The Mi17V5 helicopter, which crashed with Chief of Defence Staff (CDS) Bipin Rawat and 13 other people onboard on Wednesday, is an advanced military transport chopper that has been with the Indian Air Force (IAF) since 2012.
Manufactured by Russian Helicopters' subsidiary Kazan, the helicopter has an onboard weather radar and is equipped with the latest generation of night vision devices.
It also has the new PKV-8 autopilot system and a KNEI-8 avionics suite. It can carry a maximum take off weight of 13,000 kg and maximum payload weight of 4,000 kg.
Read also: Coonoor helicopter crash: IAF says CDS Bipin Rawat, his wife are among the 13 dead
India had in 2008 signed a deal with Russia to induct 80 Mi17V5 medium lift helicopters for strengthening its chopper fleet for humanitarian and disaster relief missions and transport operations.
The contract was later expanded for delivery of 151 Mi17V5 helicopters.
The first batch of these helicopters came to India in September 2011.
In February 2012, the IAF had formally Mi17V5 helicopters from Russia to enhance its operational capabilities including carrying troops and cargo to high altitude areas.
The helicopter is fitted with a self-defence system against heat seeker missiles, heavily-armoured cockpit, vital systems and components.
"The Mi-17V-5 military transport helicopter is designed to carry personnel, cargo and equipment inside the cargo cabin or on an external sling, drop tactical air assault forces and reconnaissance and sabotage groups, destroy ground targets and carry the wounded," said Russian government's defence exports company Rosoboronexport.
According to the company, this helicopter can achieve a maximum speed of 250 km per hour.
The helicopter is fitted with advanced TV3-117VM engines.
It is the most technically advanced helicopter of Mi-8/17 family of helicopters, and incorporates the best engineering solutions from previous generations of helicopters.