Two U.S. F-15 fighter jets came dangerously close to colliding with a pair of parachutists above southern England in April, according to a report from the United Kingdom's air safety board.

newly-surfaced report from the UK Airprox Board indicates that the parachutists were in free-fall at about 120 mph vertically above Chatteris Airfield when the F-15s, assigned to the 48th Fighter Wing at RAF Lakenheath, flew below at 345 mph during a routine flight.

“Once the parachutists had seen the F15s there was very little they could do to avoid the situation, having no control over their speed or direction whilst in free-fall,” the report states. “As they overflew the drop site, it was unlikely that the pilots would have been able to see the parachutists and take avoiding action, and in this case they were unaware that they had flown beneath them.”

(UK Airprox Board)

Air Force photo

According to the report, the lead F-15 of the pair had taken “avoiding action” after realizing a KC-135 refueling tanker “was on a collision course with the formation,” accidentally ending up over popular skydiving site at Chatteris.

The aircraft had just been handed off to air traffic controllers at RAF Lakenheath by those at RAF Coningsby when the incident occured, according to the report.

One of the parachutists, outfitted with a GoPro camera, captured footage of the F-15s flying directly underneath the pair.

As a result of the incident, personnel at RAF Lakenheath are “using this incident to reinforce the vital importance of situational awareness and attention to detail for all of our air traffic controllers and aircrew,” 48th Fighter Wing commander Col. Will Marshall
told Stars & Stripes, adding that U.K. airspace “is incredibly complex and often congested.”

Read the full report below: