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.
The Ilya Muromets is the world's first multi-engine aircraft in production and at least sixty were built.
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.
When WWI broke out, only two Ilya Muromets bombers were completed out of an initial production run of ten aircraft. In August 1914, the Ilya Muromets was introduced to the Imperial Russian Air Service and on 10 December 1914, the Russians formed their first ten-bomber squadron, slowly increasing the number to 20 by mid-1916.
Operations with the heavy bombers began on 12 February 1915 with a raid on German frontline positions.
German Fighter Pilots often were reluctant to attack Ilya Muromets in the air due to their defensive firepower including the unique tail gun position, and the difficulty in bringing down such a large aircraft.
Once engaged, small fighters also found that they were buffeted by propeller wash of the four large engines.
On 12 September 1916, the Russians lost their first Ilya Muromets in a fight with four German Albatros, three of which it managed to shoot down.
This was also the only loss to enemy action during the war; three others were damaged in combat, but managed to return to base to be repaired.
83 Ilya Muromets bombers were built for the Russian forces between 1913 and 1918.
They recorded a number of firsts in the history of military aviation, like bombing from heavy bombers, performing bomber group raids on enemy targets, night bombing, and photographic bomb damage assessment.
They were also the first to develop defensive tactics for a single bomber engaged in an air combat with several enemy fighters. Due to systematic weapon upgrades, the effectiveness of bomb-dropping reached 90%.
The Ilya Muromets performed more than 400 sorties and dropped 65 tons of bombs during the war. By 1917, attrition from constant flying had reduced the bombing fleet substantially and only four bombers remained at the front line; the other Ilya Muromets were relegated to trainer duties.
The heavy bombers of other participants appeared in 1916, all resembling the Russian pioneer to a certain degree.
The Russian government and Sikorsky himself sold the design and production license to the British and French governments.
The Germans tried to copy its design, using the fragments of the Ilya Muromets they had shot down over their territory in September 1916.
By the end of 1916, the design was generally believed to be at the end of its development cycle, with ensuing modifications to individual aircraft, such as additional armor and weapons, making the aircraft too heavy and not suitable for operational use.
Continual changes in the field as well as the factory led to many aircraft being redesignated as a new variant.[
Further designs based on the original Ilya Muromets bombers included a more dedicated attack version.