I know a lieutenant can be chief engineer or chief of Security but can a lieutenant be first officer you tell me. – The preceding unsigned comment was added by 74.101.11.249 (talk).

I'd suggest you read the article to help answer your question. As we only deal in canon information, talk pages are not for speculations about what lieutenants might or might not do.--31dot 22:56, February 9, 2012 (UTC)