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Private pilot · ACS PA.I.B · lesson pack

Airworthiness Requirements

Why this one matters

An airplane can look fine on the ramp and still not be safe or legal: an overdue inspection, an unaddressed AD, a broken instrument you need at night. Knowing how to check the documents and how to handle inoperative equipment is how you avoid flying a problem into the air.

1 · Know these cold

  • •The pilot in command decides whether the airplane is in condition for safe flight; the owner or operator keeps it airworthy.(14 CFR 91.7, 91.403)
  • •On board: the airworthiness certificate (displayed), the registration certificate, the operating limitations (POH/AFM, placards, markings) and weight and balance data.(14 CFR 91.203, 91.9)
  • •Annual inspection within the preceding 12 calendar months; a 100-hour inspection too if the airplane carries people for hire or is provided for flight instruction for hire.(14 CFR 91.409)
  • •ELT inspected every 12 calendar months; transponder checked every 24 calendar months; the altimeter/static check (24 months) is for IFR in controlled airspace.(14 CFR 91.207, 91.411, 91.413)
  • •Airworthiness Directives are mandatory; Special Airworthiness Information Bulletins are advisory.(14 CFR Part 39)
  • •Inoperative equipment without an MEL: if it isn't required, deactivate or remove it, placard it "Inoperative", and decide it isn't a hazard.(14 CFR 91.213(d))
  • •As a private pilot you may do preventive maintenance on an airplane you own or operate, and you must log it.(14 CFR 43.3(g), 43.9, Part 43 Appendix A)

