A 45-year-old man was arrested Monday morning after federal transportation agents found a loaded pistol in his carry-on luggage at Charleston International Airport.

Ned Thaxton Beck of Belle Point Drive in Mount Pleasant faces a charge of unlawfully carrying a firearm, according to a report from the Charleston County Aviation Authority Police Department. Under state law, the misdemeanor is punishable by up to $1,000 in fines and a year in prison.

The Transportation Security Administration came across the .380-caliber Ruger LCP during an inspection around 9:30 a.m., agency spokesman Jon Allen said.

Beck was planning to board a Delta flight to Atlanta, the police report stated.

A leather holster and the compact pistol, which is designed for concealed carry, were found in a zipped compartment of a black bag, the report stated. The gun’s magazine contained five hollow-point rounds, and its chamber also had a cartridge.

Airport police officers later took custody of the gun and Beck. He told them that he travels frequently, has a concealed-weapons permit and carries a gun for protection. Beck had forgotten that the pistol was in his bag, he told the officers.

He does not have an arrest history in South Carolina, according to the State Law Enforcement Division.

It was the third firearm found this year at a checkpoint in Charleston. Agents there came across three in all of 2012, a year in which 1,556 firearms were found at checkpoints nationwide, according to the TSA.

Guns are not allowed in carry-on bags. Allen said travelers are responsible for anything in their luggage, and he suggested that they thoroughly check what’s inside before getting in the TSA line at the airport.

The fine for having a loaded firearm at an airport checkpoint and beyond ranges between $3,000 and $7,500. The TSA also can refer suspects to local or airport authorities for criminal prosecution.

The TSA levied more than $1.8 million in penalties for such discoveries last year, Allen said in a statement.

Passengers also can face penalties for firearms in checked baggage if the weapons aren’t properly declared with the authorities. They also must be packaged and locked in a hard case.

Reach Andrew Knapp at 937-5414 or twitter.com/offlede.