Extreme Flight YAK-54 ARF User manual

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60" Yak-54 EXP ARF
Instruction Manual
Copyright 2014 Extreme Flight RC
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Please take a few moments to read this instruction manual in its entirety before beginning
assembly. We have outlined a fast, clear and easy method to assemble this aircraft and
familiarizing yourself with this process will aid in a quick, easy assembly.
Please read the following paragraphs before beginning assembly
of your aircraft!
THIS IS NOT A TOY! Serious injury, destruction of property, or even death may result
from the misuse of this product. Extreme Flight RC is providing you, the consumer, with
a very high quality model aircraft component kit, from which you, the consumer, will
assemble a flying model. As such it is beyond our control to monitor the finished aircraft
you produce. Extreme Flight RC will in no way accept or assume responsibility or
liability for damages resulting from the use of this user assembled product. This aircraft
should be flown in accordance with the AMA safety code. It is highly recommended that
you join the Academy of Model Aeronautics in order to be properly insured and operate
your model at AMA sanctioned flying fields only. If you are not willing to accept ALL
liability for the use of this product, please return it to the place of purchase immediately.
Extreme Flight RC, Ltd. guarantees this kit to be free of defects in materials and
workmanship for a period of 30 DAYS from the date of purchase. All warranty claims
must be accompanied by the original dated receipt. This warranty is extended to the
original purchaser of the aircraft kit only. Extreme Flight RC in no way warranties its
aircraft against flutter. We have put these aircraft through the most grueling flight tests
imaginable and have not experienced any control surface flutter. Proper servo selection
and linkage set-up is absolutely essential. Inadequate servos or improper linkage set up
may result in flutter and possibly the complete destruction of your aircraft. If you are not
experienced in this type of linkage set-up or have questions regarding servo choices, please
contact us at [e-mail] or 770-887-1794. It is your responsibility to
ensure the airworthiness of your model.

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Greetings and congratulations on your purchase of the Extreme Flight RC Yak-54
EXP ARF! Like all of the EXP series, the YAK-54 excels at both 3D and precision
maneuvers. It shares the long tail moment of the Extra, Edge and Laser which gives it
great stability in high speed precision maneuvers and it also features the famous EXP
elevator that allows for crazy pitch authority and great stability in high alpha
maneuvers. When the CG is properly set the YAK-54 has minimal coupling and is a
very neutral aircraft.
The YAK-54 EXP shares many of the attributes of the previous EXP airframes along
with some new features. The wings are slightly recessed into the fuselage sides which
provide a much cleaner appearance and insures the wings will appear flush with the
fuselage sides. The YAK-54 EXP incorporates carbon fiber and G10 composites into
the structure of the airframe, resulting in a lightweight, yet twist free structure
capable of handling extreme aerodynamic loads. Carbon and G10 are used in high
stress areas such as the landing gear mounting structure and fuselage longerons to
provide enormous strength and durability. A true piece of carbon fiber art, the
landing gear is airfoiled and has just enough "give" to cushion those not so perfect
landings. All control surfaces are pushrod driven with short linkages and use ball
links for slop free actuation with no binding. Optional Side Force Generators are
included and add to the already generous side area, increasing yaw axis authority and
adding stability in all angles of sideslip. Expertly painted fiberglass cowl and wheel
spats and 2 gorgeous high visibility Ultracote color schemes add the finishing touches
and make this an airplane that you will be proud to show up at the flying field with.
The combination of these unique elements add up to an aircraft that pushes the
boundaries of modern aerobatic flight.

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Items needed for completion:
Masking tape.
Hobby knife with #11 blades.
Thin and medium CA. We highly recommend Mercury M5T thin and M100XF
medium formulas as well as the Mercury glue tips.
30 minute epoxy. Mercury Adhesives Epoxies have worked very well for us.
Blue Loctite.
Electric drill with an assortment of small drill bits.
Small flat head and Phillips head screw drivers.
Standard and needle nose pliers.
Side cutter.
Metric ball driver or allen key set.
Sanding block and sandpaper.
4 x METAL GEARED servos with a minimum of 76oz of torque. All flight testing
was performed with Hitec HS-7245MH.
Dubro Long Super Strength servo arm set. (Dubro part #670 for Futaba, #671 for
JR and #672 for Hitec).
2 x 6” Servos Extensions for the Ailerons.
2 x 24” Servo Extensions for the rudder and elevator servos
Torque 4016T/500 MKII Brushless Outrunner.
Airboss Elite 80 Amp ESC.
6S 3300-4000 mah LiPo battery.
16 x 7 XOAR Electric wood prop.

