RBC kits L39 Albatros User manual

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Thank you for purchasing L39 Albatros from www.rbckits.com
For the first time, R/C enthusiasts we have a choice in scale and fun flyer aircraft designs.
Our goal, through computer technology and state-of-the-art production techniques, is to offer aircraft
which in the past have not been modelled simply because they weren’t popular enough to justify mass
production. Our production techniques allow us to produce aircraft which, though not as popular and
well known as P-51s and P-47s, still offer historical significance (good or bad!), Good looks and flying
characteristics, and a uniqueness that is sure to turn heads wherever you take your airplane!
Your airplane has many unique features in its design:
CAD Design
CAD design allows strength to be built into the airplane without sacrificing weight. Accurate parts
design and placement ensures a perfect fit.
CAD Drawn Plans
The plans in this kit are not copied from a master set! They are originals drawn directly from the CAD
program where the airplane was designed. We do this because it allows us to use colour, which helps
you better visualize the various components of the airplane, and we can use better quality paper,
which greatly reduces the possibility of shrinkage.
Since you’re going to build directly on the plans, they ought to be the proper size! Also, parts
placement is guaranteed to be accurate, so you can build a better, straighter model.
Small and hard-to-produce parts are simply a computer file away, so you get a more accurate airplane.
Lightening Holes
Lightening holes are cut into all ribs and formers where possible and justified. This allows us to keep

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the weight on each plane to a minimum without sacrificing strength.
The same program that generates the design and plans also drives the cnc cutter, so every part is
reproduced exactly as it was designed. Cnc cutting also allows us to fit more parts on each sheet of
wood, reducing the waste, and lowering the cost to you.
Plastics
Several parts are accurately reproduced high quality Polystyrene, the canopy is made from PETG or
Lexan
General Building Information
The L39 ALBATROS can be built by a person with experienced building skills. It is not designed for
someone who has built a trainer or low wing sport plane. No unusual building techniques are required,
although more difficult areas are explained in detail where necessary. Certain steps in the building
process must be followed as depicted, or you might find yourself digging back into the structure to
redo something. These areas are outlined when necessary. Occasionally hints will be included at
certain building steps. These are not required for completion, rather they are tips intended to ease a
particular process. The cnc router does cut through the wood, as a result of this, occasionally there will
be fraying on the surface of the wood. This is normal, and is only a surface problem and does not
affect the wood in any other way. Similarly, the cnc settings are optimized for wood thickness
averages, so occasionally, due to variations even in individual sheets, some areas might not cut
through completely. Simply use care in cutting the parts from the sheets; most of the time, the parts
will break out of the sheets!
Note that due the differences in wood thickness per sheet it is advisable to sand the tabs a bit so they
slide in easy , also sand the openings so parts slide in easy , hard pushing parts have a high risk of
breaking, it is not necessary the rework the corners of the cut-outs , this is done by the cnc machining
Hardware and an edf unit are not included in the kit. There are so many choices for quality hardware
that these choices are left to the individual preferences of the builder, rather than include something
in the kit that you’ll probably throw away anyway.
This aircraft is not a toy. It must be flown in a responsible manner according to the rules set forth by
Law. The builder assumes the responsibility for the proper assembly and operation of this product.
Rbckits shall have no liability whatsoever, implied or expressed, arising out of the intentional or
unintentional neglect, misuse, abuse, or abnormal usage of this product. Rbckits shall have no liability
whatsoever arising from the improper or wrongful assembly of the product nor shall it have any
liability due to the improper or wrongful use of the assembled product. Rbckits shall have no liability
for any and all additions, alterations, and modifications of this product.
Having said that, turn the page and start building the best airplane kits on the market!

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Material you might need:
Balsa knife, Stanley knife, straightedge, building board 1700mm,
ca glue medium, thin, thick you need approx. for wing and vertical stabilizer sheeting 4 bottles
thick and 2 bottles medium for rib gluing,, fuselage 1 medium for formers … thick for sheeting
building nails, tape
Also use white glue, and canopy glue, epoxy for the canopy and cowls
Some drilling and bending tools, wire cutter, safety goggles etc. etc.
For finishing you need:
Glass 25 gram 3mtr and filler dope or PS100 or epoxy 1 litre, brushes sanding paper
60,120,180, paint of your choice
Wheels as on the drawing, controls, motor, battery etc.
All vacuumformings should be roughened up before gluing and primed before painting
Check the pictures for additional information; a picture says more as a 1000 words so do look
at the pictures on the cd
STUDY THE DRAWING AND PICTURES TO UNDERSTAND HOW THE L39 ALBATROSS BUILD
IMPORTANT! DO MARK ALL PARTS ON THE CNC SHEETS AS PER DRAWING THERE ARE A LOT OF PARTS THAT ARE
LOOKING SIMILAR,SO MARK THEM CLEAR AS TO THE DRAWING
Vertical stabilizer
Layouts parts and assemble step by step the stab and rudder. Use the feet on the ribs
Make up the sheeting as per plan see the drawing

