The 75th percentile performance figures for airborne delay at Sydney are indicated in Figure 5. December performance met the target for the median (0.5 minutes) and did not meet the target for the 75th percentile (4.3 minutes). Compared to the same month last year, there was an increase in the airborne delay median performance (from 0.4 minutes) and 75th percentile performance (from 2.9 minutes).
The long‑term (48-month) 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
(minutes – 75th percentile)
(Contributing causes to increased delays)
|02 December||19-20||8.7||Concentration of demand due to off‑schedule internationals and late non‑compliant flights during evening peak period.|
|04 December||19-20||6.5||Reduced capacity due to an aircraft requiring return for safety issue.|
|05 December||09-11||7.5||Reduced capacity due to low cloud persisting longer than forecast (tactical rates reduced).|
|06 December||07-08||3.4||Reduced capacity due to low cloud persisting longer than forecast (tactical rates reduced).|
|07-11||12.9||Reduced capacity due to low cloud persisting longer than forecast. Level 2 GDP Revision with rates reduced.|
|11 December||07-10||9.8||Concentration of demand due to off‑schedule international flights during morning peak period.|
|12 December||07-12||11.4||Reduced capacity due to low cloud persisting longer than forecast (tactical rates reduced).|
|13 December||19-22||7.0||Diversions for thunderstorms and military airspace restrictions in the early evening. Level 3 GDP Revision (Ground Stop) at 1900L due to heavy storms. Only three arrivals in 20L hour.|
|14 December||09-13 &
|14.0||Level 2 GDP Revision in morning due to persistent low cloud and increased thunderstorm risk.
Thunderstorms in afternoon and evening resulted in increased traffic due to flights diverting to Sydney from nearby airports. Level 3 GDP Revision (Ground Stop) at 1600L due to increasing airborne delay.
|16 December||19-20||3.7||Reduced capacity due to thunderstorm during evening peak period.|
|7.5||Concentration of demand due to off‑schedule international flights during morning peak period.
Concentration of demand due to late non-complaint flights during evening peak period.
|19 December||18-21||5.7||Reduced capacity due to thunderstorm and runway changes during evening peak period.|
|20 December||17-22||9.7||Reduced capacity due to thunderstorms in the late afternoon and evening. Several periods of significantly reduced arrivals led to a Level 2 GDP Revision and a Level 3 GDP Revision.|
|21 December||09-11||6.4||Reduced capacity in morning due to Precision Runway Monitor not available (tactical rates reduced).|
|22 December||09-12||8.9||Reduced capacity in the morning due to tower staffing constraints (tactical rates reduced).|