Published: Aug 11, 2010 11:06 PM EDT
Updated: Aug 11, 2010 6:13 PM EDT

ANCHORAGE, Alaska (AP) - Three people stranded on an Alaska glacier for two days when their small sightseeing plane crashed were finally carried away by a helicopter crew Tuesday, but deteriorating weather conditions threatened to delay the rescue of nine others, authorities said.

Another Alaska Air National Guard Pave Hawk helicopter was dispatched to the Knik Glacier late Tuesday night in hopes of rescuing two other sightseers. But Alaska National Guard spokesman Maj. Guy Hayes said weather could prevent the chopper from landing on the glacier, which is about 40 miles northeast of Anchorage.

The helicopter that rescued the trio on Tuesday also dropped off a week's worth of additional food, water and other supplies, Hayes said. Weight considerations at the 8,500-foot level kept that helicopter from being able to rescue all five sightseers.

Relatives told the Anchorage Daily News that Donald Erbey, 49, was flying four friends from Texas on a short flightseeing tour from Palmer on Sunday afternoon when the plane apparently hit a downdraft and crashed into a snowbank.

The crash left two of the five with minor injuries and the plane mostly intact.

The visitors have not been identified by name or hometown.

Seven guardsmen who have been part of the rescue effort are also on the glacier. They include a four-man rescue squad that skied in Monday with provisions.

Earlier Tuesday, an Army National Guard Black Hawk helicopter slid and rolled over on the glacier. Three crew members aboard that craft were uninjured but the helicopter was heavily damaged, Hayes said.

Rescue efforts have been complicated by freezing rain, snow and whiteout conditions with winds gusting to 70 mph.