The answer to your question really depends on what you're asking, as you're not very clear regarding the nature of the operation. Is this a Part 121 airplane on a maintenance, reposition, or other ferry flight? Is it an airplane that normally only operates under Part 91, on a special flight authorization ("ferry permit")?
You can actually read this for yourself. Have you read the regulation to see what is required, or did you simply ask?
You'll require the flight manual(s), as required by the applicable regulation governing that aircraft and its certification, and registration. What those manuals are depends on the nature of the aircraft and who is operating it and for what purpose. See 14 CFR 91.9.
All applicable placards and marking are also required to be present, or amended per 91.213.
https://www.ecfr.gov/cgi-bin/text-id...91_19&rgn=div8
You're required to have airworthiness and registration certificate, per 91.203.
https://www.ecfr.gov/cgi-bin/text-id..._1203&rgn=div8
If you're operating internationally, you'll need a radio station license.
Weight and balance information ("loading information" must be included in the approved aircraft flight manual, per 14 CFR 23.2620, or 25.1583.
https://www.ecfr.gov/cgi-bin/text-id...12620&rgn=div8
https://www.ecfr.gov/cgi-bin/text-id...12620&rgn=div8
The acronym ARROW is sometimes used: Airworthiness certificate, Registration Certificate Radio station license (international only), Operating limitations (typically found in the aircraft manual, but may be separate), and weight and balance or loading information.
There may be additional documentation depending on the operation, aircraft type, country or state of registry, etc.