Dear "ia7va6o1" I have read this posting about your 6 year old parakeet who having difficulty flying and is acting quiet today. I worry when birds are quiet and uncoordinated. This is a sign that he is likely having some underlying illness such as infection or other metabolic problem. I am sure you already realize that the best course of action would be to get him to a vet asap (today) for evaluation and treatment if he has an underlying disorder. There are emergency centers that see birds. If you are unable to get him to a vet, the best thing is to keep him quiet and warm ... warmer than usual because sick birds do well when they are kept warm.
So, in summary, it would be best to get him to an avian vet asap. If that's not possible, keep him quiet and extra warm. I wish there were more things you could do at home. Please let me know if you have more questions about this. I hope he will be feeling better soon.