C.F.
Hi J.,
My husband is a private pilot, and he mostly flies Cessna 172s right now. I had the same concern when my now 2 1/2-year old son was born (I already knew that my 9-year old son could handle it), so I asked my pediatrician. Ironically enough, she told me that HER father had been a private pilot, too, and her family had been flying with him for years with no problems. In other words, she had firsthand knowledge, and I felt confident in her answer when she said that my own son should be perfectly fine flying in a 172. I've always made sure to prepare plenty of bottles (sippy cups now) for the flight, and made sure he had them in his hands when we took off, during the flight, and again at landing. If your son uses a pacifier (mine refused), even better. The sucking motion is the important thing; it helps keep their ears clear, since they are too young to understand yawning and swallowing on command, LOL.
Hope this info helps. Good luck, and enjoy the flight!