EDITOR’S NOTE: The search and rescue effort for a downed helicopter, in which three passengers are now presumed to have drowned, unfolded like a drama on radio frequencies in southern Maine. Here is one account.

A medical evacuation helicopter is down and Coast Guard headquarters is coordinating an intensive night search in choppy seas off Portland Harbor.

Radios crackle.

“Six, Zero, One Eight, Coast Guard Group Portland. Over … Portland Jetport reports they lost the guy at 1,000 feet in the middle of a right-hand turn in final approach to runway two-niner … ”

Airmed Skycare’s only helicopter, a red and yellow Bell Long Ranger, with a a pilot, two emergency personnel and a burn victim from Sulivan aboard is missing. The aircraft was inbound from Ellsworth at 8:40 p.m. Friday when it lost oil pressure and disappeared from radar screens.

” … Last known position of the helo was as follows: 43 dash 38 decimal 5 north, 070 dash 10 decimal five west,” the coast guard dispatcher radios into the night.

The location is somewhere near Peaks Island, three or four miles from the Portland waterfront.

At 11 p.m. Friday, Coast guard vessels led by the 110-foot cutter Jefferson Island, several Casco Bay passenger ferries and a flotilla of fishing boats are slogging through the heavy seas searching the swells one at a time. Volunteers on foot are combing the rocks along the mainland from Portland Head Light to Spring Point and car lights are directed seaward from Peaks Island. Wind, rain and 8-foot seas hamper the search.

The Casco Bay ferries — Island Holiday, Island Romance and Machigonne II — report no sightings and personnel in Navy and Coast Guard aircraft search from the skies to no avail.

11:42 p.m. Group Portland radios an appeal for fishing vessels with sonar equipment to offer assistance. The Christina Michael and others respond.

11:50 p.m. Long Island Fire Base reports a sighting of debris in the water near the southwest end of Overset Island. The Coast Guard dispatcher alerts aircraft 6018, which is down to 30 minutes of fuel, to “illuminate the area.”

12:05 a.m. Radio traffic picks up from Long Island. “Get your light over here …” a fishing boat captain radios.

12:15 a.m. The dispatcher asks Long Island Fire Boat if the people who spotted the floating debris had flashlights. “I want to vector in one of our boats. Over.” To the Jefferson Island, he says, “You’ll have to communicate with Long Island on channel 22 in reference to the beach party that found the stuff floating in the rocks.”

12:30 a.m. Group Portland tells the Jefferson that the fishing vessel Sheila Gail has picked up floating debris.

12:44 a.m. A cylindrical object is sighted. It is later identified as one of the helicopter’s pontoons.

1:05 a.m. The Sheila Gail reports the recovery of an oxygen bottle with the word “helicopter” printed on the side. Five minutes later a fishing vessel runs into “an awful lot of debris.”

1:20 a.m. A caller identified as the vessel Shakespeare reports a body in the water. Coast Guard dispatcher: “Break. Break. Vessel Shakespeare, we request that you stay on scene with the body. … You must not leave the scene of the body. Over.”

Radio traffic becomes frenzied. A radio officer with the Coast Guard issues a notice that a person has been seen waving frantically from the shore of Vail Island, less than a mile east of Overset.

The Shakespeare is being difficult. Several urgent calls are made, but radio communication is broken. “Ask the Shakespeare to fire off a red flare,” the base radio man says.

1:31 a.m. “Shakespeare … you are required by U.S. federal law to render assistance. … We’re on a search and rescue. … This is a humanitarian mission. We are not on a law enforcement (mission). …”

A few minutes later: “Shakespeare decided to hightail it out of there. … He claims he’s unregistered.”

Later the Coast Guard writes off Shakespeare’s calls as the work of hoaxer.

1:44 a.m. Group Portland advises searchers that the Portland Fire Boat Cavallero has the downed pilot safely aboard after he was plucked from Vail Island by members of the Cape Elizabeth Water Extrication Team. Arrangments are made for the Cavallero to bring Sean Rafter, 49, to the State Pier in Portland.

The search for others on the ill-fated helicopter continues throughout the night. At midday Saturday, heavy seas force the Coast Guard to recall its vessels and suspend operations. There will be only one survivor.