The pilot of the helicopter that crashed outside Leicester City’s stadium, killing five people including its chairman, said “I’ve no idea what’s going on” as it spun out of control.

Eric Swaffer, 53, made the comment before the helicopter hit the ground outside the King Power Stadium on 27 October 2018.

The final report into the crash has now been published.

It concluded the pilot could do “very little” to save those on board.

The crash claimed the lives of Leicester City chairman, Vichai Srivaddhanaprabha, two members of his staff – Nusara Suknamai and Kaveporn Punpare – and pilots and partners Mr Swaffer and Izabela Roza Lechowicz.

The Air Accidents Investigation Branch (AAIB)’s final report said a tail rotor bearing seized, which in turn caused the crash.

The AAIB said the crash was “inevitable” after a sequence of mechanical failures.

Chief inspector of air accidents at the AAIB, Crispin Orr, said Mr Swaffer did what he could to control the Leonardo AW169 helicopter, but the catastrophic failure in a bearing in the tail rotor resulted in the aircraft making a sharp right turn.

As the helicopter – which had reached an altitude of about 430ft (131m) – was turning out of control, a shout of “hey, hey, hey” came from the rear cabin, where Mr Vichai and his employees were seated, the AAIB said.

In aircraft voice recordings, Mr Swaffer was heard to say: “I’ve no idea what’s going on”, shortly before the helicopter crashed into a concrete step.

Inspectors said four of the passengers survived the impact of the crash, but a fire that was caused by a “significant” fuel leak, proved fatal.

Four first responders were treated for injuries caused by the heat of the fire after they attempted to rescue those inside the helicopter.

The report added two police officers who arrived at the scene one minute after the crash tried to smash the helicopter’s windscreen with their batons, but failed.

Mr Orr said: “This was a tragic accident in which five people sadly lost their lives. Our thoughts are with their loved ones, and everyone affected.”

It has taken almost five years to complete the 209-page final report, after what the AAIB previously called a “technically very complex” investigation.

Authorities from Canada, France, Italy and the US were also involved in the investigation because of where various significant components were manufactured.

The investigation discovered a worn bearing on the tail rotor had seized after the helicopter took off.

The shaft that controlled the tail rotor then unscrewed and became detached as a result, which in turn caused the helicopter to spin out of the pilot’s control.

The AAIB report stated the helicopter complied with “all applicable airworthiness requirements” and had been maintained correctly before the crash.

The wear on the rotor bearing was also found to have built up over a period of time and could not have been predicted, according to the inspectors.

Examination of the bearing was only required once it had been used for 400 hours, but the helicopter had only been flown for 331 hours when the crash occurred.

One of the “contributory factors” was that regulations do not require maintenance checks to review the condition of used bearings against their original design, the AAIB said.

Drone involvement and pilot error were ruled out.

The AAIB has made eight safety recommendations to the European Aviation Safety Agency (EASA) as a result of its investigation to “address weaknesses or omissions” in regulations for certifying large helicopters.

The crash occurred just over an hour after a Premier League match between Leicester City and West Ham United.

It sparked an outpouring of grief and tributes across the UK and abroad, with Leicester’s players travelling to Thailand for Mr Vichai’s funeral.

A statue of Mr Vichai was unveiled at the club in 2022, with the former chairman replaced by his son Khun Aiyawatt “Top” Srivaddhanaprabha.

In a statement published on Wednesday, Leicester City chief executive Susan Whelan said the club commended “the extensive and detailed body of work undertaken” by the AAIB, and hopes it “will contribute positively to the continued development of future aviation standards and safety”.

“The tragic events of 27 October, 2018, will forever be etched into the memory of the Leicester City family. It was a night we experienced the devastating loss of our beloved chairman, friends, colleagues, and family members,” she said.

“Yet, in our grief, a sense of unity and strength was forged. The extraordinary support and kindness that was extended to those affected, by communities across Leicestershire, football and the wider world will never be forgotten.”