A DHC-6 Twin Otter impacted a mountainside in Nepal February 2014 when the pilot in command lost situational awareness in instrument weather conditions. He descended even though the copilot warned not to, for three times.
Nepal Airlines flight RA183 took off from Pokhara, bound for Jumla with 18 persons on board. Upon leaving Pokhara Control Zone, the pilot in command realized that the direct track was not possible due weather and decided to proceed via a more southern track. During the flight the pilots were experiencing uncomfortable flying environment due to unfavorable weather conditions. Attempting to avoid the weather, the pilots had to fly up and down and changing the heading. Finally being unable to penetrate the weather ahead, the captain decided to divert to Bhairahawa, the nearest airport. However, the captain did not take into consideration the surrounding terrain and continued descent turning right. The cockpit voice recorder showed that the copilot had warned the captain not to descend or turn.
The aircraft initially slashed a small tree and finally impacted a ridge. Due to the heavy impact the left wing was first disintegrated and then the front part of the aircraft toppled over beyond the ridge with several subsequent impacts.
The wreckage was located the following morning at an altitude of 7190 feet (2192 m). There were no surivors.