Build the B.E.2c

Specifications

Wingspan: 50 inches

Length overall: 39 inches

Wing area: 725 sq. in.

Flying weight: 26.5 ounces

Wing loading: 5.25 ounces per sq. ft.

Power and Guidance

(1) Suppo 2217/9 outrunner motor

(1) Suppo 20-amp ESC with BEC

(1) APC 11 × 5.5E propeller

(2) Suppo SP-90 servos (rudder and elevator)

(2) Suppo SP-60 servos (one for each bottom-wing aileron)

(2) 9-inch servo extensions

(1) 6-inch Y lead

Materials List

Wood: Laser-cut wood and plastic pack (Manzano Laser Works)

^∗If the laser-cut wood and plastic pack is not used:

(4) 1/16 × 4 × 36 balsa

(4) 1/8 × 4 × 36 balsa

(1) 1/8 × 4 × 24 light plywood

(1) 1/16 × 2 × 4 plywood

(1) 1/16 square × 36-inch bass wood

(8) 1/16 × 1/8 × 36 balsa

(4) 1/16 × 3/16 × 36 balsa

(1) 1/16 × 3/8 × 36 balsa

(6) 3/32 square × 36-inch balsa

(4) 3/32 × 1/4 balsa

(8) 1/8 square × 36-inch balsa

(1) 1/8 × 1/4 × 36 balsa

(1) 1/8 × 3/8 × 36 balsa

(4) 1/4 square × 36-inch balsa

(1) 1/4 × 3/8 × 6 balsa

The Royal Air Force B.E.2, built by the Royal Aircraft Factory beginning in circa 1911, was a relatively large biplane powered by a 60 hp Renault V-8 air-cooled engine. The B.E.2c underwent a major redesign in 1914. The changes were done to enhance stability over the earlier variants, allowing the crew’s undivided attention for their reconnaissance mission. The B.E.2c also featured ailerons on all four wing halves rather than the wing warping arrangement of the earlier models.

The B.E.2c had a wingspan of 37 feet, an overall length of 27 feet, 3 inches, and a gross weight of 2,350 pounds. Power was from the 90-hp, air-cooled V-8 engine with a four-blade, fixed-pitch wood propeller. The maximum speed was 72 mph with a service ceiling of 10,000 feet. The standard armament was a single .303-caliber Lewis gun. The B.E.2c could be fitted with 224 pounds of bombs and was also flown solo with the Lewis gun removed.

In 1917, the B.E.2 was removed from the role of a front line and night fighter but continued in service in submarine spotting and as a trainer for the remainder of the war.

The Model

The model was designed with a 50-inch wingspan at 1:8.88 scale. Construction is primarily of balsa and plywood. It features true scale outlines, including scale rib spacing in the wings and tail surfaces. The wings are also removable in pairs in the event that it must be taken down for transport.

Power is provided by a Suppo 2217/9 outrunner motor with a Suppo 18-amp ESC, an APC 11 × 5.5E propeller, and a Venom 2,000 mAh, 2S LiPo battery. Control is by way of a pair of 9-gram submicro servos in the fuselage to control the rudder and elevator and a pair of 6-gram servos in the bottom wing to control the ailerons. The lower cowling serves as the battery hatch and is retained with rare earth magnets.

Wire and Tubing:

(1) .032 × 24 steel wire

(1) .046 × 24 steel wire

(1) .062 × 36 steel wire

(1) 1/8 × 6 aluminum wire

(1) 1/8 outer-diameter (OD) x 18 brass tube

(1) 3/16 OD x 18 brass tube

(1) 5/32 OD x 12 aluminum tube

(1) 7/32 OD x 12 aluminum tube

Miscellaneous Parts:

(2) 1/16 wheel collars

(3) 1/8 wheel collars

(1) Pair of 3-inch WW I-style wheels (Manzano Laser Works)

(1) Estes BT-5 rocket tube

Before Construction Begins

Before you actually begin to build the model, take a few minutes to study the plans to become familiar with the design style. The fuselage and rudder are of the conventional "stick-frame" style, where the wings and horizontal stabilizer are done in the "egg-crate" style of construction to speed the assembly process.

All of the rounded outlines are laminated from balsa to keep them strong and lightweight. I like to work up all of the preliminary subassemblies first so that everything is handy when you need it. Doing that will go a long way in simplifying the assembly process. Now is also a good time to decide, "Should I hand cut all of those parts or simply order the wood and plastic pack from Manzano Laser Works?"

Keep in mind that World War I-style airplanes typically have long tails and short noses, so keep the tail section components as lightweight as possible. The tailskid assembly is heavy, so any weight savings at the back will go a long way when balancing your model.

