ran out of field. First aircraft was destroyed due to 1. Operator inexperience 2.Aircraft not trimmed properly 3.winds were too high that day.
The Aspire has its wings epoxied together with a 1 piece center spar.
The wing snapping on that one was more than likely too much elevator on launch.
BTW it's a full size Hi start.
See you on the field :wave:

aeajr
01-26-2007, 06:53 AM
I never use any up elevator on launch with a hi-start or a winch. You should not need any.

How thick is the tubing? Hi-start tubing can be all different sizes and have all different strengths. 1/4" OD tubing is considered good for light planes up to 2M. 5/16" OD is typically standard size good for 2M to some light 3M planes. At 3X pull you would typically get about 10 pounds of pull.

3/8 is considerd strong for 2M or good for 3M.

Mine is 1/2". Very strong for 2M and powerful for 3M. At 1.5X pull I am already up to 12-14 pounds of pull. at 3X we are talking 30 pounds +. I can barely hold it.

azmotorhead
01-29-2007, 12:25 AM
I have the .
Pinnacle Hi Start (http://www.nesail.com/detail.php?productID=874) from NE sailplane.
It is a very stout Hi start.
I never use any up elevator on launch with a hi-start or a winch. You should not need any.
And knowledge like this comes from experience :)
I am still a novice at this hobby even though I'm a old fart(not really).
I appreciate the wisdom and knowledge that you and others share on the net :D . remember the old days when your knowledge base was limited to those who you knew and met at the field.
I thank you for all you help

aeajr
01-30-2007, 06:43 AM
azmotorhead,

The Pinnacle Large can definately be used for an Aspire, but it is really intended for larger planes. The Pinnacle Standard would be the one that would be the right size for the Aspire.

Having said that, I have the Pinnacle XL, which is even stronger than yours and I use it for my Spirit, but if I was buying one for the Spirit, it would be the Pinnacle Standard.

lonesomebob
03-07-2007, 10:56 AM
I cut my teeth on a hi start, 200 feet of rubber and 300 feet of nylon. nevere snapped a plane but looped off several times hogging the nose for more. How do you know when you can really fly? When your thumbs work faster than your thoughts When looping off a hi start. Bob

aeajr
03-31-2007, 06:54 AM
Loops off a hi-start can be quite exciting.

As a side note, I have found the best thing is to just ride the loop through rather than fight it. When you try to stop the loop, the plane tends to stall and that can lead to a crash.