If you like cutting and gluing wing
ribs, this scale control line model of the Curtiss P6-E Hawk is the job for you. Let
me know after doing these 92 ribs for two wings if you still feel the same way. Designed
for a .19 to .29 engine, this 31" wingspan model will certainly present a challenge even
to the experienced modeler. Of course you need to be able to apply and finish the covering
with a high level of perfection in order to fully appreciate the amount of work put into
building it. Personally, I would hate to have to use opaque paint for a scale color scheme
in order to not have to hide the framework. Then, I would be afraid to ever fly it!
Curtiss P6-E Hawk for Control Line Fans
Designed and Drawn by Paul Plecan
For the Flying Scale fan who has a weakness for
biplanes, mention of any of the Curtiss "Hawks" brings instantaneous praise. Rugged,
aesthetically pleasing in line and form, almost all "Hawk" models are generously endowed
with the multiplicity of struts, wires, ribs and stringers that set the "detail hound"
to drooling. If you are of this breed, pull up a chair, this is your meat.
Our model, drawn to a scale of 1" to the foot, performs well with anything from .19
to .29 displacement, and has scale rib spacing.
Construction is fairly straightforward, but the demands are high if a good-looking
job is to result. After all, with 50 (yes, fifty!) ribs squeezed into 31" of span for
that top wing, each one has to be "right on the button." The examination will be thorough
when the gang spots this job at the local flying site! Built right, there's nothing like
a "Hawk" to command attention, so let's clear the work bench.
Basic framework is 3/16" sq. medium hard balsa as shown in profile view. Not all framework
was shaded in on drawing; to do so would have obliterated other details. Top longeron
is straight (just under stabilizer level); the bottom conforms with the bottom edge of
the profile view. Forward of F-3 these longerons converge, ending at F-1.
bracing is a "must" as is ample drying time for the cement before removing from workbench
for cross-brace installation. Cross-brace sizes are given above cockpit area. Note two
each are required. Since 1B, 2B, 3B and 4B are similar, eight of this size will be needed.
When installing cross-braces, note slight bevels needed at those ends where the longerons
converge aft of cockpit. Those forward of F-4 do not get this treatment.
Once basic framework is built, the balsa-block areas can be worked. Side blocks cement
on first, followed by top and bottom. All cross-sections are on plan. A good bit of carving
is required. Bending stringers to conform with side curves of fuselage suffice for some
modelers, but we think it better to cut out shaped and tapered stringers as shown (S1
and S2). Then mere application is necessary, plus a bit of sanding to trim them exactly.
It will be best to "fill-in" the area between stringer S2 and bottom longeron where
lower wing passes through fuselage to obtain strength. Area below stabilizer is similarly
"filled-in," scrap 3/32" or 1/8" balsa being just right. Due to the taper, the hole in
fuselage for passage of wing will have to be large enough for rib #28 to pass through.
After Wing is cemented in place, remaining space is filled in with Aero Gloss Plastic
Balsa or similar compound to produce fillets at root of lower wing.
Wing construction is orthodox, but take care in cutting out ribs and spars - in this
model, neatness counts. Firm, straight-grained wood is a "must" for entire wing. For
the sake of simplicity, tail surfaces are 1/4 " sheet, sanded to airfoil (streamline)
cross-section. For the rare individual who has all the info on proper scale rib spacing,
etc., the tail can be built up, but it isn't necessary. Scale position of ribs can be
simulated with strips of bond paper cemented to tail where desired.
Individual ability will be governing factor in the completion of model, as will the
amount of extra detail over and above that shown on plans. Correct information on coloring
is a stumbling-block for many, so here is the data for your P6-E: fuselage was olive
drab, although just prior to WW 2, some P6-Es had blue. Nose area, L.G. struts, hawk
talons or claws on the wheel-pants, and band around rear of fuselage was black. White
trim as shown. Hawk on each side of fuselage, white. Wings entirely yellow, except for
national insignia and red stripe on top wing; black lettering and national insignia on
lower wing (bottom surface only). Hand-holds on lower wing tips and center section of
upper wing are black.
Horizontal tail surface entirely yellow, same for fin and that portion of rudder ahead
of the hinge line. Red, white and blue striping on rudder as indicated on plans. White
diamond trim on headrest. Black number on fin; same number in white on nose just above
prop. These markings are those used by 17th Pursuit Squadron based at Selfridge Field,
Michigan, in mid-thirties.
Minor variations occurred in many P6-E Hawks. Wheel-pants that exposed the outboard
face of wheel appeared on later versions in interest of faster wheel-changes or tire
repairs. While enclosed cockpits and supercharged engines were also used, it is doubtful
if these changes saw actual squadron service.
Control Line Curtiss P6-E Hawk Plans
Bill of Materials
(Balsa, unless otherwise specified)
Five pieces 1/16" x 2" x 36" for ribs, leading edge covering; (1) 1/8" x 2" x 36"
for spars, wing tips, etc.; (2) 1/8" x 3/8" x 36" trailing edge stock; (6) 3/16" x 3/16"
36" hard balsa for longerons, cross braces, etc.; (1) 3/32 x 2" x 36" for stringers,
fill-in material; (1) 1/2" x 1 1/4" x 3" nose block; (1) 1" x 2 3/4" x 14" turtledeck;
(1) 7/8" x 2 3/4" x 5 3/8" top-front cowl; (1) 1" x 2 5/8" x 5" bottom cowl; (2) 3/8"
x 3" x 5 1/4" side cowls; (1) 1/4" x 3" x 36" medium for tail surfaces (use leftovers
for wheel-pants, etc.); (1) 3/32" x 1/4" x 30" N-struts (pine or other hard wood); (1)
3/32" x 5/32" x 20" cabane struts (pine); (2) 5/16" 5/8" x 5" hard wood engine bearers;
(1) 3/32" dia. x 36" steel wire for landing gears; (1) 2 1/2" bellcrank; (1) .045" or
.049" dia. x 36" steel wire for pushrod; (1) 3/4" dia. tailwheel; (1) pair 2" dia. main
wheels; (1) 3/16" dia. brass or aluminum tubing for scale exhaust stacks; (5) .020 dia.
steel wire rigging; dope, cement, Aero Gloss Plastic Balsa as required; engine .23 cu.
in. displacement (or close). tank, fuel line, props, related flying equipment as required.
A few remarks concerning biplane U-control models will not be out of place here. Incidence
of wings is of utmost importance - making a simple scrap "jig" to position upper wing
is mandatory when struts are being cut to size and fitted. Strength of joints where struts
join fuselage and where they meet wing surface is very. very important ... you don't
want the upper wing to part company with its mate on a rough landing. A free-turning
pair of wheels is necessary, since model sets higher off ground than a monoplane. Be
ready to trot forward the moment the wheels touch down, so model rolls straight ahead
with your control lines loose.
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.
Try my Scale Calculator for Model Airplane Plans.
Posted May 3, 2014