A flight instructor died after suffering a heart attack mid-flight after his co-pilot thought his colleague was playing a prank, according to a new report.
According to the U.K.’s Air Accidents Investigations Branch, the flight instructor died while acting as a safety pilot during the flight.
When the incident occurred, the co-pilot thought the flight instructor was joking.
The aviator continued the flight in a 1978 Piper PA-28-161 with the instructor’s head slumped over his shoulder before landing safely at Blackpool Airport in Lancashire on June 29.
However, it wasn’t until the pilot tried to get the instructor up he realized the 57-year-old man was dead, according to a bulletin released earlier this month by the U.K.’s Air Accident Investigation Branch stated.
Following an autopsy of the unnamed flight instructor, it was found he had an acute cardiac failure which result in a heart attack, just four months after passing a physical.
Safety experts said that although the pilot was able to land the plane, “had this occurred on another flight, the outcome could have been different.”
“The pilot recalled that during the taxi they were talking normally,” the report stated.
“He recalled telling the instructor he would keep the aircraft into wind for the power checks and the instructor replying, ‘Looks good, there is nothing behind you.’ The pilot did not recall the instructor saying anything else after this point.”
The pilot said the instructor’s head “rolled back” not long after takeoff.
“The pilot knew the instructor well and thought he was just pretending to take a nap while the pilot flew the circuit, so he did not think anything was wrong at this stage,” the bulletin read.
He “still thought the instructor was just joking with him and continued to fly the approach” even after the instructor’s head slumped on the pilot’s shoulder.
A post-post-mortem exam revealed the pilot’s arteries were clogged with fat and that he had a blood clot in one of his arteries.
The instructor had racked up 8,876 flying hours over his career and had a valid commercial pilot’s license.
Those who had spoken to the instructor on the morning of his death said “he was his normal cheerful self,” according to the report.
The Civil Aviation Authority said they would review their cardiac guidance based on the latest research, CBS News reported.