Software engineer Robert Heaton had an epiphany on a recent flight. WiFi on aircraft comes at a cost, yet access to frequent flyer accounts (and other airline services) can be accessed for free…

I logged in to my JetStreamers Diamond Altitude account and started clicking. I went to my profile page, where I saw an edit button. It looked like a normal button: drop shadow, rounded corners, nothing special. I was supposed to use it to update my name, address, and so on.

But suddenly I realised that this was no ordinary button. This clickable rascal would allow me to access the entire internet through my airmiles account. This would be slow. It would be unbelievably stupid. But it would work.

During the rest of the flight I wrote PySkyWiFi. PySkyWiFi is a highly simplified version of the TCP/IP protocol that squeezes whole HTTP requests through an airmiles account, out of the plane, and down to a computer connected to the internet on the ground. A daemon running on this ground computer makes the HTTP requests for me, and then finally squeezes the completed HTTP responses back through my airmiles account, up to me on my plane.

Using some Python programming and after some iterations came PySkiWiFi.

Here’s the basic idea: suppose that I logged into my airmiles account and updated my name. If you were also logged in to my account then you could read my new name, from the ground. You could update it again, and I could read your new value. If we kept doing this then the name field of my airmiles account could serve as a tunnel through the airplane’s wi-fi firewall to the real world.

This tunnel could support a simple instant messaging protocol. I could update my name to “Hello how are you.” You could read my message and then send me a reply by updating my name again to “Im fine how are you.” I could read that, and we could have a stilted conversation. This might not sound like much, but it would be the first step on the road to full internet access.

DISCLAIMER: you obviously shouldn’t actually do any of this

Here’s how it works (and here’s the source code).

Read the entire fascinating article here.