If anyone knew and loved the risks of the Air Force's elite rescue unit, it was Scott Duffman.

"He'd deployed at least 20 times," Rose Duffman said this morning of her son, a 1992 La Cueva High School graduate. "He believed in what he did, until the end."

Duffman, 32, and seven other U.S. service members were killed Sunday when the CH-47 Chinook helicopter they were traveling in crashed in southeastern Afghanistan. Fourteen others on board survived.

The military said the crash resulted from a "sudden, unexplained loss of power and control" and was not caused by hostile fire.

"The pilot was able to radio in that he was having engine problems. We're confident it was not due to enemy action," said Col. Tom Collins, spokesman for NATO's International Security Assistance Force.

The crash was the deadliest single incident this year for the 47,000 U.S.-led coalition and NATO forces in Afghanistan.

Duffman, who was married with a 5-month-old daughter, lived in Albuquerque from 1984 until 1992, when he graduated from La Cueva High School and joined the Air Force, his mother said.

He continued to visit the area until she moved to Washington, D.C., in 2004.

"He loved snowboarding, skiing," his mother said. "This was always home to him. He loved the mountains."

Rose Duffman, Scott's father and his step-father have all retired from the Air Force.

"He was the ultimate Air Force brat," she said.

After graduating from basic training, Scott Duffman trained as a pararescue jumper, an elite segment of the Air Force that focuses on rescue missions in hostile territory.

That led him to a life of classified missions and frequent deployment.

"It's one of those things you just try to take in stride," Rose Duffman said. "You try to make the most of the time you have with him, because you never know when they're not going to come back."

Scott Duffman was stationed at Fort Bragg, N.C., the headquarters of the military's joint Special Operations Command.

He'd been home for the last few months of his wife's pregnancy and the first three months of his daughter's life before deploying to Afghanistan, his mother said.

His unit typically deployed for three months and then spent three months home.

The military relies heavily on helicopters for transport and operations in Afghanistan because of the forbidding terrain and lack of passable roads. Dust and high altitude of Afghan's mountains take a heavy toll on helicopter engines.

In May 2006, another U.S. CH-47 Chinook crashed attempting a nighttime landing on a small mountaintop in eastern Kunar province, killing 10 U.S. soldiers.

In 2005, a U.S. helicopter crashed in Kunar, after apparently being hit by a rocket-propelled grenade, killing 16 American troops.

Another crash of a civilian helicopter last year in southeastern Khost province killed up to 16 people, including the wife and two daughters of a U.S. civilian worker.

The Associated Press contributed to this report.