Airborne is a technical term. The Flu isn't airborne either.
Actually, it is.
http://en.wikipedia.org/wiki/InfluenzaInfluenza can be spread in three main ways:[71][72] by direct transmission (when an infected person sneezes mucus directly into the eyes, nose or mouth of another person); the airborne route (when someone inhales the aerosols produced by an infected person coughing, sneezing or spitting) and through hand-to-eye, hand-to-nose, or hand-to-mouth transmission, either from contaminated surfaces or from direct personal contact such as a hand-shake. The relative importance of these three modes of transmission is unclear, and they may all contribute to the spread of the virus.[4][73] In the airborne route, the droplets that are small enough for people to inhale are 0.5 to 5 µm in diameter and inhaling just one droplet might be enough to cause an infection.[71] Although a single sneeze releases up to 40,000 droplets,[74] most of these droplets are quite large and will quickly settle out of the air.[71] How long influenza survives in airborne droplets seems to be influenced by the levels of humidity and UV radiation, with low humidity and a lack of sunlight in winter aiding its survival.[71]
As the influenza virus can persist outside of the body, it can also be transmitted by contaminated surfaces such as banknotes,[75] doorknobs, light switches and other household items.[2] The length of time the virus will persist on a surface varies, with the virus surviving for one to two days on hard, non-porous surfaces such as plastic or metal, for about fifteen minutes from dry paper tissues, and only five minutes on skin.[76] However, if the virus is present in mucus, this can protect it for longer periods (up to 17 days on banknotes).[71][75] Avian influenza viruses can survive indefinitely when frozen.[77] They are inactivated by heating to 56 °C (133 °F) for a minimum of 60 minutes, as well as by acids (at pH <2).[77]
