A first consignment of upgraded Mi-8AMTSh assault/transport helicopters has been delivered to Russia's Ministry of Defense by Russian Helicopters.

The first consignment was composed of four aircraft, part of a long-term contract awarded last year, the company said, but no details were given as to the total number of helicopters to be delivered.

The upgrade variant of the Mi-8, aka Mi-17, have been redesigned to reduce maintenance, the company said.

It is fitted with VK-2500 engines, an upgraded and strengthened transmission and new TA-14 auxiliary power plants that generate improved thrust and power output. Increased lightweight metal cladding protects the crew and essential support systems, while batteries with enhanced capacities mean electrical systems can function autonomously for longer periods.

"The Mi-8AMTSh has been upgraded with a focus on operational efficiency and ease of maintenance," Russian Helicopters said. "The new helicopter now has a time between overhaul of 2,000 hours -- up from 1,500 -- and a service life of 35 years (up from 25), while operating costs across the life-cycle of the helicopter have been reduced by about 25 percent to 30 percent."

The aircraft is a twin-engine helicopter with a maximum speed of 155 miles per hour and a range of 289 miles. It can carry 30 troops or nearly 9,000 pounds of cargo internally.

Weaponry includes machine guns, rockets and missiles.

"The new helicopters will help strengthen our national defence capabilities," said Russian Helicopters Chief Executive Officer Alexander Mikheev. "Today the Russian Army can call on the latest technologies and equipment."

"Improving the capabilities of our helicopters is a core priority for us," said Ulan-Ude Aviation Plant Managing Director Leonid Belykh. "In conjunction with Moscow Mil Helicopter Plant, which designs Mi-8/17 helicopters, we are able to offer the Russian Defense Ministry the latest helicopters which combine their unique operating experience with the latest technologies."