Electron Flight Electron Flight

PTERO Technology

U.S. Patent 12,043,377 · Flight Proven · Electron Flight LLC

Tiltrotor and simple don't usually intersect. PTERO makes it happen. PTERO technology embeds the functionality and simplicity of a multirotor in a fixed-wing aircraft. The multirotor core sits on a free pivot along the wingspan and tilts itself by differential thrust, exactly like any multirotor, independently of the wing. There are no control surfaces, linkages or actuators.

  • Multirotor functionality inside a fixed-wing VTOL
  • No control surfaces, linkages or actuators
  • Multirotor core on a free pivot, tilted by differential thrust
  • Flexible spar acts as a torsion spring for thrust vectoring
  • Yaw by differential thrust; pitch and roll by thrust vectoring
  • Low cost, low weight, high performance, high reliability
  • Small-scale aircraft flown; larger brushless version next

PTERO Technology

Free-Pivot Multirotor Core

  • Multirotor core mounted on a free pivot along the wingspan
  • Rotates independently of the wing
  • Differential thrust tilts it from vertical lift to forward thrust
  • Tilts itself like any multirotor

Torsion-Spring Spar

  • The core's structure is a flexible spar acting as a torsion spring
  • Wingtip motor nacelles can twist relative to each other
  • Opposite twist vectors thrust for pitch and roll
  • No actuators or linkages

Fixed-Wing Efficiency

  • Wing carries the aircraft in cruise
  • Yaw by differential thrust
  • No ailerons, elevators or rudders
  • VTOL and efficient cruise in one simple airframe

PTERO vs. Conventional VTOL Fixed-Wing

FeatureConventional tiltrotor / VTOL fixed-wingPTERO technology
Rotor tiltTilt actuators and linkagesDifferential thrust on a free pivot
Attitude control in cruiseControl surfaces with actuatorsThrust vectoring via torsion-spring spar and differential thrust
Control surfacesAilerons, elevator, rudderNone
Moving partsMany actuators and linkagesPivot and flexible spar
Cost and reliabilityHigher cost, more failure pointsLow cost, high reliability

Benefits & Applications

Benefits

  • Low cost: No actuators, linkages or control surfaces.
  • Low weight: Fewer components in the airframe.
  • High performance: VTOL plus wing-borne cruise.
  • High reliability: Fewer moving parts and failure points.

Applications

  • Uncrewed VTOL fixed-wing aircraft for long-range survey, inspection and delivery
  • Defense and public-safety uncrewed aircraft
  • eVTOL research platforms
  • Low-cost training and research aircraft

How PTERO Technology Works

  • Rotatable thruster assemblies: Each side carries thrusters on either side of the assembly's rotation axis, so differential thrust rotates it from downward lift to rearward thrust.
  • Torsionally flexible shaft: Left and right assemblies are joined by a laterally mounted shaft whose outer portions twist independently, acting as a torsion spring. Symmetrical opposite twist vectors thrust for roll and pitch.
  • Yaw: Differential thrust between left and right.
  • Optional lift thrusters: Dedicated vertical-lift thrusters can be added.
Line drawing of the aircraft from above: the free-pivot axis runs through a flexible spar along the wing, with a thruster assembly at each tip.
Free-pivot axis and flexible spar, which acts as a torsion spring.
Side-view line drawing in hover: the thruster assembly is rotated so thrust points straight up, while the fixed wing stays level.
Hover: differential thrust holds the core for vertical lift.
Side-view line drawing in forward flight: the thruster assembly has rotated about the free pivot so thrust points forward, while the fixed wing stays level.
Forward flight: the core tilts on its free pivot to forward thrust.

Proven in Flight

  • Small-scaleaircraft flown
  • Zerocontrol surfaces
  • Zeroactuators
  • A small-scale PTERO aircraft has flown
  • Next: a larger brushless version

R&D Roadmap

  1. Phase 1 — Larger brushless build: Design and build the next-scale aircraft.
  2. Phase 2 — Hover and transition testing: Validate free-pivot core and torsion-spring vectoring at the larger scale.
  3. Phase 3 — Cruise performance: Characterize efficiency, endurance and control authority.
  4. Phase 4 — Reliability: Durability and fault testing.
  5. Phase 5 — Scale-up and partnering: Mission-specific variants with partners.

Intellectual Property

U.S. Patent 12,043,377 · Assigned to Electron Flight LLC

FAQ

How does PTERO tilt its rotors without actuators?

The multirotor core sits on a free pivot and tilts itself by differential thrust, like any multirotor.

How does it control pitch and roll without control surfaces?

The core's flexible spar acts as a torsion spring, letting the wingtip nacelles twist relative to each other to vector thrust.

How is yaw controlled?

Differential thrust.

Has PTERO flown?

Yes. A small-scale aircraft has flown; a larger brushless version is next.

Advance PTERO Technology With Us

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