Two passenger planes were photographed “five seconds” away from a crash that was only prevented by a control tower team, an inquiry has found.
The near miss between two Cessna 208s in April was avoided by the “narrowest margin”, the Airprox Board said.
One of the planes had just dropped off parachutists at Sibson Aerodrome, near Peterborough, while the other was being flown by a student with an instructor.
The control tower told the higher plane to loop the area again before landing.
The Airprox Board, which investigates near misses, found the parachutists’ plane was coming in to land about 50ft (15m) above the other plane.
The instructor heard the noise, saw the shade from the plane above him and took control of the aircraft from the student.
A control tower staff member told the higher plane to fly around again before attempting to land.
“Both pilots were unaware of the position of the other C208 and, if not told to go around, it was estimated that a collision would have occurred after about five seconds,” the staff member said.
The Airprox Board “commended” the intervention, which it said had “prevented a mid-air collision”.
The report said the use of one of the Cessnas for parachutist drops had the potential to put pressure on pilots for a “quick turnaround” and called for “sufficient flexibility within the parachute dropping schedule”.
Investigators said that as both planes operated from the same airfield, flight plans could have been discussed beforehand.