The helicopter involved in a crash which killed the owner of Leicester City lost control after the pilot’s pedals became disconnected from the tail rotor, investigators said.
This resulted in the aircraft making an uncontrollable right turn before it spun and crashed, according to a special bulletin by the Air Accidents Investigation Branch (AAIB).
The report revealed that a system linking the pilot’s pedals with the tail rotor failed.
An inspection at the crash site found parts of a mechanism had become disconnected and there was a “build-up of black grease” on one component.
The failure of the system led to the pitch of the tail rotor blades being changed “until they reached the physical limit of their travel”, investigators noted.
The report stated: “The initiating cause and exact sequence of the failure that resulted in the loss of tail rotor control is being investigated as a priority.”
Footage of the incident appears to show that sections of the tail rotor may have fallen off in mid-air.
The AW169 helicopter reached an altitude of approximately 430ft before plummeting to the ground near Leicester City’s King Power Stadium.
It was rapidly engulfed in a post-impact fire and all five people on board were killed.
Leicester City owner Vichai Srivaddhanaprabha, employees Nursara Suknamai and Kaveporn Punpare, pilot Eric Swaffer and his partner, Izabela Roza Lechowicz – who was also a professional pilot – were all killed in the accident on October 27.
Following the crash, the European Aviation Safety Agency ordered that safety checks should be carried out on the tail rotors of AW169 helicopters and similar models.
In November, the AAIB published its initial findings into the crash, detailing the helicopter's movements on October 27.
The helicopter's journey
- The helicopter took off on its first flight of the day from Fairoaks Airport, Surrey, just before 2pm, with the pilot and passenger on board.
- It landed just after 2pm in Battersea, where three other people got on board.
- The helicopter took off from Battersea at 2.15pm and flew to the Belvoir Drive Training Ground, landing just before 3pm.
- Everyone on board went to the King Power Stadium, Leicester.
- The pilot and a passenger returned to the training ground and at 6.45pm, it took off, with two people on board, for the short flight to the King Power stadium.
- Between 7pm and 7.30pm the pilot and four passengers boarded the helicopter for a flight to London Stansted Airport.
- The helicopter started up at 7.34pm and at 7.37pm, it lifted up from the centre of the pitch circle.
- Gear retraction started as it passed through a height of approximately 320 ft.
- The helicopter's climb then paused.
- The direction of the helicopter was initially consitent with the direction of pedal movements that were recorded.
- It then began to point right - contrary to the pilot’s left pedal command.
- The helicopter reached a height of approximately 430 ft before descending with a high rotation rate.