Found this one on the Coffee Spoons blog. It is originally from an infographic created by Sergio Peçanha of the NY Times.
The Sankey diagram shows cargo flights supposedly loaded with arms, from Doha and Riyadh (among others) to Turkey, and from Zagreb to Amman. All supposedly destined for onward transport to Syria. The “arrow widhts are proportional to the number of flights”.
An additional 2012/2013 time line shows the flight dates and their density. Interesting. One mustn’t confuse the Sankey arrows with number of arms being transported, as there might have been different planes and consequently different cargo loads.
Now I think I should also be looking for a “civil” version, with pax being transported on commercial airline flights.