Leonardo Helicopters has issued a mandatory service bulletin for the AW169, calling on operators to perform an urgent examination of tail rotor components which, if they malfunction, could cause a pilot to lose control of the aircraft.
The directive is the first safety warning to emerge in the wake of a fatal crash of a VIP-configured example in Leicester in the UK on 27 October.
Footage which emerged after the accident showed the helicopter (G-VSKP) performing a vertical take-off from Leicester City Football Club's stadium before spinning out of control and plunging to the ground.
All five passengers and crew aboard the AW169 – including Leicester City's Thai owner Vichai Srivaddhanaprabha - were killed.
Unverified text of the service bulletin circulating on social media calls for an urgent check to ensure a specific component - the tail rotor servo-actuator feedback lever installation and interface – has been installed properly and is functioning correctly.
"Incorrect installation may lead to loss of tail rotor control which, depending on the flight condition, could lead to loss of control of the aircraft," the bulletin warns.
The European Aviation Safety Agency is to make Leonardo's recommendation the subject of an airworthiness directive.
So far, the UK Air Accidents Investigation Branch has divulged little detail of its probe into the incident.
Data has been successfully downloaded from the AW169's combined cockpit-voice and flight-data recorder, but the AAIB has yet to reveal any further information.
It says it is "too early" to say if the components identified in the bulletin were directly responsible for the Leicester crash.
More detail will be provided in an interim report into the incident, says the AAIB, but stresses that it cannot give a timeline for publication.