Salvage crews are continuing to determine the extent of damage Friday to the Shell Oil-contracted drilling rig Kulluk, which remains off an island near Kodiak after it ran aground Monday evening.

In a press release Friday night, the Unified Command said five helicopter missions have been flown to the Kulluk during the day. Mobilized response assets include 14 vessels, three of which are at the scene, as well as a pair of CH-47 Chinook helicopters on loan from the 16th Combat Aviation Brigade at Fort Wainwright in Fairbanks.

Meanwhile, the city of Old Harbor is expecting workers from Shell Friday, with the owner of a local hunting lodge saying he's preparing for their arrival. The workers tried to reach town Thursday, but were turned back by poor weather.

In the meantime, some local villagers are concerned about the Kulluk’s presence, saying the longer it remains grounded off Sitkalidak Island, they more worried they are about what it’s doing to their subsistence way of life.

“It’s a major hunting area for us out there,” said Old Harbor resident Rolf Christiansen. “I go out there all the time whenever the weather lets me -- you can't mess around out there with the weather, it’s so huge, you know -- you got to hunt in here when it’s crappy out.”

The weather in Old Harbor is set to change Friday night, with locals expecting a storm to move in packing 30-mph winds which may complicate efforts on the rig.

Each passing day increases the possibility that Shell might begin its 2013 drilling season without the Kulluk, one of the rigs it used during last year’s exploratory drilling in the Beaufort Sea, putting a halt to any drilling Shell could conduct this season.

In a Friday statement, the federal Bureau of Safety and Environmental Enforcement points out that neither the Kulluk nor the Shell-contracted drillship Noble Discoverer -- cited by the Coast Guard for crew-safety and pollution-equipment violations during a November port call in Seward -- are allowed to conduct Alaska drilling on its own.

“Shell's exploration plans and spill response plans for the Beaufort and Chukchi Seas require that a backup rig be available in the event a relief well is necessary,” bureau officials wrote. “The approved plans do not allow for the Noble Discoverer or the Kulluk to operate without a backup.”

Shell has designated the Kulluk and the Noble Discoverer as each other’s backup rigs. For now, though, Shell is focusing on the current state of the Kulluk rather than looking forward to where it will be in July.

"It really is too early to speculate,” said Shell Alaska spokesperson Curtis Smith. “Of course, this is a two-rig program -- the Kulluk and the Discoverer work in tandem and they back each other up -- so they're both part of our exploration plan and they're critical to our drilling operations, both of them.”

Contact Blake Essig and Adam Pinsker