F/A-18 Hornet Article - Steve's RC Homepage

HOMEBUILT BY STEVE SHUMATE 

F/A-18 

A 

FOAMY PUSHER-PROP 

JET WITH PERFORMANCE! 

HORNET 

Caption text TK this is FPO 

text and must be replaced 

Caption text TK this is FPO 

text and must be replaced 

SPECS 

TYPE: semi-scale pusher-prop jet 

MINIMUM FLYING AREA: outdoor 

soccer field or football field 

BUILDING SKILL LEVEL: 

intermediate 

FLYING SKILL LEVEL: intermediate 

WINGSPAN: 28.4 in. 

WING AREA: 254 sq. in. 

LENGTH: 41.7 in. 

WEIGHT: 15 to 18 oz. 

WING LOADING: 8.5 to 10.2 

oz./sq. ft. 

POWER: GWS EPS-350C with 

C gearing 

PROP: GWS 8x6 Slowflyer 

RADIO REQ’D: 6-channel microreceiver 

such as the GWS R6N 

or Hitec Electron 6 

SERVOS: 2 GWS Pico for the 

flaperons; 1 Hitec HS-55 for the 

stabilator 

BATTERY: E-Tec 1200 mAh 

11.1V Li-poly 

FLIGHT DURATION: 20 min. 

COMMENTS: this semiscale 

park flyer looks remarkably realistic 

in the air. It has excellent flying 

characteristics and is easy to fly in 

small fields. It also features simple, 

foam construction so it can be 

built quickly. 

this model was inspired by the many performances of the 

Navy Blue Angels that I’ve watched over Lake 

Washington in Seattle, WA. I set out to design a simple, 

lightweight F/A-18 that could duplicate the Blue Angels’ 

aerobatic routines while flying in small local schoolyards. My 

design goals were park-flyer performance, simple construction 

and the ability to use inexpensive and readily available 

components. Slow-flight performance was achieved with low 

wing loading (less than 10 oz./sq. 

ft.), high power loading (100 

watts/lb.) and excellent handling 

qualities (provided in large part by 

the flaperon and stabilator control 

system). The ultimate result greatly 

exceeded my expectations! 

The Hornet has simple construction 

and it is built entirely from 

thin foam sheets; only minimal 

carving and sanding are required. 

To keep the model inexpensive, I 

chose readily available GWS components 

for the power system and 

radio equipment. 

The model has excellent flying characteristics 

and is surprisingly easy to 

fly. If you can handle a standard, sport 

aerobatic airplane, you can handle the 

F/A-18. This model also has a remarkably 

wide speed range. When built to be 

lightweight, it can fly slowly enough to 

easily fly in small fields such as a 

school soccer field, yet it can also do 

50mph high-speed passes in larger 

fields. The recommended GWS brushed 

motor (see sidebar) provides nearly 1:1 

thrust to weight ratio, and that will 

allow excellent sport aerobatics. With 

the recommended brushless power system, 

this model can accelerate straight 

up and provides breathtaking aerobatic 

performance. 

The Hornet can be built using either 

6mm Depron or BlueCore foam. BlueCore 

(often called fan-fold foam) is intended for 

home insulation and is widely available at 

home-improvement stores. Depron must 

be mail ordered from companies such as 

Depron USA. BlueCore is considerably 

less expensive than Depron, however, 

Depron has a much smoother finish and 

produces a better-looking model. Both 

foams weigh virtually the same and produce 

a good-flying model. 

2 BACKYARD FLYER JULY 2005 3

HOMEBUILT 

CONSTRUCTION 

Three types of adhesives are needed to 

build this model. Epoxy should be used 

for all critical joints such as attaching the 

wing and installing the motor mount. 

Foam-safe CA or foam contact glue (such 

as UHU POR or UHU Creativ) can be 

used for the remaining foam and balsa 

joints (such as assembling the fuselage). 

3M 77 spray is necessary for tacking the 

paper-parts templates to the foam and 

for creating the laminated foam 

nosecone and canopy. 

Begin construction by cutting out all of 

the part templates from the plans and 

trim them to within roughly 1/8 inch of 

the outlines. Lay the templates on the 

foam sheet; to minimize waste, organize 

them so they fit as close together as possible 

on the sheet. After all the templates 

are laid out, pick up each piece, spray one 

side very lightly with 3M 77 spray adhesive, 

and then stick it back on the sheet. 

