Question:  Memphis Belle is the nickname of a four-engine bomber which was introduced in what year?

Context paragraphs:
Sikorsky Ilya Muromets: The Sikorsky "Ilya Muromets" (Russian: Сикорский Илья Муромец ) (Sikorsky S-22, S-23, S-24, S-25, S-26 and S-27) were a class of Russian pre-World War I large four-engine commercial airliners and military heavy bombers used during World War I by the Russian Empire.  The aircraft series was named after Ilya Muromets, a hero from Slavic mythology.  The series was based on the Russky Vityaz or Le Grand, the world's first four-engined aircraft, designed by Igor Sikorsky.  The Ilya Muromets aircraft as it appeared in 1913 was a revolutionary design, intended for commercial service with its spacious fuselage incorporating a passenger saloon and washroom on board.  During World War I, it became the first four-engine bomber to equip a dedicated strategic bombing unit.  This heavy bomber was unrivaled in the early stages of the war, as the Central Powers had no aircraft capable enough to rival it until much later.  The Zeppelin-Staaken R.VI of 1916-17 was the only example of any of the Imperial German "Riesenflugzeug" airframe designs to be produced in any quantity during World War I.

Boeing B-17 Flying Fortress: The Boeing B-17 Flying Fortress is a four-engine heavy bomber developed in the 1930s for the United States Army Air Corps (USAAC).  Competing against Douglas and Martin for a contract to build 200 bombers, the Boeing entry (prototype Model 299/XB-17) outperformed both competitors and exceeded the air corps' performance specifications.  Although Boeing lost the contract (to the Douglas B-18 Bolo) because the prototype crashed, the air corps ordered 13 more B-17s for further evaluation.  From its introduction in 1938, the B-17 Flying Fortress evolved through numerous design advances, becoming the third-most produced bomber of all time, behind the B-24 and the multirole Ju 88.

Memphis Belle (aircraft): Memphis Belle is the nickname of a Boeing B-17F Flying Fortress that was used during the Second World War that inspired the making of two motion pictures: a 1944 documentary film, "", and a 1990 Hollywood feature film, "Memphis Belle".  The aircraft was one of the first United States Army Air Forces B-17 heavy bombers to complete 25 combat missions with her crew intact.  The aircraft and crew then returned to the United States to sell war bonds.  As of 2017, the aircraft was being restored at the National Museum of the United States Air Force at Wright-Patterson AFB in Dayton, Ohio with plans to put it on display May 17, 2018.

Wilhelm Batz: Wilhelm Batz (21 May 1916, in Bamberg – 11 September 1988, in Mauschendorf/Ebern in Unterfranken) was a pilot in the Luftwaffe of Nazi Germany during World War II.  The sixth-most successful fighter pilot in the history of aerial warfare, Batz flew 445 combat missions and claimed 237 enemy aircraft shot down.  234 of these victories were achieved over the Eastern Front, including at least 46 Il-2 Sturmoviks, but he did claim three victories, including one four-engine bomber against the United States Army Air Forces (USAAF) over the Ploieşti oil fields.  Batz was a recipient of the Knight's Cross of the Iron Cross with Oak Leaves and Swords.

Petlyakov Pe-8: The Petlyakov Pe-8 was a Soviet heavy bomber designed before World War II, and the only four-engine bomber the USSR built during the war.  Produced in limited numbers, it was used to bomb Berlin in August 1941.  It was also used for so-called "morale raids" designed to raise the spirit of the Soviet people by exposing Axis vulnerabilities.  Its primary mission, however, was to attack German airfields, rail yards and other rear-area facilities at night, although one was used to fly the People's Commissar of Foreign Affairs (Foreign Minister) Vyacheslav Molotov from Moscow to the United States in 1942.

Sikorsky XBLR-3: The Sikorsky XBLR-3 was a four-engine bomber designed in 1935-1936 as a competitor to the Boeing XBLR-1 (XB-15) and Douglas XBLR-2 (XB-19).  The original XBLR-3 concept was a twin-boom design with both pusher and tractor propellers and many gun stations; it later evolved into a more conventional four-engine bomber design.  The XBLR-3 was the last landplane design prepared by Sikorsky before the company committed itself to helicopters.

Tony Starcer: Sergeant Anthony L. Starcer, USAAF, (died 1986) was line mechanic for the 91st Bombardment Group (Heavy), of the VIII Bomber Command, Eighth Army Air Force, based at Bassingbourn, UK in 1942-43.  He painted many pieces of nose art on the Fortresses of "The Ragged Irregulars", including the George Petty girl "Telephone Girl" for the Memphis Belle.  The 91st Bombardment Group (H) website lists 124 aircraft that his work adorned.

Lady for a Night: Lady for a Night is a 1942 American drama film starring Joan Blondell and John Wayne.  The World War II B-17 bomber the "Memphis Belle" is named after a steamboat in this film.  It is also known as The Lady From New Orleans, Memphis Belle and Lady of New Orleans.

Memphis Belle (film): Memphis Belle is a 1990 British-American war drama film directed by Michael Caton-Jones and written by Monte Merrick.  The film features an all-star cast with Matthew Modine, Eric Stoltz, and Harry Connick Jr. (in his film debut) in leading roles.  "Memphis Belle" is a fictionalization of the 1943 documentary "" by director William Wyler, about the 25th and last mission of an American Boeing B-17 Flying Fortress bomber, the "Memphis Belle", based in England during World War II.  The 1990 version was co-produced by David Puttnam and Wyler's daughter Catherine, and dedicated to her father.  The film closes with a dedication to all airmen, friend or foe, who fought in the skies above Europe during World War II.

Memphis Belle: A Story of a Flying Fortress: The Memphis Belle: A Story of a Flying Fortress is a 1944 documentary film which provides an account of the final mission of the crew of the "Memphis Belle", a Boeing B-17 Flying Fortress.  In May 1943 it became the first U.S. Army Air Forces heavy bomber to complete 25 missions over Europe and return to the United States.

Supporting paragraphs: Memphis Belle (aircraft) Boeing B-17 Flying Fortress
Answer: 1938