All Sikorsky S92 helicopters have been grounded amid concerns over safety, causing disruption to North Sea flights.
The helicopters have been recalled by the manufacturer to undergo maintenance and inspection work. The move – repeated worldwide – could affect flights in the region for several days.
The move follows an incident involving an S92 on a North Sea platform last month. The helicopter was landing on the West Franklin platform on 28 December when it left significant gouge marks on the deck.
The Air Accidents Investigation Branch is currently conducting an inquiry into the incident.
A spokesman for Aberdeen International Airport confirmed: “All S92 helicopters have been recalled following a safety instruction.
“We are aware of a safety alert that has been issued for all S92 helicopters and are anticipating a potential impact on helicopter operations over the next few days until essential maintenance has been carried out.
“We will support the operators as much as possible through this disruption.”
The alert only affects the S92 model. Sikorsky confirmed it has issued a notice known as an alert service bulletin, which relates to the tail rotors of the aircraft. The alert demands a visual inspection of that part before its next flight.
A US-based spokeswoman for the manufacturer said: “Safety is our top priority and Sikorsky is working closely with our customer and investigative authorities to determine the root cause of the loss of tail rotor authority in the 28 December installation landing.
“Although the investigation into the 28 December incident has not been completed, Sikorsky released an alert service bulletin on 10 January to define additional interim inspection requirements for the S-92 tail rotor pitch change shaft (PCS).
“Those procedures include an off-aircraft check of the PCS bearing and that check must be done before next flight, with some leeway for getting back to base.”
She said the firm is committed to keeping its customers informed, saying: “We will further communicate findings if the investigation reveals any safety or airworthiness issues.”
The alert on a model thought of as the “workhorse” of the North Sea could disrupt operations possibly until the end of the weekend, industry sources fear.
Step Change in Safety, an organisation which campaigns to make the UK the safest place to work in the worldwide oil and gas industry, said Sikorsky’s decision will result in some short-term delays.
Its executive director Les Linklater said: “The decision made by Sikorsky is a precautionary measure to ensure continued safe flight operations and we are aware helicopter operators are working to assess the impact of this requirement, while investigating all opportunities to limit the effects on the flying programme.
“Currently, the inspections are expected to take up to 11 hours, which means some short-term delays.”