Authorities are investigating after a drone was recovered on the tarmac near a runway at San Francisco International Airport.

SFO spokesman Doug Yakel said the drone was found Wednesday afternoon on the tarmac, near a fence that runs along a frontage road parallel to Highway 101.

Yakel said the drone was around 1 foot by 1 foot in size. The incident did not have any impact on flight operations, according to Yakel.

The Federal Aviation Administration says no small unmanned aircraft can fly in Class B airspace around most major airports without permission from the FAA, and they shouldn’t fly higher than 400 feet above ground.