BANGOR – Though Bangor International Airport has been assured it will soon have a permanent federal port director and will retain its status as an emergency landing airport, it still faces the possibility that its control tower will be shut down between midnight and 5 a.m. daily.

But in that five-hour period last Friday, 13 flights carrying about 3,000 people, including American soldiers, landed, airport Director Rebecca Hupp said. More are expected this week.

“It just highlights the issue we would have if we didn’t have a tower operating during those hours,” Hupp said last week.

BIA is among 48 airports that handle few commercial and cargo flights during that time. They accounted for 292 of the airport’s 84,429 flights in 2004, but they pack a strong financial punch, generating direct revenue to the airport that Hupp said amounted to $871,000 for refueling, ground handling and landing fees.

Even more disconcerting is what Hupp said she is convinced would happen if the shutdown becomes a reality: With no control tower to direct landings during those hours, airlines likely would pack up and move their operations to an airport that has a control tower operating around the clock.

In such a case, the loss to the airport would be about $3 million, Hupp said, and that doesn’t include the financial impact to shops and businesses on and off the airport, including car rental agencies, restaurants and motels.

“It’s somewhat unsettling that this would be considered at this point in time in light of the critical role that BIA plays in the national transportation system,” Hupp said.

To fight such changes, Hupp said, the airport has been working with the state’s congressional delegation, Gov. John E. Baldacci, an attorney in Washington, D.C., who specializes in regulatory development, and local businesses.

Other developments involving the airport have been more positive. After having three interim directors in three years, the Customs and Border Protection agency at BIA will soon get a permanent port director to oversee customs and border security.

U.S. Sen. Susan Collins reported that she has received assurances from the Department of Homeland Security that a permanent director would be appointed for what the senator said was a vital position.

Janet Rapaport, a spokeswoman for Customs, confirmed last week that a new port director has been named but that the formal appointment is pending until administrative details are completed, which should be soon.

Collins has also reassured BIA officials that the airport’s status as a landing spot for planes needing refueling, ground services or medical or mechanical emergencies, which all come under the category of technical stops, would continue. Roughly 1,000 such technical stops by international flights were made last year at BIA, providing financial windfalls to the airport and reaffirming the importance of BIA’s role as an emergency landing area in the nation’s transportation arena, Hupp and Collins said.

“It is important for flight safety and homeland security that technical stops be allowed to continue,” Collins said in a prepared statement.