Lavionic
Free tool

Lavionic Ground Crash Calculator

Enter the size, mass and speed of your unmanned aircraft, how it would come down and who is below. The calculator shows the critical area drawn to scale, the SORA column it falls in and the intrinsic ground risk class (iGRC).

v0.3.1 · 2026-10-22 · HTML · works offline

Use online(opens in a new window)

New in this version: The Table 2 column now follows the width and the maximum speed, each by its own rule.

What you enter

  • The width of the aircraft, its take-off mass and its maximum speed.
  • How it comes down after a failure: a glide at 10°, a crash at full speed at 35° (the case SORA uses for its table), a steep ballistic fall, or a parachute descent with wind.
  • The population density below the flight, from a controlled ground area to under 50,000 people per km².

What you get

  • The critical area in m², with and without the obstacle factor for buildings, trees and cars, drawn to scale.
  • The column of the SORA 2.5 ground risk table that the width and the maximum speed fall in.
  • The intrinsic ground risk class, with every step of the calculation and the clause it comes from.
  • An edit panel: change one value and the result follows at once.

Online or offline

Use it online in your browser, or download it once as one HTML file. The file opens in Chrome, Safari, Edge or Firefox, works without an internet connection and sends no data anywhere.

The calculator is an aid, not a means of compliance. The regulation and your competent authority decide.

Sources

  • JARUS SORA 2.5 Annex F
  • EASA Easy Access Rules for UAS (June 2026)
  • EASA MOC Light-UAS.2512-01