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Tips for Success:
1. Before starting assembly, take a few minutes to read the entire instruction manual
to familiarize yourself with the assembly process.
2. Please take a few minutes and go over all the seams on the aircraft with a covering
iron on a medium heat setting. Also, due to climate changes, wrinkles may develop
in the covering. These are easily removed with a little bit of heat. Use a 100%
cotton t-shirt or microfiber cloth and your heat gun and heat the covering while
gently rubbing the covering onto the wood with the t-shirt. Be careful not to use too
much heat as the covering may shrink too much and begin to lift at the edges. Take
your time, and a beautiful, paint-like finish is attainable.
3. Take a few minutes and apply CA to high stress areas such as servo mounting trays,
landing gear mounts, anti-rotation pins, and motor box joints.
4. By the time your aircraft arrives at your door step, it will have been handled by a lot
of people. Occasionally, there are small dings or imperfections on some of the
surfaces. An effective method to restore these imperfections to original condition is
to use a very fine tipped hypodermic needle and inject a drop of water under the
covering material and into the ding in the wood. Apply heat to the area with a
sealing iron and the imperfection will disappear. Deeper marks may require that
this process be repeated a couple of times to achieve the desired result, but you will
be surprised at how well this technique works.
5. Use a high quality epoxy for installing the composite control horns. We highly
recommend the new Mercury Adhesives 30 minute Epoxy.
6. When applying decals, first clean the area where the decal will be applied with
alcohol. Mist the area lightly with Windex or Rapid Tack before applying the decal
which will allow you to properly position it, and then use a rubber squeegee to push
all of the liquid from under the decal. This will result in very few air pockets
trapped under the decal.
7. Take the time to properly balance and trim your aircraft and set up rates and
exponential values. Your flying experience will be greatly enhanced once your plane
is properly dialed in.

