Bulgaria-based Cargo Air has begun to remove 737 Classics from its fleet, replacing them with 737NG freighters, and looking to add its fifth 737-800 by yearend. The airline recently sold a 1989-vintage 737-400SF (24474, ex-Calima Aviacion) to Frontera Flight Holdings, an affiliate of Mexico-based Aeronaves TSM, as it took redelivery of a freshly converted 2001-vintage […]