Building the Preliminary Subassemblies

Make up all of the bowing patterns from artist’s foam board using the provided patterns then make the wingtip, horizontal stabilizer, and rudder outlines. Bend the main landing gear struts to shape and cut the axle to length.

Build up the landing gear assembly jig and solder the gear together on the jig. Make up the tailskid assembly jig from a 3/4-inch pine block and drill using the provided pattern. Assemble the tailskid on the jig and solder the components together then wrap the joints securely with fine copper wire and resolder.

Bend the cabane struts and wingtip skid loops to shape and, finally, create the elevator control linkages according to the detail drawings. Set them aside with all of the other subassemblies.

Vertical Fin and Rudder

The fin and rudder assemblies are built directly over the plans. Shims are used to center the outline on the ribs. When the basic framing is done, sand the assembly to an airfoil shape and taper the rudder hinge spar into the outline at the top and bottom.

With the shaping done, align and glue both CHM1s in place flush with the outside edge of the ribs and dry-fit the control horn in place. Cut in and dry-fit the hinges in place to complete the assembly.

Horizontal Stabilizer

The stabilizer and elevator assemblies are also built directly over the plans. To begin, cut the shims from 1/8-inch balsa and place them over the plans at the locations shown. Dry-fit all of the SR2 ribs on FS and HS and pin them in place on the plans. Secure each point of contact with a drop of thin CA adhesive.

Next, align and glue the 1/8-inch square balsa leading edge (LE) and tips in place, followed by the corner bows, SR1 ribs, and SR3 and SR4 false ribs.

Pin HS1 in place, dry-fit each of the ER1 ribs in place, and then add the 1/16 × 1/8-inch balsa trailing edges (TEs), followed by the ER2 ribs, C1s, and corner bows. Remove the assembly from the board, cut the elevator free, and sand it to shape. Align and glue all of the CHM2s flush with the ribs, followed by the 1/8-inch square balsa hard points, and sand them flush with the outer edges of the ribs. With that completed, cut in and dry-fit the hinges in place.

Top Wing Panels

To begin, dry-fit all of the ribs on the front and rear spars. Align the assembly in place over the plans, and pin it in place, and then add a drop of thin CA glue at all points of contact. Pin the 3/32 × 1/4-inch balsa TE in place, including the aileron bay, and glue it in place. Glue the 1/4-inch square balsa LE in place, followed by the tip bow.

Use the R6 rib detail drawing for reference to sand the bevel into the bottom of AS, and then assemble the aileron in place in the wing. When all of the shaping and sanding is done, cut the brass wing retention tubes to length and glue them in place.

Remove the wing assembly and sand it to a basic shape. Align and glue the four S1s and ALT flush with the bottom of the wing. Cut the aileron free, sand it to the final shape, and then cut in and dry-fit the hinges in place.

Repeat the process to build the other wing half. With both wing halves completed, fit and glue the brass wing-retention tubes in place. Build the top wing center section according to the assembly drawing, and then test-fit the wing panels on the center section.

Bottom Wing Panels

The bottom wing halves build much the same as the top ones. With the major assembly done, sand it to rough shape then glue four S1s in place flush with the top of the wing, A4 flush with the bottom, and ALB flush with the top of the aileron. The servo mount is glued in place along with the rigging blocks and wing-skid mounting blocks.

With the final sanding done, glue the brass wing retention tubes in place. The aileron servo is glued to ASM using silicone caulk. When it is dry, run the extension leads through the wing. Build the second wing half in the same fashion.

Fuselage Assembly

Build the fuselage side frames directly over the plans. Align and glue B2 in place in the inside of each frame. Add the 1/16 × 1/8-inch balsa stiffeners on formers 2 through 6. Make up the landing gear mount beams according to the detail drawings and pin them in place over the plans. Pin the side frames in place and glue at the landing gear beams, and then add formers 1 through 4 and the bottom crosspieces. Pull the tail together and glue B3 and B4 in place, followed by formers 5 through 8 and all of the remaining crosspieces.

Remove the frame from the board and glue the 1/8 × 1/4-inch balsa tail post in place at B3 and B4. Using a razor saw, cut most of the way through the side frame at the location shown and glue it in place at B3 and B4. Fill the gaps with bits of scrap balsa and glue. Finally, align and glue all of the 3/32-inch square balsa stringers in place and rough-sand the, to shape. Build up cabane mounts CM and CMA and glue them in place.

Mount the rudder and elevator servos at the locations shown. Dry-fit the rudder onto the fuselage. Run in the pull-pull cables and mark the location where the cables exit the fuselage on the plans. Next, install the 5/32 brass bushings into CHM3 on both sides, followed by the wing receiver tubes.

Fit the elevator control rod into the bushings, along with EC1 and both ECs. Ensure that the control system runs smoothly with no binding. Adjust the bushings, if needed, for smooth operation.

