Answer the following question: Information: - Military transport aircraft or military cargo aircraft are typically fixed wing and rotary wing cargo aircraft which are used to airlift troops, weapons and other military equipment by a variety of methods to any area of military operations around the surface of the planet, usually outside the commercial flight routes in uncontrolled airspace. Originally derived from bombers, military transport aircraft were used for delivering airborne forces during the Second World War and towing military gliders. Some military transport aircraft are tasked to perform multi-role duties such as aerial refueling and, rescue missions, tactical, operational and strategic airlifts onto unprepared runways, or those constructed by engineers. - A fixed-wing aircraft is an aircraft, such as an aeroplane, which is capable of flight using wings that generate lift caused by the vehicle's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinct from rotary-wing aircraft, in which the wings form a rotor mounted on a spinning shaft, and ornithopters, in which the wings flap in similar manner to a bird. - A monoplane is a fixed-wing aircraft with a single main wing plane, in contrast to a biplane or other multiplane, each of which has multiple planes. - The Savoia - Marchetti SM.75 Marsupiale ( Marsupial ) was an Italian passenger and military transport aircraft of the 1930s and 1940s . It was a low - wing , trimotor monoplane of mixed metal and wood construction with a retractable tailwheel undercarriage . It was the last of a line of transport aeroplanes that Alessandro Marchetti began building in the early 1930s . The SM.75 was fast , robust , capable of long - range flight and could carry up to 24 passengers for 1,000 miles . - Uncontrolled airspace is airspace where an Air Traffic Control (ATC) service is not deemed necessary or cannot be provided for practical reasons. According to the airspace classes set by ICAO, both class F and class G airspace are uncontrolled. It is the opposite of controlled airspace. - Aerial refueling, also referred to as air refueling, in-flight refueling (IFR), air-to-air refueling (AAR), and tanking, is the process of transferring aviation fuel from one military aircraft (the tanker) to another (the receiver) during flight. The two main refueling systems are probe-and-drogue, which is simpler to adapt to existing aircraft, and the flying boom, which offers faster fuel transfer, but requires a dedicated boom operator station. - An airlift is the organized delivery of military supplies or military personnel primarily via military transport aircraft. - An aircraft is a machine that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. - A trimotor is an aircraft powered by three engines and represents a compromise between complexity and safety and was often a result of the limited power of the engines available to the designer. Many trimotors were designed and built in the 1920s and 1930s, when engine power lagged behind the designers' power requirements. - A cargo aircraft (also known as freight aircraft, freighter, airlifter or cargo jet) is a fixed-wing aircraft that is designed or converted for the carriage of cargo rather than passengers. Such aircraft usually do not incorporate passenger amenities and generally feature one or more large doors for loading cargo. Freighters may be operated by civil passenger or cargo airlines, by private individuals or by the armed forces of individual countries (for the last see military transport aircraft). Aircraft designed for cargo flight usually have features that distinguish them from conventional passenger aircraft: a wide/tall fuselage cross-section, a high-wing to allow the cargo area to sit near the ground, a large number of wheels to allow it to land at unprepared locations, and a high-mounted tail to allow cargo to be driven directly into and off the aircraft. - Military gliders (an offshoot of common gliders) have been used by the military of various countries for carrying troops and heavy equipment (see Glider infantry) to a combat zone, mainly during the Second World War. These engineless aircraft were towed into the air and most of the way to their target by military transport planes, e.g., C-47 Skytrain or Dakota, or bombers relegated to secondary activities, e.g., Short Stirling. Military gliders do not soar. Once released from the tow craft near the front, they were to land on any convenient open terrain close to target, hopefully with as little damage to the cargo and crew as possible as most landing zones (LZ) were far from ideal. The one-way nature of the missions meant that they were treated as disposable leading to construction from common and inexpensive materials such as wood. - Airborne forces are military units, usually light infantry, set up to be moved by aircraft and "dropped" into battle, typically by parachute. Thus, they can be placed behind enemy lines, and have the capability to deploy almost anywhere with little warning. The formations are limited only by the number and size of their aircraft, so given enough capacity a huge force can appear "out of nowhere" in minutes, an action referred to as "vertical envelopment". - A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While a biplane wing structure has a structural advantage over a monoplane, it produces more drag than a similar unbraced or cantilever monoplane wing. Improved structural techniques, better materials and the quest for greater speed made the biplane configuration obsolete for most purposes by the late 1930s. What entity does 'savoia-marchetti sm.75' has the relation 'subclass of' with?
Answer:
military aircraft