8 months old is quite hard to travel with alone as the baby can't sit alone, can't leave alone even if you need to go to the tiolet. Prepare all the necesities needed specially the milk formula, bring with you even his water,sterilized, you can buy the baby water available in the supermarket so you would not need to sterilized it. Milk should be measured ready and bring more extra feeding bottle, empty or with sterilized water readily measured for every feed. Bring extra nappies,blankets, clothes and take enough sleep before your flight. Because surely, you will be sleepless through the long flight. If you are breast feeding, take plenty of soup and milk and water in the flight so you will not run out of milk for him.Most importanly, you must have all the things pack in a light back pack and make it as light as possible. And take a direct flight. Make frends at the airport so as to have someone to help you in your luggage, specially in filling papers. Have a big or many pockets to put in your passport, or ticket or tissue for easy reach, big pocket to temporarily hold the feed bottle. Don't forget the child's favourite toy or book to read.
I hope these helps, have a happy flight.Take care..