[TomGuy]

The most prominent assumption is that the missles, if in the US, would be related to airplanes/airports. However, we can't necessarily assume that. Consider:

Boxcutters are to airplanes as surface-to-air missles are to ?????.

They could be intended for a totally non-aircraft related purpose.

[goody2shooz]

Of course. A weapons use is only limited by the lack of creativity (deviency?) exhibited by the individual who wields said weapon.

I just happened to use the LAX runway as an expample of a physical sighting used as an intelligence confirmation. Sheesh!