Boeing (BOE, Chicago O'Hare) says it has secured thirteen additional commitments for its B737-800 Boeing Converted Freighter (BCF) programme bringing the overall number of firm orders to thirty and commitments to twenty-five.

In a statement, the US manufacturer named the new buyers as China's SF Airlines (O3, Shenzhen), Bulgaria's Cargo Air (CGF, Sofia), and an undisclosed operator.

Last year, YTO Cargo Airlines (YG, Hangzhou) ordered ten conversions with commitments for ten additional conversions while China Postal Airlines (CF, Tianjin) ordered ten conversions. An unannounced customer also ordered five conversions with two commitments while GE Capital Aviation (GECAS), which will provide the programme's initial aircraft, has ordered five conversions.

The modification process includes the installation of a large main-deck cargo door, a cargo-handling system and accommodations for up to four non-flying crew members or passengers.

The first B737-800BCF is expected to be delivered during the fourth quarter of 2017.