Required aircraft certificates on board14 CFR 91.203 Civil aircraft: Certifications required
A civil aircraft must carry an appropriate and current airworthiness certificate and an effective U.S. registration certificate (or one of the alternatives the rule lists). The airworthiness certificate must be displayed at the cabin or cockpit entrance where passengers or crew can read it.
By the ATIS Alerts team · Updated October 15, 2026 · Regulation text current as of October 14, 2026. A study aid based on the official regulation text, not legal advice or an FAA interpretation.
At a glance
- An appropriate and current airworthiness certificate must be in the aircraft (a)(1).
- An effective U.S. registration certificate issued to the owner must be in the aircraft, or one of the listed alternatives (a)(2).
- The airworthiness certificate must be displayed at the cabin or cockpit entrance, legible to passengers or crew (b).
- A fuel tank in the passenger or baggage compartment needs a Part 43 installation and a copy of FAA Form 337 on board (c).
- Civil airplanes using U.S. airports must meet the Part 34 fuel venting and exhaust emissions rules (d).
In plain English
Section 91.203 is about paperwork that has to be physically in the aircraft. Paragraph (a) says no person may operate a civil aircraft unless it has within it two documents: an appropriate and current airworthiness certificate, and an effective U.S. registration certificate issued to its owner. With a few listed exceptions, such as a special flight permit, the airworthiness certificate must show the registration number assigned to the aircraft under Part 47 or 48.
Paragraph (a)(2) lists alternatives to the standard registration certificate. For operation within the United States, it also accepts the second copy of the Aircraft Registration Application as provided for in 47.31(c), a Certificate of Aircraft Registration as provided in Part 48, or a registration certification issued under the laws of a foreign country.
Having the airworthiness certificate somewhere in the aircraft is not enough. Paragraph (b) requires it to be displayed at the cabin or cockpit entrance so that it is legible to passengers or crew.
The last two paragraphs cover special cases. Paragraph (c) applies when a fuel tank is installed inside the passenger compartment or a baggage compartment: the installation must have been done under Part 43, and a copy of the FAA Form 337 authorizing it must be on board. Paragraph (d) requires civil airplanes, domestic or foreign, operating into or out of a U.S. airport to comply with the Part 34 fuel venting and exhaust emissions requirements.
Common mistakes
- Carrying the airworthiness certificate but not displaying it. Paragraph (b) requires display at the cabin or cockpit entrance.
- Assuming this section lists every document a pilot carries. It covers the airworthiness and registration certificates (plus the Form 337 case in (c)); other documents come from other rules.
The official text
14 CFR 91.203 as published on the eCFR, current as of October 14, 2026.
(a) Except as provided in § 91.715, no person may operate a civil aircraft unless it has within it the following:
(1) An appropriate and current airworthiness certificate. Each U.S. airworthiness certificate used to comply with this subparagraph (except a special flight permit, a copy of the applicable operations specifications issued under § 21.197(c) of this chapter, appropriate sections of the air carrier manual required by parts 121 and 135 of this chapter containing that portion of the operations specifications issued under § 21.197(c), or an authorization under § 91.611) must have on it the registration number assigned to the aircraft under part 47 or 48 of this chapter. However, the airworthiness certificate need not have on it an assigned special identification number before 10 days after that number is first affixed to the aircraft. A revised airworthiness certificate having on it an assigned special identification number, that has been affixed to an aircraft, may only be obtained upon application to the responsible Flight Standards office.
(2) An effective U.S. registration certificate issued to its owner or, for operation within the United States, the second copy of the Aircraft registration Application as provided for in § 47.31(c), a Certificate of Aircraft registration as provided in part 48, or a registration certification issued under the laws of a foreign country.
(b) No person may operate a civil aircraft unless the airworthiness certificate required by paragraph (a) of this section or a special flight authorization issued under § 91.715 is displayed at the cabin or cockpit entrance so that it is legible to passengers or crew.
(c) No person may operate an aircraft with a fuel tank installed within the passenger compartment or a baggage compartment unless the installation was accomplished pursuant to part 43 of this chapter, and a copy of FAA Form 337 authorizing that installation is on board the aircraft.
(d) No person may operate a civil airplane (domestic or foreign) into or out of an airport in the United States unless it complies with the fuel venting and exhaust emissions requirements of part 34 of this chapter.
Questions pilots ask
What documents does 91.203 require on board?
An appropriate and current airworthiness certificate (91.203(a)(1)) and an effective U.S. registration certificate or one of the listed alternatives (91.203(a)(2)). If a fuel tank is installed in the passenger or baggage compartment, a copy of the authorizing FAA Form 337 must also be on board (91.203(c)).
Where must the airworthiness certificate be displayed?
At the cabin or cockpit entrance so that it is legible to passengers or crew (91.203(b)).
Can I fly with the second copy of the registration application?
Paragraph (a)(2) accepts, for operation within the United States, the second copy of the Aircraft Registration Application as provided for in 47.31(c). The conditions for using it are in 47.31(c), not in 91.203.