8
PREFLIGHT
IMPORTANT:
If you are an inexperienced modeler we strongly urge you to seek the assistance of a competent, experienced
R/C pilot to check your model for airworthiness AND to teach you how to fly. The L-39 is a model designed for pilots with inter-
mediate to advanced piloting skills. Attempting to learn to fly on your own using this model is dangerous and may result in its
quick destruction or even injury to yourself and others. Therefore, find an instructor and fly only under his or her guidance and
supervision until you have acquired the skills necessary for safe and fully controlled operation of your model.
Takeoff
Less-experienced flyers should fly the L-39 only in calm (less than five miles per hour) conditions. Frequently, winds are calm in
the early morning and early evening. Often these are the most enjoyable times to fly anyway!
Until you have the L-39 properly trimmed for level flight, we recommend having an assistant hand-launch the model instead of
launching it yourself.
Turn on the transmitter and plug the battery into the speed control. Turn on the receiver by following the instructions that came
with your speed control. Secure the canopy hatch in place.
IMPORTANT:
Confirm that the transmitter operates the controls properly by moving the sticks and watching the surfaces respond.
When ready to launch, the assistant should hold the L-39 behind the canopy
hatch, with the model in front of him and pointed into the wind. With the pilot
(that would be you!) standing behind the plane, fully advance the throttle to
start the motor. When the motor is at full power, the hand launcher should
firmly give the model an underhand toss into the air with a slightly nose-
up attitude. Be certain the model is being launched into the wind and be
immediately ready to make corrections to keep the airplane flying straight,
level and into the wind.
When the model has gained adequate flying speed under its own power, gently
pull the elevator stick back until the airplane starts a gradual climb. Many
beginners tend to pull too hard causing the model to stall, so be gentle on
the elevator and don’t panic. If you do pull too hard and you notice the model
losing speed, release the elevator stick and allow the model to regain airspeed.
Continue a gradual climb and establish a gentle turn (away from yourself and
others) until the airplane reaches an altitude of 20 to 30 meters [75 to 100'].
Flight
The main purpose of the first few flights is to learn how the model behaves and to adjust the trims for level flight. After the model
has climbed to a safe altitude, reduce the throttle slightly to slow the model, yet maintain altitude. The L-39 should fly well and
maintain adequate airspeed at about 1/2 throttle.
Adjust the elevator trim so the model flies level at the throttle setting you are using. Adjust the aileron trim to level the wings. It
may take a few minutes to get the trims adjusted, but this should be your first priority once at a comfortable altitude. Continue to
fly around, executing turns and making mental notes (or having your assistant take notes for you) of what additional adjustments
or C.G. changes may be required to fine tune the model so it flies the way you like.
Landing
Begin the landing approach by flying downwind at an altitude of approximately 6 meters [20 feet]. When the airplane is
approximately 15 to 30 meters [50 to 100 feet] past you, gradually reduce power and make the “final” 180° turn into the wind
aligning the airplane with the runway or landing area. Do not dive the airplane, as it will pick up too much speed. Instead, allow
the airplane to establish a gradual descent. Concentrate on keeping it heading into the wind toward your landing area. When the
plane reaches an altitude of about 3 feet [1 meter], gently apply a little “up elevator” to level the plane, but be careful as too much
up elevator will cause it to stall. While holding a slight amount of up elevator the airplane will slow and descend as it loses flying
speed, thus touching-down on the ground.
Until you are able to accurately judge how far the L-39 can glide, it may be helpful to reserve some battery power to run the motor
so the plane can be flown back to your landing area in case you need to throttle up and make another landing pass.
Best of luck and happy fl ying!
