Link Airways Saab 340 Experiences Instrumentation Fault During Sydney Approach

The Australian Transport Safety Bureau releases its final report on a Saab 340 aircraft's descent below the glideslope during approach to land at Sydney Airport

On October 24, 2022, a Link Airways Saab 340 aircraft encountered an instrumentation fault while on approach to Sydney Airport, resulting in the aircraft descending below the glideslope. The incident occurred during an instrument landing system (ILS) approach to runway 34 left.

According to the report by the Australian Transport Safety Bureau (ATSB), the pilots were presented with erroneous on-slope indications without any failure warning due to the instrumentation fault. As the approach continued, the crew noticed the aircraft was not descending as expected. "The captain increased the descent rate before re-engaging the autopilot," the ATSB report stated. This led to the aircraft descending significantly below the glideslope.

Recognizing the deviation, the crew initiated a missed approach. They subsequently identified the erroneous glideslope indications and were able to complete a safe landing using a different approach type.

Why this matters: The incident highlights the critical importance of accurate instrumentation and pilot attentiveness during aircraft approaches. Instrumentation faults, even without clear failure indications, can lead to potentially hazardous situations if not promptly identified and corrected by flight crews.

While the precise source of the error could not be determined during the investigation, Link Airways developed and implemented several maintenance-related safety measures in response to the incident. These included a standardized component reinstallation procedure and additional guidance for maintenance personnel.

The ATSB's investigation into the incident underscores the ongoing efforts by aviation authorities and operators to identify and mitigate risks associated with instrumentation faults. "The operator developed and implemented several maintenance-related safety measures following the incident," the ATSB noted, emphasizing the proactive steps taken by Link Airways to enhance safety procedures and prevent similar occurrences in the future.

Key Takeaways

• Link Airways Saab 340 encountered instrumentation fault during ILS approach to Sydney.
• Erroneous on-slope indications led to aircraft descending significantly below glideslope.
• Crew initiated missed approach, identified fault, and completed safe landing on different approach.
• Incident highlights importance of accurate instrumentation and pilot attentiveness during approaches.
• Link Airways implemented maintenance-related safety measures to prevent similar occurrences.