What happened
An incident occurred involving a PA-28 and an ATR aircraft during approach operations. The pilot of XDI was instructed to track behind the ATR, but was unaware that the ATR was a transport category aircraft performing a straight-in approach. As the PA-28 turned onto the base leg of the circuit, the pilot assumed the ATR had already landed or was on short final, leading to a failure to check for traffic on long final. Meanwhile, the crew of the ATR was aware of other traffic in the vicinity but did not visually locate the PA-28 until a TCAS TA was triggered. This proximity resulted in the ATR crew initiating a missed approach.
The investigation
The investigation examined the communication and monitoring procedures between the pilot and the controller. It was found that while the controller had established a sequencing plan, they did not require a readback of the instruction to follow the ATR, which prevented the confirmation of the pilot's understanding. Furthermore, the controller's attention shifted to a third aircraft, which reduced the visual scanning of the two primary aircraft involved. This lack of monitoring, combined with the pilot's failure to report that the ATR had not been sighted, meant the developing conflict went unnoticed by both the crew and the controller.
Findings
- The pilot of XDI failed to sight the ATR as instructed and did not notify the controller that the aircraft was not visible before turning onto the base leg.
- The crew of the ATR did not visually assess the position of the PA-28 relative to their flight path until the TCAS TA activated.
- The controller did not seek confirmation that the pilot of XDI had successfully sighted the lead aircraft.
- The controller's focus on a third aircraft interrupted the effective monitoring of the separation between the PA-28 and the ATR.