747-400C
The 747-400C does not exist; the aircraft usually meant is the 747-400M Combi.
The 747-400C does not actually exist its actually the 747-400M which stands for “Mixed”. There may have been some confusion with the C designation as cargo. The M series goes under the name Combi.
More in Boeing 747 Family
Boeing 747 Family
Every Boeing 747 variant built between 1968 and 2023 — the 747-100, -200, -300, -400 and 747-8, with freighter, combi and short-range models explained.
747-100
The original Boeing 747-100 entered service in 1970 with six upper-deck windows and a lounge; later aircraft offered a ten-window upper deck.
747-100B
The 747-100B added a stronger airframe and undercarriage and a 750,000 lb maximum takeoff weight. Only Iran Air and Saudia took delivery.
747-100F
Freighter specification for the Boeing 747-100F, covering main-deck and belly cargo volumes, pallet counts and upper-deck crew lounge options.
747-100SR
Built for Japanese domestic routes, the 747-100SR traded fuel capacity for seats, carrying up to 550 passengers on short high-frequency sectors.
747-100SP
The shortened 747SP was built for Pan Am and Iran Air to fly ultra-long routes such as Tehran-New York, then the longest nonstop service.