What happened
An instructor pilot and his student pilot were returning from a cross-country training flight. The crew made three attempts to complete an instrument landing system (ILS) approach to the airport during heavy fog conditions. During each of the initial approaches, the instructor partially lost control of the aircraft but was able to recover. On the third attempt, the aircraft struck the ground before the instructor could effect a recovery.
The investigation
The instructor later complained of experiencing vertigo during the landing approaches. This physiological issue likely contributed to the partial loss of control experienced during the first two attempts and the subsequent collision with the terrain on the final approach.
Findings
The primary factor in this accident was the instructor's experience of vertigo while attempting to land in instrument meteorological conditions. The heavy fog significantly reduced visibility, increasing reliance on flight instruments which may have conflicted with the instructor's vestibular system.