Does it really matter what percentage of the fare is considered a "fuel surcharge"? Airlines(just like every other business in the world) charge a total price that is equal to what a customer is willing to pay. If you want to stay in business you don't set your price based on your costs, you set it based on what the value is to the customer, and what the market will bear. Ideally you price your product differently for each customer based on what the value is to them, so you can extract $$$$$ from someone who places a high value on your product, yet still get some positive revenue from someone who doesn't value your product quite as high.