The Heavy Line F421 frame is designed for unmanned platforms with a large payload, extended flight time, and high structural stability requirements. It is suitable for applications in cargo transportation, industrial inspection, hybrid or long-range drones.

The base of the structure is made of aircraft-grade 3K carbon fiber, with additional stiffening along the beams to provide resistance to bending and vibration. The central section with an area of about 180×180 mm allows for the installation of large modules: PDB power supply board, several ESCs, FC controller, sensors or additional communication elements, or any other additional equipment.

There are ventilation slots for cooling and integration of transceiver and navigation equipment. The frame is compatible with 50xx-60xx class motors, 80A+ ESC, and supports X8 configurations and servo-stabilized cameras.

Diagonal size: 21 inches (compatible with propellers up to 21 × 6.5)
Material: aviation grade 3K carbon, reinforced along the length of the beam
Spars: 10-12 mm
Center section: ~180 × 180 mm, dual power support
Mounting base for FC/ESC: 30.5 × 30.5 mm (M3)
Integration: places for antennas, stabilizers, flexible power cables
Compatibility with motors: 50xx-60xx
Supported ESCs: 80A+
Configurations: X8, coaxial, with gimbal
Package weight: ~520-580 g