For most babies air travel would not be considered appropriate. This brings us to the point when can an infant travel. Before you are going to fly out evaluate the following pointers.
The age of your baby
The doctors are going to discourage air travel shortly after birth. Most new born are in a phase where their immune system is developing and with air travel catching an infectious disease is around the corner. If you are choosing to travel with an infant rely on a hand sanitizer or wash your hand on a frequent basis which avoids contact with the fellow air travellers.
The ears of your baby
The cabin pressure that is exerted during course of a travel would cause temporary changes in air pressure paving way for ear pain. In order to pacify during take-off give them a bottle of milk or pacifier to suck during the initial phase of travel. It would be sensible to time feedings of your baby so that they are not hungry during such times. In the last couple of weeks if a baby has some form of ear infection or an ear surgery just ask your doctor how early you can travel with a baby. Their nod of approval is needed before you are planning to fly.
The noises in an air cabin are on the louder side particularly during the phase of take-off. You can consider using cotton balls or headphones to restrict noise. To limit exposure of noise small air plugs could be an option that would put them to sleep without much noise.
The breathing of your baby
When a flight takes off the air pressure existing in the air cabin would be a lot more than the air pressure that you find on the land. This temporary change in oxygen levels would not be a major cause of concern for the healthy babies. But in case if you have a premature baby, or someone with chronic heart or lung problems or it could be breathing issues, then consult a doctor before you are planning to fly.
The safety seat of your baby
There are infant car seats that are certified for your baby. Most airlines allow babies to travel on the lap of their mothers or fathers but experts suggest that certified air seats are a definite must for air travel. In case if you are not planning to purchase tickets for your baby, then ask for open seats when you are flying. If no one is assigned those seats it can be given to your baby.
Do not fall into the temptation of giving your baby an over the counter medicine when you are travelling. Example would be Benadryl that would encourage the baby to sleep during the course of air travel. This is a practice that is not recommended at all as sometimes medication can have an opposite effect. The doctor can guide you on how to make air travel safe for your baby.