inch long piece of 1/8-inch heat-shrink tubing onto the shutoff
cable. The shutoff cable wraps around the trigger wire in the
space between the washers, then back through the crimp
sleeve. It should be able to rotate freely around the trigger
The shutoff should trip with about 5/16 inches of down-elevator. Crimp the cable at the appropriate length then cover
with heat shrink material. If test-flying reveals that the shutoff
needs to be adjusted, the solder joint can be reheated and the
cable moved forward or back, or simply adjust the clevis if
The model should now be complete, so check the center of
gravity (CG). It should be approximately equal to the front of
the bellcrank opening. If it is ahead of this, don’t worry about
changing it until after it has flown. If it is more than 1/4 inch
aft of this, you may want to add some nose weight for the first
Make a set of .015-inch stranded lines, trying to get as close
to the minimum length of 52 feet as you can. This is the length
from the handle grip to the center line of the fuselage, not the
actual length of the lines. Remember, an extra foot of length is
equivalent to an extra second for every 52, or an extra 10 or 11
seconds in a race.
The controls on this airplane are set up for a typical 4-inch
handle spacing, so try that first. Don’t forget the preflight pull
If the airplane seems jumpy, try adjusting more down-elevator into the handle. If that doesn’t help, try a handle with
narrower line spacing. If it is still too touchy, add some nose
weight. You did check the CG, didn’t you?
When you are satisfied with the model’s general flight
characteristics, try the fuel shutoff. Make your first attempts
directly over your pit person. Give a quick blip of down-elevator, followed by a quick blip of up-elevator, then level off.
If this is your first time using a fuel shutoff, don’t worry if it
didn’t trip on the first try. Relax, regroup, and try again. Don’t
just keep trying, because then you lose track of where you shut
off relative to your pit person. If you can’t ever seem to get it
to trip, you will probably need to adjust the shutoff so that it
trips with less down-elevator. Don’t go too far, or it may trip
when you don’t want it to.
Okay, you’ve got the hang of the shutoff. Now, when you
shut off right over your pit person, where does the model
land? If it stops short of the person by a quarter lap, then hit
the shutoff a quarter lap later. You want the model to come
to your pit person at a speed that is comfortable for both of
you. As you become more proficient at this, try fluttering the
elevator up and down after the shutoff. This will allow you to
slow the airplane faster, which means you don’t have to shut
off as soon.
Shutting off directly opposite your pit person means only
a half lap of gliding instead of a full one. This can save several
seconds on every pit stop, but if the person can’t make the
catch, you’ve just wasted those seconds—and probably more.
Consistency first! Get comfortable with your airplane by
practicing your pitting until is second nature.
Flying with another person in the circle can be intimidating
at first. Even if you don’t have anyone to race with, fly any
sport model with one or two friends to get the feel of having
other people in the circle. If possible though, try to find
some other racers to practice with. Chances are you will be
welcomed with open arms.
Here in Dallas we always encourage new fliers to come out
and fly with us, and we are happy to give them all the help
If you can’t get together with anybody except at contest
time, try to arrange some practice with another team before
or after the contest. Your flying will benefit, and you will
make new friends or improve existing friendships. That makes
everyone a winner!
Best of luck with Margaret June. I’ll look for you at the 2015
Margaret June Air Racing
Aircraft Spruce & Specialty Co.
Bob Smith Industries
Williams Brothers Model Products
Pacer Technology/Super Glue
MJ 6 Model Aviation JUNE 2015 www.ModelAviation.com