A few days ago, a colleage pointed met at AirServices Australia's new fancy flight tracker, which allows you to watch planes coming and going in the airspace around Sydney airport. There are plenty of things not to like - MS Virtual Earth ;), the nasty click-through EULA that you have to agree to before you even find out what the site provides...

But, that aside, it's fairly cool. Planes, flying, around Sydney! Results from noise-level meters, so you can see just how noisy your new suburb is going to be. Even details about the planes - type of plane, altitude, flight numbers..

So today there was a tragic accident involving two planes with trainee pilots. SMH have a video online which shows the flight tracker, and shows the two planes involved colliding (and then one of them dropping off the radar - literally). According to the timestamps superimposed on the video, the crash happens just after 11:23am

The site lets you see historical data: in the box on the lower-left, un-tick the "Show Current Flights" button, then use the controls to choose the day and time you'd like to look at. So it's easy enough to go back to 11:20am and run through the next few minutes and see the crash for yourself.

Except... that it's not. There are no planes in that area at that time. In fact, there's no light aviation at all. Someone has excised all light aviation records between 11:00am and 11:59:16am. If you set the timer to start art 10:59, you see a whole bunch of planes:


suddenly dissapear:


It's not a subtle removal either, even if you ignore all the planes which freeze and then vanish from the graph. There's a nice graph showing you the number of movements per hour for the day - spot what's odd about today:


I fail to understand this. I... just fail. I really don't understand why this is considered sensitive, and why it's been removed.