I wrote a small Google App Script with Google Spreadsheets to track when flight tickets get cheaper in advance. I weekly tracked the minimum return-ticket price from Sydney to Colombo for a fixed departure date (07th of April 2014). The answer was, ticket prices get minimum in advance of 5 months in average. Due to the disappearance of Malaysian airliner, MH370, I noticed a sudden fall of Malaysian air-line ticket prices after 8th of March 2014. So I added two charts. 1st one doesn't includes deviations related to MH370. 2nd chart includes the relevant deviations.