line speed has been around for many decades. As with all other areas
of specialty, the state of the art has advanced significantly since
the time of Bill Wisniewski's reign as king of the C/L speed domain
with his venerable Pink Ladies. Today's C/L speed models have a
single long inboard wing and often have computer-designed airfoils
and fuselage shapes. In the 1958 timeframe, the record speed was
in the 160 mph range. The
video below shows a new F2A world speed record of 208 mph being
set in October of 2009.
The "Pink Ladies" have quite a history. The class "A" model detailed
here has won every contest it has entered... with speeds varying
from 138 to 154 mph. It has held the A.M.A. record for class "An
since 1955. The first record was set at 141.40 that year at the
Nationals held at Los Alamitos. This mark was upped to 145.10 during
the California State Championships at Santa Ana in 1956. Shortly
after the State Championships I went to the Nationals at Dallas
and raised the record again.
Record-holder Wisniewski with Class A "Pink Lady" (left). From
top, Ladies are Class A, FAI and A/2. Full size plans for "A"
version is on Group Plan # 858 from Hobby Helpers (7Sc)
Latest achievement was during the 1957 Nationals at Willow Grove,
when the little beasts turned 154.58 mph. (An interesting note is
that the 1956 record was broken three times at the 1957 Nationals
by three different people, Nick Sher, Arnold Nelson, and myself.)
I have used the same airplane since 1955 and it is still in good
shape, picking up speed all the time. Pink Lady "A" has been clocked
unofficially over 157 mph.
I don't know exactly what is
making the airplane go as fast as it is, unless it is a combination
of Mono-Line control, airplane design, and fuel. The engine is the
same old Torpedo 19 that has been so successful in the past. Reworked
just like the article in June, 1957 American Modeler. The fuel also
is the same as in that article.
Mono-Line is one of the
greatest advances in speed flying. The models seem to trim out better.
The reduction in drag is quite evident. Speeds have gone up at least
10 mph in all classes because of the switch to Mono-Line.
Assuming you have mastered the Mono-Line control you must learn
to get around the pylon. The best way to do this is through practice.
Always fly from a pylon when testing your airplane and you will
soon learn how to keep from stumbling.
You should also have
a reliable takeoff system, either a dolly or hand launch. I prefer
a dolly. A good one is sketched. The airplane should bind a little
on the two prongs going into the pan. This will assure a take off
without jumping the dolly.
Your helper or your mechanic is
very important. Pick an interested modeler to help (not necessarily
experienced as he can learn along with you). Learn to be familiar
with the sound of a rich or lean mixture in a running engine. Reworked
engines combined with hot fuels should be set rich on take off.
Just how rich will have to be determined by trial and error. Always
let your helper set the needle valve to become familiar with the
sound. Since (unless you have unusually long arm's) you cannot change
the setting from the pylon.
Making the pattern for the pan
is simple. First select two blocks of white pine or basswood 1"
x 2" x 14". Install wood screws about 1/2" from the ends to hold
the blocks together. Turn fuselage on a lathe or carve by hand to
the shape shown. Leave it approximately 1/16" heavy all over. Take
apart and hollow one half to approximately 1/8" thickness except
where stab bolts on. Leave this part solid. This half will be the
pattern for your pan. Carve blocks for the motor mount pads allowing
approximately 7° draft angle and cement in place. This enables the
pattern to be lifted from the mold without breaking it. Taper 1/4"
dowels for the dolly pin supports and cement in place. Also cement
a small piece of 1/4" dowel for rear hold down bolt. Pan pattern
should be smooth finished by applying 4 or 5 coats of sanding sealer,
sanding between coats.
Pink Lady Lineup
Pink Lady Launch Dolly
Finish with coat of lacquer or dope. Have your local foundry cast
your pattern in aluminum or magnesium. If you can't find facilities
for having them cast write to me at the following address: 4261
Petaluma Avenue, Lakewood, California. I can supply you with a pan
at nominal cost.
Construction of the airplane itself is
fairly easy. Sand the top of the pan to make it flat. Drill and
tap for the engine: File the pan to 3/32" thickness and file the
front to fit the spinner-which can be machined from bar aluminum
or cut down from a 1-3/4" Froom spinner.
Cut out the
other half of the turned fuselage to fit over the engine. Spot cement
the fuselage top to the pan. After the cement has dried carve and
sand the top to fit the bottom and spinner as it was left oversize
when turned. Remove top from pan and hollow to 1/8" thickness.
Next comes the wing. Select a straight grained piece of
hickory for the spar. Cut to the dimensions shown. Two pieces of
white pine make up the wing stub. Cement the aft end of wing stub
to spar permanently. Spot cement the forward end of stub. Cut out
the fuselage to take the wing. Lay wing on the fuselage and mark
where fuselage joins the wing. File the airfoil shape in the wing
stub except where the wing joins the fuselage. That part is left
flat. No incidence is used. The wing panels are made as follows:
Layout wing pattern on .012 2024- T4 aluminum. Bend in center
on a brake or over a straightedge to a 30° angle. Form the airfoil
by hand. Make wing tips from hardwood. Sand areas to be bonded with
coarse sandpaper. Clean with acetone or Methyl-Ethyl Ketone. Apply
a coat of cement (Acorn #177 or brake bonding cement) to each surface.
