Free eVTOL Corpus

A structured prior art commons covering eVTOL aircraft and eVTOL-adjacent flying machines: passenger air taxis, cargo eVTOL, jetpacks, hover bikes, personal VTOL, tilt-rotor and tilt-wing demonstrators, military VTOL, ducted-fan and vectored-thrust craft, drive+fly transformers, and the science fiction and academic literature that anticipated all of them.

Coverage is global and deep: 247 entries spanning ~2,500 years from the Pushpaka Vimana (Sanskrit Ramayana, ~5th c BCE) and the 1001 Nights flying carpet (~9th c CE) through Verne's Albatross (1886, 74 distributed lift airscrews — the foundational engineering anticipation of distributed-electric- propulsion) and the deep helicopter-pioneer base (Cornu 1907, Oehmichen 1924, Focke Fa 61 1936, Sikorsky VS-300 1939, Flettner Fl 282 1941, Bell Model 30 1942), the Cold War VTOL demonstrators (XV-3 1955, X-13 Vertijet 1957, X-14 1957, VZ-2 1957, X-18 1959, P.1127 1960, X-22 1966, XV-15 1977, V-22 1989, Yak-141 1987, F-35B 2008), and the modern commercial eVTOL ecosystem (Joby, Archer, Beta, Wisk, Volocopter, Lilium, Vertical, EHang, AutoFlight, AeroHT, Hyundai Supernal, Eve, AMSL, ePlane, Zuri, Crisalion, Manta, AeroMobil, Klein Vision, PAL-V, Pivotal, Jetson, AIR, ASKA, etc.) through 2024.

31 countries on six populated continents — US, FR, GB, JP, DE, RU, CH, CN, IT, CA, AT, IN, AU, KR, SE, AR, BR, ES, IL, NL, SG, SK, ZA, CZ, DK, EG, GE, HU, IE, NZ, SI. All 20 lift-architecture categories are populated, including fictional_repulsor (Star Wars repulsorlift 1977, Back to the Future Part II hoverboard 1989, The Fifth Element 1997), cyclorotor (Kirsten-Boeing cyclogiro 1922 → D-Dalus 2011 → CycloTech 2022), buoyant_hybrid (LTA Pathfinder 1, Airlander 10, Flying Whales, Aeros Aeroscraft), ground_effect_hybrid (Soviet ekranoplans 1966, Wigetworks AirFish, REGENT seaglider), and coleopter (Heinkel Lerche II 1945 → SNECMA Coléoptère 1959).

The corpus also covers the adjacent lineages that bound any future commercial eVTOL patent claim: modular / transforming / swarming / self-assembling aerial robots (ETH Distributed Flight Array 2010, UPenn ModQuad 2018, University of Tokyo DRAGON 2018, KMel/UPenn nano-quad swarm 2012, Intel Shooting Star 2016, Airbus Pop.Up and Bell APT modular-pod concepts 2017-2018); fully-actuated omnidirectional multirotors (ETH Omnicopter 2016, Voliro 2018, CycloTech 2022); historical personal-VTOL platforms (Hiller VZ-1 Pawnee 1955, de Lackner HZ-1 Aerocycle 1955, Williams X-Jet 1982, SoloTrek XFV 2001); compound rotorcraft (Fairey Rotodyne 1957, Eurocopter X3 2010, Airbus RACER 2024, Sikorsky/DARPA X-Wing 1986); electric airships and WIG craft (LTA Pathfinder 1 2023, Hybrid Air Vehicles Airlander 10 2012, Flying Whales LCA60T 2012, REGENT seaglider 2021); and drive+fly transformers across folding-wing, modular-capsule, whole-body-rotation, and autogyro variants (Terrafugia Transition 2009, Klein Vision AirCar 2020, Alef Model A 2022, Airbus Pop.Up 2017, PAL-V Liberty 2024).

Hand-written invalidity-contention packets target the Joby Aviation, Archer Aviation, Beta Technologies, and Volocopter patent estates by mapping their architectural claim domains to corpus entries that anticipate each. Auto-generated subsystem packets cover 50 distinct architectural / certification / safety / autonomy / modular-docking / morphing / swarm / omnidirectional / buoyant-hybrid / stopped-rotor domains.

