LONDON (AP) — A new report says an A320 passenger plane approaching London's Heathrow Airport just missed colliding with a large drone at 10,000 feet (3,048 meters) last November.

The report by the Airprox Board says the plane had just started its descent on Nov. 11, when both pilots noticed a large gadget with multiple arms and rotors passing below the plane's right wing.

The pilots exclaimed: "Was that a drone? At 10,000 feet!" The pilot said there was no time to react. The separation between the two craft was 100 feet (30 meters) vertically and 200 meters (656 feet) horizontally.

It was one of four near-misses in the February report, which shares incidents that may compromise air safety in the U.K.

The police were informed but the drone operator could not be traced.