Mil Mi-26

https://en.wikipedia.org/wiki/Mil_Mi-26

The Mil Mi-26 (Russian: ???? ??-26, NATO reporting name: Halo) is a
Soviet/Russian heavy transport helicopter. Its product code is izdeliye 90.
Operated by both military and civilian operators, it is the largest and most
powerful helicopter to have gone into series production.

The Mi-26 was the first factory-equipped helicopter with a single, eight-blade
main lift rotor. It is capable of flight in the event of power loss by one
engine (depending on aircraft mission weight) thanks to an engine load sharing
system. While its empty weight is only slightly higher than the Mi-6's, the
Mi-26 has a payload of up to 20 metric tons (44,000 lb). It is the second
largest and heaviest helicopter ever constructed, after the experimental Mil
V-12. The tail rotor has about the same diameter and thrust as the four-bladed
main rotor fitted to the MD Helicopters MD 500.

The Mi-26's unique main gearbox is relatively light at 3,639 kg (8,023 lb) but
can absorb 19,725 shaft horsepower (14,709 kW), which was accomplished using a
non-planetary, split-torque design with quill shafts for torque equalization.
The Mil Design Bureau designed the VR-26 transmission itself, due to the normal
gearbox supplier used by Mil admitting that it could not design such a gearbox.
The gearbox housing is stamped aluminum. A split-torque design is also used for
the 12,500 lb (5,670 kg) gearbox on the American three-engine Sikorsky CH-53K
King Stallion.

As of 2016, the Mi-26 still holds the Fédération Aéronautique Internationale
world record for the greatest mass lifted to 2,000 metres (6,562 ft) – 56,768.8
kilograms (125,153.8 lb) on a flight in 1982.

In July 2010 a proposed Russian-Chinese development of a 33-ton heavy-lift
helicopter was announced.

Rostvertol, the Russian helicopter manufacturer, was contracted to refurbish and
upgrade the entire fleet of Mi-26s serving in the Russian Air Force, estimated
to be around 20 helicopters. The upgraded aircraft is comparable to a new
variant, the Mi-26T. Contract completion was planned for 2015. The contract also
covered the production of 22 new Mi-26T helicopters. Eight new-built helicopters
were delivered to operational units by January 2012. Under the 2010 contract, 17
new-production helicopters were delivered by 2014.

In all, Rostvertol delivered fourteen Mi-26s to domestic and foreign customers
in the period 2012–14 and six helicopters in 2015. Deliveries to the Russian Air
Force were continued in 2016 and 2017.


Role
Heavy lift cargo helicopter

National origin
Soviet Union/Russia

Manufacturer
Rostvertol

Design group
Mil Moscow Helicopter Plant

First flight
14 December 1977

Introduction
1983

Status
In service

Primary users
Russian Air Force
Aeroflot
Ukrainian Air Force
Indian Air Force

Produced
1980–present

Number built
316 as of 2015

Unit cost

US$20–25 million (Mi-26TS, 2011)

In the spring of 2002, a civilian Mi-26 was leased to recover two U.S. Army
MH-47E Chinook helicopters from a mountain in Afghanistan. The Chinooks,
operated by the 160th Special Operations Aviation Regiment, had been employed in
Operation Anaconda, an effort to drive al Qaeda and Taliban fighters out of the
Shahi-Kot Valley and surrounding mountains. They found themselves stranded on
the slopes above Sirkhankel at altitudes of 2,600 metres (8,500 ft) and 3,100
metres (10,200 ft). While the second craft was too badly damaged to recover, the
first was determined to be repairable and estimated to weigh 12,000 kilograms
(26,000 lb) with fuel, rotors, and non-essential equipment removed. That weight
exceeded the maximum payload of 9,100 kilograms (20,100 lb) at an altitude of
2,600 metres (8,500 ft) of the U.S. military's Sikorsky CH-53E.

The Mi-26 was located through Skylink Aviation in Toronto, which had connections
with a Russian company called Sportsflite that operated three civilian Mi-26
versions called "Heavycopters". One of the aircraft, aiding in construction and
firefighting work in neighboring Tajikistan, was leased for $300,000; it lifted
the Chinook, flew it to Kabul, then later to Bagram Air Base, Afghanistan to
ship to Fort Campbell, Kentucky, U.S. for repairs. Six months later, a second
U.S. Army CH-47 that had made a hard landing 100 miles (160 km) north of Bagram
at an altitude of 1,200 metres (3,900 ft) was recovered by another
Sportsflite-operated Mi-26 Heavycopter.

Specifications (Mi-26)

General characteristics
Crew: Five: 2 pilots, 1 navigator, 1 flight engineer, 1 flight technician
Capacity:
90 troops or 60 stretchers
20,000 kg cargo (44,090 lb)

Length: 40.025 m (131 ft 3¾ in) (rotors turning)
Rotor diameter: 32.00 m (105 ft 0 in)
Height: 8.145 m (26 ft 8¾ in)
Disc area: 804.25 m2 (8,656.8 ft²)
Empty weight: 28,200 kg (62,170 lb)
Loaded weight: 49,600 kg (109,350 lb)
Max. takeoff weight: 56,000 kg (123,450 lb)
Main rotor speed: 132 RPM
Powerplant: 2 × Lotarev D-136 AI-136 (or PD-12V altpw) turboshafts, 8,500 kW
(10–11,398 shp or ~ 10–12,000 of PD12V) each

Performance
Maximum speed: 295 km/h (159 kn, 183 mph)
Cruise speed: 255 km/h (137 kn, 158 mph)
Range: 800 km (430 nmi; 500 mi) ()
Ferry range: 1,920 km (1,036 nmi, 1,190 mi) (with auxiliary tanks)
Service ceiling: 4,600 m (15,100 ft)




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