Mi-8 Hip - Further Modifications

In the course of development and operational service of the Mi-8 the design of its parts and assemblies was constantly improved. The helicopter provided for a good basis for testing various experimental designs. One major problem which took a long time to crack was the development of a long-life anti-torque rotor for the Mi-8. The EDB engineers had to conduct a lot of research aimed at improving the design of the rotor and optimizing its performance. Experimental anti-torque rotors of various types were tested on the Mi-8. These included a three-blade rotor with a cardan shaft-mounted hub and glass fibre blades; a four-blade rotor with drag and flapping hinges and elastic links between the blades; a four-blade and a five-blade semi-rigid rotors. The latter type was recommended for series production but never reached the production stage.

For many years the Mi-8 was used for testing new main rotor blades. These included reinforced all-metal blades with spars and ribs of various designs; mixed-construction blades with a glass fibre-plated steel spar and glass fibre ribs; blades with honey­comb, Styrofoam or Nomex-filled pockets; and others.

Under the conditions of planned economy it was not easy to bridge the gap between an experimental design which had proved its high efficiency, and its production model. The governing bodies of the Soviet aircraft industry were always reluctant to undertake changes in the well-established production routine. Far from all successful designs of various devices or assemblies could be introduced into series production.

In the course of more than 30 years of operational service of the Mi-8, the Mil OKB designers together with their colleagues from Kazan and Ulan-Ude and specialists from the Izotov EDB succeeded in significantly improving its design and extending the life of its aggregates. The assigned life of the Mi-8T current versions exceeds 20,000 hours. In 1980 the Mi-8 became the first Soviet helicopter to receive a type certificate in accordance with the US FAR-29 regulations when operating in Japan. In the 1970s and 1980s Mi-8s were equipped with vibration dampers installed above the main rotor hub, a Doppler speed and drift indicator and a radar. The pendulum-type system for the carriage of the slung cargoes was replaced by a cable sling system capable of handling the slung loads weigh­ing 3 tonnes. Combat survivability was enhanced, armor protection introduced and heavier armament fitted; various items of equipment were upgraded several times. A version developed to meet an order from the Polish Air Force provided accommodation for 37 troops in the cargo cabin.

Development and improvement of various aggregates of the Mi-8 were conducted not only by specialists in the home country; the same task was tackled by foreign operators. In particular, the Egyptian Air Force installed dust filters developed by the British company APME (Aircraft Porous Media Equipment) on the air intakes of its Mi-8Ts and the Finnish Air Force equipped its Mi-8s with navigation radars. In the second half of the 1980s the Mil EDB conducted a comprehensive research programme designed to improve the helicopter's aerodynamics: the external strap-on tanks were deleted, new clamshell cargo doors were installed, fairings were fitted to the swashplate and the exhausts etc

Powerplant upgrades played a crucial role in enhancing the Mi-8's performance. Shortly after the helicopter entered production improved TV2-117A engines were introduced. From 1973 onwards, helicopters intended for delivery to countries in southern areas were fitted with specially modified engines optimized for operation in 'hot-and-high' conditions. At the end of the 1970s an uprated version, designated TV2-117F was developed; it had a 1,700-shp emergency rating. This engine powered the Mi-8PA variant which was successfully certificated in Japan in 1980. In the 1980s production Mi-8 helicopters received the longer-life TV2-117AG turboshaft with graphite seals in the compressor bearings. This version was designated Mi-8AT. This version was the basis for the development of different modifications, mainly civil ones. Mi-8AT helicopters powered by the cheap TV2-117AG engines are in widespread operational service in non-mountainous areas with moderate ambient air temperatures.

In 1987 the Mil EDB developed the experimental Mi-8TG version powered by TV2-117TG engines; this was the world's first helicopter adapted for operation on liquid methane. To increase the reliability of power plant operation, dust filters of various types were devel­oped. Of these, the so-called 'mushroom' type was selected in 1979 for series production and operational service. However, the most notable chapter in the history of the Mi-8's development was the helicopter's modernization to accept the new and more powerful TV3-117MT engine.

Experimental

• V-8 - The first prototype with one gas turbine engine AI-24V designed by A. G. Ivchenko. The first flight was June 24, 1961. Mi-8 prototype incorporating Mi-4 main rotor and transmission and one 2700shp Soloviev AI-24V turbine mounted on top of fuselage. First flown on 24 June 1961. Subsequently fitted with 5-blade rotor and two 1400shp Isotov TV2-117 engines.
• V-8A - The second prototype with two TV2-117.
• V-8AT - The third prototype.
• V-8AP - The fourth prototype.

  Passenger

• Mi-8P (export designation - Mi-17P ) - passenger helicopter with 28 seats. Has rectangular portholes.
• Mi-8PA - modification of the Mi-8P with TV2-117F engines.
• Mi-172

  Transport

• Mi-8T - airborne transport helicopter for the Air Force.
• Mi-8TS is an export version of the Mi-8T for the Syrian Air Force, modified for dry climate conditions.

