Climate change has driven up wildfire risk across the western United States. The U.S. Forest Service employs 11,187 wildland firefighters — and openly admits it isn't enough; 170 firefighters died fighting wildland fires between 2007 and 2016. Aerial Flame Force is a specialized quadcopter drone with a fire suppression unit, built using considerations from the U.S. Forest Service and customer interviews, designed to extinguish wildfires early — before they spread — and to create proactive fire lines.

The chassis went through four major iterations, all CAD-designed in OnShape and 3D printed — moving from a conventional bolt design to countersunk screws for flush aerodynamic surfaces, then adding structural ridges for print rigidity.

The final iteration integrated lightweight injection-molded propeller guards, protecting the blades without adding meaningful weight or restricting flight performance.

Four concepts were explored before committing to a direction. Concepts 1–3 used staggered box/hole water-release mechanisms; Concept 4 — a two-part system where a servo releases four fire suppressant boxes onto the fire — was selected for its mechanical clarity.

Three iterations refined it, with early versions running heavy and fighting servo fit issues — solved by eliminating the separate top piece entirely so the whole system could print as one part, with a servo that actuates a release plate at 45° to deploy the suppressant. The boxes themselves are wax paper, chosen because it burns without releasing harmful particulates, letting the dry powder suppressant inside contact the fire directly.

The electronics subsystem detects smoke and heat, monitors faults, transmits telemetry, and avoids obstacles. An Arduino Nano V3 was chosen for its compact size and I²C support, letting the gyroscope and infrared sensor share two pins via unique addresses.

A finite state machine integrates a heat-seeking algorithm, geolocation, and sensor fusion on a custom 100mm × 60mm PCB. Autonomous control lets the drone ascend, navigate via GPS and gyroscope, sweep for smoke, detect fire via infrared, and release suppressant — with auto-return on low battery and a lost-drone beacon mode.

RS2205 motors and HQ4045 propellers were selected to hit the thrust-to-weight ratio needed for a 3 lb drone, arranged two CW and two CCW for stability. A 12V 100A power supply was chosen over LiPo batteries for safety.

The hub — the reloading station the drone returns to between deployments — went through three iterations, from a magnetic water-pump concept to a string-and-stepper lifting mechanism, before landing on a centrally-located screw driven by a motor that lifts replacement suppressant units into the chassis for reloading, with a locking mechanism at the top and a platform that extends outward to align the units precisely.

Aerial Flame Force was built by a team of five. I owned the Fire Suppression subsystem end to end, and contributed across the other four as well.

With all five subsystems complete and integrated, the Aerial Flame Force is a fully functional autonomous drone capable of detecting, navigating to, and suppressing small wildfires — without putting a single firefighter at risk.