Sneezing, coughing and vomiting could induce airborne transmission, especially in a crowded airline cabin.
The CDC upgraded from N-95 facial masks , to N-100, to improved particulate respirators, and transparent facial shields
since mucus membranes (eyes, nose, and throat) are the most susceptible receptors to the Ebola virus.
The Ebola virus, if airborne, can remain active as a contaminant for up to two hours outside the host.
There is a significant difference between artificially aerosolized Ebola virus (as done experimentally) and the natural shedding mechanisms from infected people.
It takes contact with bloody bodily fluids to catch Ebola. Thus, only people adjacent to a symptomatic Ebola patient would be in any danger, and only if that person vomited, sneezed, or otherwise exposed the healthy passenger to contaminated bloody bodily fluids.
Another factor to consider is that the air inside airplanes is filtered and very dry. These two conditions make survival of microorganisms or viruses highly unlikely.
If you are next to someone who is visibly sick, it is probably a good idea to move, regardless of what you think the illness is. And keep your hands clean and watch what you touch.