BOISE, Idaho – A United Airlines pilot died after suffering a major heart attack while flying from Houston to Seattle, forcing crew members to make an emergency landing in Idaho while two doctors on board did CPR in the first-class cabin.

Pilot Henry Skillern, 63, of Humble, Texas, was still alive when firefighters and paramedics ran to his aid Thursday night on the Boise Airport tarmack. He died a short time later while being treated at Saint Alphonsus Regional Medical Center, spokeswoman Jennifer Krajnik said.

Skillern had been a pilot for United Airlines for 26 years.

Boise airport spokeswoman Patti Miller said it’s not uncommon for a medical emergency to force a plane to divert to the nearest airport. The Boise airport has had three such diversions in the past two days, she said. But it’s rare for a serious malady to strike pilots who undergo regular medical screening to keep their Federal Aviation Administration certification current.

Passengers aboard the Boeing 737-900 flown by Skillern seemed to handle the emergency well, Miller said.

“It seemed like they felt that everything that could be done, was being done,” she said. “The passengers were concerned for him, but everyone was very calm.”

Passenger Bryant Magill described a professional scene onboard. “I’m really impressed with all the flight attendants,” Magill told a Seattle TV station. “They kept themselves calm. They kept it professional. There was no panic on the plane.”

United spokeswoman Christen David declined to release details about how the crew members realized the pilot was in distress and what their next steps were. The first officer radioed air traffic controllers at 7:55 p.m. to report the aircraft needed to make an emergency landing; the airplane was on the ground in Boise by 8:10 p.m., Miller said.

The two doctors and an off-duty United Airlines pilot were among the 161 people aboard the flight. The off-duty pilot aided the first officer — who is also a trained pilot — in landing the plane while the physicians performed CPR.