US-based ACMI service provider Southern Air has added a Boeing 777 and a Boeing 737-400 to its freighter fleet, bringing the total main deck aircraft in operation for DHL Express to ten.

Southern Air, an operating subsidiary of Worldwide Air Logistics Group, said that the addition of a fifth B777F for DHL Express is part of the lessor’s nine-year flight services agreement with the global logistics operator announced last year.

The B737-400F, also a fifth of the type now working for DHL Express, expands a separate long-term flight services arrangement.

Dan McHugh, chief executive of Worldwide Air Logistics Group, said: “This fleet expansion further enhances our support of the growing needs of DHL Express and its customers worldwide.”

Southern Air was the first ACMI operator to fly the B777F, which it describes as “the most technologically advanced, fuel efficient, wide-body freighter in the world”.

“Southern Air shares DHL Express’ commitment to performance excellence, superior customer service and environmental responsibility, and we look forward to continuing to meet DHL’s demands for safe, efficient and cost-effective airlift,” said Paul Chase, chief operating officer of Southern Air.