The 75th percentile performance figures for airborne delay at Sydney are indicated in Figure 5. September performance met the target for the median (0.5 minutes) and was above the target for the 75th percentile (3.6 minutes). Compared to the same month last year, there was an increase in the airborne delay median (from -0.1 minutes) and 75th percentile (from 2.5 minutes) performance. The long‑term trend for airborne delay at Sydney is upwards. However, the 24‑month trend is flat.
Figure 5: Sydney airborne delay 75th percentile (last 24 months)
Click image to enlarge
The following commentary describes the notable airborne delay events during September in Sydney:
03 September (1800-1900 local) – Delay 7.1 minutes
- Concentration of demand due to the late arrival of several compliant aircraft during a low capacity period.
- Decreased capacity due to lower rates for showers did not allow this concentration to be absorbed which resulted in increased airborne delay.
06 September (0600-0700 local) – Delay 2.9 minutes
- Decreased capacity in the early morning due to Simultaneous Opposite Direction Parallel Runway Operations (SODPROPS).
07 September (1600-2000 local) – Delay 7.9 minutes
- Decreased capacity in afternoon due to multiple severe thunderstorms.
- Level 3 GDP Revision at 1830 local. Rate dropped to zero for 30 minutes and remained 10 to 14 lower than planned for the remainder of the evening.
- No arrivals for 49 minutes starting at 1804 local.
08 September (0600-0700 local) – Delay 2.8 minutes
- Concentration of demand during early morning due to off‑schedule international arrivals.
- Decreased capacity during this period due to tactical rates reduced for low cloud did not enable the concentration to be absorbed which resulted in increased airborne delay.
14 September (0900-1100 local) – Delay 7.9 minutes
- Reduced tactical rates due to unavailability of Instrument Landing System (ILS) for runway 34L.
- Runway configuration changed to 16 parallel to mitigate impact of ILS outage.
- Level 2 GDP Revision conducted to increase rates from 30 to 38.
19 September (1700-1900 local) – Delay 6.0 minutes
- Decrease capacity during afternoon period due to single runway operations required to continue for one hour later than planned.
26 September (1700-1900 local) – Delay 7.3 minutes
- Concentration of demand due to late non‑compliant and exempt flights during a busy period.
28 September (1800-1900 local) – Delay 4.4 minutes
- Decreased capacity due to thunderstorms during the busy evening period.
- Level 2 GDP Revision with rates lowered by two arrivals per hour.