A pair of Royal Air Force aircraft came within “20-50ft” of a high-speed collision in March this year, with only luck preventing an accident, UK safety investigators have determined.
Disclosed by the Civil Aviation Authority’s Airprox Board (CAAB), the 12 March incident involved a formation of three Eurofighter Typhoon jets and a Shorts Tucano T1 turboprop trainer over RAF Coningsby in the east of England.
Having observed the Typhoons approaching from astern “with a high overtake speed”, estimated at around 190kt (388km/h), the instructor in the rear seat of the Tucano was forced to initiate evasive action and take control from his student after he saw the lead aircraft “initiate a break directly towards him” from only 100-200m (330-660ft) away.
“Without time to say ‘I have control’, he aggressively pushed forward on the control column and heard the jet noise of the Typhoon as it passed directly overhead in a right-hand breaking turn,” says the CAAB report.
“The instructor assessed that the Typhoon’s right wing-tip was within 20-50ft of the Tucano.”
Although the Typhoon pilots were informed of the presence of the Tucano, which had been conducting a touch-and-go manoeuvre ahead of them, “all three formation pilots perceived that the Tucano had transited down and was past the upwind end of the runway”, the report says.
The pilot of the lead Eurofighter then made a visual scan of the Coningsby runway to check for other aircraft before breaking to join the circuit to land, but still failed to detect the Tucano.
However, the CAAB says, he “first saw the Tucano at the point at which he rolled right to break, directly below his aircraft” which required him to take “immediate evasive action up and away”.
Visibility was good at the time of the incident, which occurred at around 16:00.
The Typhoon and Tucano pilots both assessed the risk of collision as “very high”, with the CAAB classing it as a category A incident – the most serious on the ICAO scale.
The CAAB concludes that a number of factors were at play during the incident but “the fact that the Typhoon pilot did not gain visual contact with the Tucano before breaking into the circuit was contributory to the airprox”.
The Typhoon had “flown into conflict with the Tucano”, it says, adding that “chance had played a major factor in the aircraft not colliding”.
It emphasises that all other traffic in a circuit needs to be visually identified before a break is commenced.