When you’re finished, cut out all the parts 

on. The nosecone and canopy are made 

by laminating several pieces of foam 

together using 3M 77 spray adhesive, and 

then carving and sanding them to shape. 

Start with coarse (100 grit) sandpaper and 

work your way to finer (220 grit) sandpaper. 

When finished, glue the nosecone to 

the front of the fuselage with epoxy. 

Now begin assembly of the aft fusethe 

Hornet has been a highly controversial plane ever since it 

was first proposed. Its detractors point at their hero—the massive 

F-14—and say that the Hornet isn’t worthy of following in 

that great airplane’s steps: no range; no load; no nothin’. 

Well, folks, guess what? Right or wrong, the Tomcat is on its way out, 

and the Hornet will soon be the only combat 

airplane on deck. 

For several reasons, the Hornet has a confusing 

history. For starters, as it’s known 

today, the Hornet is a MacDonald-Douglas 

airplane; only, it isn’t. It was designed and 

originally built by Northrup. 

Confusing things even more, the Hornet 

wasn’t designed for the Navy. Furthermore, at 

its inception, it was a failure: known then as 

the XF-17, it was the loser in the U.S. Air 

Force’s design competition that was eventually 

won by the F-16 in early 1975. 

The same year the Northrup XF-17 lost the 

USAF competition, Navy brass were casting 

around for a less expensive, cheaper-tooperate 

airplane that could replace the 

aging Phantoms, A4s and A6s in the fleet. If 

you think carefully about the characteristics 

of the planes in that grouping, you’ll realize 

that the brass were biting off a mighty big 

chunk: they wanted one airplane to be a 

fighter and a specialized, tactical-attack machine. They wanted to raise 

aerial multitasking to a new level. 

Once upon a time, fighting a war meant just one thing: can we beat 

what the Russians are flying? That’s no longer the case. Recent wars 

have meant something else: can we get in, drop a lot of ordnance and, at 

the same time, knock down less well-trained pilots flying old Russian aircraft? 

Then, another factor was added to the mix: is there a way we can 

4 BACKYARD FLYER 

This is the beginning of fuselage assembly, 

before the nose cone has been carved to shape. 

Note the sheet-foam construction with balsa 

triangle stock at the corners. 

by going around the lines with a sharp X- 

Acto knife. 

FUSELAGE 

Begin assembly with the forward fuselage 

section. Glue the balsa triangle stock and 

bulkheads to the fuselage sides, then glue 

the two sides together but leave the aft 

end open. Glue the fuselage bottom piece 

F/A-18 HORNET: A DYNASTY IN THE MAKING 

This picture shows the internal details of the 

fuselage. Note the laminated-foam motor-mount 

support with its 3/8-inch hardwood motor mount. 

go to war on the cheap? Where can we save a few bucks? And that’s a 

big part of the rationale behind the original decision to build the Hornet. 

The Hornet had to be a capable airplane, and in today’s world, it has 

more than met the Navy’s objectives. It operates at far less expense 

than a Tomcat; for instance, it requires something like half the number of 

man-hours to keep it flying. 

The Hornet was designed from the ground 

up to be a digital airplane: it’s a computer 

geek’s dream. Even the very early “A” models 

were strictly fly-by-wire planes in which the 

pilot flies the computer, and the computer flies 

the airplane. 

As the Hornet has evolved since its initial 

operational deployment in 1983 (wow; it has 

already been in the fleet for 22 years!), the 

digitalization of its flight deck has continued. 

The latest models have all-glass cockpits 

with touchscreen controls. Plus, their combat 

systems have been redesigned to drop fewer, 

but smarter, weapons. The concept is simple: 

don’t bomb the general area; put it through 

the window of the general’s bedroom. 

Pilots love the airplane because it’s so 

easy to fly, and it removes a lot of the pucker 

factor from landing on the boat. The larger, 

more powerful Super Hornets have additional 

capabilities, one of which is performing as 

aerial tankers, and the latest F/A-18G—the “Growler”—will even 

replace EA-6Bs in the arena of electronic warfare. 

It’s just a matter of time before the only fixed-wing airplanes 

on a carrier are the Hornets and the CODs. Now, if they could just modify 

it so it could replace those pesky helicopters …. 

