San Francisco International Airport personnel discovered the body of a man in the wheel well of a 747 that had arrived from Shanghai on Thursday morning, an airport official said.
Airport spokesman Mike McCarron said the body was found during a post-flight inspection of United Airlines Flight 858, which landed at 7:42 a.m. after an 11-hour flight.
San Mateo County sheriff's and coroner's investigators, along with immigration officials, are investigating the discovery, McCarron said.
Bodies are periodically found in the wheel wells of airplanes, usually after people seek covert entry into the United States or Europe. Such stowaways usually die during the flight.
"There's no air to breathe," McCarron said. "And the cold temperature is probably minus 30, 40 degrees at altitude, so you freeze to death."
That appeared to be the cause of death of a man found in the wheel well of a US Airways flight that landed in San Francisco in 2001. The dead man, later identified as the son of a Zairean general, had fled to Britain before apparently trying to stow away to the United States.
Other stowaways have narrowly survived the flight, including a man who lived through a flight from Tahiti to Los Angeles in 2000, arriving with a body temperature of 79 degrees. He was later repatriated to Tahiti, though a Cuban man who rode the wheel of a DC-10 to Montreal in 2002 was granted asylum.
San Mateo County Coroner Robert Foucrault said the body at SFO was that of an Asian man in his 50s or older. The man carried no identification, Foucrault said, but was dressed in five or six layers of clothing -- including two jackets. His pockets carried only small amounts of foreign currency and some over-the-counter medicine, Foucrault said, and it appeared he died from exposure or lack of oxygen.
Federal Aviation Administration spokesman Ian Gregor said that since 1947 there have been 74 known stowaway attempts involving 64 flights worldwide, including Thursday's incident. He said 60 of the 74 people have died, or 80 percent.
In January alone, he said, there were three attempts -- all fatal. The last time somebody was found alive after stowing away on a flight was in March 2004, on a flight from the Dominican Republic to Miami.
"Obviously, most stowaway attempts end tragically. People either freeze to death, are crushed to death, or they are asphyxiated," he said. "When people climb Mount Everest, they need oxygen, and airplanes fly at considerably higher altitudes than the top of Mount Everest."
It was not immediately known how, when or where the man gained access to the airplane. Airports in other countries do not necessarily follow the same security standards as U.S. airports, which is why international travelers arriving here are required to go through domestic security screening before transferring to flights to other U.S. destinations, said Transportation Security Administration spokesman Nico Melendez.
Federal law does, however, require the TSA to conduct security assessments at all international airports from which U.S. and foreign airlines provide service to this country, Melendez said. If foreign airports are not meeting standards set by the International Civil Aviation Organization, the homeland security secretary can send a letter to that government giving them 90 days to bring the airport up to standards.
After 90 days, the secretary can officially notify the traveling public that the airport isn't meeting international standards, Melendez said, as the secretary did in 2004 after finding that Port-au-Prince airport in Haiti was failing to meet the standards. The warning was lifted in 2006. A similar warning was issued for Bandara Ngurah Rai International Airport in Bali, Indonesia, in 2005.
In May 2007, the Government Accountability Office reported that the TSA's efforts had strengthened the security of U.S.-bound flights, but recommended the TSA strengthen oversight of its foreign airport and air carrier evaluation programs.
Body found in the nose gear of a United Airlines jet that had just arrived in San Francisco from China on Thursday, and officials said the person might have been a stowaway.
Although ridership has been gradually bouncing back, passenger load remains down about 10 percent from 2000.
The body of a male stowaway was found Sunday in the wheel well of a British Airways jet at Los Angeles International Airport.
A British Airways pilot found the body during a routine preflight check and notified LAX officials.