Norway's Statoil ASA (NYSE: STO) has stopped all flights of its Sikorsky S-92 helicopters for safety checks, leaving oil workers stranded on offshore platforms for at least a couple of days, the company said on Jan. 10.

The Sikorsky Aircraft Corp., which manufactures the helicopters, issued a service notice on Jan. 10, saying the tail rotor and bearing assemblies of the S-92 should be checked, following an incident in Scotland last December.

Sikorsky is a unit of Lockheed Martin Corp.

"All 13 S-92 helicopters were grounded after a note from the manufacturer today. We are prepared for inspections to take a couple of days," a Statoil spokesman said.

"This means some delays in replacing people on the oil platforms, but production hasn't been affected," he added.

The Norwegian state-controlled oil company stopped using Airbus's H225 Super Puma helicopters after a fatal crash off Norway last April, leaving the S-92 as the only model for transporting offshore workers.

S-92 flights were also stopped on the other side of the North Sea, in Britain, with one offshore operator--Royal Dutch Shell Plc (NYSE: RDS.A)--saying it was working on alternative flight provision.

Shell added its production wasn't affected, either.

Britain's oil and gas lobby group said the grounding of the helicopters would create some "short-term disruption to operations" in the North Sea while checks were carried out.

Sikorsky said in a separate note it was working closely with customers to determine the root cause of a problem with the tail rotor during a landing on a rig off Scotland on Dec. 28.

A spokesman for Britain's Air Accidents Investigation Branch said the authority was still investigating an incident near Aberdeen on Dec. 28.

Statoil said in December it would not resume using H225 Super Puma helicopters even if Norway's Civil Aviation Authority decided to lift a ban imposed after April's fatal crash.