Allow to dry to an aggressive tackiness. Clamp trailing edge together
with wing tip in place. Clamp only 1/16" of trailing edge. Otherwise
the airfoil will flatten out. Note that the tips are washed out
slightly. Bake in an oven at 275° for 3 hours. Notch the wing stub
and file spar to slip inside the wing panels for positioning. Mark
area to clear Mono-Line unit. Remove forward end of wing stub and
cut to clear Mono-Line unit. Install Mono-Line unit on spar (note
the angle). Drill hole to clear stem of Mono-Line unit to allow
free movement in inboard side of forward wing stub. Cut outboard
side of forward wing stub to clear other end of MonoLine unit. Cement
both pieces in place permanently. Pour 1/2 oz. of melted "cerro-bend"
into outboard wing panel and slip panel into place over spar and
stub. Cerro-bend is a low melting point alloy used to bend tubing.
This might be of interest to you tricksters. It is also used to
make those spoons that melt in hot coffee. If cerro-bend hardens
before you get the. panel positioned simply hold wing over the gas
or electric burner of your stove until the cerro-bend melts. Drill
a 3/32" hole in tip of inboard wing panel and elongate to 1/8";
The aft side of hole should be in line with stem of Mono-Line unit
to' assure no-bind operation. Drill two 1/16" holes in each wing
panel and 1/16" into spar in position shown on plans to take #0
x 14 wood screws. Cement wing in place on fuselage.
is made from a block of balsa wood 1-1/2" x 4-3/4"x 1-7/8". Drill
a 1-5/32" diameter hole for cylinder. Carve the outline leaving
1/32" wall at the hole. Carve to fit over the exhaust stack and
to fit fuselage. Cut off top of cowl to allow 3/32" of the cylinder
head to stick thru when fuselage top and cowl are positioned on
the pan over the engine. Carve the baffles to the outline and depth
shown on the. plans. Make the top from a piece of hardwood. Carve
to clear cylinder head. Drill a %" hole to clear glow plug. Coat
inside of cowl with a heat resistant paint or fiberglass resin.
Sand smooth. Cement the top on the cowl. Do not cement the cowl
on the fuselage at this time.
Make the rudder from 1/16"
plywood. Sand to a symmetrical airfoil. Cut out to clear pushrod
and control horn as shown. Slot the rear of the fuselage to take
the rudder. Cement the rudder in place. No offset on. rudder. Cement
1/16" balsa covers over clearance cutout in rudder. Stabilizer
is made from 1/16" plywood.
Mark area where stab is to set
on pan. Sand to a symmetrical airfoil except where stab rests on
the pan. Leave this area flat. Cut the elevator from the stab and
sand the cut edges smooth. Cut a slot in the stab to clear the control
horn. Make the control horn from 3/64 music wire. The height of
the control horn is critical. It should be 14" plus or minus 1/32".
If it is too long there will not be enough control. If it is too
short there will be too much control. Notch the elevator to take
the control horn wire. Install the control horn. Drill a series
of small holes through the elevator approximately 1/8" from control
horn stem. Thread thin copper wire through holes around control
horn stem and solder. Install "Z" type cloth hinges. Drill two holes
in stab for hold down bolts. Drill and tap the pan to match. Make
the pushrod from 3/64 music wire. Install pushrod and bellcrank.
Fit the rear alignment block and cement in place. Make the pushrod
cover from balsa. Cement in place. Be sure that control system works
freely. Cement cowl in place. Form wing fillets from Plastic Wood.
Fill all cracks and joints with Plastic Wood. Allow to dry at least
8 hours. Use a rat-tail file to file all fillets as it is easier
to control than sandpaper. Sand all surfaces smooth and apply 3
coats of clear dope. Drill holes for hold-downs and cut the front
of fuselage to clear Dooling type needle valve assembly. Cover all
surfaces including inside surfaces (except inside the cowl) with
#120 glass cloth using cement as the adhesive instead of resin.
Sand surfaces to remove rough spots at breaks in the glass cloth.
I have been using Ditzler synthetic primer for finishing
as it is fuel proof and is very easy to work with. It comes in 4
colors: White, Red Oxide, Grey, and Orange-yellow. I use white with
a little red enamel added to give a pink color. It works best if
sprayed on, The number of coats depends on how smooth the airplane
is before applying primer. I usually use 3 coats, Wet sanded with
320 wet or dry sandpaper between coats. Wet sand with 400 wet or
dry sandpaper on the final coat. Then use rubbing compound to smooth
it out. A coat of wax will give a slightly glossy finish.
Make very sure your controls work freely. If they don't your
model' will be washed out the first time flown.
is the old standard "pen bladder" type made from a natural rubber
ink sac. Get the smallest ink sac available. Cut off to 1" long.
Cut a- piece of 1/8" O. D. brass tubing about 1/4" long. Insert
it into the end of a 1" piece of neoprene tubing. Slip the ink sac
over the end of the neoprene and brass tubing assembly. Cut a penny
balloon about 3/4" longer than the ink sac and put about 7 drops
of castor oil in it. Insert ink sac and tubing into balloon and
wrap entire assembly with thin wire or thread.
should track to the outside of the circle. If you fly on grass or
dirt more track-out is required than on cement or asphalt.
Pick a calm day to test fly. You should have no trouble flying
Here is a video showing a new F2A world speed record
set by Kalmár Sándor (335,8 km/h) at on October 10, 2009, in Pécs
The AMA Plans Service offers a full-size
version of many of the plans show here at a very reasonable cost. They will scale the plans any size for you. It is always
best to buy printed plans because my scanner versions often have distortions that can cause parts to fit poorly. Purchasing
plans also help to support the operation of the Academy of Model
Aeronautics - the #1 advocate for model aviation throughout the world. If the AMA no longer has this plan on file, I
will be glad to send you my higher resolution version.