Drone collisions with aircraft will cause more impact damage than a bird strike of equivalent size and speed, concludes a study conducted for the FAA.

The stiff structures and concentrated masses of batteries and cameras on small unmanned aircraft systems (UAS) will inflict more damage to aircraft structures than flexible birds, says the study by a consortium of universities under the Alliance for System Safety of UAS through Research Excellence (Assure).

Release of the final report on the UAS airborne collision hazard severity evaluation follows the April publication of the results of a parallel Assure study of ground collision severity that showed the risk of harm to humans was less than expected because multicopter drones fall more slowly than other objects.

Instead, the study is based on simulating collisions using aircraft and drone structural models validated by component-level impact testing. Simulation allowed for quick changes in impact conditions and provided for repeatability between tests and appropriate comparisons between impact scenarios.

Researchers selected and modeled the popular 1.2-kg (2.7-lb.) DJI Phantom quadcopter and 1.8-kg PrecisionHawk Lanchester fixed-wing small UAS. The target aircraft were modeled on the Boeing 737 and Learjet 31A business jet.

A collision between a business jet and either type of drone may result in a damage severity level of medium-high on the horizontal and vertical stabilizer, medium on the wing leading edge and, on the windshield, from medium-low for a quadcopter to high for a fixed-wing UAS.