U.S. Customs and Border Protection approved Key West International Airport’s request to support increased scheduled air service between Key West and Havana, Cuba, a route applied for by Silver Airlines.

In a letter dated June 21, 2016 the CBP approved up to 20 passengers per flight, doubling the previous capacity that has been allowed since 2011.

“We are hopeful that Silver Airlines will be granted the Key West to Havana route and we made this request in preparation for that possibility,” said Donald DeGraw, Director of Airports for Monroe County, which owns and operates the airport. “This increase would greatly increase Silver’s ability to be successful in the route.”

Fort Lauderdale-based Silver Airlines operates 34-seat Saab 340B turboprops. It was one of six airlines that won permission June 10 from the U.S. Department of Transportation to fly commercial air service from the United States to Cuba, the first time this has been allowed in five decades. But the DOT has yet to award the 20 permitted daily flights to Havana, the most sought after Cuba destination for U.S. airlines.

The CBP allowed Key West the increased capacity of arriving flights from Havana with operation restrictions. They are: one flight per day, flight days on Monday through Friday, arrival time between 2 and 3 p.m., no cargo and no Sunday flights.

Any proposed scheduled flights that are not in accordance with the restrictions must be pre-approved by CBP and operate with a limit of 10 passengers per aircraft, unless otherwise approved by CBP. This includes possible Saturday flights.

Key West International Airport currently is in the second phase of a four-phase project to upgrade the Customs and Border Protection facility. Phase 1 was a $306,000 upgrade to the entrance, bringing it into compliance with CBP standards. Now, a $1.3 million, 2,000 square-foot addition is being built that will be used for arrival passengers to line up for processing. Phases 3 and 4 will involve renovating the existing facility into CBP compliance to allow for up to 70 passenger per hour to be processed.

“We hope that once our entire facility is upgraded to CBP standards, all restrictions will be lifted and there will be no passenger constraints for Silver,” DeGraw said. “But that is a few years away.”

There currently is no scheduled Air Carrier service from Key West to Cuba. However, since March 2015, Air Key West has been operating charter flights three times a week on Mondays, Wednesdays and Fridays to Cuba on its 10-seat (pilot and nine passengers) turboprop Islander operating from the Signature Flight Support general aviation facility .

From May 1 until June 21 of this year, Customs has processed 33 charters and 66 private aircraft. That is more than double the 19 charters and 30 private aircraft that were processed during the same time period of 2015.

“This jump was mostly due to arrivals from Cuba,” DeGraw said. “If restrictions continue to ease for Americans traveling to Cuba, we expect to see these numbers improve even more.”