2.5. Testing of new and modified drones

See ‘Airworthiness of drones’ for background on the testing of new drones.

Civil aviation authorities have very strict rules regarding modifications of planes used for manned flights. For drones the rules are a lot less stringent and in most countries only require a preflight inspection carried out by the pilot in command.

Depending on the risk profile of drone operations a more systematic and thorough process than a visual inspection might be required. Such requirements should be formalized in the form of written instructions or procedures.

All modifications to aircraft and control equipment carry the risk of unintended consequences. Such modifications should only be performed by specialists or at the very least should be thoroughly tested before the drone is returned to normal use in flight operations.


  1. Injury and damage on the ground caused by malfunctioning or crashing drone.
  2. Loss of control and in-air collision with manned or unmanned aircraft.
  3. Damage or loss of payload (sensors, cameras and gimbals are often more valuable than the drone itself).

Audit Steps

  1. Assess the system in place to check new drones and modified drones before they are released for normal service.
  2. Review records documenting the testing and the release of new drones and of modified drones.