Here it is:
The airport is obviously a much more official organization than a fictional facility inside a 14 year old game. However, it is likely that the Black Mesa Logo itself has been copyrighted at some point in time by someone.The only real explanation is that it is a clue. Not only is it an ARG that will inevitable lead us to the next E3 announcement of Half-Life: Revelations, but it is proof, that Valve is not working alone. In fact, this new game is being developed under the supervision of the Federal Government of the United States.
At first, you can clearly see that the plane has a semi-significant jet stream left behind it. In order to not make the logo obvious, this jet stream is not the main focus of the logo itself, and is subliminally trying to tell us, that the Combine are in fact, not the enemies of the early years of the Half-Life Universe, and that it is actually the Federal Government that transformed into telekinetic bugs, hell-bent on human enslavement.
The jet-stream shows that planes carried and dumped chemicals intended to give us all cancer, mitigate/cause global warming, or to seed the skies with electrically conductive materials as a part of a massive electromagnetic super weapon program based around the High Frequency Active Auroral Research Program.
If this isn’t proof enough that the next Half-Life game will release a twist, look at the tree in the picture. Obviously there are no trees in Black Mesa. So they must be referring to a new and improved Black Mesa. Sound familiar? Not only will Half-Life: Revelations be announced at E3, but BMS will RELEASE at E3. Of course, this can only be a sign of an even more complicated ARG.
What will it involve? Will we got morse code sound files where we have to time the sounds and align them to bible verses? Only time will tell.