What happened
On May 27, 2019, a serious incident involving a loss of separation occurred at Leite Lopes Aerodrome (SBRP) in Ribeirão Preto, Brazil. An AS 350 B2 helicopter, registration PR-NIA, took off from runway 18, intending to fly to Orlândia. Simultaneously, an ATR-72-212A, registration PP-PTQ, operated by Passaredo Transporte Aéreo, was performing an RNAV (GNSS) approach to the same runway.
After takeoff, the PR-NIA performed a tight left turn toward its destination. While maintaining a trajectory parallel to the runway axis, the helicopter intersected the path of the PP-PTQ. At the moment of intersection, the helicopter was at approximately 700 feet and the turboprop was at 300 feet, resulting in a vertical separation of only 400 ft and no horizontal separation. The proximity was sufficient to trigger an Advisory warning on the PP-PTQ's Traffic Collision Avoidance System (TCAS). No injuries were reported among the crew or the 5/57 passengers on board the ATR-72, and no damage was sustained by either aircraft.
The investigation
CENIPA's investigation focused on the actions of the flight crews and the air traffic controller at the Ribeirão Preto Tower (TWR-RP). The investigation examined radar images, which showed the helicopter's turning radius was significantly smaller than that of a fixed-wing aircraft, contributing to the conflict.
Investigators analyzed the instructions provided by the tower, noting that while the controller issued warnings to the helicopter pilot to clear the runway axis and avoid interfering with the approaching traffic, the controller did not provide a specific heading to ensure safe separation. The investigation also reviewed the pilot's experience, noting that the PR-NIA pilot did not hold an IFRH rating and lacked experience flying under instrument flight rules.
Findings
- Inadequate pilot judgment: The pilot of the PR-NIA failed to establish sufficient separation from the approaching aircraft, incorrectly assuming that 400 feet of vertical separation was adequate for safety.
- Deficient air traffic planning: The TWR-RP controller did not issue a specific heading or course to the helicopter to guarantee separation from the PP-PTQ and inappropriately left the responsibility of defining the separation distance to the helicopter crew.
- Flawed decision-making: The helicopter pilot chose to maintain his intended course toward Orlândia despite being aware of approaching traffic and instructions to avoid the final approach path.
Safety action
- A recommendation was issued to the Airspace Control Department (DECEA) to work with INFRAERO to improve mechanisms and procedures for providing separation between aircraft operating within the Ribeirão Preto CTR.