Aircraft from the Coast Guard and the Alaska Air National Guard raced toward an Asian cargo ship taking on water south of the Aleutian Islands on Monday in an attempt to rescue its 22 crew members.

The 654-foot Cougar Ace, which was carrying nearly 5,000 cars from Japan to Canada, had rolled practically onto its side.

A Coast Guard helicopter, two Pave Hawk helicopters, two refueling planes and a C-130 plane were en route from an Air National Guard base in Anchorage.

The hope was that the helicopters could hoist the stranded crew members to safety.

Earlier Monday, a Coast Guard plane dropped three life rafts, but roiling Pacific waters shoved the rafts underneath the ship, about 230 miles from Adak Island in the Aleutians.

Rescuers then dropped an additional raft, but the crew members had taken refuge on the high side of the tilted vessel and the raft was 150 feet below, beyond their reach. The crew were wearing survival suits, officials said.

A merchant marine ship reached the vessel Monday morning. Its crew tried, but failed, to rig a line to the Cougar Ace to keep it from tilting further.

The Singapore-flagged vessel contained life boats and rafts, but it would have been too risky for the crew to venture to the area where they were stored, said Greg Beuerman, a spokesman for the ship owner, Tokyo-based O.S.K Lines.

Communications became difficult when the batteries in the crew's hand-held radio began losing power, said Coast Guard Lt. Mara Booth-Miller. Crew members had to shout to the merchant ship, which relayed messages to the Coast Guard.

It was not immediately clear what caused the ship to list. Its crew had sent out an SOS late Sunday.

One crew member had a broken leg, but no other injuries were immediately reported, authorities said.

The Coast Guard had alerted a clinic in the small town of Adak, a former Naval air station on the island of the same name, to gear up for treating the broken leg and possible hypothermia cases.