The UK Airprox Board investigated a drone near-miss reported by a Cessna 560XL Citation XLS near Biggin Hill Airport on 25 June 2016. Separation distance reported as less than 200 feet.
The pilot reported that they were taking radar vectors for weather avoidance and had a high cockpit workload. The PM visually acquired a contact on the nose at a range of about 1/2nm, and estimated it to be below. He made the PF, who was in the right-hand seat, aware and within 2 seconds of the PF acquiring the contact (and 5 seconds from when the PM had first seen it), a drone passed down the right-hand-side of the aircraft, 20ft below and 30ft to the right of the cockpit position, therefore only just beyond the wing-span. The object was a day-glo orange drone with 4 rotors and an under-slung camera housing with a ‘fisheye’ lens bubble, estimated to be about 1 cubic ft. It could have been hovering, although it looked to be slowly drawing to the right.
Reported separation: 20 ft (6 m) vertical / 32 ft (10 m) horizontal.
Aircraft: Cessna 560XL Citation XLS
Aircraft altitude: 3000 ft
Separation: 32 feet
Please note that separation distances are solely based on pilot’s judgements and not necessarily accurate since horizontal and vertical separation distances can be hard to judge.