2 · The lesson

Certificates and who is responsible
  • The owner or operator is primarily responsible for keeping the airplane airworthy, including AD compliance.(14 CFR 91.403(a))
  • The pilot in command is responsible for deciding the airplane is in condition for safe flight, and must end the flight if it isn't.(14 CFR 91.7)
  • The airworthiness certificate must be on board and displayed at the cabin or cockpit entrance, visible to passengers. A standard airworthiness certificate stays valid as long as the airplane is maintained and operated as required.(14 CFR 91.203(b), 21.181)
  • The registration certificate must be on board. Registrations now expire after 7 years.(14 CFR 91.203(a)(2), 47.40)
  • Standard airworthiness certificates cover normal, utility, acrobatic, commuter and transport categories. Special airworthiness certificates (experimental, light-sport, restricted, special flight permit and others) carry their own operating limitations, which you must follow.(14 CFR 21.175, 91.319)
  • The POH/AFM, placards and markings are the operating limitations and must be on board and followed. Weight and balance data must be current.(14 CFR 91.9)
  • Special certificates carry real limits. An experimental airplane (91.319): no carrying persons or property for compensation or hire, day VFR only unless the FAA authorizes otherwise, no flight over densely populated areas or in a congested airway unless authorized, and you must tell each person on board that it is experimental.(14 CFR 91.319(b)-(e); 21.175)
Inspections and the logbooks
  • Annual inspection within the preceding 12 calendar months.(14 CFR 91.409(a))
  • 100-hour inspection if the airplane carries any person (other than crew) for hire, or is provided by the person giving flight instruction for hire. You may exceed it by up to 10 hours to reach a place where it can be done; that time counts toward the next one.(14 CFR 91.409(b))
  • ELT: inspected within the preceding 12 calendar months; battery replaced after 1 cumulative hour of use or half its useful life.(14 CFR 91.207)
  • Transponder: tested within the preceding 24 calendar months to use it.(14 CFR 91.413)
  • Altimeter and static system: within the preceding 24 calendar months, required for IFR in controlled airspace.(14 CFR 91.411)
  • Inspections, AD compliance and alterations are recorded in the airframe, engine and propeller logbooks. Check them; don't assume.(14 CFR 91.417)
  • Who signs: an annual must be performed and approved by someone authorized under 43.7, in practice a mechanic with an Inspection Authorization (A&P/IA), an appropriately rated repair station or the manufacturer. A 100-hour can be done and approved by an A&P without an IA. Both use the same Appendix D scope. An annual counts as a 100-hour; a 100-hour counts as an annual only if done by someone authorized to do annuals and entered as an annual.(14 CFR 91.409(a)-(b); 43.7; 65.95(a); Part 43, Appendix D)
  • The ELT is required only where 91.207 requires it. Exceptions include training flights conducted entirely within 50 nm of the airport where the local flight began, and aircraft with only one seat; an airplane may also be ferried for ELT repair or removal without one. Where an ELT is installed, the 12-month inspection and battery rules apply.(14 CFR 91.205(b); 91.207(a), (c)-(f))
ADs, SAIBs and special flight permits
  • Airworthiness Directives address unsafe conditions and are mandatory. Some are one-time; recurring ADs need compliance at set intervals. Compliance is recorded in the logbooks.(14 CFR Part 39, 91.417)
  • Special Airworthiness Information Bulletins (SAIBs) are recommendations, not requirements.(PHAK (FAA-H-8083-25C), Aircraft Documents, Maintenance, and Inspections)
  • A special flight permit (a "ferry permit") lets an airplane that doesn't currently meet airworthiness requirements, but is capable of safe flight, fly to a place where it can be repaired or inspected. You get it from the FAA (a Flight Standards office or designee) before the flight.(14 CFR 21.197, 21.199)
  • The special flight permit process: the application states the purpose, the required crew, how the airplane doesn't comply, and the restrictions needed for safe operation. The FAA may inspect or require a mechanic's or repair station's finding that the airplane is safe for the route. The permit comes with operating limitations you must follow: essential crew only, no persons or property for hire, and the permit carried as specified.(14 CFR 21.197; 21.199(a)-(b))
Preventive maintenance
  • A certificated pilot (not a student pilot) may perform preventive maintenance on an airplane they own or operate that isn't used under Part 121, 129 or 135.(14 CFR 43.3(g))
  • Preventive maintenance is the list in Part 43 Appendix A: simple jobs like changing oil, replacing tires, servicing landing gear struts, or replacing safety belts.(14 CFR Part 43, Appendix A(c))
  • Log it with the full 43.9(a) entry: a description of the work (or a reference to acceptable data), the date it was completed, the name of the person who did it if not the approver, and, if the work was done satisfactorily, the signature, certificate number and kind of certificate of the person approving it. That signature is the approval for return to service for that work only.(14 CFR 43.9(a); 43.7(f))
  • Performing and approving are separate steps. A Part 61 pilot certificate holder may perform preventive maintenance on an airplane they own or operate that isn't used under Part 121, 129 or 135 (a sport pilot only on a light-sport aircraft they own or operate). Only someone holding at least a private pilot certificate may approve it for return to service.(14 CFR 43.3(g); 43.7(f))
  • Adding oil is servicing and needs no maintenance entry. Changing the oil (and filter or screen work in Appendix A) is preventive maintenance and needs the full entry. Replacing position and landing light bulbs, reflectors and lenses is also preventive maintenance.(14 CFR Part 43, Appendix A(c); 43.9)
Required equipment and inoperative equipment
  • Day VFR equipment includes: airspeed indicator, tachometer, oil pressure and oil temperature gauges, manifold pressure gauge (altitude engines), altimeter, temperature gauge (liquid-cooled engines), fuel gauges, landing gear position indicator (retractable gear), anticollision lights (airplanes certificated after March 11, 1996), a magnetic direction indicator (the compass), an ELT if 91.207 requires one, safety belts for each occupant 2 years or older (metal-to-metal latching), shoulder harnesses for each front seat in small airplanes made after July 18, 1978 (all seats if made after December 12, 1986), and, if operated for hire over water beyond power-off gliding distance from shore, flotation gear for each occupant and at least one pyrotechnic signaling device.(14 CFR 91.205(b))
  • Night VFR adds position lights, anticollision lights, a landing light if operating for hire, an adequate source of electrical energy, and spare fuses if fuses are used.(14 CFR 91.205(c))
  • With an approved MEL (a letter of authorization for that specific airplane), follow it.(14 CFR 91.213(a))
  • Without an MEL, inoperative equipment is allowed only if it isn't required by the VFR-day type certification, the equipment list or kinds of operation equipment list (KOEL), 91.205 or other rules, or an AD. Then it must be removed or deactivated and placarded "Inoperative", and the pilot must decide it's no hazard.(14 CFR 91.213(d))
  • Many POHs include a KOEL listing what must work for day VFR, night VFR, IFR and icing.(PHAK (FAA-H-8083-25C), Aircraft Documents, Maintenance, and Inspections)
  • A discrepancy found before flight is recorded and placarded; it is not just ignored.(14 CFR 91.213(d)(3), 43.11)
  • 91.213(d) applies only to the aircraft listed in (d)(1): rotorcraft, non-turbine-powered airplanes, gliders and lighter-than-air aircraft (small ones only, if a master MEL has been developed for the type). If an item is removed, placard the cockpit control and record the maintenance under 43.9; if deactivated, placard it "Inoperative", and any deactivation that is maintenance must be done and recorded under Part 43. The no-hazard decision is made by a certificated, appropriately rated pilot or by an appropriately rated maintenance person.(14 CFR 91.213(d)(1)-(4))

