By Don Szczur
One of the local pilots at my home field recently expressed an interest
competitively for the upcoming pattern season. His enthusiasm is particularly
inspiring, since he does not even know the sequences yet. In fact he is
not even sure which class he will be flying in next year! He is no stranger
to aerobatics though, placing first in sportsman at several local IMAC
contests. After discovering that we lost the District 1 vs. District 2
pattern competition in August by one class, he became committed to help
us win it back next year. He recently got his pattern plane flying and
is ready to start practicing. The 5 steps below will assure that he will
start off on right track. If you are thinking of getting into pattern
(or other precision aerobatics flying for that matter) this primer may
contain some helpful hints for you as well.
|Photo taken by Bob Kane at the 2001 NATS after a 4th
place finish. Don (left) and his father and caller, Tony. Aircraft
uses JR 10X transmitter, 950 rx, 8131 servos (elevator), 8411 servo
(rudder), and 7005 servos (ailerons).
My inspiration comes from the legendary Steve Stricker, who coached me
about 7 years ago on the basics of setting up a pattern plane for competition.
I thank him for his patience and have followed his advice closely. I guess
its worked somewhat because as soon as I took the time to set up my plane
appropriately, I found myself making it to the finals at the NATS on a
1. The first thing to do is either purchase or construct a control throw
meter to set your control surface deflections. I use the CRC meter which
is available from Central Hobbies. Check each aileron separately and start
with the same amount of throw up and down for each aileron. Do the same
for the elevator halves.
2. The next step is to set flight trims. I normally start with straight
and level flight back and forth making sure the ailerons and elevator
are trimmed for cruise (about half to three quarter throttle) rather than
full throttle. Why do this? Basically, you want to trim the plane at the
speed you will be flying at in competition.
3. Step 3 is trimming the up's and down's. This is important because up
and down lines impact heading changes during transition back to horizontal
flight. I often do a series of stall turns (right to left and left to
right) to check thrust. As the plane slows on the up line, it shows any
thrust angle adjustments that are needed. I adjust the thrust to give
hands-off up lines. For down lines, I use the throttle to elevator mix.
I offset the mix to kick in at just a couple of clicks of throttle stick
so it will only impact down lines. Set the mix on the 10X to "orig"
so any throttle trim lever adjustments will not affect the mix rate. I
also use throttle to aileron mix to adjust any rolling tendency on downlines.
Again, I set the (offset) to begin the mix with a couple of clicks of
throttle. As a side benefit, I found this mixing helps spin entries and
outside loops (where throttle is at idle on the backside). Finally, I'll
do some rolls up and down to adjust roll differential. Get a helper to
determine which wing is "dragging" behind the other during vertical
up and down rolls. Put more up aileron throw in the wing that is leading
to set up for nice axial rolls.
4. Now the easy part, that is, its easy when setting up knife edge
mixing with the JR 10X. I use the rudder to aileron and elevator mix (pre-set
mix function). It is important to set up knife edge mixing even in lower
classes that do not have knife edge maneuvers. Why? You'll find that the
roll/pitch coupling with rudder impacts maneuvers such as loops (with
rudder correction) and even stall turns. The mixing helps all maneuvers
5. Finally, check for control throws. I found that maximum flight scores
resulted from using only enough control throw to execute the maneuvers
safely. I set up high rates for spins and snaps but normally fly low rates
elsewhere in the sequence. This result in high degree of smoothness and
This trimming process takes a lot of discipline, but if you take the
time to trim the plane out using the five simple steps above, it will
enable great looking maneuvers with less work. I love doing just a simple
square loop with a perfectly trimmed pattern airplane. In calm weather
its just a matter of pulling elevator on the four corners and letting
the plane fly itself through for a perfect maneuver. Try it!