HILO, Hawai'i — A new federal report on a Hawai'i Air Ambulance crash on the Big Island in 2004 that killed three people does not give any specific cause for the crash, but the head of the air ambulance company said the report clears his company and the pilot of any wrongdoing.

The National Transportation Safety Board last week posted a fact-finding report on the crash near Laupahoehoe of the Cessna 414A on Jan. 31, 2004, that killed pilot Ron Laubacher, 38, along with Honolulu paramedics Joseph Daniel Villiaros, 39, and Mandy Shiraki, 47.

The crew was headed to Hilo to pick up a patient, but at about 1:40 a.m. crashed into a stand of 80-foot eucalyptus trees on the shoulder of Mauna Kea at about the 3,600-foot elevation. The wreckage was found on Feb. 2 about 21 miles northwest of Hilo.

Hawai'i Air Ambulance CEO Andrew Kluger said the NTSB conducted an extremely thorough review of the crash that took two years to complete, and said it is important that the agency found "no culpability" on the part of the company or the pilot.

Kluger said he could not guess what actually caused the crash. "It could have been wind shear, it could have been the weather ... an act of God, who knows?" he said.

The company has about a dozen pilots flying inter-island medevac missions in five Cessna aircraft, and Kluger said Hawai'i Air Ambulance did not change any operating procedures after the crash. The NTSB and the Federal Aviation Administration did not recommend any changes, he said.

An off-duty police officer who lived at 'Umikoa Village at the 3,500-foot elevation, and about three miles from the crash site, reported hearing a low-flying plane overhead at about 1:30 a.m., and walked out of his house in time to see a plane heading south about 500 feet off the ground, according to the NTSB report.

The police officer reported there was a light rain falling, and a half-moon provided "fair" illumination.

Laubacher had filed a plan to fly under visual flight rules, meaning he planned to guide the aircraft primarily by sight. However, the NTSB report shows poor weather conditions at the crash site called for instrument-guided flying.

The NTSB report notes that Hawai'i Air Ambulance pilots who are using mostly visual cues normally fly over 'Upolu Point at 9,500 feet, and then begin their descent 15 to 20 miles farther.

However, radar tracking the air ambulance flight showed Laubacher crossed 'Upolu Point at about 7,400 feet altitude, and descended to about 6,400 feet near Waimea before radar contact with the plane was lost.

According to the report, pilots for the air ambulance company normally use visual flight rules even at night and in weather conditions that called for instrument-guided flight because the instrument-guided flights are delayed in Honolulu and Kona, which causes delays in the movement of patients, according to the report.

Instead, the company normally files visual-flight-rule plans to get under way more quickly, and if necessary the pilots can seek clearance for instrument-guided flight plans on the way to their destinations, according to the report.

An autopsy found traces of diphenhydramine, a drug used to relieve allergies, colds and motion sickness, in Laubacher's body. Kluger said Laubacher had been taking it as an allergy medicine, and said it was no cause for concern.