Mammoth and Aspire MRO have successfully installed the main cargo door on the 777-300ERMF freighter, progressing toward the completion of its conversion and Supplemental Type Certification (STC). The aircraft, MSN 35299 (N463AC), will be delivered to BBN Istanbul, the launch customer through Avia Solutions Group. Originally delivered to Cathay Pacific, this 17.4-year-old aircraft was withdrawn from service in 2018. AviaAM Leasing has ordered six 777-300ERMF aircraft, while Mammoth, Kansas Modification Center, and Israel Aerospace Industries offer various conversion programs, though none have received STC approval yet.

Source: https://www.stattimes.com/air-cargo/mammoth-aspire-mro-install-main-cargo-door-on-777-300ermf-1354595