Here is more detail of what I am getting at, plus one web link:
Here is a graph of weekly Brent Crude prices:
http://tfc-charts.w2d.com/chart/BC/W
"A" means April, O means October.
Many airlines first put on fuel surcharges in August, when prices were in the low 30s. Swiss, for example, doubled the surcharges in December, exactly when the price hit 50. Now it's at 40 and trending downwards.
Momo