Preflight Briefing and Flight Initiation
An instructor pilot and a student instrument pilot received a preflight weather briefing that forecast strong headwinds, mountainous terrain, severe turbulence, and pilot reports (PIREPs) of severe turbulence along the proposed flight route. Despite these conditions, they took off for a night instrument flight rules (IFR) training flight.
In-Flight Events
During the flight, the aircraft entered a mountain wave and subsequently descended into a mountain. Another aircraft in the area suggested that the descending aircraft make a 180-degree turn. However, there was no effort on the part of the pilot to maneuver the aircraft out of the mountain wave, nor did the Air Route Traffic Control Center (ARTCC) controller direct the aircraft to reverse course.