Final Report


On 28 April 2017, at about 0936 Central Standard Time, a Cessna 310R, registered VH‑COQ (COQ), was on approach to land at Tindal Airport, Northern Territory.

Tindal Airport has bi-directional hookcables, used to stop military jets in an emergency, positioned at both ends of the runway. The air traffic control tower had opened for a scheduled military jet departure and was therefore active when COQ made its approach to land. During the tower opening checklist procedure, the tower controller annotated the ‘cables’ check was completed. About 21 minutes after the tower opened, COQ requested a clearance to land from the base leg position for runway 14. The tower controller scanned the control console, noted that both hookcable pushbutton lights were green, and cleared COQ to land on runway 14.

When COQ was on short final approach to land on runway 14, the pilot noticed the approach end hookcable was raised. The pilot adjusted their aim point beyond the hookcable and landed without incident. The pilot of COQ reported the position of the hookcable to the tower controller, who then rectified the situation.

This incident highlights the risks of expectation bias. The tower controller observed two green lights on the control console, but did not recognise they were the UP indicators. However, the design of the indicators, where green lights can have two different meanings, removes the usefulness of the colour of the lights in determining whether the hookcable is up or down. 

The pilot detected the problem in time to avoid trampling the hookcable during the landing. However, pilots should take note that the hookcables will automatically raise in the event of a power failure.


Aviation Short Investigations Bulletin - Issue 62

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