Wing Assembly
1. Locate the 2 wing panels as well as the composite aileron control horns and base
plates. Note that one of the control horns is shorter than the others – it’s used for
the elevator. Use a soldering iron or sharp hobby blade to remove the covering over
the slot for the aileron horn. Make sure you are doing this on the bottom of the
aileron!
2. Insert the horn into the base plate and into the slot in the aileron. Use a fine tipped
felt marker to trace the base plate.
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3. Remove the horn assembly and use a #11 blade to remove the covering from inside
the ink line you traced around the control horn base. Wipe away the ink line with a
cotton cloth or paper towel soaked in denatured alcohol.
4. Use sandpaper to scuff the portion of the horn that will be inserted into the aileron
as well as the bottom of the base plate.
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5. Apply 30 minute epoxy to the slot in the aileron and the scuffed potion of the control
horn that will insert into the aileron. Use a zip tie to ensure the slot is completely
filled with epoxy.
6. Install the aileron horn into the aileron slot and wipe away any excess epoxy with a
paper towel or cloth soaked with denatured alcohol.
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7. Remove the aileron from the wing to ensure all hinges are centered between the
wing and aileron. One way to ensure the hinges are centered is to fold them in half
and re-install into the aileron using the crease as a reference point.
8. Making sure the aileron is properly aligned between the wing root and wing tip,
hold the aileron fully deflected and apply a drop of thin CA to each hinge. Flip the
wing over and repeat.
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9. Before installing the aileron servo, take a minute and apply some CA to the servo
tray and the anti-rotation pins.
Before moving to the next step, it would be a good time to seal the hinge gap with a
strip of Ultracote or Blenderm tape. Be sure to fully deflect the control surface
when sealing the gap to allow for full deflection once the gap is sealed. Also, take a
few minutes to go over all of the seams in the covering with a sealing iron on a
medium heat setting, paying special attention to stripe edges and ends.
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10. Attach a 6” servo extension to the servo and secure with thread or heat shrink
tubing. Use the manufacturer supplied mounting hardware to install the servo with
the output shaft toward the trailing edge of the wing. Electronically center the servo
and install the second longest servo arm from the Dubro servo arm kit.
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11. Locate 2 of the short threaded metal pushrods and 4 ball links along with 4 x 2mm
screws, nuts and washers. Thread the ball links onto each end of the pushrods and
secure to the bottom of the servo arm and to the control horn as shown in the
picture below. Remember to use Loctite on all nuts. Repeat this process for the
other wing half. Clean the wing panels with a soft cloth and put them away in their
wing bags.
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Fuselage Assembly
12. Locate the carbon fiber landing gear, 4 x 3mm bolts and washers. Place the landing
gear onto the landing gear plate with the gear angled towards the front of the fuse.
Secure the landing gear to the fuselage with the 3mm bolts and washers as shown in
the picture below. Make sure to use a drop of blue Loctite on each bolt!!!
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13. Locate the 2 axles, 2 locking nuts, 2 wheels, 2 wheel collars and 2 wheel spats.
Center the wheel on the spat as shown in the picture below.
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14. Drill a hole through the spat using a 5/32nd drill bit. If flying on a grass field you
may want to drill the spat about ¼” below center to allow the spat to be positioned
slightly higher than center to prevent it from making contact with the ground.
15. Insert the threaded portion of axel through the spat, then mount the axel and spat
onto the landing gear by attaching the lock nut and washer onto the axle. Tighten
the nut, making sure the wheel spat is positioned properly.
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16. Place the wheel on the axel and secure with the wheel collar.
17. When satisfied with the position of the wheel pant, drill a 1/16th hole through the
wheel spat at the location of the hole in the landing gear and secure with a wood
screw. Repeat this process for the remaining wheel and spat.
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18. Before installing the horizontal stab you will need to remove the piece of balsa at the
rear of the stab slot. The factory leaves this piece intact so that the rear of the
fuselage will remain true during the covering process and during transit. First place
a couple strips of masking tape on the fuselage to give you a guide to cut by and to
prevent the Ultracote covering from tearing.
19. Use a razor saw to carefully make the cut, then sand smooth.
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20. Locate the horizontal stabilizer/elevator assembly. Turn it upside down on your
building table and remove the covering over the right slot on the bottom of the
elevator where the elevator control horn will be installed. Using the same process as
with the ailerons, insert the horn into the base plate and into the slot. Trace around
the base plate with a fine tipped marker.
21. Use a sharp hobby knife to remove the covering 1/16" inside the line you traced.
Wipe away the ink line with a cotton cloth or paper towel soaked in denatured
alcohol.
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22. Scuff the portion of the control horn that will insert into the elevator as well as the
bottom of the base plate with sandpaper. Secure the control horn to the elevator
with epoxy just as you did with the aileron horns.
23. Slide the elevator onto the hinges in the stabilizer making sure the hinges are
centered in the hinge gap and secure with thin CA.
Before moving to the next step, it would be a good time to seal the hinge gap with a
strip of Ultracote or Blenderm tape. Also, take a few minutes to go over all of the
seams in the covering with a sealing iron on a medium heat setting, paying special
attention to stripe edges and ends.
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24. Insert the stabilizer into its slot and the carbon fiber wing tube into the fiberglass
sleeve. Use a ruler to insure that the stabilizer is centered in its slot and compare the
stabilizer to the wing tube to make sure it is properly aligned. Sand or shim the slot
if necessary to ensure proper alignment.
25. Once satisfied with the alignment, glue the horizontal stab in place by applying CA
along the joint between the stab and fuse. Make sure to apply CA to the top and
bottom of the stab, being careful not to get CA on the covering.
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26. Remove the covering over the slot on the right side of the rudder. Follow the same
procedure as with the ailerons, Use a sharp hobby knife to remove the covering
1/16" inside the line you traced. Wipe away the ink line with a cotton cloth or paper
towel soaked in denatured alcohol.
27. Scuff the portion of the control horn that will insert into the ruder as well as the
bottom of the base plate with sandpaper. Secure the control horn to the rudder with
epoxy just as you did with the aileron horns.
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28. Slide the rudder onto the hinges in the vertical stab, making sure the hinges are
centered between the rudder and stab. Also, make sure the rudder is flush with the
top and bottom of the stab. Once satisfied, glue the hinges in place with thin CA
making sure the rudder is fully deflected.
29. Locate the carbon fiber tailwheel assembly in the hardware package. Secure the
tailwheel bracket to the bottom rear of the fuselage with the provided wood screws,
making sure the pivot point of the assembly is over the hinge line of the rudder.
Secure the tiller using the provided screw, but do not over tighten as the tiller
should be able to move on the screw as the rudder is deflected.
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