By Stephen Brown BUENOS AIRES, Argentina, Feb 7 (Reuters) - An apparently drunken, unarmed Uruguayan passenger tried to force his way into the locked cockpit of a United Airlines flight from Miami to Argentina on Thursday before pilots hit him with an ax and tied him up. The man kicked down one panel of the cockpit door demanding to see the captain and got part of his body in before being overpowered by the crew and passengers. The incident alarmed other passengers and may raise new concerns about safety after the Sept. 11 attacks on the World Trade Center and Pentagon. The 28-year-old man, said to have drunk whiskey before the flight, was subdued by crew and passengers like suspected "shoe bomber" Richard Reid, who allegedly tried to ignite explosives in his footwear on an American Airlines flight in December. United Airlines (UAL) said metal bars reinforcing cockpit doors since September prevented the man, named as Pablo Moreira, from endangering the flight. The airline's Chairman Jack Creighton commended the crew's "quick action." Moreira was arrested when the Boeing 777 with 142 passengers and 15 crew landed safely in Buenos Aires. Argentine officials said he would be flown back to Miami later on Thursday to be questioned by a Florida state prosecutor. Cockpit doors on big U.S. jetliners have been reinforced with bars since the September attacks, when suspected hijackers apparently gained entrance to the flight decks of four planes, two of them United jets. A passenger on United Airlines Flight 855, Jan Boyer, told CNN that Moreira had managed to break down part of the lower half of the door by "kicking in a kung fu style." "The cockpit door is divided into two sections and the lower section actually opens up and isn't protected by the barriers that they had put in," said Boyer. "He had actually inserted himself ... his torso into the cockpit." A LOT OF BLOOD But the pilots inside "used an ax that they have in the cockpit to basically hit him bluntly on the head. This led to a lot of blood all over the place," said Boyer. The small panel on the cockpit door is designed to pop out in case of an aircraft pressurization emergency. Jorge Reta, spokesman for the Argentine air force, said such precautions "stopped what happened today from being more serious. It's an example of how to act to protect passengers." In Miami, FBI spokeswoman Judy Orihuela said the plane left Miami around midnight and the incident occurred about five hours later over Brazil. "The worst moment was when I heard the voice of the captain, who sounded desperate, asking for help," said one passenger at the airport, a 50-year-old Argentine woman who identified herself only as Lucia. The U.S. Federal Aviation Administration ordered the industry last month to install new cockpit doors to resist intrusion and certain gunfire and explosives on more than 6,000 commercial jets. The government gave airlines 18 months to make the changes, which include mandatory locking devices only accessible to the pilots. The cockpit upgrades are expected to cost the industry at least $100 million. Separately, U.S. aviation regulators have proposed new training guidelines to help flight crews, including flight attendants, deal with potential hijackers and unruly passengers. The U.S. government also is considering a proposal to let cockpit crews carry stun-guns. Axes are kept in cockpits in case pilots have to evacuate in an emergency. Reta said Moreira "feels sorry for what he did and admitted he had drunk whiskey before boarding the plane." The FBI said Moreira, whom it described as a bank employee, would probably be charged with "interference with a flight crew."