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Use the 8mm dowels, you can glue them, but take care of the length. Sheet
Place your steering servo inside rudder and route the wiring
Sheet other side and make rudder also. Place leading edge and pre sand fairings, sand rudder and tip,

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Place leading edge at rudder and sand to shape, place rudder tip and sand to shape place fairings and
sand to shape

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Horizontal Stabilizer:
Make the parts as per plan and take out all parts from their sheets, sand of all small holding tabs Cut
the sheeting from 1,5mm balsa to the plan and sheet assembly do not glue the dowels yet just place
them in to help for straightness
Turn over stabilizer clean edges and sheet other side. Pin down the help formers at their positions and
Place sheeting to assembly. Place leading edges and tips and sand all to shape
Take out elevators and sand to shape making sure for enough deflection

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Place stabilizer fuselage with the dowels taking care for straightness in accordance with rudder the
elevators have each a separate steering wire the rudder has a servo inside.
You can make dummy trim tabs, looks nicer.
Wing:
Place wing drawing under a sheet of clear plastic.

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Start by making the wing sheeting from 1,5mm balsa as per plan, see the templates for cutting the
sheets and the wing top view for the glue and cut template, and do make oversize! And join with tape
and ca
Take out all parts that are needed for the wings and clean them up with a sanding block from the small
holding tabs. , make up the retract formers with a layer of glass 160-200gr and join with white glue

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Make the main formers from cnc parts and the 3x3 spruce along a straightedge
Place the capping to the mainformers to take the joiners; do not glue the joiners in yet

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Place the Retract former R8/9 into R2 and R3, gluing is ok these parts
Make up the wing framing with ribs and formers, , place retract formers ribs combo step by step place
ribs and formers, a drop of glue may help holding but do not glue all yet

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Place flap and aileron formers
Draw up rib and former lines on sheeting, place some scrap fill under retract formers to take the space
between formers and sheet, sand to shape first, then place assembly to sheet
Set up the frame work with ribs and main formers and place in position on bottom sheeting.
Start gluing Main formers to bottom sheeting start at the root and work your way to the tip along the
main formers, glue bottom front to ribs as last.

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Place sub leading edge and flap and aileron edges, mark edges through sheet, easier for later
Place servo doublers and scrap fills for hinges and horns, place ribs from scrap for flaps, cut ribs for
taking flap and aileron leading edges,
Place servos ,make openings at bottom and mark hinge lines flap and aileron. Note for the flap servo
they should be orienting the horn to the left or right for both wings both the same, do not forget to
place scrap balsa in the mid trailing edge for the wing fasteners
Place wing assembly on work plate and fasten at the X marked spots with the 3x6 help former under
the wing see the position on the drawing for this.

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Sheet top of wing, we joined the trailing edge with tape and then flipped over the sheet to the top.
Now mark trailing edge as per plan and cut clear the trailing edge and sand, take out ailerons and
flaps,.check disk for pictures.
Place leading edge sand all as per drawing

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Join wings with the spruce joiner, make sure for a good fit do try and test do make it slide easy in and
out , Do glue with epoxy do not use white glue (it will seize direct and you spoiling your wing)
Use strip of glass (160gr) to join the wing
Make flap and aileron hinges as per plan. Make tip tanks do test fit before gluing , tip tanks are 2
halves joined with balsa joiner test fit inner sides and glue test fit outer sides and glue then join.

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Make z-bends for aileron and you need a kwiklinks for the flap steering for adjusting (see pictures)
Clean up retract space and place retracts, we used electrics.do try fit and working
We make the retract covers from 0,5mm aluminium sheet and flattened 5mm brass tube
When your retract is stalled when retracted, most of the time it is because of too tight closing fit, a
little push will open the set it is binding in closed position, we solved this by adding a small piece of
wood between leg and housing, this keeps the retract open enough to not bind, just try with some
different thickens of wood sheet, until in and out is working ok.

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After fuselage is finished.
Mounting the wing to the fuselage... drill the 5mm for the fasteners place fastener rings line out wing
and glue rings to wing.
Place belly formers and sheeting sand to fit fuselage

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Fuselage:
Take out all parts and clean up the small tabs on the parts.
Make the front retract parts , join the retract 12x3 ply with glass and white glue or epoxy, step by step
join front retract strip 3x12 with some glass between them
Place all formers as per drawing in the sequence as shown Note that F13 is in 1 piece no need for
joining, we have basically a front part a mid-part and a back part of the fuselage, and front part
formers are placed

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Now place retract formers in front, place canopy framing F22 place F11 and place F12
Midpart.
Make former F19 with doubler place F20 to F19; place F29, F31, and F32
Place F25, F26, F27 and place F28, note that all is done without gluing, or maybe a small drop to hold
parts.

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Now place the temp build moulds F47to, F46, F45, and F44 the formers with a small drop of glue just
to hold them
Draw a straight line onto your building board, and place the fuselage to the board with the help
formers lined out and glue the help formers with a drop of glue to the building board, start in the front
step by step
Join the front and the midpart of the fuselage

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Place the formers for the back part of the fuselage step by step until you are at the tail end, place the
Build helpformers F43, F44 to the building board