Build the P-38 Park Flyer

The center pod arrangement also allowed for a powerful array of armament. Eventually, four .50- caliber machine guns and one 20mm cannon were standard. Because of the placement of the weapons, it allowed for a greater effective firing range—the guns did not converge as they do with wing-mounted weapons.

The prototype first flew in January 1938 and it quickly proved to be a very fast aircraft. To demonstrate its performance, the XP-38 flew from California to New York in a record-breaking flight of slightly more than 7 hours (excluding the time needed for refueling).

Unfortunately, the aircraft was lost as it attempted to land; however, the performance was enough to earn Lockheed additional construction contracts. These contracts eventually led to more than 10,000 P-38s with many variations along the way. In fact, the P-38 turned out to be one of the most versatile fighters in the US inventory.

In addition to its role as a fighter, the P-38 was an exceptionally successful reconnaissance aircraft. It was used as a dive bomber when attacking the Ploiesti oil refineries in Romania. It served as a dual-seat night fighter, and could also be used as an air ambulance, with the passengers held in large drop tanks with a small glass bubble at the front.

Although not without challenges (such as dive limitations and compressibility issues), the P-38 was flown by America’s top two aces of the war, most notably Richard Bong with 40 confirmed victories. Another famous American aviator to fly the P-38 was Charles Lindbergh. He helped to find methods of leaning the Lightning’s engines to significantly increase their range. He was also unofficially confirmed to have an aerial victory while piloting a P-38.

Another famous action was the long-range interception of Isoroku Yamamoto, the admiral who was responsible for planning and implementing the attack on Pearl Harbor. The only aircraft available at the time with the range necessary was the Lightning. The Pacific was the theater where the P-38 really shined as a fighter, and it also fought successfully in the Mediterranean and North African areas of operation.

Although it did fight in the European front, the Lightning was not as successful in this theater of operations. However, the Luftwaffe was often on the losing side when tangling with the Forked Tailed Devil. Robin Olds, another famous fighter pilot of both WW II and Vietnam, became an ace flying the P-38. He is also credited with one of his victories in "glider mode," having forgotten to switch fuel tanks and running one of them dry.

The P-38 stayed in production throughout the entire war, and more than 160 pilots became aces flying the Lightning. Not bad for Lockheed’s first fighter design.

Design

The P-38 is the seventh model in the park flyer series. With a wingspan of 40 inches, it is the earlier F/G version with the more streamlined booms under the spinners. Construction is mostly of 3/32-inch balsa and 1/8-inch light plywood, with some 1/16- and 1/4-inch balsa and various basswood used.

The plans, parts, build and covering instructions, and tissue templates can be downloaded for free on the Model Aviation website; however, if you don’t want to hand cut the parts, you can get a short kit from Manzano Laser Works.

Power comes from two 24-gram motors spinning 8 × 4.5-inch, three-blade, counter-rotating propellers. Rabid Models offers both 3D-printed spinners and wheels designed specifically for the model. The company also offers a power package that includes motors, spinners, propellers, and some accessories. Both Manzano and Rabid are listed in "Sources."

Similar to the other models in this series, the canopy is made from flat, clear sheet folded to shape and the boom radiators are built-up; however, replacement plastic parts from the Guillow’s P-38 could also be used.

The model can be built in three configurations in terms of its landing gear. It can be a "belly flopper," have plug-in gear, or can be built with retracts. All three options are listed on the plans.

Conventional electric retracts, even in the smaller sizes, add significant weight; therefore, metal-geared 9-gram servos are used with the struts attached to the servo horn via EZ connectors. The prototype was built using these retracts and has proven to work quite well; however, if you fly off of a rough field, it might be best to use the plug-in gear option.

The model is not a difficult build but it is complex so be sure to read and follow the build and covering instructions and thoroughly review the plans before beginning construction. There is also a link to the build thread on RCGroups in the "Sources" listing. When you have hand cut your parts or have your laser-cut short kit, it’s on to the build!

Build

The horizontal stabilizer is made from 3/32-inch balsa and has cutouts for stringers to be added to help prevent warping. The center leading edge (LE) is made from 2mm carbon-fiber rod. After the stringers and rod are in place, sand the top and bottom and shape the edges before cutting the elevator free. Hinge with trimmed CA hinges, but do not glue them in at this time.

The center pod is built in halves over a center keel. The top and bottom keels are connected with stringers. When all of the keels and stringers are glued together, sand the top of the keel assembly to remove any unevenness and any bumps from glue.

Add the magnets to F1A, F3A, F3, and C2 at this time, minding the polarity. The left-hand formers are glued on top of the keels and stringers and are added at this time. Be sure to have the etching/marking lines on F2 and F3 facing toward each other. The lower hatch rail and the 3/32-inch stringers below it can be added next.

Block in behind F7 for shaping later. Remove the assembly from the board and add the other former halves. Depending upon your landing gear choice, prepare the nose-gear mounting plate and add the support stringers to F2 and F3. Mount the plate and add the remaining stringers, noting that the bottom- most stringer on the right side is made from basswood. Omit stringers 7 and 8 between F2 and F3 if using retracts. This will allow access to the servo and will be covered later with a paper template. Use clear tape on the lower hatch rail, F1, and F3 to help prevent them from being glued to the hatch parts.

Install and glue the upper hatch rail, F1A, and F3A, along with the remaining stringers. Glue nose cone 1 and 2 together and add balsa block on all sides, trimming the block to match the nose cone profiles. Glue the nose block in place, and shape it and the block behind F7 with a small plane before finishing with sandpaper. Set the center pod aside for now.

