Photograph by InSapphoWeTrust

An American pilot suffered a heart-attack mid-air during a flight from Houston to Seattle, forcing the plane to an emergency landing.

United Airlines pilot Henry Skillern was treated mid-flight from a doctor on-board the flight, before being quickly brought off the plane by fire crew and then rushed by paramedics to nearby Saint Alphonsus Regional Medical Center where he later died.

An off-duty pilot was also on-board the flight to aid with the emergency landing at Boise airport in Idaho.

Passengers on board the flight showed concern for the health of the pilot, but remained calm during the emergency according to United Airlines staff.

After Skillern was evacuated from the plane, another pilot took over the flight and flew the plane and passengers to the original destination of Sea-Tac Airport in Seattle.

United Airlines Christen David said in a statement:

“I am sad to confirm that our co-worker passed away last night. Our thoughts are with his family at this time”