SITKA, Alaska — A mechanical problem prevented a rescue helicopter from responding quickly to the scene of a fatal January air ambulance plane crash in Alaska, according to U.S. Coast Guard flight logs.

The logs indicate the helicopter that should have flown within 30 minutes of the call from Sitka to the crash site about 22 miles (35 kilometers) west of the small community of Kake.

But the helicopter was grounded until the next morning due to an engine malfunction, CoastAlaska reported Tuesday.

As a result, no aerial search was conducted in the 12 hours after the Beechcraft King Air 200 plummeted more than 2,500 feet (762 meters) in 14 seconds and vanished from radar, CoastAlaska reported after obtaining the logs through a Freedom of Information Act request.

A second helicopter was requested from Kodiak — 600 miles (about 966 kilometers) away — after the malfunction was detected, Coast Guard Commander Michael Kahle said.

"The goal that we should shoot for is, from the time of notification, 30 minutes to get off the deck," Kahle said.

A Coast Guard cutter and local search and rescue teams responded overnight, according to officials, who said it is still unclear what caused the crash in which a pilot, paramedic and nurse were lost at sea.

The cockpit’s voice recorder was recovered by searchers, but a National Transportation Safety Board official said the device was in poor condition.

Engineers are trying to recover its information.