Sangma, the then Meghalaya community development minister, three legislators and six others were killed in a helicopter crash in September 2004.

Punjab governor Surendra Nath and nine members of his family were killed when the government's Super-King aircraft crashed into high mountains in bad weather July 9, 1994 in Himachal Pradesh. Nath was then acting Himachal governor also.

But many were lucky.

Former prime minister Morarji Desai famously escaped when his Air India One crashed in Assam in November 1977. P.K. Thungon, who was the then Arunachal Pradesh chief minister and was accompanying him, also survived.

Congress leader Ahmed Patel and union ministers Prithviraj Chauhan and Kumari Selja had a similar miraculous escape in 2004 in Gujarat.

Former Punjab chief minister Amarinder Singh and minister Pratap Singh Bajwa survived one such chopper accident when it hit electrical wires soon after taking off in Gurdaspur in September 2006.

Punjab Deputy Chief Minister Sukhbir Singh Badal escaped unhurt after his chartered helicopter made an emergency landing in Ferozepur Aug 30.

BJP president Rajnath Singh and vice president Mukhtar Abbas Naqvi had a miraculous escape last year when they were travelling to Rampur in Uttar Pradesh. The chopper landed close to a pile of dry grass that caught fire. The pilot immediately took off again and landed at a safe place.

Rajasthan Chief Minister Ashok Gehlot escaped after his helicopter fell on a tree in Chiru district in 2001.

Aviation experts say the primary culprit in most helicopter accidents is the pilots' tendency to operate under Visual Flight Rules (VFR) instead of the Instrument Flight Rules (IFR).

IFR allows pilots to fly by just relying on the instrument panels even if they cannot see anything outside the cockpit windows. The VFR, on the other hand, are used by pilots to fly by relying on what all they can see from the cockpit.