This Custom-Built RC Biplane Is Perfect for Tight Spaces

Outside of a museum, a biplane is a rare sight these days. With modern propulsion systems and high-speed air travel, stacked wings just don’t make sense anymore. However, this dual-wing design does still have some interesting flight characteristics that can come in handy for special purposes. The extra lift generated by the larger wing surface area lowers a biplane’s stall speed and makes it more maneuverable at low speeds, as compared to a monoplane.

It is these factors that made a stacked-wing design perfect for a custom RC plane build by YouTuber dvfpv adventures. He wanted an aircraft that was perfectly tailored to flying in highly restricted indoor environments or small outdoor spaces, such as neighborhood parks. Rather than buying something off the shelf, he built a tiny, low-speed flyer completely from scratch that weighs in at under 70 grams.

Over the course of several months, the builder went through several complete redesigns before arriving at a stable and controllable final version. Although the original goal was to keep the aircraft below 50 grams, additional reinforcements, hardware upgrades, and structural changes pushed the finished weight to 68.5 grams.

To save weight while maintaining rigidity, the aircraft uses a hybrid construction approach combining thin foam sheets with custom 3D-printed parts. Instead of a conventional enclosed fuselage, the design centers around a lightweight square tube that acts as the aircraft’s structural backbone. The wings, tail assembly, electronics, and landing gear all mount directly to this central spine.

The stacked wings are supported using a triple-connection mounting system that passes through the square tube. At the rear, a dedicated tail block locks the rudder and elevator assemblies firmly into place. Hot glue was used throughout the build for rapid assembly, though it contributed noticeably to the final weight.

Building the propulsion system was one of the biggest challenges. Early versions used an all-in-one receiver board paired with brushed motors and integrated control hardware. While lightweight, the setup struggled to generate enough thrust once the plane became heavier during later revisions. Control linkage flexing and alignment issues also made maneuvering difficult.

The solution involved switching to a brushless motor. A tiny brushless outrunner motor was mounted to the nose using a custom 3D-printed motor bracket, while a miniature electronic speed controller and dedicated receiver were installed on the fuselage. The upgrade dramatically improved the thrust-to-weight ratio and gave the aircraft enough power for stable flight.

Dedicated micro servos drive the control surfaces through rigid pushrods and custom 3D-printed control horns. The aircraft also features several clever mechanical details, including a sliding battery tray that allows the center of gravity to be adjusted before takeoff. Even the tiny landing gear incorporates miniature ball bearings inside the wheels to reduce rolling resistance during taxiing and landing.

For more details on the build, be sure to check out the video below.