There have been a series of chopper crashes in the high altitude areas of Arunachal Pradesh.
The Tawang helipad is one of the highest in the world, located at an altitude of 11,000 feet, bordering China's Tibet region.
Seventeen people, including two children and three crew members, were killed when a Pawan Hans helicopter crashed at Tawang in Arunachal Pradesh on 19th April 2011 afternoon.
In November last year, 11 Air Force personnel and an army lieutenant colonel were killed when an Air Force Mi-17 helicopter crashed at Tepsha village in the Bomdir area, about 6km from Tawang. The chopper was on its way to Guwahati from Tawang when it crashed on a wooded hillock.
In August last year, a cabin crew member Dhananjay Roy fell to his death when an IAF chopper was flying from Namsai to Tezu on routine passenger service.
In June 2009, 13 defence personnel were killed when an aircraft — AN32 — crashed near Mechuka.
In May 2001, Arunachal Pradesh Education Minister Dera Natung and five others were killed when their Pawan Hans craft crashed near Tawang because of poor visibility.
In November 1997 in which Minister of State for Defence NVN Somu and three others were killed when their Cheetah helicopter hit a 1,300 feet peak about 40 kms from Tawang.
Arunachal Pradesh has witnessed a large number of air crashes since World War II, when the Allies lost many aircraft in the eastern Himalayan mountains.
The US defence department estimates that about 400 Allied airmen were killed in crashes, caused mainly by poor visibility, along the route.
The flight path over Arunachal Pradesh, used by American aircraft to ferry supplies to Chinese forces battling the invading Japanese, was nicknamed “the Hump” by the Allies.
Wrecks of some of the US aircraft are still found in the Arunachal mountains.