The pilot of the helicopter involved in a crash that killed the owner of Leicester City Football Club said: “I have no idea what's going on” as the aircraft spiraled out of control.
Eric Swaffer, 53, made the comment seconds before the helicopter hit the ground outside the club's King Power Stadium on October 27, 2018, an Air Accidents Investigation Branch (AAIB) report revealed.
Leicester City owner Vichai Srivaddhanaprabha, officials Nursara Suknamai and Kaveporn Punpare, Mr Swaffer and his partner Izabela Roza Lechowicz – also a professional pilot – were killed in the crash, which happened shortly after the helicopter took off from the pitch .
The Leonardo AW169 helicopter reached a height of about 430 feet before plummeting to the ground.
The pilot's pedals became disconnected from the tail rotor, investigators found.
This resulted in the aircraft making a sharp right turn that was “impossible” to control.
The AAIB described it as a “catastrophic failure”, causing the helicopter to spin rapidly, around five times.
As the helicopter spiraled out of control, there was a shout: “Hey, hey, hey!” it came from the rear cabin, where Mr Vichai and his staff were sitting, the AAIB said.
Mr Swaffer, who was a very experienced pilot, responded by saying: “I have no idea what's going on” and “hit an exclamation mark”, according to the report.
He “took the most appropriate actions” which included raising a lever to reduce the helicopter's bank angle and “mitigate the impact”, the AAIB said.
The aircraft landed on a concrete step, resting on its left side.
Four of the five occupants survived the initial impact, but none survived as the helicopter caught fire within a minute of a major fuel leak.
The accident happened about an hour after the Premier League match between Leicester City and West Ham United.
The AAIB investigation found that the control system failed because a bearing in the tail rotor broke due to its ceramic balls sliding instead of rolling, due to a build-up of pressure.
Asked if this was ‘an accident waiting to happen', AAIB senior engineering inspector Adrian Cope told reporters: ‘It was a process that was constantly building.
“The damage to this bearing accumulated over a period of time.”
The bearing inspection was only required after it had been in use for 400 hours, but the helicopter had only flown for 331 hours when the accident occurred.
One of the “contributing factors” to the crash was that regulations do not require maintenance checks to review the condition of used bearings against their original design, the AAIB said.
The 209-page report ruled out drone involvement and pilot error.
AAIB Chief Inspector of Air Accidents Crispin Orr said: “The AAIB has carried out an extensive investigation to establish why the accident happened and how safety can be improved.”
Authorities from Canada, France, Italy and the US were also involved in the investigation because of where several important components were manufactured.
The AAIB made eight safety recommendations to the European Aviation Safety Agency (Easa) – whose rules for aircraft certification are mirrored by the Civil Aviation Authority in the UK – to “address weaknesses or omissions” in helicopter certification regulations .
These deal with the design, validation and monitoring of safety critical components.
Other changes were made to the AW169 and AW189 fleets by the manufacturer and Easa as investigators became aware of issues.
A statue of Mr Vihai was unveiled at the stadium in April last year.