An update from the investigators blamed the disaster on the “apparent loss of yaw control”, an axis pilots use to navigate.
The Air Accidents Investigation Branch (AAIB) also revealed the helicopter’s manufacturer has issued a safety alert to all owners of the particular model – AW169 – involved in the crash on 27 October.
They have been told to carry out a “precautionary inspection” of the system which controls the tail rotor.
Owners of another model – AW189 – which has a similar tail rotor control system, have also been warned.
The helicopter came down outside the King Power Stadium, killing the club’s owner, Thai billionaire Vichai Srivaddhanaprabha; the helicopter’s pilot Eric Swaffer; Mr Swaffer’s partner Izabela Lechowicz; ex-Thai beauty queen Nursara Suknamai; and Kaveporn Punpare, who worked for the Leicester City owner.

