WWF helicopter vanishes in Nepal
A Mi-17 helicopter.
The helicopter has been identified as a Russian Mi-17
A helicopter carrying 24 people, including WWF conservationists from the US, Canada and Australia, has gone missing in eastern Nepal.

The helicopter lost radio contact during bad weather. It is not clear whether it crashed or was forced to make an emergency landing.

The helicopter took off from the mountainous district of Taplejung.

A Finnish diplomat, two Russians and several Nepalis were on board, including a junior forestry minister.

Map
Two prominent Nepali conservationists and a renowned Nepali anthropologist were also on board.

An American aid worker from the organisation USAid was among seven foreigners.

The helicopter party was returning from a landmark ceremony to hand over the Kangenjunga conservation area from the government to the local community.

The helicopter, identified as a Russian-made Mi-17, had been on a 20-minute flight to a local airport, where the passengers had been due to take a flight to the capital, Kathmandu.

Bad weather forced a rescue helicopter to suspend its search, but two rescue teams were heading to the area on foot, setting off from opposite directions.

The two Russians on board were part of a four-strong crew.[url][/url]http://news.bbc.co.uk/2/hi/south_asia/5373624.stm

Well, they found it... but not good news. 

http://news.yahoo.com/s/nm/20060925/wl_nm/nepal_helicopter_dc_12

To get an idea of how rugged the terrain is in the area, consider that in the article it says the bodies would have to be carried for two hours to the nearest suitable chopper LZ.
I'd imagine the crew was very seasoned, but I'd be very leery of flying anything around there in bad weather... scary.