Aircraft used
Larger cargo airlines tend to use new or recently built aircraft to carry their freight.[9] Current passenger aircraft such as the Boeing 777 and Airbus A330 offer freighter variants either new from the factory or as a conversion. Compared to the passenger variant, the freighter has a supernumerary area, which includes four business-class seats forward of the rigid cargo barrier, full main deck access, bunks, and a galley. Passenger planes converted to freighters have their windows plugged, passenger doors deactivated, fuselage and floor reinforced, and a main-deck cargo door installed.
Many cargo airlines still utilize older aircraft, including those no longer suited for passenger service, like the Boeing 727, Douglas DC-8, McDonnell Douglas DC-10, McDonnell Douglas MD-11, Airbus A300, and the Ilyushin Il-76. Examples of the 80+-year-old Douglas DC-3 are still flying around the world carrying cargo (as well as passengers). Short range turboprop airliners such as the Antonov An-12, Antonov An-26, Fokker Friendship, and British Aerospace ATP are being modified to accept standard air freight pallets to extend their working lives. This normally involves the replacement of glazed windows with opaque panels, the strengthening of the cabin floor and insertion of a broad top-hinged door in one side of the fuselage.
The Antonov An-225 Mriya, an enlarged version of the Antonov An-124 Ruslan, was the world's largest aircraft, used for transporting large shipments and oversized cargos.[10][11]
Usage of large military airplanes for commercial purposes, pioneered by Ukraine's Antonov Airlines in the 1990s, has allowed new types of cargo in aerial transportation.
Passenger and cargo
In the past, some cargo airlines would carry a few passengers from time to time on flights, and UPS Airlines once unsuccessfully tried a passenger charter airline division.
Passenger airlines regularly use their largest passenger aircraft like the Boeing 777-300 to earn additional revenue beyond passengers on a scheduled flight, by transporting a limited amount of cargo alongside passengers' luggage underneath the passenger cabin.[12] This is known as mixed operations or belly freight, and makes up % airline cargo traffic as of 2018.[1] Alaska Airlines operates a series of short flights nicknamed the "Milk Run" to small towns in Southeast Alaska that do not have road access, using five Boeing 737-400 Combi aircraft whose cabin is divided in half with cargo up front and 72 seats in the back.[13]
Low-cost carriers do not tend to operate cargo subsidiaries.
