KANE'OHE BAY — Forty years ago today, Marine Heavy Helicopter Squadron 463 was activated as the first CH-53 Sea Stallion squadron in the Marine Corps.

The squadron made the first of several Vietnam War deployments that same year in 1966, and saw duty in the 1991 Gulf War.

It's been a long time since the more than three dozen CH-53D Sea Stallions at the Marine Corps base have been in a combat zone, short of five of the helicopters that flew missions in Iraq in late 2004 and early 2005.

But that started to change yesterday as the first two of 10 Sea Stallions and 23 Marines and sailors lifted off for Iraq tucked inside a behemoth C-5 Galaxy cargo aircraft.

About 175 Marines with HMH-463 will have Iraq duty for seven months, and in October will be replaced by another Kane'ohe Bay squadron, HMH-363. The replacement unit will use the helicopters already in the country.

Following that, it will be HMH-362's turn.

"Everybody's looking at us. There's a lot of pressure to make sure everything goes smoothly," said Cpl. Michael O'Bryant, 22, a crew chief from Knoxville, Tenn., who was one of those leaving for Iraq. "But we're real proud to be the first (full CH-53D) squadron to go since Desert Storm."

HMH-463 participated in Hurricane Iniki relief in 1992, has deployed to Cambodia to assist in missions to recover U.S. service members killed in the Vietnam War, and the big single-rotor helicopters have seen duty in Okinawa.

Ironically, it's the high-tech replacement for the aging, Vietnam-vintage choppers — the tilt-rotor V-22 Osprey — that is now partly responsible for sending the CH-53Ds back into battle.

All of the Sea Stallions are assigned to Marine Corps Base Hawai'i at Kane'ohe Bay.

The V-22 Ospreys, which take off like a helicopter and fly like an airplane, are also replacing another Vietnam-era helicopter in the Marine Corps, the twin-rotor CH-46E.

"If you take a look at what's going on in Marine Corps aviation, a lot of folks have deployed throughout the Corps, and we're presently under the process of transitioning to the V-22," said Lt. Col. Randel Parker, the commanding officer for HMH-463. "So as they start to bring CH-46 squadrons off line, it takes a while to transition those squadrons. They are out of the deployment cycle and we're able to roll in."

Parker said all 10 of his Sea Stallions were new when the Vietnam War was still going on, but the airframe is proven. The CH-53Ds may be replaced by Ospreys by 2011.

"Forty years later, we're still doing great things with these helicopters," he said, adding that engines have been overhauled and updated avionics are inside.

There was a safety setback when one of the CH-53Ds crashed into a university campus in Okinawa on Aug. 13, 2004. Three crew members were injured, but no one on the ground was hurt. Improper maintenance of the tail rotor was blamed.

In Iraq, the squadron will operate out of Al Asad Air Base west of Baghdad, and Parker said there will be a heavy demand for the helicopters.

"It's a well-rounded asset for a commander," he said. "It can haul a lot of Marines. It can haul a lot of gear around."

The aircraft can carry 24 combat troops with its basic configuration.

With centerline seating, the number increases to 55.

A newer version of the helicopter, a CH-53E out of California, crashed in a sandstorm in western Iraq on Jan. 26, 2005 with 26 Hawai'i Marines and one sailor onboard. All were killed.

Hawai'i squadron members with the five Sea Stallions there at the time were sent to the crash site to recover the dead.

Sgt. Joel Kosoris, 21, from Waukesha, Wis., who left yesterday as part of the 23-Marine advance party, was one of the Marines who made that trip a little over a year ago.

"It's really hard for me. I don't really want to talk about it," he said as he prepared to board the big C-5 cargo carrier.

An investigation found that the crew of the CH-53E became disoriented when weather turned bad, did not realize the helicopter was banking to the left and flew the aircraft into the ground.

Kosoris said big sandstorms that kick up a cloud of grit are a concern.

"They come out of nowhere, pretty much," he said. "I flew into one once. Just a wall of sand, and all of a sudden, you can't see."

Kosoris, who is married, said this deployment will be hard for his wife. The couple got married in September.

Christy Hughes, was one of about four wives who watched the C-5 lumber down the runway and take off.

Her husband, Corpsman Joseph Hughes, 34, has been in the Navy for 16 years, but it's his first combat duty since Haiti in 1994.

"I feel lost, but I know he's trained in what he's going over there to do," she said.

Reach William Cole at wcole@honoluluadvertiser.com.