Want it all on one page, with scenarios? Read the full lesson.

3 · Say it out loud

Answer each one out loud, then check yourself and mark how it went.

  1. Remember Recall it

    “What documents must be on board the airplane?”

  2. Understand Explain why

    “Why does a rental airplane need a 100-hour inspection when your own airplane only needs an annual?”

  3. Apply Use it on a flight

    “During preflight for a day flight you find the landing light is burned out. Can you go?”

4 · Common mistakes

  • Treating the 24-month altimeter/static check as required for VFR.

    91.411 applies to IFR in controlled airspace.

    Instead: Know which inspections apply to this flight: annual, 100-hour if for hire, ELT, transponder; altimeter/static only for IFR.

  • Listing a radio station license as always required.

    It's only needed for international flights.

    Instead: Use the required list: airworthiness, registration, operating limitations, weight and balance.

  • Flying with broken equipment because "it's not on the 91.205 list".

    91.213(d) also checks the type certificate, the equipment list/KOEL and ADs, and requires deactivating and placarding.

    Instead: Walk through every step of 91.213(d), then decide whether it's a hazard on this flight.

5 · Quick check

Answer, then reveal. Flag anything you want to see again.

  1. 1. How often is an annual inspection required?

  2. 2. When is a 100-hour inspection required?

  3. 3. How often must the ELT be inspected?

  4. 4. Are SAIBs mandatory?

  5. Scenario5. Your airplane has no MEL and the fuel gauge on one side is broken. Can you fly day VFR?

  6. 6. What do you need to fly an airplane with an overdue annual to a maintenance shop?

  7. 7. What must a preventive maintenance logbook entry include?

Trained it? Now prove it: practice airworthiness requirements out loud with our examiner.

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Connect it

One situation that runs across this lesson and its neighbors in the same ACS area. Decide first, then check.

Connect it · Preflight Preparation

A July afternoon. You plan a 90 NM trip from a 2,800-foot runway at 1,500 feet elevation; it's 33 °C. The destination TAF has a TEMPO for thunderstorms starting about when you'd arrive.

How do the weather, the airplane's performance and your fuel plan change one another, and what do you decide? Decide, then see the worked answer

Work the density altitude first. Standard temperature at 1,500 feet is about 12 °C, so 33 °C is about ISA +21 °C and the density altitude is roughly 4,000 feet (more if the pressure is low). Enter the POH takeoff and climb charts at the actual pressure altitude and temperature, never the field elevation, and compare the ground roll, the distance over a 50-foot obstacle and the climb with the 2,800 feet and the obstacles, with a margin. If it's tight, cut payload and baggage first. Never cut fuel below trip fuel plus fuel to divert to an alternate plus the 91.151(a)(1) day VFR reserve of 30 minutes at normal cruise. After any load change, recompute the weight and balance and the CG, and check the landing distance at the destination too. The TEMPO puts thunderstorms over the destination at your arrival. Don't plan to beat the TEMPO window or to divert closely around cells: avoid thunderstorms with severe or intense radar echoes by at least 20 miles, never take off or land in the face of an approaching thunderstorm, and wait storms out on the ground. With thin performance margins and storms at the far end, the better answer is the cooler, calmer morning.

PHAK (FAA-H-8083-25C), Aircraft Performance and Weather Theory; AC 00-24C, Thunderstorms; 14 CFR 91.103, 91.151

Brings together: Weather Information · Cross-Country Flight Planning · Performance and Limitations

Teaching this? The instructor lesson plan →

Study aid, not FAA guidance. Sources: 14 CFR Part 91; 14 CFR Parts 21, 39, 43, 47; Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C); Your airplane's POH/AFM. Checked against current sources 2026-11-12.