  Multi-purpose

• Mi-8TB
• Mi-8TV - an export version of the Mi-8TB. It was distinguished by the installation of the ATGM 9M14M "Baby" or their complete absence.
• Mi-8AT
• Mi-8AV is an airborne mine layer for land forces. The BMP-1 minelayer was installed. Could set from 64 (in the first versions) to 200 minutes.
• Mi-8AD - a modification of the airborne mine loader for the ground forces intended for the production of small-sized, non-recoverable anti-personnel mines.
• Mi-8MT - modification with engines TV3-117.
• Mi-8MTV or Mi-8MTV-1 - modification with TV3-117VM engines. Launched in mass production in Kazan in 1988.
• Mi-8MTV-2
• Mi-8MTV-3
• Mi-8MTV-5 - the shape of the nose (“dolphin nose”) has been changed.
• Mi-8MTKO is an option with lighting technology adapted to the use of an aerobatic night vision system.
• Mi-17-1V is an export version of Mi-8MTV.
• Mi-8AMT (export designation - Mi-171 ) - a variant of the Mi-8MTV with slight modifications, produced at the Ulan-Ude Aviation Plant (since 1991).
• Mi-17KF - modification of the Mi-8MTV-5 with avionics company Honeywell. Designed by Mil Design Bureau in conjunction with the KVZ commissioned by the Canadian company Kelowna Flightcraft. First flight August 3, 1997.
• Mi-8TG - a modification of the Mi-8P with poly fuel TV2-117G.
• Mi-14 is a multi-purpose amphibious helicopter.
• Mi-18 is an elongated version of the Mi-8MT. Serially not produced.

  Special purpose

• Mi-8TECH-24 - flying technical and operational part. Equipped with locksmith, electrical, test and other equipment used in the operation and repair of helicopter equipment.
• Mi-8TZ is a tanker and a fuel transporter.
• Mi-8BT - towing vehicle .
• Mi-8SP - special marine rescue.
• Mi-8SPA - search and rescue helicopter for searching astronauts and crews of aircraft in case of splashdown.
• Mi-8TL is a forest fire modification equipped with a massive water discharge system and a water cannon.
• Mi-8S - staff helicopter with round portholes.
• Mi-8PS - staff helicopter with square portholes.
• Mi-8KP is a special command post for conducting large-scale integrated search and rescue operations.
• Mi-8GR or Mi-8R is a reconnaissance aircraft designed for visual observation and photographing in the front line.
• Mi-8K - artillery spotter.
• Mi-8TAKR - a helicopter with a complex of television surveillance.
• Mi-8VD is a radio-chemical intelligence agent.
• Mi-8S is a modification with a combined power plant of turboshaft engines operating on a rotor and a traction turbojet.
• Mi-8MTL is a scout with the ability to simultaneously use thermal imaging reconnaissance and radio interception with accurate determination of target coordinates.
• Mi-8MTU - It was built in a single copy. Designed to detect descent vehicles, small surface targets, radar antenna in the nose. Used by the Ukrainian Air Force.

  Air command posts

• Mi-8VKP or Mi-8VzPU - air command post.
• Mi-8IV or Mi-9 - air command post for division commanders, serial modification.
• Mi-19 is an air command post for commanders of motorized rifle and tank divisions. Equipped with an automated communications system. It was created in 1987 on the basis of the Mi-8MT.
• Mi-19R is an air command post for commanders of missile divisions of the Strategic Missile Forces. Equipped with an automated communications system. It was created in 1987 on the basis of the Mi-8MT.

  Medical

• Mi-8MB - air hospital. Created on the basis of Mi-8T.
• Mi-8MTB - armored air hospital. Created on the basis of Mi-8MT.
• Mi-8MTVM is a medical modification of the Mi-8MTV.
• Mi-8MTV-MPS is a medical search and rescue helicopter based on Mi-8MTV.
• Mi-17G is an export version of the air hospital.
• Mi-17-1VA Ambulatory is an export version of the Mi-8MTV in the sanitary version.

  Jammers

• Mi-8SMV is a jammer equipped with a Smalt-V jamming station.
• Mi-8PP is a REP helicopter equipped with the Pole complex.
• Mi-8PPA - A modified version of the Mi-8PP.
• Mi-8MTP - jammer.
• Mi-8MTPB - jammer.
• Mi-8MTPI - jammer.
• Mi-8MTPSh - jammer.
• Mi-8MTD - jammer.
• Mi-8MTR1 - jammer.
• Mi-8MTR2 - jammer.
• Mi-8MTS - jammer.
• Mi-8MTSh1 - jammer.
• Mi-8MTSh2 - jammer.
• Mi-8MTSh3 - jammer.
• Mi-8MTYA - jammer.
• Mi-8MT1S - jammer.

  Agricultural

• Mi-8ATS is an agricultural version with fertilizer spraying devices. Created on the basis of Mi-8T.
• Mi-8MTSkh - agricultural helicopter. Created on the basis of Mi-8MT.

  Shock / Assault

• Mi-8AMTSh (export designation - Mi-171Sh ) is a transport and attack helicopter equipped with an armament kit equivalent to the Mi-24 and adapted for the use of night vision technology. At the Farnborough-99 air show, he received the name "Terminator."