— Budd Davisson 

VISIT BUDD ON THE WEB AT AIRBUM.COM. 

lage. Notice on the plans how the aft 

fuselage parts have a slight curve in 

them. These curves are formed by gently 

heating the foam with a heat gun or hair 

dryer and then bending them to the 

required shape. To judge the amount of 

curvature required, simply hold up each 

piece next to the part it will be attached 

to. Glue the triangle stock to the aft fuselage 

sides and then glue the sides to the 

fuselage bottom. 

Next, tape the free ends of the forward 

fuselage together and draw a centerline 

on the inside of both the forward and aft 

fuselage assemblies; then epoxy them 

together. Let this cure thoroughly. 

Laminate the two identical motor-mount 

supports together with 3M 77. After the 

glue has dried, epoxy the hardwood 

motor mount into place and let it cure. 

Check the fit of the elevator servo used 

and trim or shim the foam as necessary to 

ensure a tight fit. Epoxy the laminated 

motor mount onto the centerline of the aft 

fuselage. After the glue has cured, sand 

the bottom fuselage corners round. Also 

epoxy into place the thin-foam simulated 

inlet diverter at the front of the inlet. 

STABILATORS 

Install the hardware for the pivoting stabilators. 

The 0.157-inch-diameter carbon 

stabilator rod pivots inside three short 

pieces of 3/16-inch-diameter aluminum 

tube that are supported by four small 

squares of 1/64-inch ply glued to the fuselage 

sides (study the plans carefully!). 

Begin by gluing the plywood supports to 

the fuselage sides; center them over the 

precut holes in the foam. After the epoxy 

has cured, drill 3/16-inch holes through all 

of the plywood supports and then glue in 

place; make sure it is aligned with the left 

one. Both stabilators should be flush with 

the fuselage sides. 

Install the elevator servo. It should fit 

very tightly and can be held in place with 

tape. Make and install the 1/32-inch musicwire 

stabilator pushrod. After everything 

is centered and aligned, glue the stabilator 

control horn and end stop onto the carbon 

tube with CA. 

Install the motor, receiver and ESC and 

tape all the wires flat against the inside of 

the fuselage. Install and then solder on 

the wire extension that will connect the 

ESC that’s in the aft fuselage to the battery 

pack; use the connectors of your 

choice (I used Deans Ultra connectors). 

Make sure that the radio and motor are 

properly installed, and that they work corf 

To order the fullsize 

plan, turn to 

“RCStore.com” on 

page XXXXXXXXX. 

This shows the details of the stabilator pivot mechanism and motor 

installation. Note the stabilators are attached to a carbon tube that pivots 

inside three short pieces of aluminum tube. A drilled-out spare servo arm 

is used as a control horn. 

the aluminum-tube bearings with epoxy. 

Slide the carbon rod inside the bearings 

while the epoxy is curing to ensure proper 

alignment—don’t get any epoxy on the 

carbon rod! Make sure that the carbon rod 

turns freely within the bearings. After the 

epoxy has cured, slide the stabilator control 

horn and end-stop bearing onto the 

carbon tube, but don’t glue them yet. I 

used spare servo horns for both of these 

applications; I simply enlarged the horn’s 

center holes to fit the carbon tube. 

With fine sandpaper, round the stabilator 

leading edges and form a tapered contour 

on the trailing edge. Glue the left stabilator 

onto the carbon rod with 5-minute 

epoxy, making sure that the carbon tube 

is centered in the fuselage. After the glue 

has cured, epoxy the right stabilator in 

This shows the 1/32-inch plywood vertical-tail supports and the foam aftfuselage 

top sheeting. The foam sheeting is formed to shape by gently 

heating it with a heat gun or hair dryer before installation. 

JULY 2005 5

HOMEBUILT 

The removable canopy allows access to the battery compartment, and a hatch 

over the wing provides access to the receiver compartment. The canopy is 

held in place with bamboo skewers forward and small strips of Velcro ® aft. 

This is the completed model. It can be flown just like this; a paint job 

would be nice, but it isn’t required. Note how all the fuselage corners have 

been sanded round. 

rectly; after the fuselage is completed, it 

will be difficult to access that equipment. 

WING 

Sand the leading edge round and taper the 

trailing edge. Install the left and right carbon-tube 

wing spars with epoxy. Cover the 

wing with wax paper and place several 

heavy books on top of the pieces while the 

epoxy cures to ensure the wing will be 

perfectly flat. After the epoxy has cured, 

install the 1/32-inch plywood doublers on 

the top and bottom of the wing at the spar 

center section. 