Build up the motor mount and fit the motor onto MM. Glue the magnets into CMF and CMR, place another magnet on each, then align them flush with the outside edge and glue them in place. Trim the vacuum-formed cowling from the carrier sheet and glue it to each of the magnets.

When it’s dry, remove the lower cowling. All of the paper cockpit fairings can now be cut from file folder paper and glued in place, starting at the back and working forward. The aft cowling fairing won’t be glued in until the wings are set up. Finally, lash the landing gear in place.

Covering the B.E.2c

I covered my model with Polyspan and dope, but silkspan or any of the lightweight iron-on coverings will also do well. Before covering begins, do a final detail sanding to remove any irregularities. It’s also a good idea to scallop the fuselage formers between the stringers. Cover the top wing center section on the bottom only. The fuselage will be covered except for the bottom, leaving easy access for installing the control systems.

Final Assembly

Fit the cabane struts into the fuselage. Plug the bottom wing halves into the fuselage and the top wing halves onto the center section. Using the wing alignment jig and interplane struts, dry-fit the top wing in place. Align the wings then tack-glue the cabane struts into the top center section. When you are satisfied that the alignment is good, pot the cabanes at CS4 and CS5 with a generous drop of 5-minute epoxy. When they are dry, remove the wings and cover the top of the center section then fit and glue the rear cowling fairing in place.

Fit and glue all of the hinges in place then reinstall the elevator control system and run in the rudder cables. Align and glue the vertical and horizontal stabilizers in place and tie off the rudder cables at RCH. Install the motor and ESC, connect the receiver, and secure all of the components in the fuselage. Cover the bottom of the fuselage and glue the tailskid in place.

Make the aileron pushrods from .032-inch steel wire, fit the control horns in place, and glue. Reinstall the wings and align and glue the interplane struts in place. Rig the wings with an X brace between each bay, both spanwise and chordwise, using heavy-duty nylon thread. The forward drag bracing is added using ship model deadeyes drilled into CSR and CSL. These are a slip-fit only—if you glue these in place, you won’t be able to remove the wings.

The tail bracing is added next, and finally, run the control cables from the external control horns on the fuselage to the elevator control horns and secure. Last but not least, rig the upper and lower aileron linkage according to the detailed drawing.

Adding the Final Details

Build up the dummy V-8 engine and glue it in place. The main wheels were built from 3-inch WW I wheel kits available from Manzano Laser Works. The Lewis gun is built up from scrap balsa, Styrene plastic, and wire. Make up the windshields from .008-inch acetate. Glue the windshields in place and add the lower access hatch and any other details that are desired to complete the model. From here, you can add all of the desired details. The model is laid out in scale outline and visible structure, so the more, the better.

With all of the details added, balance the model 3-3/16 inches from the top wing’s LE. The Venom 2,000 mAh 2S LiPo battery ended up inside the motor mount under the cowling with no additional ballast required.

A 1/32-inch plywood plate was glued inside the motor mount box and the battery was secured with Velcro. Set up the control throws as shown, with a 70% dual rate on each. Because the model exhibits a severe adverse yaw, a 50% differential aileron throw isn’t a bad idea.

Flying the B.E.2c

The B.E.2c is a great-flying model, but it is a WW I-era airplane and flies accordingly. With a finished weight of 26.5 ounces, the model came in with a wing loading of slightly more than 5 ounces per sq. ft. and it has adequate power using a 2S battery.

On takeoff, add power slowly because the rudder is pretty lively. Too much power at too low of a speed can get a little exciting. After it is in the air, keep the climb shallow and steer the model with mostly rudder and just a pinch of aileron because the adverse yaw with aileron input is noticeable.

Climb to a safe altitude and trim the model for straight-and-level flight at roughly 2/3 power. In the air, turning is done primarily with the rudder. You’ll also notice right away that the model is so stable in a roll that as soon as the rudder is released, it immediately returns to wings-level flight. For that reason, a small amount of rudder input is needed to maintain the roll.

To land, reduce the power just enough to start the descent. Overall, the model is slow and docile, but because of the extreme drag from the exposed rigging, you’ll need to carry a significant amount of power on approach to control sink.

The best bet is to fly the model all the way to the ground and land on the wheels with the nose slightly up. When the model is trimmed, you can start checking out the ailerons to get a better feel for flying with more balanced control inputs.

After you have it mastered, you’ll find the B.E.2c to be a gentle, docile aircraft for those reconnaissance missions over your local flying field.

SOURCES:

Manzano Laser Works

https://manzanolaser.com

APC Propellers

(530) 661-0399

www.apcprop.com

Royal Aircraft Factory

www.militaryfactory.com/aircraft/detail.php?aircraft_id=1102