The Mil Mi-4 (USAF/DoD reporting name "Type 36", NATO reporting name "Hound"). was a Soviet transport helicopter that served in both military and civilian roles.
The Mi-4 was designed in response to the American H-19 Chickasaw and the deployment of U.S. helicopters during the Korean War. While the Mi-4 superficially resembles the H-19 Chickasaw, it is a larger helicopter and is able to lift more weight. The first model entered service in 1952, and replaced the Mi-1. The helicopter was first displayed to the outside world in 1952 at the Soviet Aviation Day in Tushino.
One Mi-4 was built with a jettisonable rotor. It served as an experimental vehicle for future pilot's means of safety and ejection designs.
Operational history
The Mi-4 transport helicopter laid the beginning of the Soviet Army Aviation, it was widely used both in the armed forces and in the national economy and for several decades remained the main type of helicopter in the inventory of the Soviet Armed Forces and of the Civil Air Fleet. The Mi-4 went out of service with the development of the Mi-8. It is not used by the Russian Air Force anymore, though it remained in service in some countries as a utility helicopter or as a military transport a while longer. Albania was thought to be the final country using the helicopter and by 2005 all were out of service. The Mi-4 played a very important role in Bangladesh liberation war of 1971. The Mi-4 was the workhorse of the Indian Army at the time. A highly successful heli-borne operation, the Meghna Heli Bridge, using Mi-4s helped the Indian Army's 57 Mountain Division clear the Meghna River. The helilift of a battalion of Indian troops to the outskirts of Sylhet was the first heli-borne operation of the Indian army.
Much like the UH-1 Huey, after it was gradually phased out of military service, it was used in various domestic roles: search and rescue, firefighting, polar expeditioning, construction site cargo helicopter, commercial flights and many others.
An official video of a North Korean Air Force combat flying skills competition released in 2014 shows that the Mi-4 is still in limited service in North Korea.
Variants
V-12
Prototype. Designation reused for the Mi-12.
Mi-4 (NATO – Hound-A)
Basic production version.
Mi-4A
Assault transport helicopter.
Mi-4AV
Armed versions based on the Mi-4A.
Mi-4GF
Factory designation for demilitarised Mi-4 for use in the Civil Air Fleet.
Mi-4L Lyukes
Six-seat VIP transport version, sometimes converted into an air ambulance helicopter.
Mi-4VL
Fire-fighting version of Mi-4L.
Mi-4M (NATO – Hound-C)
Armed close-support helicopter, fitted with a gun turret. Designation alternatively applied to the Mi-4VM, and also reused for ambulance variant for the Soviet Ministry of Health. Export designation Mi-4ME.
Mi-4MR
Upgraded version of Mi-4VM.
Mi-4P / Mi-4VP
Civil transport helicopter, with accommodation for between 8 and 11 passengers, plus eight stretchers and a medical attendant for air ambulance duties.
Mi-4PL (NATO – Hound-B)
Anti-submarine warfare helicopter.
Mi-4PS
SAR version.
Mi-4S Salon
VIP transport helicopter.
Mi-4Skh
Multi-role agricultural helicopter, with a large chemical container in the main cabin. Also used as a fire-fighting helicopter.
Mi-4T
Major military production version, equipped with a large diameter main rotor and bulged windows.
Mi-4VM (VM-12)
Anti-submarine warfare helicopter.
Mi-4BT
Minesweeper with floats.
Mi-4RI
Mi-4M equipped with the Rion experimental sonar.
Mi-4MT
Torpedo-carrying ASW attack (killer) aircraft derived from Mi-4M.
Mi-4MU
Attack helicopter.
Mi-4MO
Search helicopter with Oka sonar.
Mi-4MS
Search helicopter with Soora infra-red sensor.
Mi-4FV (Mi-4KV)
Photographic and guidance helicopter.
Mi-4Schch
"Polar version" of Mi-4FV for working at the Soviet Arctic and Antarctic research stations.
Mi-4SP
Special rescue modification.
Mi-4PG
Experimental version equipped with an external load sling system.
Mi-4SV
Mi-4 with improved heat insulation for working in the Far North.
Mi-4N "Filin" (Horned owl)
Experimental reconnaissance version intended for night-time use.
Mi-4KK (Mi-4VKP)
Mobile command post.
Mi-4KU (Mi-4VPU)
Mobile command post for controlling Air Force units.
Mi-4U
Target-designator version carrying the Oospekh (Success) system.
Mi-4GR
Mi-4 fitted with Grebeshok-3 (Haircomb-3) wide-range panoramic detection and relay radar.
Mi-4TARK
TV-equipped artillery reconnaissance and spotting helicopter.
Chinese military transport helicopter. Chinese production version.
Harbin Z-6
Prototype turbine powered version of the Z-5, no production undertaken.
Xuanfeng
Chinese civil transport helicopter. Chinese production version.
Unnamed Variants
Mi-4 minelayer version produced by converting troop-carrier helicopters.
Mi-4 modified for transporting and laying gas pipelines.
Mi-4 with Panorama 360 cin camera system produced by conversion.
Mi-4 with the Pristavka (Add-on) radio equipment developed in 1957 for guidance of remote-controlled reconnaissance balloons.
Mi-4s used as testbeds. Apart from the above-mentioned versions, the Mi-4 and Mi-4A were widely used as testbeds of various kinds for testing subassemblies and systems of future aircraft, as well as equipment for other branches of industry.
