LUDINGTON, Mich. - A pilot who volunteered to fly a man with cancer, his wife and a doctor to the Mayo Clinic on Friday was rescued by boaters in Lake Michigan hours after his small plane crashed into the water, authorities said. The search for a co-pilot and the three passengers was ongoing.

U.S. Coast Guard Petty Officer Brandon Blackwell said Jerry Freed of Alma was rescued hours after the plane lost power and crashed a few miles off the coast of Ludington. He was in good condition at a local hospital.

An air and marine search continued for co-pilot Earl Davidson, Alma schools' superintendent Don Pavlik, his wife, Irene, and Dr. James Hall.

"We're crazy trying to figure out what might be going on," Alma school board vice president Tony Costanzo said late Friday afternoon. "Some of the best people in town were on that plane."

Don Pavlik was diagnosed earlier this year with cancer of the esophagus and Freed and Davidson had volunteered to take to the Rochester, Minn., medical center, Costanzo said. Hall, he said, came along because he wanted to help his ailing friend.

Freed's wife, Carol, told The Associated Press earlier Friday that her husband and Davidson regularly flew people to Mayo on a volunteer basis. The Freeds owned the plane.

The plane left Alma, about 150 miles northwest of Detroit, Friday morning. It went down shortly after 10 a.m. a few miles off the shore the resort town on Michigan's west coast.

Randall Schmidt of Park Ridge, Ill., who was on his boat with his wife, Kristin Berg, said he heard a marine radio call about the plane going down nearby.

"We had made one pass south, one pass north and we were about to turn back south when my wife ... saw a man in a yellow inflatable lifejacket close to our boat," Schmidt told the Ludington Daily News Friday.

Schmidt said Berg threw the life ring to Jerry Freed and brought him into their boat to wait for the local sheriff's department marine unit.

Water temperatures and conditions will have a lot to do with whether other survivors are found, Ludington Coast Guard Station Chief James Hendricks said. Waves in the area of the crash were 2 to 4 feet high, and the wind speed was about 18 mph. Hendricks said the temperatures likely were in the 70s.

"They can survive for a while. There's always a chance to make rescues," he said.

Reached early Friday afternoon at Davidson's home, his stepson, Zach Everett, declined to talk about the crash until the family had information confirmed by the Coast Guard. The telephone rang unanswered later Friday.

About 10 minutes before the plane went down, the pilot reported a loss of power to an air traffic controller at the Minneapolis Center, the Federal Aviation Authority said. At the time, it was overcast with light winds and visibility of about 10 miles, the National Weather Service said.

A map of the plane's flight path from flightaware.com suggests problems developed about one-third of the way into the flight when the westbound plane doubled back over Lake Michigan. It then made a steep decline in altitude near Ludington.

The small plane took off about 9 a.m. Friday from Gratiot Community Airport south of Alma, said airport assistant manager Lucas Locke. He said the crash was unsettling for many area pilots because they know one another

"A lot of people have been coming out to see what's been going on," Locke said.

Friday's crash wasn't the first time a medical flight has plummeted in Lake Michigan. A Survival Flight plane carrying donor organs for a double lung transplant operation crashed in June 2007 into the lake near Milwaukee on its way to the University of Michigan Health System hospital in Ann Arbor. All six people on board the Cessna 550 Citation were killed.