by Danny John - SMH

Amid all the ructions caused by the rising - and now falling - cost of oil, one of the most controversial responses came from the airlines, which imposed fuel surcharges on ticket prices.

Everyone watches and talks about the price of a litre of petrol at the bowser, but many eyes are also trained on aviation levies.

And in fairness to small and large carriers alike, at least these levies are easy for consumers to understand - unlike the cost of petrol at your local service station, where prices shift in odd relationship to the cost of extracting oil from the ground, transporting, refining, distributing and marketing it.

The financial pressures that apply to jet fuel are the same that apply to what we pump into our cars every day. So it appears that the airlines work with a greater degree of transparency.

But before that notion triggers an outburst of bowser rage, let me add that is about as helpful as the airlines get.

They have, almost in unison, been quick to raise fuel surcharges at each and every sustained rise in the oil price and they have been reluctant to drop or remove the levies when the oil price has fallen.

For the best example of this, look at the rollercoaster ride of the oil price over the past year.

The market price of a barrel of oil rose over 12 consumer and industrial heart-stopping months to a record $US147 a barrel in July, then dropped to an equally staggering four-year low 10 days ago of $US32.40.

This, understandably, made the planning and management of fuel bills extremely difficult in corporate Australia, not least for the airlines given the sensitivity of consumers and the pressure on airlines to quickly return what they so eagerly took by way of additional charges on the cost of travel.

At the same time, airlines in Australia have had to cope with the dramatic fall in the value of the Australian dollar against the greenback. This has curtailed the room for manoeuvring, particularly because jet fuel is priced in US dollars.

Whereas hedging exercises would have protected domestic carriers against such steep increases in the past, hedging would have been to their detriment after the recent large falls.

But complaints that the airlines have been far too slow to pass on cost savings are also understandable.

Of the local duopolists, Qantas and Virgin Blue came to the party last week, albeit with rather differing outcomes.

Populist as ever, Virgin scrapped the $19 surcharge on one-way domestic trips and cut the levy on single international journeys by between $10 and $25.

The financial pressures at Qantas were no different, but it took a more tight-fisted approach. It reduced domestic fares by just $3, left its surcharge at $18, and cut international fares by between $10 and $30 a ticket, depending on the destination. Travellers going to Europe will still have to pay an additional $160 a ticket.

The interesting part of the Qantas announcement was that it projected its fuel bill for this financial year would still be $400 million higher than last year's bill.

In fact, that is a drop of $350 million on the annual estimate it made little more than four weeks ago.

Which raises a question: exactly how much lower does a four-year low in oil prices have to go before Qantas scraps its surcharge altogether?