What happened
On July 10, 2018, a Boeing 737-800, registration LV-CBF, was preparing for a scheduled domestic flight at Aeroparque Jorge Newbery in Buenos Aires. Following instructions from the Tower Controller, the aircraft was cleared to hold at the head of runway 31. After a one-minute hold, the crew received takeoff clearance and began its takeoff roll.
During the acceleration phase, the flight crew observed an Embraer LV-GIK being moved by a tractor across the runway at taxiway 3W. The towed aircraft entered the active runway without communicating on the primary tower frequency. Recognizing the immediate danger, the crew performed a rejected takeoff at a low speed. Simultaneously, the tower controller issued an immediate instruction to abort the takeoff.
The investigation
The investigation examined communications between the surface and tower frequencies. Recordings confirmed that the operator of the LV-GIK had requested permission to begin towing from the industrial apron to the commercial apron via the surface frequency. While the controller authorized the movement via taxiway 3, the instruction included a specific restriction: the operator was required to request crossing authorization on the primary tower frequency before entering the runway. The operator acknowledged this instruction.
However, the investigation revealed a significant discrepancy in operational procedures. A new runway crossing procedure had been implemented on May 28, 2018, which required the two-step frequency communication process. While this was communicated to tower personnel via email, the investigation found that the procedure had not been effectively disseminated to all relevant stakeholders, and formal training sessions had been delayed.
Findings
- The primary cause of the incident was a runway incursion by a towed aircraft that crossed the active runway without obtaining the necessary authorization from the tower frequency.
- A new runway crossing procedure was implemented without providing adequate training to all personnel involved in the execution of the task.
- There were significant discrepancies between the updated procedures used by the air navigation service provider and the existing procedures used by airline maintenance personnel.
- The operator of the towed aircraft failed to execute the required frequency change and subsequent crossing request, likely due to an automated mental process based on long-standing, routine practices.
- The delay of one minute while the Boeing 737-800 held at the runway head may have contributed to confusion for the towing operator regarding the priority of the crossing movement.