A US Airways pilot who accidentally discharged his gun in a plane's cockpit during a Saturday flight from Denver to Charlotte, N.C., has since been suspended, according to a spokesman for the airline.
Government aviation sources say a bullet was discharged by the pilot in the left seat, pierced the left side of the aircraft's cockpit wall and exited the aircraft, but the hole did not result in depressurization of the cabin.
The Airbus A319 landed safely and without any injuries to the 124 passengers on board, a spokesman for the TSA told ABCNews.com.
"There have been a number of studies that have made clear that it's highly unlikely that a round discharged in an aircraft's cabin can cause any major failure," said the TSA spokesman, who added that no other damage to the plane has been discovered so far in the investigation.
The TSA said the passengers were unaware that a gun had been fired in the cockpit.
The pilot, who both the TSA and US Airways declined to identify, was a member of the Federal Flight Deck Officer program, an initiative put in place after the Sept. 11, 2001, terrorist attacks. The initiative allows authorized members of cockpit crews to carry weapons on board.
"There are thousands of federal flight deck officers and this has never happened before," said the spokeswoman. "This was probably a bit of a fluke."
The pilot in question has since been removed from the Federal Flight Deck Officer program pending the investigation, a TSA spokesman told ABCNews.com.
The Federal Flight Deck Officer program provides training to eligible crew members on the use of firearms, use of force, legal issues, defensive tactics, the psychology of survival and program standard operating procedures, according to TSA's Web site.
Flight deck officers must requalify for the program twice a year; the pilot involved in Saturday's incident requalified in November 2007.
The gun went off in the plane's cockpit but spokespeople for both US Airways and TSA declined to comment on the position of the weapon when it was discharged, citing an ongoing investigation.
"Federal flight deck officers are authorized and trained to carry their firearms on their person inside the flight deck of an aircraft," said the TSA spokeswoman.
The weapon used by the officers are H&K 40-caliber semiautomatics.
The US Airways aircraft has been grounded since the incident, for examination.
ABC News' Matt Hosford contributed to this report.