The last man conscious in the cockpit of a doomed Cypriot airliner (search) made a desperate call for help — "Mayday! Mayday!" — two seconds before the plane carrying 121 people smashed into a mountain near Athens.

The man, apparently a flight attendant with pilot training, twice issued distress calls in the final 10 minutes of Helios Airways Flight 522 (search), chief investigator Akrivos Tsolakis told The Associated Press on Monday.

"The second time was a couple of seconds before the crash," Tsolakis said, adding the man had "a very weak tone of voice."

Earlier Monday, Tsolakis issued a preliminary report on the Aug. 14 crash, which killed all 115 passengers and six crew, that said the Boeing 737-300 lost cabin pressure and eventually ran out of fuel.

The report was the most comprehensive statement the government has released on the investigation since the crash. It came after pressure from the media and the airline industry for Greece and Cyprus to start answering questions about what caused the accident.

Still, it remained unclear what caused the loss of cabin pressure. Greek investigators, aided by the U.S. National Transportation Safety Board, are continuing to probe the crash, the deadliest airline disaster for Greece and Cyprus and considered one of the most baffling in aviation history.

Tsolakis presented his initial findings following analysis of flight recorders and autopsies on all 118 bodies — many still unidentified — recovered from the site. Three bodies have not been found, including that of the plane's pilot, a German.

"The crash is like an explosion and the pilot's body may not necessarily have ended up close to the cockpit," Tsolakis told state-run NET television. "He may be one of the [recovered] unidentified bodies."

The report appears to confirm initial suspicions that people aboard the Helios Airways plane were incapacitated by a loss of cabin pressure early in the flight at about 34,000 feet and that someone tried to save the flight shortly before it crashed.

On the day of the crash, two Greek air force F-16 fighter planes were scrambled to intercept the flight shortly before the accident.

Pilots reported seeing the co-pilot slumped over the controls, apparently unconscious, and the pilot not in his seat. On their second pass by the airliner, the F-16 pilots saw two people in the cockpit, apparently trying to take control of the plane.

According to the report issued Monday, a man wearing an oxygen mask, believed to be 25-year-old flight attendant Andreas Prodromou, tried to steer the plane for the last 10 minutes and contact air-traffic control authorities.

In his first appeal, he cried "Mayday!" three times — but the plane's communications had apparently been set to the wrong frequency, Tsolakis said.

It remains unclear how the would-be rescuer stayed conscious.

The Helios flight from Larnaca, Cyprus (search), to Athens ran out of fuel before crashing near the scenic village of Grammatiko, 25 miles north of Athens, the report said.

The plane crashed in Greece after circling for more than an hour in a holding pattern above the Aegean Sea island of Kea (search), southeast of Athens International Airport.

"There are indications of technical problems in the pressurization system... There is proof that the engines of the plane stopped working because the fuel supply was exhausted, and that this was the final cause of the crash," the two-page report said.

A former chief mechanic at Helios said last week that the same plane lost cabin pressure during a flight from Warsaw, Poland, in December, after a door apparently was not sealed properly.

Both Athens and Nicosia have come under strong public pressure to reveal all they know about the crash, in part to calm worries that terrorism or criminal action or neglect was the cause. Police searched Helios offices shortly after the accident.

Tsolakis said the investigation was making good progress.

"I am a conservative guy but I can judge it as a very fast-moving one," he said.

The full report on the Helios disaster is due in about six months. The government, which has said it will not comment on an ongoing investigation, has promised to make the report public.