Make the wing LEs from medium, 1/4-inch balsa using the templates on the plans, and the trailing edge (TE) from a 3/32 × 3/8-inch plank. Add TE 1 through 3 parts and glue the assembly together. Glue the three washout jig parts together and slide it beneath the assembly according to the plans. (This will help build the washout into the wing.)

Set the bottom 3/32-inch stringers in place and note that stringer 4 and the rear of W11 sit on top of the washout jig. Glue the wing ribs in place, noting that W1 is angled toward the tip by using the dihedral guide. Mark the boom centerline on the LE, TE, and stringers.

Test the servo before mounting it to the plate according to the plans. Add the top stringers and the aileron LE, making the aileron ribs from scrap 3/32-inch balsa. Remove the panel from the board and shape the LE using the templates on the plans.

Sand the wingtip and the TE before cutting the aileron free. Infill with scrap between the top and bottom four stringers in the aileron bay. Shape the aileron LE and hinge with CA hinges (similar to the horizontal stabilizer). Build the opposite wing panel the same way. With both panels on the board, block up each wing 2 inches at W11 and glue the two panels together.

When it has dried, add the additional 3/32-inch basswood stringers forward of stringer 2 and the 1/16 infill between W4 and W5, top and bottom. Review the spar 1 detail and remove the forward section of the W1s, adding the spar and W2A ribs.

The booms are constructed much like the center pod and there are details for both the right and left on the plans. Build the right boom first. Note on the plans that the "inner" half is built on the board. Build the keel structure first before adding the inner former halves. Add the wing saddle and the K4A assembly, along with the top two stringers (1 and 2).

Review the former details according to the plans and note the change in stringer locations at B5. Add the stringers from B5 forward, notching into the wing saddle as needed. Add the formers from B5A aft, noting the basswood stringer in notch 6 if you are installing retracts.

Remove the assembly and add the outer former halves. Slide the gear mounting plate into B5A-O and B6O, adding the additional supports or servo per the gear choice. Add the stringers and the wing mounting plate after removing the precut sections of B5A and B6.

Sand the overall structure and shape the K4As and V3 and 4 blocks to match the boom contours. Use the template to cut out the chin intakes and add the cardstock ducting. Add B1, test-fit the motor, and install B3A fore and aft of B3 as needed for spacing between the rear of the spinner and the front of the boom. Build the left boom over the plans the same way, starting with building the inner section on the board.

The radiators are built in place over the booms and also contain the two rudder and two elevator servos. Their location assists in balancing the model without adding additional ballast. Place clear tape on the boom where the radiator will be located. Using the plans template, mark a 3/32-inch stringer, and then tape it in place over the boom, using the etching/marks on B8 and B9. Add the R formers then the top stringer. Review plans sheets four and five for the servo orientation. (This is important to ensure that they are moving in the correct direction.) Add the servo mounts and repeat for the other three radiators.

Dry-assemble the model. Install the motors and the servos in the radiators. Measure the extensions needed for the servos and the motor wires. (The ESCs will be mounted in the center pod in the nose-gear bay.) The servo wire on the prototype was cut in two, and an extension (30 AWG wire was used) was soldered between the servo and the connector. These will run from the boom through the wing to the receiver that is mounted in the center pod in front of spar 1. Motor extensions were made from 20 AWG and need to reach the ESCs.

The prototype was covered with printed tissue. Templates are available for free download along with the plans. The model can also be covered with lightweight film. Cover the booms, wing halves, center pod, horizontal, and all of the control surfaces. Install the motors and servos into the booms and slide them in place on the wing.

Use the horizontal and the boom/motor alignment tool (slide it onto the motor shafts) to help with alignment. When satisfied with the fit and squareness, glue the booms to the wing and the horizontal to the booms.

Snake the boom servo wires, motor wires, and aileron wires through the wing and into the center pod area. Test-fit the center pod to the wing and glue it in place (noting the spacing between F3 and the wing’s LE). Referring to the plans, build the canopy hatch in place over the wing and center pod.

The canopy is made from flat 3 mil plastic sheet with paper framing. (The templates are included in the tissue panels.) Follow the build and covering instructions for creating and installing canopy panels. Replacement plastic parts for the Guillow’s P-38 could also be used.

Attach all of the control surfaces and glue the hinges. Mount the receiver and connect all of the servos, testing the direction before installing the control rods (see the plans for additional details). Connect the motors and check their direction. They should rotate outward and opposite from each other when viewed from the cockpit.

If using a Y harness on the ESCs, one of the connector’s positive wires to the receiver (typically the red one) will need to be disabled on one of the ESCs. This will prevent the model from having two BECs because only one is needed. Add the radiator covers and the landing gear according to the version being built.

The battery used on the prototype was a 900 mAh 2S LiPo and needed to be mounted in the rear section of the battery hatch for the model to balance at the 20% mark on the plans. Ensure that the controls are in the correct direction and set the deflections to be plus or minus 3/8 to 1/2 inch for the ailerons and plus or minus 1/2 inch for the elevator and rudders.

Flying

Choose a day with lighter wind for the initial flights. Because the nose gear is fixed, point the model into the wind and smoothly apply power. It will lift off in roughly 15 to 20 feet. Keep the power on through the climbout and pull back slightly for cruise and trim. The power setup will not result in a Reno racer, but it will have sufficient power for climbing and scalelike speeds.

Standard maneuvers are capable with the deflection settings and the battery should provide 4 to 5 minutes of flight time, depending on throttle use. Stalls are straightforward; the nose will drop, and recovery is done by applying power. Landings are simple with a continual reduction in power on final until shortly before the flair.

The model has a great presence in the air and looks formidable cruising around the field looking for a lone Stuka, Macchi, or Nate. If you are interested in something different, give the P-38 a try.

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