Yes, The TSA officially doesn't require it. What some airlines require is another thing. Many gate agents follow prompts on their screens to do their job and really have no idea what the rule is. So you will be ask for it when you use any Delta connection carriers because the agents are just checking boxes. If you don't jumpseat on Delta connection you can still go if there is a seat in the back. I believe that the above is a pretty good gauge for the rest.
Call the Passport office (sorry don't have the number, google). Anyway, stay on hold forever till you get a hold of a person, be nice and mention you are a commercial pilot and need it for work. They expedited mine an no cost. Very friendly about it too. Had it like 3 days later via express mail.