Before you climb into any aircraft and advance the throttle, the Federal Aviation Regulations place a clear legal burden on you as pilot in command: you must ensure the aircraft is airworthy. That word has a precise meaning in aviation law — it means the aircraft conforms to its type design and is in a condition for safe operation. Demonstrating airworthiness to an inspector or understanding it for the FAA knowledge test starts with four specific documents that must be aboard the aircraft during any flight. Pilots remember these using the acronym AROW.
This article walks through each AROW document in detail, explains what airworthiness really means under the regulations, covers the maintenance inspections required to keep a certificate valid, and highlights the exam traps that catch students every year.
What AROW Stands For
The four letters represent four documents, each required by a different section of 14 CFR Part 91:
- A — Airworthiness Certificate (14 CFR 91.203(a)(1))
- R — Registration Certificate (14 CFR 91.203(a)(2))
- O — Operating Limitations (14 CFR 91.9 and 91.203(a)(2))
- W — Weight and Balance data (14 CFR 91.9 and the aircraft's type certificate data sheet requirements)
All four must be on board the aircraft during any civil flight operation. They do not have to be displayed, but they must be immediately producible if an FAA inspector or law enforcement officer requests them. The pilot in command is responsible for verifying their presence before flight.
The Airworthiness Certificate
The Standard Airworthiness Certificate (FAA Form 8100-2) is issued by the FAA when an aircraft is found to conform to its type certificate and is in condition for safe operation. For most general aviation aircraft you will fly — Cessnas, Pipers, Diamonds — this is the relevant certificate. There is also a Special Airworthiness Certificate issued for experimental, light-sport, restricted, limited, and provisional categories, each carrying its own operating limitations.
The standard airworthiness certificate has no expiration date printed on it. It remains valid indefinitely, as long as the aircraft is maintained in accordance with the applicable regulations and remains in an airworthy condition. This is a critical distinction: the certificate does not expire on a calendar date the way a pilot certificate or medical certificate does, but it can become invalid if the aircraft is not properly maintained or if an unsafe condition exists. Once the aircraft is returned to airworthy condition, the certificate becomes valid again — no new certificate needs to be issued.
The certificate must be displayed at a cabin or cockpit location where it is legible to passengers and crew, per 14 CFR 91.203(b). In practice this usually means it is in a plastic sleeve on the instrument panel or sidewall.
The Registration Certificate
The Aircraft Registration Certificate (FAA Form 8050-3) proves that the aircraft is registered with the FAA Civil Aviation Registry and that a specific person or entity holds legal title. Under 14 CFR 91.203(a)(2), this certificate must be on board during flight. Under current FAA rules, aircraft registration certificates must be renewed every 7 years. When an aircraft changes ownership, the new owner has a temporary operating period during which the pink copy of the Bill of Sale or a proper application can serve as a substitute while the new certificate is processed.
Registration is separate from airworthiness — a beautifully maintained aircraft flying with an expired registration is still operating illegally, even if mechanically perfect.
Operating Limitations
The Operating Limitations define the envelope within which the aircraft may legally be flown. For most certificated aircraft, these limitations are found in the FAA-approved Airplane Flight Manual (AFM) or the Pilot's Operating Handbook (POH) that contains FAA-approved sections. Under 14 CFR 91.9, no person may operate an aircraft above its maximum certificated operating weight, outside its approved center-of-gravity range, or in excess of any other operating limitation established for that aircraft.
Importantly, for aircraft certificated after March 1, 1979, the FAA requires a full AFM. For older aircraft, operating limitations may instead appear as a placard in the cockpit, markings on the instruments, or a combination document. In all cases, whatever constitutes the approved operating limitations for that specific aircraft must be on board. Simply downloading a generic POH from the internet does not satisfy this requirement — the document must be specific to that aircraft's serial number and configuration.
Operating limitations cover items such as: Vne (never-exceed speed), Vno (maximum structural cruising speed), maximum and minimum operating altitudes, approved maneuvers, fuel types approved for use, and required equipment for certain types of flight.
Weight and Balance Data
The Weight and Balance information includes the aircraft's current empty weight, empty center of gravity, and equipment list. This data is aircraft-specific — every time equipment is added, removed, or relocated, the weight and balance must be recalculated and the records updated. The current, accurate weight and balance data must be on board and must reflect the actual configuration of the aircraft.
Weight and balance is covered in depth in the FAA Weight and Balance Handbook (FAA-H-8083-1), but from an airworthiness standpoint the key point is that operating outside the approved weight or CG limits renders the aircraft unairworthy — and renders the airworthiness certificate effectively invalid for that flight.
