Era digs deep to survive a brutal winter. Ariel joins in on a desperate search for her missing friend. Sarah Fraher attempts a difficult landing to aid a pilot stranded mid-runway. Ponts attempts an emergency medical drop over the isolated Kavik camp.

Villagers in Wainright lose their water supply due to the Arctic cold. Solar flares leave Ponts and Ben in harm's way. In Unalakleet, a criminal is on the loose and the Tweto's are on edge.

Alaska's harshest winter in years wreaks havoc on Era's fleet. Sarah Fraher's aircraft door opens mid-flight. Doug's brakes freeze on an icy runway while carrying explosive chemicals. Jim attempts a risky landing atop the frozen Anvik River.

The epic Iditarod dog sled race begins in Anchorage. Pilot Doug Stewart tests his limits while landing on a runway that is melting into the ocean. Pilot John Kapsner races to locate two snow-machiners that are lost overnight deep in the Alaskan Bush.

In Bethel, pilot Erik Snuggerud is plagued by mechanical issues. On Alaska's North Slope, pilots Doug Stewart and John Rende battle to keep their plane from careening off an icy runway. In Unalakleet, Ariel receives a surprise visitor.

In the skies above western Alaska, Ariel disappears from radio contact, putting emergency services on high alert. Over the remote village of Hooper Bay, pilot Erik Snuggerud battles to touch down on a dangerously narrow runway.

Jim makes an impossible landing in Unk. Pilot Sarah Fraher battles strong headwinds while attempting to deliver 2,000 pounds of fuel to the research station. Pilot Ben Pederson braves 50 mph winds to retrieve an elusive priest for Easter service.

In the series finale, after 30 years of running Era Alaska, Jim Tweto sets his eye on a new path. Doug loses all avionics while flying over the North Slope. Ariel comes face to face with the FAA in the last step of getting her pilot's license.