Report: Air Evac craft spun to the right before crashing

A preliminary report released Thursday on the Dec. 30 fatal Air Evac helicopter crash in Colbert County notes that witnesses heard a decrease in engine noise, then saw the helicopter spin to the right, with a "fireball" near the engine exhaust while the craft was falling.

The report from the National Transportation Safety Board does not give a cause of the crash. That will not come until the agency's final report, which is expected to take six months to a year to complete. Instead, the two-page document goes into detail about the event, including damage to and position of the helicopter after the crash.

The crash killed the three Air Evac workers on board: pilot Michael Baker and medical technicians Allan Bragwell and Tiffany Miles. The trio was involved in the search for a lost hunter in the Freedom Hills Wildlife Management area. The site is about a mile off Mount Mills Road in the southwestern part of Colbert County.

It occurred at 3:06 a.m. while the helicopter either was hovering or in a very slow flight, with a spotlight from the helicopter shining upon the hunter, according to the report.

The Bell 206L-3 helicopter flight was a voluntary mission by Air Evac, leaving Northwest Alabama Regional Airport around 2 a.m. and arriving at the scene around 2:15 a.m., the report states.

Emergency workers were on the ground, searching for the hunter, and heard a gunshot, presumably a signal from the hunter. They followed the sound and found the hunter's vehicle. The helicopter then used a searchlight on the hunter, the report states. The aircraft was about 100 to 150 feet above the trees.

That's when "the witnesses heard a decrease in engine noise, followed by an increase in engine nose," according to the report. "They then observed the helicopter spinning right, with a 'fireball' near the engine exhaust, as it descended vertically into wooded terrain. The helicopter subsequently came to rest inverted, and a post-crash fire ensued."

The area where the crash occurred is heavily wooded with trees ranging from 60 feet to 80 feet tall. The report notes numerous tree strikes from the blades were seen above the area where the wreckage was found. The terrain slopes at 20 to 30 degrees.

Fire consumed the cockpit and fuselage, according to the report. "The tail boom had separated about 1 foot aft of the tail boom attach point," it states. "That separation exhibited crushing damage, consistent with ground impact overstress separation."

Other forms of damage were consistent with being struck by the main rotor, according to the report.

Buel Springer, a Lauderdale County man who was a helicopter pilot for the U.S. Army 101st Airborne Division and instructor at Fort Rucker, read the report.

He said an educated guess on the cause would be something called compressor stall.

That occurs when the wind doesn't go through the engine fast enough. That causes the power turbine to stall and the heat no longer is totally consuming the energy of the fuel, so it starts to show a flame.

He said the stall decreases power, which would affect the tail rotor more than the main rotor. That would cause the helicopter to spin to the right.

Having said that, Springer stresses that's just an educated guess. "Not being there, just looking at the report, not looking at the crash scene, that's my best theory," he said. "I'm guessing that somehow there was a decrease in the operating RPMs of that compressor."

He said if his guess is correct, it still wouldn't determine whether the problem was mechanical or pilot error. "That will be determined by the investigation."

Springer said he is impressed by the experience of Baker, the pilot. The report states Baker had accumulated about 3,500 hours of flight experience, including 2,900 in helicopters. Those include 400 hours in the same make and model of the Bell helicopter that crashed.

"That's excellent experience," Springer said.

Baker's family members say he is retired from the U.S. Coast Guard, where he flew numerous missions.

The report notes that the helicopter's most recent inspection was an "Event 1 Check" that was completed four days before the crash. The helicopter had flown 4.9 hours since the inspection.

Springer said that would be considered a recent inspection.

The helicopter had accumulated 5,087 hours of operation during its lifetime.

Weather conditions listed on the report include visibility of 5 miles in mist and a broken ceiling at 7,500 feet. The winds were calm.

"Those are good conditions," Springer said.

Bernie Delinski can be reached at 740-5739 or bernie.delinski@timesdaily.com.