Norwegian investigators have revealed that a light aircraft collided with an unmanned air vehicle just days before the country’s air navigation service cautioned about their proliferation.

Investigation authority SHT declines to identify the aircraft type involved, but says it was a “low-wing, two-seat” monoplane.

The incident took place on 30 August at around 19:00 just north of Vasser, a district near Sandefjord, south of Oslo.

SHT says the collision occurred at a height of around 2,500ft. “The pilot encountered what is believed to be a drone and, a moment later, heard a bang,” it states.

The flight continued without any technical problems and an inspection after landing revealed no evidence of damage.

SHT says the pilot assumes the drone struck the aircraft’s left-hand landing-gear. It wants the operator of the drone – or anyone who finds the drone wreckage – to contact investigators.

“Lately there have been several potentially-dangerous incidents at various airports around the world,” it states.

Air navigation service Avinor urged drone operators on 4 September to comply with restrictions, warning: “We’ve had several cases of drones that could constitute a hazard to aviation safety.”

Norway’s civil aviation authority says that drones should not be flown at a height exceeding 125m (410ft).

Source: Flight International