TUPUNGATO, Argentina (AP) _ Hoping to solve one of the Andes' great riddles, army mountaineers set off Saturday to climb the 21,848-foot Tupungato volcano in search of a British plane that vanished 52 years ago.

Two camouflage green army trucks carrying soldiers sped out of an army base in this mountain town hours from the volcano base, despite cloudy weather threatening to delay the first day of the trip. The team of Argentine army officers is on a quest to bring down bodies and pieces of wreckage that may shed light on the airplane's disappearance.

``We'll drive about four or five hours to reach a smaller camp before trying to climb up on Sunday,'' said Col. Mario Luis Chretien, who heads the regiment leading the expedition.

Successfully recovering the plane's remnants could help solve one of the longest-running aviation mysteries in the Andes, the mountain range that was a virtual graveyard for planes during the first half of the century.

Operated by the now defunct British South American Airways, the plane called Stardust was carrying 11 people _ five crew members and six passengers _ and was headed to Santiago, Chile when it vanished during a snowstorm on Aug. 2, 1947. The passengers included three Britons, a German woman, a Palestinian and a Swiss man.

The last message from the plane has puzzled aviation investigators for years. Radio operators in Chile reportedly received a Morse code message reading ``STENDEC'' _ an acronym investigators say has no meaning.

Following the crash, search teams from England, Chile and Argentina combed the area by air and on skis but turned up nothing.

Theories abounded about the plane's disappearance. Some speculated it had been sabotaged to kill a British diplomatic messenger reportedly on board.

But severe weather was believed by many to have been the cause. Records indicate heavy snow fell for three days at the time the plane vanished over the South American mountain chain, and aviation experts said the plane _ a converted World War II bomber _ did not have de-icing capabilities and was unfit to travel through frigid conditions.

The plane and its passengers went undetected for more than five decades.

But then, in January, five mountaineers climbing through ice fields atop Tupungato, just east of the Argentine-Chilean border, stumbled across the remains of the four-engine plane. Argentine army official Alberto Quinones said the group of climbers discovered pieces of the propeller, wing and fuselage along with scraps of clothing spread across a two-square-mile area.

Quinones said the remains of at least three passengers had also been spotted _ their limbs almost perfectly preserved in year-round subfreezing temperatures atop Tupungato.

Hearing news of the discovery, authorities quickly arranged the recovery mission before the end of the Southern Hemisphere summer and the onset of harsh weather conditions that dominate Tupungato the rest of the year.

``We are very lucky,'' Chretien said. ``With warmer temperatures the past few years, the glaciers (on the mountain) have been moving quite a bit. That's how we were able to find the remains.''

Lt. Col. Federico Frugoli said he hoped the remains would be brought down during the week.

Frugoli said Argentine army mountaineers and air force personnel have spent days mapping a path to the upper reaches of the volcano, where the wreckage sits at 16,500 feet.

After acclimating themselves to the high altitude and freezing conditions, elite mountaineers shadowed by journalists were expected to venture out on the last leg of the climb _ a rigorous seven-hour mountaineering ascent of the snowcapped volcano.

Using ski poles to balance themselves and wearing special cleats, the climbers will ascend the steep southern face of the volcano _ a side that rarely sees the sun and whose peak is mostly covered in snow and ice.