Sikorsky Ilya Mourometz (Series) History

The Sikorsky Ilya Mourometz series of aircraft were the world's first four-engine bombers in operational service. Igor Sikorsky, his name synonymous in the modern world for the company's line of American helicopters, was already making a name for himself in Russia as chief designer at the Russo-Baltic Railroad Factory. There, he developed the world's first four-engine aircraft - the 1913 Russky Vitaz (S-21). This spawned the basic design for the Bolshoi Bal'tisky ("Great Baltic") Type B aircraft which flew for ten minutes on May 13th, 1913. The Bolshoi Bal'tisky became the basis of the larger Ilya Mourometz (S-22).

The aircraft was conceived of as a four-engine, luxury commercial passenger transport featuring such revolutionary amenities as cabin windows, an in-flight berth complete with a washroom, a heated and lit passenger compartment separated from the crew cockpit and relatively comfortable passenger seating for up to 16 on wicker chairs. The cabin floor was also glazed over to allow for a unique passenger perspective of high-altitude flight. Doors on either side of the fuselage permitted mechanics to service and repair the engines in flight.

The most common model in the IM line became the Type V (S-23) to which some 32 to 34 were produced from 1914 through 1916. Type V's were the first in the Mourometz line to be developed from the start as a bomber (the previous offerings were conversions). These were fitted with 4 x Sunbeam Crusader V8 engines of 148 horsepower each. The Type V No 151's arrived in 1915 with their 4 x Argus engines of 140 horsepower each. The Type V No 159 was a crew trainer from 1915 onwards and was fitted with just 2 x 225 horsepower engines of the Sunbeam brand - no doubt in an effort to commit engines to war-bound aircraft instead. 4 x RBVZ-6 engines of 150 horsepower each were added to the design of the Type V No 167, also appearing in 1915.

1916 brought about more faces in the IM line, this including the Type G-1 with her 4 x Sunbeam engines of 160 horsepower each. Likewise, the Type G-2 "Russobalt" utilized an arrangement of 4 x RBVZ-6 series engines of 150 horsepower each (RBVZ designating its Russo-Baltic Carriage Factory origins) and were built in 30 production examples. The Type G-3 saw fit to combine 2 x Renault engines of 220 horsepower (each) with 2 x RBVZ-6 engines of 150 horsepower each. The final IM production model became the Type E "Yeh-2" model with her 4 x Renault engines of 220 horsepower, appearing in only 10 production examples. By 1918, only 13 IM aircraft were built, effectively signaling the end of the IM's wartime production run. Some 80 total Ilya Mourometz were eventually produced.

As an aside, one IM aircraft was produced with water floats and, though it provided for some successful water-based landings and take-offs, the arrangement was not found to offer much in terms of military value. Other costly (manpower and financial) developments were also pursued with many ending up abandoned. License production was undertaken by the British and French while the Sikorsky four-engine bomber concept was copied throughout the world during the war years and beyond. The aging Ilya Mourometz line was replaced during the war World War 1 by Sikorsky's new Alexander Nevsky bomber design beginning in 1916. In all, the Mourometz line served through some 400 combat sorties against targets in Germany and Latvia, mostly from Vinnitza in Poland during the war.

The Ilya Mourometz proved herself a capable mount in her relatively short time along the Front. Despite missing out on the chance to become the world's first four-engine, multi-passenger commercial airliner, the IM instead developed many "firsts" in the realm of military aviation. The IM was the world's first purpose-designed, four-engine bomber featuring an internal bomb bay, bomb sighting device and excellent defensive armament. Specialized techniques were also developed for machine gun crews when combating multiple enemy fighters at one time. As the war rolled on, bombing effectiveness from IM platforms reached near-excellent levels.

IM's enjoyed a short-lived existence after the war with a handful still being produced. From May through October of 1921, Moscow-Kharkov line was finally able to utilized the aircraft in its originally intended role of passenger transport until these aircraft were deemed too fragile for further use. The aged technology and construction methods had finally taken their toll on this fine machine. After 1921, IM's were all but extinct with the last IM's flying in 1922. Beyond the Russian Empire Air Force and soon-to-follow USSR Air Force, Poland was the only other operator of the aircraft.

Incidentally, the name, Ilya Mourometz, is a hero based in Russian mythology.

Sikorsky Ilya Mourometz (Series) Specification

BASICS

Year:
1913
Status:
Retired, Out-of-Service
Crew:
4 to 12

MANUFACTURING

[ 85 Units ]:
Russo-Baltic Wagon Company - Russia

ROLES

- Ground Attack

- Reconnaissance (RECCE)

DIMENSIONS

Length:

57.41 ft (17.5 m)

Width/Span:

97.77 ft (29.8 m)

Height:

13.12 ft (4 m)

WEIGHTS

Empty Weight:

7,716 lb (3,500 kg)

MTOW:

11,023 lb (5,000 kg)

(Diff: +3,307lb)

POWER

4 x RBVZ-6 engines devliering 150 horsepower each.

PERFORMANCE

Maximum Speed:

75 mph (120 kph; 65 kts)

Service Ceiling:

9,843 feet (3,000 m; 1.86 miles)

Maximum Range:

311 miles (500 km; 270 nm)

Rate-of-Climb:

364 ft/min (111 m/min)

ARMAMENT

Various combinations of 12.7mm and 15,3mm Maxim, Lewis, Madsen or Colt machine guns as well as recoiless Gelvig/Oranovsky 3" cannons and Hotchkiss 37mm cannons.

Rocket and bomb load up to 1,100 lb.

VARIANTS

No 107 - Appearing 1913; fitted with 4 x Argus engines of 100 horsepower each.

Kievsky No 128 - Appearing 1914; fitted with 2 x Argus engines of 140 horsepower each and 2 x Argus engines of 125 horsepower each.

Type B No 135 - Appearing 1914; fitted with 4 x Argus engines of 130 horsepower each.

Type B No 136 - Appearing 1914; fitted with 2 x Salmson engines of 200 horsepower each and 2 x Salmson engines of 136 horsepower each.

Type B No 137 - Appearing 1914; fitted with 2 x Salmson engines of 200 horsepower each and 2 x Salmson engines of 136 horsepower each.

Type B No 138 - Appearing 1914; fitted with 2 x Salmson engines of 200 horsepower each and 2 x Salmson engines of 136 horsepower each.

Type B No 139 - Appearing 1914; fitted with 2 x Salmson engines of 200 horsepower each and 2 x Salmson engines of 136 horsepower each.

Type V (S-23) - Appearing 1914; fitted with 4 x Sunbeam Crusader V8 engines of 148 horsepower each; 32 to 34 Type V examples produced in whole.

Type V No 151 - Appearing 1915; fitted with 4 x Argus engines of 140 horsepower each.

Type V No 159 - Trainer Aircraft; appearing 1915; fitted with 2 x Sunbeam engines of 225 horsepower each.

Type V No 167 - Appearing 1915; fitted with 4 x RBVZ-6 engines of 150 horsepower each.

Type G-1 - Appearing 1916; fitted with 4 x RBVZ-6 engines of 150 horsepower each.

Type G-2 "Russobalt" - Appearing 1916; fitted with 4 x RBVZ-6 engines of 150 horsepower each.

Type G-3 "Renobalt" - Appearing 1916; fitted with 2 x Renault engines of 220 horsepower each and 2 x RBVZ-6 engines of 150 horsepower each.

Type D-I DIM - Appearing 1916; fitted with 4 x Sunbeam engines of 150 horsepower each.

Type E "Yeh-2" - Appearing 1917; fitted with 4 x Renault engines of 220 horsepower each; 12 examples produced.

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