What happened
On February 1, 2014, at Sorocaba Aerodrome (SDCO) in Brazil, a collision occurred between two aircraft during ground operations. The Cessna C-208B Caravan, registration PT-MEO, had recently landed and was taxiing along taxiway "J". Simultaneously, a Robinson R-44 helicopter, registration PP-MCI, was parked near a hangar in sector "E" and was in the process of starting its engine.
As the helicopter's main rotor blades began to rotate, the right wingtip of the taxiing Cessna C-208B struck one of the helicopter's main rotor blades. The impact caused substantial damage to the leading edge and wingtip of the PT-MEO, while the PP-MCI sustained damage to a rotor blade and the main rotor mast head. Despite the significant damage to both aircraft, all occupants—including the crews and passengers of both aircraft—were unharmed.
The investigation
CENIPA's investigation focused on the lack of effective communication and situational awareness between the two crews. The aerodrome lacked an active control tower or ground control, relying instead on a coordination frequency (FCA) for pilots to communicate intentions.
The investigation established that while both crews claimed to be monitoring the frequency, they failed to hear each other's transmissions. It was noted that the crew of the PT-MEO had momentarily switched to a different frequency to contact the airport administrator, which may have caused them to miss the helicopter's startup intentions. Furthermore, the investigation found that the helicopter's parking position, necessitated by the proximity of a nearby building, left its rotor arc directly in the path of the taxiway, creating an unavoidable conflict with the passing aircraft.
Findings
- Ineffective communication: The use of the coordination frequency was not effective, as neither crew successfully perceived the other's intentions.
- Failure in cockpit coordination: Monitoring of the aerodrome coordination channel was inadequate, preventing the enhancement of situational awareness.
- Improper piloting judgment: The pilot of the Cessna C-208B failed to properly evaluate the clearance required for the helicopter's rotor arc, deciding to proceed with the taxi maneuver despite the proximity of the parked aircraft.
- Lack of perception: Neither crew adequately perceived the approaching or moving aircraft, preventing any evasive action before the collision.