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ATM network performance: Perth

Airborne delay

The 75th percentile performance figures for airborne delay at Perth are indicated in Figure 11. July performance for the median (0.0 minutes) and the 75th percentile (2.4 minutes) met the targets. Compared to the same month last year, there was an increase in the airborne delay median performance (from -0.2 minutes) and 75th percentile performance (from 2.0 minutes).


Figure 11: Perth airborne delay 75th percentile (last 24 months)

Notable events

Table 8 describes the notable airborne delay events during July in Perth.

Day Local Time Delay

(minutes – 75th percentile)

Event Descriptions

(Contributing causes to increased delays)

3 July 18-19 6.0 Off-schedule internationals and non-compliant flights during busy period plus one flight that returned back to Perth.
4 July 10-11 &


14.4 Morning: Thunderstorm at airport resulting in ground staff off ramp areas and arrival delays.

Evening: non-compliant flights, medical flight and two emergency flights during period of low visibility (reduction from planned rates).

17 July 10-11 4.3 Compression of compliant flights during a busy period led to an increase in delay.
18 July 10-11 5.0 Cloud lower than forecast (reducing rates below plan). Compression of compliant flights during this busy period also contributed to an increase in delay.

Table 8: Notable event descriptions for Perth.