What happened
On April 26, 2014, an AS355N helicopter, registration PR-HFC, was conducting a police mission over the caatinga vegetation in the state of Pernambuco. The aircraft, operated by the Brazilian Federal Police, was flying near Orocó to survey a restricted area.
During an attempt to land in the restricted zone, the aircraft yawed to the left, causing the tail rotor to strike a bush. The pilot immediately aborted the landing and performed a go-around, subsequently finding a safe location to land and inspect the aircraft. After the crew confirmed there were no immediate abnormalities, the helicopter returned to Orocable, PE. A technical inspection later revealed scratches on the tail rotor blades and damage to the impact fingers.
All five occupants (two pilots, one crew member, and three passengers) were uninjured, and the aircraft sustained only light damage.
The investigation
CENIPA's investigation focused on the flight dynamics and crew coordination during the critical landing phase. Investigators examined the approach profile, the environmental conditions of the restricted area, and the communication between the flight crew and the tactical operator. The investigation also reviewed the organizational training programs of the Federal Police's Operational Aviation Coordination (CAOP/DPF) regarding the integration of tactical operators into aerial missions.
Findings
- The crew's approach speed was excessive, leading to an improper approach path and a lack of attention to ground obstacles.
- The pilot failed to use effective pedal inputs to counteract the effects of the wind on the helicopter.
- Ineffective crew coordination and non-standardized phraseology between the pilots and the tactical operator led to a reduction in situational awareness.
- The tactical operator was not adequately adapted to this specific type of aerial operation.
- The organization lacked formal processes to evaluate the proficiency of tactical operators specifically for air-police missions.
- The crew experienced "tunnel vision," focusing more on the police activities on the ground than on the immediate hazards of the landing site.