BOSTON (CBS) — A local Army colonel who has been flying Blackhawk helicopters since 1985 said the Navy Seals who killed Osama bin Laden faced a difficult mission.

“They did this, at night, with night vision goggles, with people shooting at them. Incredible amount of proficiency it takes,” said Col. Paul Bricker, who’s spending a year at Harvard University’s Weatherhead Center for International Affairs.

Col. Bricker served two tours in Afghanistan and one in Iraq. He says the team rehearsed the operations many times and was proficient in the execution.

“They got nerves of steel. They got to hold those helicopters stationary, while people are shooting at them, so the Seals can get off those ropes.”

He says the conditions were harsh, that it was dusty and challenging to fly in. “As soon as you get close to the ground the dust just envelops your helicopter.”

“They did a great job, and so my hat’s off to them.”

WBZ-TV’s Jim Armstrong contributed to this report.