I think it entirely unrealistic to expect people with babies and children to abstain from travelling - it is not unduly selfish to do so. However, some parents have next to no control over their children and they cause unacceptable disruption on flights. Our younger was less than three months old on his first flights (longer than the one you are proposing) and never cried the whole way. He was fed frequently during flights. His brother was not a lot older when he started flying. The trick is to have plenty food to offer and have lots of distractions (toys, colouring books, games, the lot) and pay as much attention to them as is necessary - but not fuss or regiment. For children old enough, explain in advance what to expect and go over it a few times, then give advance warning when each new thing is about to come. Children enjoy understanding processes and generally they like "systems" that they are familiar with. The seat belt rule is particularly important.