Next, cut the flaperons from the wing. 

Cut a 45-degree bevel in the flaperons’ 

leading edges using a ruler and hobby 

knife. I hinged the flaperons using strips of 

3M Satin tape on top and bottom. Draw 

centerlines on both the wing and fuselage, 

and then epoxy the wing to the top of the 

fuselage. Using fine sandpaper, sand the 

wing strakes to the cross-section shown 

on the plans. Glue the strakes in place with 

5-minute epoxy. The tabs and slots on 

them assure the proper alignment. 

VERTICAL TAILS 

Epoxy the aft fuselage top into place. As 

mentioned earlier, this piece should be 

preformed to the proper curvature with a 

heat gun before installation. Cut slots in 

the fuselage for the 1/32-inch-ply verticaltail 

supports, and then epoxy them into 

the fuselage. Sand the leading edges 

round and taper the trailing edges. Cut a 

20-degree bevel into the bottom of each 

vertical tail (be sure to make left- and 

right-side mirror images), and then trim 

the pieces to fit the aft fuselage. Cut 

matching slits for the plywood verticaltail 

supports, and then slide them onto 

RECOMMENDED POWER SYSTEMS 

» BRUSHED POWER SYSTEM 

MOTOR: GWS EPS-350C with “C” 

gearing (5.3:1) 

PROP: GWS 8x6 Slowflyer 

BATTERY: E-Tec 1200 mAh 11.1V Li-poly 

SPEED CONTROL: Castle Creations Pixie 20 

brushed controller 

COMMENTS: this setup provides excellent 

performance at minimum expense, 

generating 15 ounces of static thrust and a 

50mph top speed. The downside is that the 

motor won’t last long at these power settings 

(perhaps 3 to 5 flight hours), however, the 

motors are inexpensive and easy to replace. 

» BRUSHLESS POWER SYSTEM: 

MOTOR: Himaxx HA2015-4100 with “B” 

gearing (4.4:1) 

PROP: APC 9x6 Slowflyer or GWS 9x7 

Slowflyer 

BATTERY: Thunder Power 1320mAh 

11.1V Li-poly 

SPEED CONTROL: Castle Creations 

Phoenix 25 brushless controller 

COMMENTS: this setup will provide 

significantly more power than the brushed 

system and will last for years. It will produce 

21 ounces of static thrust with a 50mph 

top speed. 

the plywood tail supports and epoxy 

them in place. 

FINAL ASSEMBLY 

Install the fuselage turtle deck. First, glue 

the turtle-deck sides to the top of the 

wing; take care to approximate the curvature 

shown on the plans and to join the 

ends on the fuselage centerline. After the 

glue is dry, glue on the turtle-deck’s top 

piece and sand all the corners round. Cut 

an access hatch into the turtle deck above 

the receiver compartment to allow access 

to the receiver. Secure the hatch with 

small strips of tape. 

At this point, I recommend the application 

of a strip of 3M Satin tape around the 

leading edges of the wing and tail. The 

tape provides a smooth leading-edge and 

also provides more durability against the 

inevitable “hangar rash.” 

The removable canopy allows easy 

access to the battery compartment. It is 

held in place with two bamboo skewers 

forward (toothpicks can also be used) that 

slide into matching holes in the forward 

bulkhead and two small strips of Velcro® 

aft that are mounted to short pieces of 

1/4-inch balsa triangle stock. 

Install the flaperon servos and plug the 

servo leads into the receiver. The servo 

holes in the fuselage should be cut tightly 

enough that the servo is held in place 

with friction. Install the flaperon control 

horns and make a pushrod from 1/32-inch 

music wire. 

Test-fit the battery in the forward fuselage 

to determine where it should be positioned 

to provide the correct center of 

gravity (CG). The prototype model 

required the battery to be positioned all 

6 BACKYARD FLYER

HOMEBUILT 

This is the finished model after painting. Since the model was inspired by 

the Blue Angels, that was the only paint scheme that would do! 

Here is a close-up of the motor installation with the GWS EPS-350C geared 

motor. Installing a “soft-mount” prop saver is highly recommended; it will 

protect the prop from damage during landings. 

the way forward, and no other ballast was 

required. After the best battery location 

has been determined, apply a strip of 

Velcro® to the centerline of the fuselage 

and to the battery. This will allow easy 

adjustments of the center of gravity. 

