The Century Formation – Mil Mi-8/17/171 “Hip”

A Mil Mi-171 of the Czech air force in 2014.
A Mil Mi-171 of the Czech air force in 2014.

The Eastern All Rounder

This long lived family of transport helicopters created by the Mil design bureau comprised of the Mi-8, 17 and 171 and collectively known as “Hip” in NATO’s code naming system is still going strong and showing no signs of slowing down with age.

More than five decades after the first flight of its prototype and over 12,000 units built; this legendary family of aircraft has been used by civil and military operators in over 60 countries and built in a myriad of variants and sub variants that would make the most learned of experts break into sweats to sort out.

At the heart of this longevity and world wide popularity is a level of adaptability to a wide assortment of missions and environments as well as to new systems and technologies that few other helicopters in its class can match.

Mil “Hip” Milestones

1958: Single engine prototype designed using Mil Mi-4 “Hound” as a basis.
1960: Approval for development of a twin engine prototype granted.
1961: First flight of single engine prototype.
1962: First flight of twin engine prototype.
1963: Main rotor design changed from four blades to five.
1964: Mass production commences.
1967: Mil Mi-8 introduced to Soviet military service.
1969: First flight of Mil Mi-14 “Haze” amphibious helicopter development of Mi-8.
1975: Mi-14 “Haze” enters military service.
1977: Mi-8MT variant enters Soviet military service.
1981: Mi-8MT introduced to the export market as Mi-17.
1991: Production of Mi-8AMT begins, Mi-8AMT designated Mi-171 for export purposes.
2008: License production of “Hip” helicopters begins in China.
2011: 50th anniversary of prototype’s first flight.

Czech Mi-17 marked as a trainer in 2013.
Czech Mi-17 marked as a trainer in 2013.

A Product of One-upmanship

As popular as the aircraft family has become over the years, its beginnings were not smooth. Before the 1950s were out, Mikhail Mil proposed the idea of a two engine, turbine powered helicopter to replace his piston powered Mi-4. The Soviet military, being satisfied with the Mi-4, were luke-warm to the idea at first; however, Mil tried presenting it to them a second time as a development of the Mi-4 rather than an outright replacement and in doing so got approval to design and build a prototype which was designated V-8.

While the V-8 had a single turbine engine as opposed to its modern descendants’ twin turbine arrangement, the addition of the second engine is often attributed to a 1959 diplomatic trip taken by Nikita Khrushchev to America. Khrushchev was said to be very impressed with the Sikorsky S-58 helicopters he was shuttled around in during his visit and wanted to be certain he had something superior to transport the American president when the reciprocal visit was made to the Soviet Union.

After returning home, Khrushchev took a test flight in an Mi-4 modified for VIP transport. Mil took the opportunity to convince Khrushchev that the V-8 would be a more appropriate machine but required two engines to be completely up to the job. Khrushchev gave Mil the approval to develop a twin engine prototype before the V-8 had flown for the first time.

While the Soviet government took the first production Mi-8s as passenger and VIP aircraft in the mid 1960s, it was not until the later 1960s that the Soviet military started seeing value in the machine and eventually took it into service.

Slovak air force Mi-17 in 2013.
Slovak air force Mi-17 in 2013.

Trading the Dog for a Hippo

The Mi-4 “Hound” had proven itself a success internationally and Mikhail Mil kept certain aspects of the aircraft when setting about designing what would become the Mi-8. Most notably, he kept the earlier design’s clam shell cargo doors which made up the rear of the fuselage and allowed vehicles and larger items to be carried internally. As the doors were completely removable, they also allowed the rapid boarding and deployment of foot soldiers or paratroopers. Ahead of the tail and clam shell doors, the aircraft was redesigned completely.

The Mi-8 not only had the advantage of turbine power, it also had double the lifting ability of the Mi-4. In common with its forerunner, the Mi-8 adapted well to the armed helicopter role as well as being robust and serviceable in spartan operating conditions.

