Norwegian investigators have determined that weak altimeter procedures resulted in a Wideroe De Havilland Dash 8-300 crew’s forgetting to set and check the correct QNH pressure during an approach to ...

Altimeters measure atmospheric pressure, not true altitude, and are prone to inherent errors because real-world conditions rarely match the "standard atmosphere" they are calibrated against.

But with a QNH setting for the altimeter the aircraft would have been barely 120m above the airfield elevation. While still 15km from Tynda’s runway, the An-24 collided with trees at an altitude of ...