PAINTING 

Due to the all-foam construction, painting is 

not required, but the model certainly looks 

better with a good paint job! Inexpensive 

acrylic paints (available at most craft stores) 

work well; they are inexpensive and can be 

sprayed or brushed on. Several brands of 

spray-can enamels can be used as well, but 

test first to ensure the paint is compatible 

with the foam. To keep weight to a minimum, 

use the foam’s natural color in your 

paint scheme if at all possible. Note that a 

full coat of lightly-sprayed acrylic paint on 

this model adds 0.75 ounce. 

FLIGHT CONTROLS 

This model was designed to use full-span 

flaperons and full-flying stabilator flight 

controls, driven by three microservos. 

Flaps help this model perform at its best, 

providing not only improved takeoff and 

landing performance but also better 

maneuverability. A 6-channel transmitter 

with flaperon mixing is required to use 

the flaps. Ideally, they should be set at 10 

degrees for launch and at 30 degrees for 

landing. When flying in small fields, the 

flaps should be set at 10 degrees throughout 

the flight, which will allow the model 

to fly slower and turn tighter. If you’re flying 

in a larger field and want faster 

speeds or better aerobatics, retract the 

flaps to zero after launch. For even better 

performance, transmitter mixing can be 

used to mix elevator and flaps to provide 

maneuverable flaps that are similar to 

those found on the real F/A-18. To do this, 

set up a mix so that full up-elevator input 

will drop the wing flaps’ trailing edges 

down about 15 degrees. 

If you don’t have a transmitter with flaperon 

mixing, this model still flies fine with 

ailerons only. Note that when flying in 

small fields, you can set up the aileron 

linkages to droop the ailerons 10 degrees 

for better slow speed performance. 

FLYING 

Before flying, make sure that the control 

deflections and CG location are set as specified 

on the plans. Use the forward-CG 

location for your first flights since it provides 

the most stability. As you gain flight 

experience with the model, you can move 

the CG aft for more maneuverability. The 

CG location can be easily changed by moving 

the battery forward or aft in the nose. 

Launching the model is easy. Grip the 

airplane near the CG, set 10 degrees flaps 

(optional) and 50-percent throttle, and 

throw it moderately hard straight ahead 

and parallel to the ground. Be careful to 

keep your hand away from the prop as 

you throw it! Slowly add throttle soon 

after launch, and after the model has 

gained some speed and altitude retract 

the flaps if desired. 

You’ll find this model handles very well 

and is capable of big graceful aerobatics 

just like the Blue Angels. 

While landings can be made without 

flaps, adding up to 30-degrees flaps before 

landing really helps slow the airplane 

down and allows it to float in much easier. 

Note that it’s very important to return the 

elevator to neutral just before touchdown 

to prevent the stabilator tips from digging 

into the grass! Also, be sure to pull the 

throttle back completely before touchdown 

to prevent damage to the prop. It’s a very 

good idea to use a “soft-mount” prop protector 

adapter such as the Wobbly Adapter 

from All E R/C to help prevent prop damage 

during landings. 

The functional wing strakes add an 

interesting dimension to the flying characteristics 

of this model. Just like on the fullsize 

F/A-18, they allow the airplane to fly 

at very high angles of attack (AoA), 

enabling beautiful, nose-high, flared landings 

and extremely tight turns and loops. 

Because they allow a strong lift to develop 

forward of the CG, the strakes create a 

moderate pitch-up tendency at very high 

AoA (30 degrees or higher) that pilots 

need to be aware of. This usually occurs 

only when flying straight and level at very 

low speeds and is easy to control if the 

pilot knows about it ahead of time. But if 

you’d prefer not to experience this, just 

don’t fly the airplane to very high AoA. 

This model is easy to build from 

scratch, but for those that have difficulty 

finding Depron or BlueCore foam or want 

to save time cutting out templates and 

parts, laser-cut kits are available from 3D 

Foamy (3dfoamy.com). 

Good luck; I hope you have as much 

fun with this model as I have. A 

See the Source Guide on page XX for 

manufacturers’ contact information. 

BACKYARDFLYER.COM 

FOR MORE 

CONSTRUCTION 

PHOTOS 

7 BACKYARD FLYER

F/A-18 Hornet Article - Steve's RC Homepage

Create successful ePaper yourself

Delete template?

Save as template?