Airworthiness in the Maintenance Context
Beyond documents, a certificated aircraft must undergo a series of scheduled inspections to remain legally airworthy for flight under 14 CFR Part 91.
Annual Inspection
Under 14 CFR 91.409(a), most general aviation aircraft must receive an annual inspection every 12 calendar months, performed by an FAA-certificated Airframe and Powerplant (A&P) mechanic who holds an Inspection Authorization (IA). The calendar month counts to the last day of the twelfth month — so an annual completed on March 15 remains valid through March 31 of the following year. An aircraft with an expired annual is not airworthy for flight (with narrow exceptions for ferry permits).
100-Hour Inspection
Under 14 CFR 91.409(b), aircraft used for hire — for flight instruction or rental — must also undergo a 100-hour inspection at intervals not exceeding 100 hours of flight time. This inspection may be performed by any certificated A&P mechanic (an IA is not required). Importantly, the 100-hour limit may be exceeded by up to 10 hours to reposition the aircraft to a maintenance facility, but those extra hours count against the next 100-hour interval. The annual inspection can serve as a substitute for a required 100-hour inspection, but not vice versa.
Other Required Inspections
Other time-sensitive airworthiness items include the ELT battery (must be replaced or recharged per 14 CFR 91.207 when cumulative use time exceeds one hour or when 50% of the battery's useful life has expired), the altimeter and static system (tested every 24 calendar months for IFR flight under 14 CFR 91.411), and the transponder (tested every 24 calendar months under 14 CFR 91.413). While these last two apply specifically to IFR operations, knowing them is tested on the private pilot knowledge exam.
Why This All Matters
The AROW documents and airworthiness inspection requirements are not bureaucratic box-checking — they reflect the FAA's layered approach to keeping aircraft safe. An airworthiness certificate that was valid when issued tells you the aircraft met a known standard of design and construction. The required inspections tell you that standard is being maintained over time. The operating limitations tell you the boundaries within which that standard applies. And the weight and balance data tell you whether your specific loading today falls within those boundaries.
As pilot in command, you carry legal responsibility under 14 CFR 91.7 to not operate an aircraft you know or have reason to know is in an unairworthy condition. That means the preflight document check is as important as the physical preflight inspection.
Key Numbers and Rules
- AROW — Airworthiness Certificate, Registration, Operating Limitations, Weight & Balance: all four must be on board.
- Standard airworthiness certificates do not expire by date; they become invalid if the aircraft is not maintained per regulations.
- Annual inspection: required every 12 calendar months; IA required.
- 100-hour inspection: required for hire operations; A&P (no IA needed); may be exceeded by up to 10 hours to reach a maintenance facility.
- Annual can substitute for a 100-hour; a 100-hour cannot substitute for an annual.
- 14 CFR 91.7: PIC is responsible for airworthiness determination before flight.
- Registration certificates for individual owners: must be renewed every 7 years under current FAA rules.
- Operating limitations must be aircraft-specific — a generic POH is not sufficient.
Memory Aid
The acronym AROW itself is the standard mnemonic used throughout FAA training materials and is worth locking in cold:
- A — Airworthiness Certificate
- R — Registration Certificate
- O — Operating Limitations (AFM/POH)
- W — Weight and Balance data
Some instructors extend this to ARROW by adding a second R for the Radio station license — required when flying internationally, though not required for domestic U.S. flights. Know both versions: the standard four-document AROW for domestic operations, and ARROW if your aircraft will cross international borders.
Common Test Traps
- Trap 1 — The airworthiness certificate expiration myth. The FAA knowledge test frequently implies or asks whether a standard airworthiness certificate expires. It does not expire by date — it becomes invalid only when the aircraft is not maintained per regulations or is in an unsafe condition.
- Trap 2 — Confusing annual and 100-hour authority. An IA is required for an annual; a plain A&P can do a 100-hour. An annual substitutes for a 100-hour but not the reverse. Many students mix these up.
- Trap 3 — The 10-hour 100-hour extension. You may exceed the 100-hour limit by up to 10 hours to reach a shop, but those extra hours count against the next interval, not reset it.
- Trap 4 — Generic POH on board. A POH downloaded from the manufacturer's website is not the aircraft's approved operating limitations unless it matches that specific aircraft's serial number and current configuration. The document on board must be aircraft-specific.
- Trap 5 — ARROW vs. AROW. For flights entirely within the U.S., the radio station license (the second R) is not required on board. For international flights, it is. Know the context before selecting an answer.