What happened
On March 6, 2021, a Tecnam P2002 MKII, registration LV-S084, operated by Aerotec Argentina S.A., was conducting a mountain flight demonstration near Uspallata, Mendoza. The flight departed from the Aerotec Argentina S.A. aerodrome in Rivadavia for a mission focused on mountain flight familiarization.
After approximately 90 minutes of flight under visual meteorological conditions, the aircraft was navigating at low altitude through the pre-cordillera region. During the flight, the pilot noted that the aircraft was falling below the altitude of a preceding aircraft and was unable to climb over the approaching terrain. Despite applying full power, the aircraft could not maintain its flight path. As the descent rate increased, the pilot attempted to pull back on the controls, but the stall warning activated. The pilot subsequently reduced power just before the aircraft struck a mountain slope. The nose wheel and propeller made initial contact with the upward slope, followed by the left wing, leading to a significant impact and subsequent wreckage.
The investigation
Due to COVID-19 travel restrictions and the remote nature of the accident site, investigators were unable to visit the scene directly. The investigation relied on testimonies from the crew and witnesses flying in the area.
Investigators examined the operational context, noting that while the crew had attended theoretical briefings on mountain flying the previous day, this was their first experience operating in such high-altitude terrain. Previously, their operations had been conducted in the Buenos Aires province, where terrain elevations typically did not exceed 150 feet. The investigation focused on the impact of high-density altitude on aircraft performance and the crew's adherence to established safety altitudes.
Findings
- The aircraft was operating in an environment with elevations between 11,000 and 13,000 feet, which significantly degraded engine and aerodynamic performance.
- The aircraft was flying below the minimum safety altitude of 1,000 feet prescribed by Argentine Civil Aviation Regulations (RAAC) for mountainous terrain.
- High-altitude operations caused a reduction in engine power due to the naturally aspirated engine's lack of turbocharging, alongside decreased lift due to lower air density.
- The investigation suggests the aircraft likely entered a state of low-speed stall due to the inability to maintain altitude while navigating the terrain.
Safety action
- Flight schools and operators should incorporate risk assessments regarding the degradation of aircraft performance in high-altitude environments.
- It is critical to maintain the regulatory minimum separation of 1,000 feet from terrain when operating in mountainous regions.