What happened
On March 21, 2010, at approximately 17:15, an ATEC V.O.S. Zephyr 2000 ultralight aircraft, registration CS-UOE, departed from the Castelo Branco airfield for a planned 90-minute recreational flight. The aircraft, owned by the National Authority for Civil Protection (ANPC) and operated by the Aeroclube de Castlo Branco, was carrying a 44-year-old pilot and a 37-year-old passenger.
At approximately 18:42, the aircraft approached the airfield at a very low altitude, estimated at roughly 100 feet, while flying north-south. After crossing the runway, the pilot initiated a steep right-hand climbing turn with a bank angle of approximately 60 degrees. During this maneuver, the aircraft reached the top of the climb at low airspeed and high engine power, subsequently entering an acute descent. The aircraft struck the ground in a thicket of tall vegetation approximately 700 meters south of the hangar. The impact was severe, causing the aircraft to capsize and remain inverted. Both occupants sustained fatal injuries due to the high deceleration forces of the impact.
The investigation
The GPIAAF investigation examined the aircraft's mechanical condition, the pilot's flight experience, and the regulatory framework. Examination of the Rotax 912 S engine and the engine monitoring system revealed that the engine was fully operational and producing power until the moment of impact, with the pilot actually reducing power during the final descent. The investigation also noted that the aircraft's onboard parachute was not deployed.
Investigators also reviewed the pilot's flight records, noting that while the pilot held a valid ultralight license, he had only accumulated 14 hours and 35 minutes of flight time in this aircraft type over the previous 12 months, and had not flown for four months prior to the accident.
Findings
- The primary cause of the accident was the loss of control of the aircraft at a low altitude, which left no opportunity for recovery.
- The pilot's lack of recent flight experience and proficiency was a significant contributing factor, as the maneuver attempted was beyond his demonstrated skill level.
- The aircraft was flying at an altitude below the 1,000-foot minimum required for overflying populated areas under VFR regulations.
- There were no mechanical failures or engine power losses identified prior to the impact.
Safety action
- The investigation recommended that the National Civil Aviation Authority (INAC) consider revising ultralight pilot qualification regulations. The current rules allow pilots to maintain valid qualifications for up to three years without recent flight activity; the report suggests indexing qualification validity to recent flight activity to ensure the maintenance of pilot proficiency.