AUSTIN, Texas - National Transportation Safety Board officials revealed their findings during a hearing in Washington on Tuesday. They pinned the blame for last year's deadly crash on the pilot.

"The pilot should not have been flying. Never mind carrying paying passengers," said NTSB Chairman Robert Sumwalt.

Investigators from the National Transportation Safety Board say the pilot, Alfred ``Skip'' Nichols, had enough Benadryl in his system to have the equivalent blood-alcohol level of a drunken driver.   

Nichols was apparently told during a weather briefing that clouds could hamper visibility during the flight by he allegedly said, “We just fly in between them.”

Medical experts say Nichols should have been grounded because of ailments and drug use. But unlike fixed-wing commercial pilots, commercial balloon pilots aren't currently required to have a medical certificate from a doctor allowing them to fly.

That has some lawmakers calling for tighter requirements for balloon pilots.

"We need to assure that no one's flying a balloon that does not have the same medical certificate as an aircraft pilot," said U.S. Rep. Lloyd Doggett, D-Austin. "This accident should never have happened."

Congressman Doggett currently has a pending amendment to FAA legislation that would require medical certificates for commercial balloon operators, a requirement the NTSB is also recommending.

Other countries like England and Canada already require medical certificates from balloon pilots, but the FAA has kept them optional in the U.S. after resistance from ballooning associations that want to keep the medical certificates optional.