The Mi17V5 helicopter, which crashed with Chief of Defence Staff (CDS) Bipin Rawat and 13 other people on board on Wednesday, is an advanced military transport chopper that has been with the Indian Air Force 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.
However, IAF's Mi17V5 chopper has been involved in quite a few incidents in the last decade.
One of these choppers with the IAF crash-landed in eastern Arunachal Pradesh on November 8. However, the two pilots and three crew members suffered just minor injuries.
Six people on board IAF's Mi17V5 helicopter escaped unhurt on April 3, 2018, after it crashed near the Himalayan shrine of Kedarnath in Uttarakhand.
On October 7, 2017, a Mi17V5 helicopter crashed near Tawang in Arunachal Pradesh while it was heading for the China border, killing all seven armed forces personnel onboard.
On June 15, 2013, one of these helicopters crashed while returning from Kedarnath on a rescue mission during the Uttarakhand floods. A total of eight people, including five crew members, were killed in this accident.
Nine IAF personnel were killed around 10 km from Jamnagar airbase in Gujarat on August 30, 2012, when two of these choppers crashed into each other.
Twelve defence personnel were killed on November 19, 2010, when an Mi17V5 helicopter carrying them crashed near Tawang in Arunachal Pradesh.
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.
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 inducted 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.