The corpus IS the prior art commons. Every entry, at the moment of timestamped commit and quarterly release, is a defensive publication. There is no separate commons layer above this catalog — the structured data here, combined with the cryptographic timestamping in releases/, is itself the invalidity-contention material.

License

CC0-1.0. Public domain dedication. See LICENSE.

What's in here

SCHEMA.md           — schema spec (currently v0.1)
TIMESTAMPING.md     — release ceremony for cryptographic timestamping
RELEASE_RUNBOOK.md  — step-by-step first-release procedure
README.md           — this file

corpus.jsonl        — master corpus (one JSON object per line)
private.jsonl       — generated mirror, entries with corpus="private"
open.jsonl          — generated mirror
fictional.jsonl     — generated mirror
academic.jsonl      — generated mirror

CORPUS_INDEX.md     — generated alphabetical index
lineage.json        — generated ancestor/descendant DAG

cross_cuts/         — generated per-subsystem prior art views
  INDEX.md          — table of all cross-cuts with counts
  <tag>.md          — chronological view of all entries disclosing <tag>

tools/
  validate.py       — schema and quality-bar enforcement
  index.py          — generates CORPUS_INDEX.md, lineage.json, per-corpus mirrors
  cross_cuts.py     — generates cross_cuts/

release.sh          — quarterly release ceremony with timestamping

Quick start

# Validate the corpus passes structural and quality-bar checks
python3 tools/validate.py corpus.jsonl --strict

# Regenerate all derived artifacts after editing corpus.jsonl
python3 tools/index.py .
python3 tools/cross_cuts.py

# Run a quarterly release with cryptographic timestamping
./release.sh 2026.Q3

Quality bar

An entry is commons-grade (not draft: true) when:

1. disclosure_citation resolves to a primary source verifiable by a third party.
2. first_disclosure_date is the earliest verifiable public disclosure, defensible against challenge.
3. prior_art_notes reads as a 102/103 anticipation analysis someone unrelated to us could cite without rewriting.
4. sources cite primary references.
5. For patented entries, ip_citations lists actual patent numbers.

Entries that don't yet clear this bar are merged with draft: true and have explicit work items in their notes field.

Cross-cuts as the working tool

The cross-cut files (cross_cuts/<tag>.md) are the operational form of the commons. Each file lists every entry disclosing a given subsystem, in chronological order, with their prior_art_notes and disclosure_citation inline.

Use these when assessing patent claims:

• A claim about distributed electric propulsion? Open lift-distributed-electric-propulsion.md — anchored at Verne's Albatross (1886, ~74 vertical lift rotors), through de Bothezat (1922), Curtiss-Wright VZ-7 (1958), to modern multirotor air taxis.
• A claim about tilt-rotor transition? Open lift-tilt-rotor.md — anchored at Bell XV-3 (1955) and XV-15 (1977), through V-22 Osprey (1989), to Joby S4 and Archer Midnight.
• A claim about vectored-thrust VTOL? Open lift-vectored-thrust.md — Hawker P.1127 (1960), AV-8B Harrier (1985), Yak-141 3-bearing swivel duct (1987), F-35B (2008), Lilium ducted-fan array.

Contributing

Contributions are welcome under CC0-1.0. By submitting an entry you dedicate the contribution to the public domain.

A good entry is one that holds up as defensive publication. The contribution guide (CONTRIBUTING.md) covers what that means in practice. Briefly:

• Cite primary sources, not Wikipedia.
• Identify specific subsystems disclosed using the taxonomy in SCHEMA.md.
• Write prior_art_notes as element-by-element anticipation analysis.
• For patented entries, point back at academic, military, or fictional prior art that anticipates the claims.

If unsure, mark the entry draft: true and document the work needed to clear the quality bar.

Provenance

Originated within Open Interface Engineering (OpenIE) as a sister project to the Free Humanoid Corpus, applying the same defensive-publication methodology to a different patent-thicket-formation field. The corpus serves the entire eVTOL and personal aerial mobility field, not any specific platform.