N147UA 747SP United ( c/n: 21548 )
United 747SP N147UA was operating as United Airlines flight UA815, a direct service from LAX – Los Angeles USA to SYD – Sydney Airport.
The planned flight time was 14 hours 38 minutes, and the aircraft carried fuel for 16 hours 17 minutes.
Because of equipment unserviceability and crew duty time limitations, the planned departure time was delayed by some 13 hours. The aircraft had departed Los Angeles at the maximum brakes release weight of 315740 kilograms, which included 153300 kilograms of fuel. The maximum fuel capacity for the aircraft was 154960 kilograms.
The flight proceeded without recorded incident and the crew contacted Sydney Arrivals Control at 1844 hours, when the aircraft was 200 nautical miles (370 kilometres) east of Sydney. The controller advised that holding would be required, with an expected duration of 10 to 15 minutes. The aircraft was subsequently cleared to descend from flight level 420 to flight level 210, with a requirement to reach the new level by 60 miles by Distance Measuring
Equipment (DME) from Sydney.
The aircraft entered a holding pattern at 60 DME at 1908 hours. Sydney Airport was closed to arriving aircraft at 1900 hours, because of thunderstorm activity. This information was relayed by the controller at 1905 hours by virtue of an all-stations call. However, as indicated by the subsequent transmissions, that call was not heard by the crew of the aircraft.
The crew made two requests for an expected approach time, and were advised at 1912 hours that the delay was anticipated to be about 10 minutes.
At 1923 the crew reported that a fuel emergency situation would be declared if clearance was not forthcoming in 5 minutes, and at 1925 the crew reported a remaining fuel endurance of one hour.
They were advised that Sydney was closed to all operations because of thunderstorms. A fuel emergency was declared at 1928, and the crew requested approval to conduct an approach to Sydney. This was refused and the aircraft was directed to the RAAF base at Williamtown, where a safe landing was made at 1949 hours. Fuel remaining after landing was 7250 kilograms. Sydney Airport re-opened for normal operations at 1952 hours.
Sydney Operations Control had imposed a requirement for arriving aircraft to carry an additional 30 minutes fuel endurance to allow for the thunderstorms at Sydney. However, the particular
storm took over 2 hours to cross the Sydney Airport airspace.
The Airport was closed from 1900 to 1918 hours, and from 1924 to 1952. It was evident that the 30 minutes fuel requirement was inadequate under the existing circumstances.
United Airlines is one of three overseas based carriers which has been approved by the Department of Aviation to be responsible for its own operational control. This control is exercised from Chicago, USA.
For aircraft on the Los Angeles – Sydney route, approval to proceed past a point located to the east of Norfolk Island is dependent on the fuel state of the aircraft and the expected weather conditions at Sydney. The necessary clearance had been obtained in this case.
However, by subsequently closing Sydney Airport to all aircraft and denying the United flight the opportunity to conduct an approach, Sydney ATC over-ruled the operational control which the
airline had been approved to exercise. When remaining fuel endurance is requested, Australian pilots are taught to provide a figure which relates to the total fuel on board. However, the United Airlines policy is for the pilot to give a figure based on the remaining flight fuel only i.e., the figure given does not include the 30 minutes mandatory reserve.
This anomaly needs to be explored and resolved in order that pilots and ATC are aware of the actual fuel situation, so that priorities can be accurately established.
The fuel policy of United Airlines provides for a minimum of 17000 pounds (7710 kilograms) to be available on arrival at Sydney. This is sufficient to allow the aircraft to go around from the landing approach in the event of the preceding aircraft blocking the intended runway, proceed to a suitable emergency alternate aerodrome (Williamtown), and land with the mandatory reserve fuel intact.
The pilot in command had elected to divert to Williamtown before the last possible time for such a diversion. His decision was probably related to the advice given by ATC that Sydney was closed because of a stationary thunderstorm over the aerodrome.
As a result of the investigation of this incident, the Bureau makes the following recommendations.
- The question of whether overseas carriers should abide by the fuel policy of the state of registry or the fuel policy
of Australia should be resolved.
- The right of ATC to deny approaches and otherwise impose operational control on overseas carriers which have
been approved to exercise this control themselves should be examined.
- The current policy of requiring 30 minutes extra fuel be carried when thunderstorms are forecast to affect
aerodromes for periods of up to 30 minutes should be reviewed, in the light of the difficulty of accurately assessing
the speed and duration of such storms.
- That ATC ensure, that information regarding the change in status of an aerodrome has been received by all
aircraft affected by that change