What happened
On November 28, 1989, an EMB-712, registration PT-NXZ, departed from Sorocaba, São Paulo, on a visual flight rules (VFR) navigation training flight destined for São Carlos. The aircraft was operated by Aeroclube de Sorocaba and carried an instructor and a student pilot.
During the flight, the aircraft collided with the Serra de Itaquer andqueri. The impact occurred in a mountainous area with dense vegetation. The aircraft struck the terrain in a nearly frontal attitude, slightly banked to the left, resulting in substantial damage to the airframe and the deaths of both pilots at the scene.
The investigation
CENIPA's investigation established that the flight was being conducted for student pilot training. While the instructor was properly qualified and the aircraft was airworthy and within weight limits, the crew was not instrument-rated (IFR), and the aircraft was not certified for instrument flight.
Investigators found that the meteorological conditions were unfavorable for VFR operations, as a cold front had introduced a layer of cumulus clouds with bases at 2,000 feet, partially obscuring the higher terrain of the mountain range. Evidence from the wreckage and witness accounts suggested the crew may have been attempting to maintain visual contact with the ground while navigating through deteriorating weather, leading them approximately 5km off their intended route.
Findings
- Adverse weather conditions: The presence of low cloud layers made visual navigation difficult and obscured portions of the terrain.
- Flight indiscipline: The crew operated under conditions that required instrument capabilities they did not possess.
- Inadequate flight planning: The instructor failed to properly account for the deteriorating weather along the route.
- Inadequate managerial supervision: The flight school lacked sufficient operational oversight to prevent instructors from making isolated decisions to depart under marginal weather conditions.
- Improper navigation tools: The aeronautical chart used by the crew contained numerous erasures and errors, which may have hindered accurate navigation.