ASSOCIATED PRESS A passenger van sits outside the office of the Island Hoppers tour company at Kona Airport. One of the company's aircraft went missing Tuesday, and a group reported hearing a plane's engine above Mauna Loa that day.

Search turns to Mauna Loa

Crews will refocus on an area near Punaluu after a group reports hearing an engine

Helicopter pilot David Okita dropped off the Conservancy group at a camp at the 4,500-foot elevation of Mauna Loa above Punaluu at about noon Tuesday, Coloma said. When Okita returned yesterday to pick them up, they had been out of contact for days and did not know a tour plane with three people on board was missing.

But they told Okita that about an hour after they were dropped off, they heard the engine of a plane, Coloma said. The sound suddenly stopped, rather than slowly fading away, they told Okita. They did not hear a crash, and the sound appeared to come from upslope, they reported.

They heard the sound about an hour after their noon drop-off, a time when the missing Island Hoppers flight could have been in the area above Punaluu after leaving Kilauea caldera 25 miles to the northeast. The Cessna's pilot made his last radio contact from Kilauea at 12:45 p.m.

The search for the tour plane was to resume at 5:15 a.m. today, focusing on the southeastern slope of Mauna Loa, Coloma said.

The missing people are pilot Katsuhiro Takahashi, 40, of Kailua-Kona, and passengers Nobuhiro Suzuki, 53, and his wife, Masako, 56, of Urayasu, Japan.

The area where the plane may have gone down has been flown over by helicopters and planes many times before during the search, but Coloma said such searches in forested areas are difficult.

He recalled the Jan. 31, 2004, crash of a Cessna 414A air ambulance into the forest on the Hamakua Coast north of Hilo. The plane was found at the end of the second day of search in an area that had already been searched.

"We passed right over it, but we didn't know because we were going at a different angle. You almost have to hover to see it."

The only part of the plane that remained together was the tail, he said.

"You're not going to find a plane intact," he said.

Searchers looked in the Manuka area on the western side of Mauna Loa yesterday, where a hand-held meter indicated a locator beacon. Nothing was found.

Besides the focus on the area above Punaluu, repeated flights over the southern slopes of Mauna Loa will continue, Coloma said. The Coast Guard ended its aerial search on Thursday evening.