Vayu X5 VTOL

Remove last mile medical delivery drone

2016Director of Flight Testing and Aircraft DevelopmentVayu Inc
UAVsCompositesFlight Testing

Overview

Led the rapid development of the Vayu X5, a tandem-wing electric VTOL UAV built for medical payload delivery in remote areas. In under six months, we took the program from initial concept to a fully operational, field-proven aircraft with 90+ minute endurance and exceptional payload/CG tolerance. My role as technical lead and primary designer encompassed overall aircraft architecture, tandem-wing aerodynamic and structural design, propulsion and lift-fan sizing, and all flight testing operations leading up to a pilot program in Madagascar.

Inherited design suffered from a critical flaw: the vertical-lift system’s center of lift was severely misaligned with the vehicle’s CG envelope, rendering the airframe unflyable. I rapidly diagnosed the issue and redesigned the tandem-wing layout to correctly align lift centers, allowing for stability and payload flexibility. Separately, early prototypes exhibited dangerous yaw instability in hover under windy conditions; iterative flight testing revealed that canting the lift motors inward by a few degrees restored full yaw authority.

Very early X5 prototype used to validate the tandem wing design. The fuselage is a simple structure with a cardboard fairing.

Later stage prototype of the Vayu X5.

Flight testing an X5 prototype.

Flight testing with a water bottle as a dummy payload.

Version of the X5 used for the Madagascar pilot-project.

Getting some lunch during another long day of flight testing.

Accomplishments

  • Delivered a 90+ minute endurance, payload-tolerant eVTOL from concept to Madagascar field deployment in <6 months.
  • Identified and corrected critical center-of-lift misalignment in third-party tandem-wing design, turning an unflyable platform into a highly stable one.
  • Solved severe hover yaw instability via motor-canting discovery; solution adopted company-wide.
  • Led all flight-test campaigns and the Madagascar pilot-project while technically directing a non-technical CEO through aggressive milestones.

Lessons Learned

  • Small angular changes in lift-fan geometry can yield massive stability improvements in multi-rotor configurations.
  • Aligning the natural airframe flex with the yaw control is critical to stability.

Skills Used

VTOL AircraftTandem Wing AerodynamicsComposite Structural AnalysisFlight Testing

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