What really set the “Hip” apart was its unprecedented adaptability not only to a wide variety of missions, but also to a wide variety of climactic conditions. Equally at home in the Antarctic, jungles or deserts; there is almost nowhere the “Hip” family can’t be operated.

This flexibility has seen the helicopter serve both civil and military users well in the high mountains of Afghanistan and Pakistan, the rain forests or Asia and South America, the deserts of the Middle East, the grasslands of Africa among many other environments. In fact, the current standard of the aircraft is approved for operations in temperatures ranging from -50 to 50 degrees Celsius.

The NATO code name was not unknown to operators of the type in former Warsaw Pact nations and there have been more than a few crew patches, pieces of nose art and other such things featuring comical depictions of the hippopotamus playing on the code name created in association with the aircraft.

Looking at the aircraft, with its blunt nose and sausage like fuselage, it’s not at all difficult to see its resemblance to a hippo.

Croatian Mi-171 in 2008.
Croatian Mi-171 in 2008.

Acting Newer and Newer

Through it’s life, the “Hip” family has seen almost non-stop development and modification, much more than many other aircraft. This has created an aircraft with a very convoluted family tree that features many overlaps and multiple designations given to the same model.

The first major development of the Mi-8 after it first entered service was the Mi-8MT; it is through the Mi-8MT that the Mi-17 was born. These two aircraft are an excellent example of the overlaps which exist in the “Hip” lineage as they are the same machine. Mi-8 simply denotes machines made for the domestic Soviet/Russian market while Mi-17 denotes export market models.

The Mi-8MT came about after the Mi-14 “Haze” amphibious naval helicopter was developed from earlier Mi-8 models. While the Mi-14 was ultimately different enough from the “Hip” line to deserve its own separate terminology; what the Mi-8MT inherited from the Mi-14 was more powerful engines and transmission along with a redesigned main rotor.

Another major change came to the “Hip” line in 1991 with the introduction of the Mi-8AMT and its export counterpart, the Mi-171.

Of the many external changes made, the most noticeable is certainly the replacement of the rear clam shell cargo doors with a single piece retracting cargo ramp. Other notable changes include the re-positioning of the cabin air conditioning unit to a spot higher on the right side of the fuselage near the engine compartment.

Internally, the newest versions have very modern cockpits with many of the old analog instruments replaced by multi-function digital displays and western avionics.

As testament to the adaptability of these aircraft, many older members of the family have been overhauled and retrofitted with avionic systems which came in with later family members.

A Czech Mi-171 in 2012 with a variety of modernization items attached.
A Czech Mi-171 in 2012 with a variety of modernization items attached.

Staying on Top of the Game

While the fall of Socialism saw many militaries and civil organisations discard their former Soviet made equipment for western produced machines, the change in politics only served to find new customers for the “Hip” when western buyers expressed interest in it.

At the time of writing, the “Hip” family is still very much in production and taking pride of place in the catalog of Russian Helicopters, the descendant company of Mil.

Beyond newly build airframes, the “Hip” has also traditionally done quite well for itself on second hand markets.

Beyond the continued production in Russia and China, a worldwide network of service centres has been established to support the aircraft wherever they might be and a licensed overhaul and modernization facility exists for the type in the Czech Republic.

As it stands, there really seems to be no end in sight for this family of helicopters. Five decades haven’t slowed it down in the least bit and it looks quite fit to do another five decades easily.

Learning More

Here are links directly to the Mi-8/17 and Mi-171 pages on the Russian Helicopters company site:

http://www.russianhelicopters.aero/en/helicopters/civil/mi-817.html

http://www.russianhelicopters.aero/en/helicopters/military/mi-817.html

http://www.russianhelicopters.aero/en/helicopters/civil/mi-171a2.html

This link will take you to the website of LOM Praha, the Czech company licensed to overhaul and modernize the “Hip” and an overview of their work with the aircraft:

http://www.lompraha.cz/en/mi-8-17-171-helicopters-maintenance-and-upgrades

http://www.lompraha.cz/en/modernization-of-aviation-technology

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s