Question: The Lisunov Li-2, originally designated PS-84, was a license-built version of the Douglas DC-3, a fixed-wing propeller-driven airliner, its lasting effect on the airline industry, and which event makes it one of the most significant transport aircraft ever made?
Context: The Lisunov Li-2, originally designated PS-84, was a license-built version of the Douglas DC-3.  It was produced by Factory #84 in Moscow-Khimki and, after evacuation in 1941, at TAPO in Tashkent.  The project was directed by aeronautical engineer Boris Pavlovich Lisunov. The Douglas C-47 Skytrain or Dakota (RAF designation) is a military transport aircraft developed from the civilian Douglas DC-3 airliner.  It was used extensively by the Allies during World War II and remains in front line service with various military operators. The Sverdlovsk plane crash of 5 January 1950 killed all 19 persons on board, including almost the entire national ice hockey team (VVS Moscow) of the Soviet Air Forces – 11 players, as well as a team doctor and a masseur.  The team was on board a twin-engined Lisunov Li-2 transport aircraft, a licensed Soviet-built version of the DC-3, heading to a match against the Dzerzhinets (Chelyabinsk) (Traktor Chelyabinsk) hockey club.  Due to poor weather at Chelyabinsk, the flight diverted to Sverdlovsk.  The crew attempted four approaches but during the fifth approach to Koltsovo Airport at Sverdlovsk in the Soviet Union' s Russian Soviet Federated Socialist Republic, the aircraft crashed near the airport in extremely adverse weather conditions involving a heavy snowstorm with strong winds. The 1951 LOT Li-2 Tuszyn air disaster occurred on 15 November 1951 when a LOT Polish Airlines Lisunov Li-2 flew into power lines near Tuszyn, crashed and burst into flames.  All 15 passengers and 3 crew died.  It was the first LOT aircraft disaster since the end of World War II. The Douglas DC-3 is a fixed-wing propeller-driven airliner.  Its cruise speed (207 mph ) and range (1500 mi ) revolutionized air transport in the 1930s and 1940s.  Its lasting effect on the airline industry and World War II makes it one of the most significant transport aircraft ever made. Showa Aircraft Industry Co., Ltd. (昭和飛行機工業株式会社 , Shōwa Hikōki Kōgyō Kabushiki-gaisha ) is a Japanese company.  Its headquarters are at Akishima-shi, Tokyo Prefecture, a region of Tokyo Metropolis.  It was established in 1937 as a manufacturer of military aircraft in Akishima-shi.  In World War II it was one of two companies manufacturing the Showa/Nakajima L2D, a license-built Douglas DC-3 variant.  It also manufactured other military aircraft. This is a list of variants of the Douglas DC-3 family of airliner and transport aircraft. The Lockheed R6V Constitution was a large, propeller-driven, double-decker transport aircraft developed in the 1940s by Lockheed as a long-range, high-capacity transport and airliner for the U.S. Navy and Pan American Airways.  Only two of the aircraft were ever built, both prototypes.  Although these two planes went into service with the Navy, the Constitution design ultimately proved underpowered and too large for practical airline use at the time.  Although the Martin JRM Mars flying boat had a slightly longer wingspan, the Constitution remains the largest fixed-wing aircraft type ever operated by the U.S. Navy. The Tupolev Tu-75 was a military transport variant of the Tu-4 bomber, as was a similar airliner, the Tu-70, both using a new, purpose-designed fuselage.  The first Soviet military machine of this class, it was equipped with a rear fuselage loading ramp.  It was not placed into production because the VVS decided it would be cheaper to modify its existing Tu-4s for the transport mission and to use its existing Lisunov Li-2 and Ilyushin Il-12 transports. The Shōwa L2D and Nakajima L2D, given the designations: Shōwa Navy Type 0 Transport and Nakajima Navy Type 0 Transport, were license-built versions of the Douglas DC-3.  The L2D series, numerically, was the most important Japanese transport in World War II.  The L2D was given the Allied code name Tabby.
Answer: World War II