Final Report


On 15 July 2015, a Cessna 210L aircraft, registered VH-TCI (TCI), was inbound to Broome Airport, Western Australia. The pilot was the only person on board. At about 1037 Western Standard Time (WST), when the aircraft was about 40 NM from Broome, the pilot made an inbound call on the Broome air traffic control Tower frequency. The Tower controller was unable to hear what the pilot said, and responded by broadcasting that the calling aircraft was transmitting a carrier wave only, with no voice modulation.

The pilot checked the aircraft radio equipment, but was unable to identify any faults. The pilot set the transponder code to indicate a loss of two-way communications, and established the aircraft in a holding pattern to the north of Broome, just outside Broome Class D airspace at an altitude of about 5,000 ft.

At about 1046 (about 9 minutes after the pilot of TCI reported making an inbound call that was only transmitting a carrier wave), the pilot of a Cessna 208, VH-PGA (PGA) made an inbound call on the Broome Tower frequency. At that time, the aircraft was about 43 NM from Broome at about 6,500 ft. On board were the pilot and 12 passengers. The Tower controller acknowledged the call and cleared PGA to enter controlled airspace (Class D airspace), tracking to Broome via Willies Creek, and descending to 1,500 ft.

At about 1053, the pilot of PGA heard the aircraft’s traffic information system alert ‘traffic 12 o’clock same level’ (or similar words), indicating that an aircraft (subsequently identified as TCI) was directly ahead of PGA, at the same altitude, and within 0.25 NM. The pilot of PGA sighted the aircraft (subsequently identified as TCI) and observed it flying in the opposite direction on the right side, in close proximity. At about the same time, the pilot of TCI recalled that an aircraft (later identified as PGA) was seen to fly overhead.

The Tower controller was subsequently able to establish limited one-way communication with the pilot of TCI (who was still unable to transmit voice communication). The Tower controller then broadcast a telephone number for the pilot, and asked the pilot to make contact on that number if possible. The pilot of TCI contacted the Tower controller by telephone on the number provided, and was cleared to follow PGA to Broome, via Willies Creek.

At about 1103, the Tower controller cleared TCI for a visual approach as number two to land, PGA landed ahead of TCI at about 1104. TCI landed without further incident.

This occurrence highlights the fundamental importance of communication – where the quality of communication is compromised for any reason, an effective pilot lookout becomes increasingly important. Awareness of the limitations of the see and avoid principle may assist pilots in developing effective lookout techniques. The ATSB publication Limitations of the See-and-Avoid Principle provides information on the limitations on seeing and avoiding another aircraft and measures that can be taken to increase the chance of sighting other traffic.


Aviation Short Investigations Bulletin - Issue 48

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