Flight below minimum sector altitude following missed approach at Launceston

What happened

During an approach to Launceston, the flight crew of VH-XMO, a Boeing 73 and 737 (implied by registration/context as a commercial aircraft), performed an instrument landing system (ILS) approach due to poor weather. Because of the weather conditions, a missed approach was anticipated. Following the missed approach, the captain initiated a left turn to reposition the aircraft for a second attempt. However, the turn was halted on a south-easterly heading, which directed the aircraft into a different airspace sector. This resulted in the aircraft flying at 4,400 ft within a sector requiring a minimum sector altitude (MSA) of 5,800 ft. Air traffic control (ATC) subsequently issued a safety alert for terrain proximity and instructed the crew to climb immediately.

The investigation

The investigation examined the flight path and the briefing procedures used by the crew. While a standard approach briefing was conducted, it failed to include a specific plan for how the aircraft would be manoeuvred after the missed approach. Because Launceston Tower was closed at the time, the airspace below 1,500 ft was uncontrolled Class G, meaning the crew needed to obtain ATC clearance before manoeuvring beyond the published missed approach path. The investigation found that the crew's decision to turn left into a sector with a higher MSA was not coordinated with ATC, and the lack of a detailed go-around briefing contributed to the confusion regarding altitude and tracking requirements.

Findings

• The flight crew did not discuss subsequent manoeuvring or flight path intentions during the initial approach briefing.
• The aircraft entered a sector with a 5,800 ft MSA while only at an altitude of 4,400 ft.
• The lack of a detailed go-around briefing meant there was no shared understanding between the pilot and co-pilot regarding terrain clearance and ATC coordination.
• The aircraft was operating in a sector where the required altitude was not maintained, though no 0 fatalities or injuries occurred and the aircraft was not in immediate danger of collision.