Every design starts here. DRONA treats form factor as a first-class type parameter — not a label applied after the fact. The chat picks the form factor from the mission, the compatibility engine branches per form factor, the 3D viewer renders a per-form-factor model, and the specs engine computes specs via a per-form-factor dispatch. The seven production classes below cover the working drone universe. The niche and research sub-types at the bottom are documented for taxonomy completeness.
Multiple fixed-pitch rotors arranged radially, controlled by differential thrust. The canonical hobby and commercial drone. Covers 30 g tiny-whoops through 60 kg agricultural heavy-lift in one consistent control paradigm. Hovers precisely; forward flight is thrust-vectored tilt.
prop-clearance · propeller radius vs adjacent-motor distance on the radial framemotor-count · count must match frame typetwr · class-specific TWR target (racing ≥ 4 · freestyle ≥ 3 · cinematic ≥ 2)prop-shaft · M5 or M8 conventions matchedLift produced by airfoil, forward thrust by propeller (tractor or pusher) or ducted fan. The efficient long-distance workhorse. At the same energy budget, a fixed-wing covers 5–10× the range of a multirotor. Trades hover for endurance.
wing-loading · W/S within class targets (20–130 g/dm²)stall-speed · warns if Vstall > 30 km/h on trainer classcg-mac · CG within 25–33% MAC for conventional layoutservo-torque · required control torque ≤ 70% servo ratedaspect-ratio · class-specific AR target (delta 2–4 · sport 5–8 · HALE 20+)Vertical launch and landing plus efficient forward flight. The fastest-growing commercial segment: delivery, SAR, long-range inspection. Combines every physics concern from both multirotor and fixed-wing, plus a transition envelope that must be mathematically continuous.
transition-envelope · V_cruise > 1.3 × V_stall before lift motors idlesingle-motor-fail · (N−1) lift motors ≥ AUW · hard errortilt-servo-torque · tilt servos ≥ 3× conservative nominal (MKS HV6130 class)A single large rotor with variable blade pitch. Aerobatic, fast, highly efficient in hover relative to multirotors, but mechanically complex. The passionate $500–3,000 hobby market uses CP helicopters; commercial agriculture and cinema use them for heavy lift and unique motion quality.
disc-loading · within class target · warns outside 3–12 kg/m²tip-mach · tip speed < 0.7 Mach to avoid compressibility losstail-authority · Ttail × Lboom ≥ Qmain × 1.3swash-servo-count · 3 for 120°/140° CCPM · 1 for FP headgear-ratio · main gear teeth / pinion teeth = target RPM ratioNeutrally buoyant submersibles with thrust-vectoring electric thrusters, tethered to a surface operator via fiber-optic umbilical. BlueROV2 defined the hobby-pro tier. Applications span reef research, wreck archaeology, aquaculture, offshore inspection, and subsea pipeline work.
buoyancy-balance · neutral to +50 g · flag otherwisecb-above-cg · center of buoyancy above CG or roll-over occursdepth-rating-margin · pressure rating ≥ mission depth × 1.5seal-integrity · all electronics inside pressure vessel or IP68 penetratortether-gauge · conductor gauge adequate for length · voltage drop < 10%Buoyancy-lifted aerostat with low-speed electric propulsion. Silent, long-endurance, non-threatening. Used for indoor events, wildlife observation, persistent surveillance, and research. Speeds capped around 30 km/h by drag-cubed power scaling; cruise altitude limited by envelope material.
lift-margin · gas lift × volume ≥ dry weight × 1.05envelope-pressure · pressure drop ≤ 5% over mission durationwind-tolerance · max wind < ½ × cruise speed (else drift > progress)ballonet-size · required for outdoor airships > 5 m³A multirotor suspended in a protective spherical or geodesic cage, decoupled via gimbal bearings so the inner craft stays level as the outer cage bumps walls, tanks, or people. Flyability Elios 3 is the reference commercial platform. Application: confined-space inspection — sewers, pressure vessels, boilers, ballast tanks, industrial stacks.
cage-inner-clearance · inner quad rotor diameter + 20 mm gap fits cage IDtwr-cage-penalty · TWR computed against AUW including cagelighting-lumens · onboard LED output sized for enclosed darkness (no GPS, no ambient light)slam-capable-fc · FC with companion computer (VOXL, Jetson) for visual odometryA long tail of form factors we document because they appear in real-world conversations and literature, even if they are not on our roadmap. Some (tethered, nano swarm, heavy-lift agricultural) are already covered as sub-types of the main classes. Others (ornithopter, cyclocopter, monocopter) are genuinely experimental.
| Class | What it is | Why it exists | Status |
|---|---|---|---|
| Tethered MR | Multirotor + power/data cable | Indefinite hover for security, events, comms relay | MR sub-type |
| Nano / swarm | Sub-30 g MR · Crazyflie-class | Research, STEM, Vicon labs, covert micro-ISR | MR sub-type |
| Heavy-lift MR | Agricultural octocopter · 20–90 kg AUW | Spraying, granular spreading, frost protection | MR sub-type |
| Solar HALE | High-altitude electric fixed-wing · 20–40 m span | Persistent stratospheric ISR, comms relay | FW sub-type, later |
| Parafoil / PPG | Ram-air canopy + pusher prop | Precision airdrop, slow-scan mapping | Research |
| Turbine jet | Miniature kerosene turbine FW | Scale jets, target drones, competition aerobatics | FW sub-type, deferred |
| Gas IC FW | 2-stroke gasoline engine FW | Long endurance, scale modeling, giant-scale aerobatics | FW sub-type, deferred |
| H2 fuel-cell | MR or FW with hydrogen fuel cell | 2–4 hour endurance for logistics, survey | Deferred |
| Compound heli | Rotor + wings + pusher | High-speed helicopter alternatives | Research |
| Ornithopter | Flapping-wing biomimicry | Research, biology, covert surveillance | Research only |
| Cyclocopter | Horizontal cycloidal rotor | Research · agile low-noise hover | Research only |
| Monocopter | Spinning single-wing · maple-seed | Disposable surveillance (CICADA) | Research only |
| Hybrid air-ground | Flies and drives · rotors as wheels | Last-100-m delivery, indoor mapping | Research only |
| Sail-drone / USV | Autonomous surface sailboat | Persistent ocean sensing | Separate product |
| UGV | Wheeled / tracked ground robot | Ag scouting, warehouse logistics, perimeter | Separate product |
| Manned eVTOL | Passenger-class tilt-rotor (Joby, Archer) | Regulated as aircraft; out of DRONA scope | Taxonomy only |
You don't need to know the difference between a deadcat and a stretched-X, or whether your array wants a quadplane or a fixed-wing. The chat figures it out.
Join waitlist