International helicopter manufacturer Sikorsky is requiring all operators of its S92A helicopters to undertake a mandatory inspection of all aircraft worldwide after a rig landing accident in the North Sea late last month.
Following media reports of a fleet-wide grounding, Sikorsky is stressing that the requirement is to undertake a global fleet-wide inspection; it is not a grounding of aircraft.
The S92A is a variant of the Sikorsky-manufactured S92, which are popular among the offshore oil and gas operators. The inspections are expected to disrupt offshore oil and gas industry operations in the short term, the HeliOffshore, the global offshore helicopter safety association, said.
The UK Maritime & Coastguard Agency, which uses S92’s operated by Bristol Helicopters at some its search and rescue bases, said inspections have been going on all day. “Helicopters at Sumburgh, Stornoway, Humberside, Newquay, and Prestwick and Inverness are all now back in service. Helicopters at Caernarfon will also shortly return to service,” the MCA in an update on Tuesday.
Sikorski issued Alert Service Bulletin (ASB 92-64-011) on Tuesday, requiring inspections and health and usage monitoring system download and analysis on all S92A aircraft, worldwide. More specifically, operators are required to conduct one-off inspections of the tail rotor and bearing assemblies before next flight and also have to complete a specific check of Health and Usage Monitoring System data for each aircraft.
The company said the bulletin was issued following an on-going investigation into a December 28 rig landing accident on a platform in the North Sea.
“Sikorsky is working closely with our customer and investigative authorities to determine the root cause of the loss of tail rotor authority in the Dec. 28 rig landing incident. We have communicated additional guidance to S-92 operators regarding Health and Usage Monitoring System usage and will continue to provide information as it becomes available,” Sikorsky said.
An update from the company added:
“Jan 10 Update: Although the investigation into the Dec. 28 incident has not been completed, Sikorsky released an Alert Service Bulletin on Jan. 10 to define additional interim inspection requirements for the S-92 Tail Rotor Pitch Change Shaft. 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.
“Safety is our top priority, and we are committed to keeping our customers informed. We will further communicate findings if the investigation reveals any safety or airworthiness issues that affect the S-92 helicopter fleet.”
Sikorsky later tweeted that the mandatory inspections were expected to be completed within 24-48 hours.
“We anticipate that the majority of the fleet will have the initial inspection accomplished within the next 24-48 hours depending on their operational tempo. Many operators have already informed us that they have completed this inspection. From that point, there is a recurring inspection on a continual basis,” Sikorsky said.
In 2015 Sikorsky was acquired by Lockheed Martin.