What happened
On September 26, 2006, at approximately 19:45 local time, an amateur-built Herculino, registration EC-ZRI, crashed at the Rozas Aerodrome in Lugo, Spain. The aircraft had been conducting flight tests and several takeoffs and landings throughout the day. Following a climb to approximately 5,500 ft and a subsequent descending spiral, the pilot established a left base pattern for runway 22.
During the flight, the pilot communicated via radio that they were approaching runway 04, despite actually being positioned over runway 22. After being corrected by the aircraft's constructor on the ground, the pilot attempted to reposition the aircraft toward runway 04. While flying at an altitude of approximately 40 m with low airspeed, the pilot executed a sharp right turn followed by a very tight left bank. This maneuver caused the aircraft to enter a stall, resulting in an inverted impact with the center of the runway. A post-impact fire completely destroyed the aircraft. The pilot sustained fatal injuries due to polytrauma, though witnesses were able to recover the body from the wreckage before the flames spread.
The investigation
The CIAIAC investigation focused on the aircraft's mechanical condition, human factors, and the aerodynamic sequence of the stall. Investigators confirmed that the aircraft held a provisional airworthiness certificate and had passed a technical inspection by the DGAC just ten days prior. No mechanical failures or component malfunctions were identified as contributing to the accident.
Regarding human factors, the investigation examined the pilot's spatial orientation. The pilot's incorrect radio report regarding their position suggested a period of transient spatial disorientation following the high-intensity spiral maneuver. Furthermore, the investigation noted that the aircraft was not equipped with a stall warning device, meaning the pilot relied entirely on airspeed monitoring and physical cues.
Findings
- The primary cause of the accident was an aerodynamic stall resulting from a very tight turn performed at low altitude and low airspeed.
- A contributing factor was likely a period of momentary spatial disorientation following a rapid descent spiral, which led to the pilot's incorrect perception of their position relative to the runway headings.
- The pilot's limited experience in this specific aircraft (approximately 10 hours of flight time) may have hindered the ability to recognize the onset of the stall in time to recover.