HILO, Hawai'i — A tour flight with three people on board disappeared this afternoon after passing over Kilauea volcano, prompting a search by other air tour pilots and the U.S. Coast Guard.

The Cessna 172 departed from Kona airport at about 10:15 a.m. on a tour flight headed clockwise around the Big Island, and was last seen by another pilot with the same tour company, said Ian Gregor, spokesman for the Federal Aviation Administration.

The Cessna 172 filed a flight plan using visual flight rules, and was last seen at 12:45 p.m., Gregor said. The flight was due back in Kona at about 1:30 p.m. to 1:45 p.m., he said.

"When it didn't return to Kona on time, the company reported it missing," prompting the search, Gregor said. At least one aircraft from another tour company helped the Coast Guard in the search, he said.

Gregor said the plane is owned by Sporty's Academy Hawaii. That company was founded by President Phil Auldridge, who began commercial flying in Hawai'i in 1986. The company changed its name to Hawaii Flight Academy in 2000, according to material posted on the Web by the company.

The tour flight was operated by Island Hoppers, and a company representative declined comment this evening.

"We were hoping to review radar drags and see if we could tell anything from that, but it was just a VFR flight, the pilot wasn't talking to air traffic controllers and we don't have good radar coverage in the Kiiauea area because of all the mountains, so we're not too hopeful there will be anything anything from that," Gregor said.

The FAA called the Coast Guard command center to report the overdue plane at about 3:15 p.m., and the Coast Guard immediately launched an HH-65 Dolphin rescue helicopter crew and C-130 search plane crew from Coast Guard Air Station Barbers Point to begin the search.

Petty Officer 3rd Class Luke Clayton said the Coast Guard aircraft has the ability to search in the dark, but said crews had not determined how late the search would continue tonight.

A Coast Guard Auxiliary aircraft crew also joined in the search of the Hawai'i Volcanoes National Park and the surrounding area. The search expanded outward from the Kilauea area to include the ocean and coastline, Clayton said.

"We're doing several different types of patterns, and we're spreading the units out evenly," he said. Aircraft from the Big island Fire Department and the Civil Air Patrol joined in the search "to cover as much space as possible," he said.

Island Hoppers bills itself as "both the largest and oldest Big Island air tour company, yet still small enough to provide personal, family-style attention to all our clients," according to the company Web site.

Island Hoppers has daily flights from Hilo and Kona airports, and boasts an 18-year fatality-free operation history.

However, a pilot and two passengers on an Island Hoppers flight were seriously injured on April 18, 2004, when their Piper Warrior tour plane struck a hillside near Miloli'i and caught fire.

The National transportation Safety Board found that pilot Jelica Matic had flown around the Big Island less than a dozen times, and was relatively inexperienced with the aircraft she was using.

Matic told investigators the Island Hoppers plane was forced down by a powerful downdraft. She and her two passengers, Dallas and Catherine Ratcliff of West Portsmouth, Ohio, all suffered burns from the fire.