"Doesn't even remember the flight," FBI spokesman Tom Simon in Honolulu told The Associated Press on Sunday night. "It's amazing he survived that."
The boy was questioned by the FBI after being discovered on the tarmac at the Maui airport Sunday morning with no identification, Simon said.
"Kid's lucky to be alive," Simon said.
Simon said security footage from the San Jose airport verified that the boy from Santa Clara, Calif., hopped a fence to get to Hawaiian Airlines Flight 45 on Sunday morning.
The boy scaled the fence under the cover of darkness and remained undetected as he crossed the airport ramp, San Jose airport spokeswoman Rosemary Barnes said. San Jose police say they will be reviewing whether charges are warranted against the boy.
The child had run away from his family after an argument, Simon said. Simon said when the Boeing 767 landed in Maui, the boy hopped down from the wheel well and started wandering around the airport grounds.
"He was unconscious for the lion's share of the flight," Simon said. The flight lasted about 5 1/2 hours.
Hawaiian Airlines spokeswoman Alison Croyle said airline personnel noticed the boy on the ramp after the flight arrived and immediately notified airport security.
"Our primary concern now is for the well-being of the boy, who is exceptionally lucky to have survived," Croyle said.
A photo taken by a Maui News photographer shows the boy sitting upright on a stretcher as authorities get ready to load him into an ambulance.
Simon said the boy was medically screened and found to be unharmed.
His misadventure immediately raised security questions. A congressman who serves on the Homeland Security committee wondered how the teen could have sneaked onto the airfield at San Jose unnoticed.
"I have long been concerned about security at our airport perimeters. #Stowaway teen demonstrates vulnerabilities that need to be addressed," tweeted Rep. Eric Swalwell, a Democrat who represents the San Francisco Bay Area's eastern cities and suburbs.
Barnes said Mineta San Jose International Airport's security program exceeds federal requirements, but no system is 100 percent secure.
Airport police were working with the FBI and the Transportation Security Administration to review security at the facility as part of an investigation, Barnes said.
"Our concern is with this young boy and his family. Thank God he survived and we hope his health is OK," she said.
Officials at Kahului Airport referred questions to the State Department of Transportation, which did not return a phone call seeking comment. A TSA spokesman who declined to be named referred questions to the FBI and airport authorities.
The boy was released to child protective services and not charged with a crime, Simon said.
In August, a 13- or 14-year-old boy in Nigeria survived a 35-minute trip in the wheel well of a domestic flight after stowing away. Authorities credited the flight's short duration and altitude of about 25,000. Others stowing away in wheel wells have died, including a 16-year-old killed after stowing away aboard a flight from Charlotte, N.C., to Boston in 2010 and a man who fell onto a suburban London street as a flight from Angola began its descent in 2012.