That depends on each pilot. I know some FO's and Captains that don't do any extra fly. I know some that did a ton this year. I flew with one Captain who was giving his whole line away (we have very good trip trade/giveaway rules) and was doing ALL his flying for 1.5 times pay. He told me he was on par to make over 300K this year. Anyway, it's up to each individual and their needs. My first five years I did very little extra flying. This year, because some of my older kids needed a little help, I flew alot. As a six year FO I will make over 170K this year. I did work hard for the money, but it beats not even having the option of making extra.