Are Australian Met Services Up To Standard?

He will also be given a computer-calculated flight plan which will show the minimum fuel permissible for the flight. If an alternate airport is required because the destination forecast is below certain limits then this will be already built into the computer flight plan. The Captain’s objective is to uplift the minimum fuel he considers necessary for the flight bearing in mind that additional fuel loaded costs money because of the extra weight of the aircraft.

I will now give some statistics regarding the diversion of Qantas flights for 1984-85. During this period we flew 34,763 747 sectors for 171 diversions. Diversions occur for several reasons but the primary one is the state of the weather at the destination. If the destination is forecast preflight to be below alternate criteria then an alternate will be planned and the fuel loaded accordingly. The flight will then proceed to the destination and then divert to the alternate if the weather at the destination is unsuitable. Diversions also occur because on certain long sectors, insufficient fuel is available in the preflight stage to reach the planned destination and still have the required reserves in the tanks.

For 1984-85 almost all sectors on the Qantas network with the exception of Los Angeles to Sydney would be able to meet this requirement. I have deleted Los Angeles/Sydney sectors from all calculations on diversions because to include them (17 diversions in 270 flights) would show Australia up in an even more unfavourable light.

My calculations show that flights with destinations outside Australia diverted 96 times in 22,497 flights, or 0. 43%, while flights with Australian destinations diverted 75 times in 12,266 flights, 0. 61%. I realise that the percentage of diversions is low in both cases but the figures were taken over a large number of sectors and I believe it is valid to say that diversions in Australia are far higher (40% in fact) than for the rest of the world. This is despite Australia having generally excellent weather conditions by typical world standards.

I can only put this down to a combination of our Air Traffic Control and the Met service. Most of the diversions, judging from the incident reports submitted, suggest that both en route and terminal forecasts are not up to scratch. It is not uncommon to lose 15 minutes en route on a 7-hour flight into Australia because of inaccurate en route wind forecasts – this then causes you to perhaps not have sufficient fuel planned to remain at the destination and hence an en route diversion occurs.

For terminal forecasting, the low cloud is almost never a problem while fog is. I don’t believe our forecasters have any idea how to accurately predict fog, especially at Perth, as we had 7 diversions in 436 Singapore/Perth sectors.

Weather in Australia is generally good when compared to the European winter so there must be some significant reasons for the greater incidence of diversions at Australian airports. I would suggest that inaccurate en route forecasts coupled with bad terminal forecasts is one of the primary reasons for the high number of Qantas diversions in Australia. However it is very difficult to point the finger solely at the Met service because other factors are obviously important. One is the practice of Australian ATC to close airports (a situation peculiar to Australia and to be examined in a future article) and the other, to a much lesser extent, is the lack of CAT 2 ILS equipment.

Why is the Australian Met Service below world standards? One of the primary reasons is cost. By that I mean that the amount of money available from the Government to pay for the service is not sufficient to provide pilots with accurate information. Another reason is the physical geography of the country whereby it is difficult to obtain consistent met information from a vast region of the interior.

Perhaps the service should be more accountable. As a suggestion, the Met service should be asked to pick up the tab for the additional landing and navigation charges incurred when an international aircraft diverts from its planned destination because of an inaccurate forecast. Additionally incident reports submitted by Qantas pilots about inaccurate forecasting in the Australian area are invariably not answered to the pilots’ satisfaction.

Perhaps I am being hard by suggesting that the Met service is the principal cause for the 40% higher diversion rate in Australia but if they aren’t then what is the main reason for this excessive diversion rate?