Aeronautical Engineers, Inc. (AEI) has signed a contract with CargoAir that will see it converting a Boeing 737-400SF freighter for the Bulgaria-based carrier.

Work on the aircraft — which will be carried out by AEI partner Commercial Jet in Dothan, Alabama — is scheduled to start in September this year.

AEI’s B737-400SF conversion will provide CargoAir with a "highly flexible Ancra cargo loading system that is capable of carrying multiple ULD’s".

"This unique flexibility has been designed by AEI to allow cargo operators to immediately adapt to multiple ULD configurations at a moment’s notice," AEI explained in a statement. "When combined with proven reliability, the AEI-converted B737-400SF will allow CargoAir to keep their aircraft in the air, generating revenue."

Robert Convey, AEI senior vice president of sales and marketing, commented: “CargoAir is a long-time and highly valued customer of AEI’s.

“The airline currently operates three AEI B737-300SF and 7 AEI B737-400SF freighters.”

Angel Petrov, CargoAir ground operations and commercial director, and purchase and fleet acquisitions director, added: “AEI and CargoAir have had a successful partnership dating back to 2009.

“We appreciate the strong collaboration between our companies and firmly believe in the capabilities of AEI and their authorised AEI Conversion Center, Commercial Jet.”