Visual guide 2 of 6
Which inspection, when, and who signs
Start at the top: the aircraft's airworthiness certificate decides which inspection rule applies. Then check how the aircraft is used — carrying people for hire or providing it for paid instruction adds an hours-based inspection.
Decision tree
Annual — 12 calendar months
No one may operate the aircraft unless, within the preceding 12 calendar months, it had an annual inspection per part 43 and was approved for return to service by a person authorized by 43.7 — or an inspection for issuance of an airworthiness certificate. 14 CFR 91.409(a)
+ 100-hour if it carries any person (other than crew) for hire, or if the person giving flight instruction for hire also provides the aircraft. 91.409(b)
Condition inspection — 12 calendar months
Once every 12 calendar months, using inspection procedures developed by the manufacturer or a person acceptable to the FAA. 14 CFR 91.327(b)(2)
+ 100-hour if towing a glider or unpowered ultralight for hire, or giving flight training for hire in an aircraft the instructor provides. 91.327(c)
Per operating limitations
Experimental aircraft receive operating limitations under 91.319; the FAA typically requires a condition inspection within the preceding 12 months, performed to the scope and detail of part 43 Appendix D. AC 65-32B ¶2.6.3
+ 100-hour for a 21.191(i)(1) aircraft used to tow a light-sport glider/unpowered ultralight or for flight training for hire. 91.319(g)
Annual vs 100-hour vs condition — side by side
| Annual (standard) | 100-hour (standard) | Condition inspection (S-LSA) | Cite | |
|---|---|---|---|---|
| Interval | 12 calendar months | 100 hours time in service | 12 calendar months | 91.409(a), (b); 91.327(b)(2) |
| Required when | Always (unless a progressive or other program, 91.409(c)–(e)) | Persons carried for hire, or flight instruction for hire in an aircraft the instructor provides | Always | 91.409; 91.327 |
| Who signs | IA (also the aircraft manufacturer, 43.3(j)(3)) | A&P (or IA) | LSR-M, appropriately rated mechanic or repair station | 65.95; 65.85; 65.87; 91.327(b)(2) |
| Overfly | None | May exceed by up to 10 hours only en route to where it can be done; the excess counts toward the next 100 | 91.327(c)'s 100-hr rule has no en-route extension | 91.409(b); 91.327(c) |
| Substitution | An annual satisfies the 100-hour requirement | A 100-hour counts as an annual only if done by a person authorized to do annuals and entered as an annual | — | 91.409(a), (b) |
| Scope | Same scope: checklist covering at least Appendix D; engine run before approval | Manufacturer's (or acceptable person's) procedures | 43.15(c); 91.327(b)(2) | |
| Record | 43.11 entry: type and extent, date, total time, signature/cert no./kind, airworthy or discrepancy statement | 43.11 entry (part 43 applies to S-LSA) | 43.11(a); 43.1(d) | |
Engine run before signing an annual or 100-hour
Before approving a reciprocating-engine aircraft for return to service after an annual or 100-hour inspection, run the engine(s) to check, per the manufacturer's recommendations: power output (static and idle rpm), magnetos, fuel and oil pressure, and cylinder and oil temperature. Turbine aircraft: run per the manufacturer's recommendations (also after a progressive inspection). 14 CFR 43.15(c)(2)–(3) Use a checklist — your own, the manufacturer's, or another source — that covers at least Appendix D. 43.15(c)(1)
What "12 calendar months" looks like
A calendar-month interval runs to the end of the month. An annual signed off on March 3 is good through the last day of the following March.
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Teal: inspection completed. Rust: last day the aircraft may be operated without a new inspection ("within the preceding 12 calendar months" — 14 CFR 91.409(a)). The same counting applies to 24-calendar-month tests (91.411, 91.413) and the 12-calendar-month ELT inspection (91.207(d)).
100-hour overfly, worked
100-hour due at 1,250.0 hours tach/time in service. The aircraft is away from base and arrives at the shop at 1,257.5 (7.5 h over — within the 10-hour allowance, permitted only to reach the place where the inspection can be done). Next 100-hour is due at 1,350.0, not 1,357.5: the excess time "must be included in computing the next 100 hours." 14 CFR 91.409(b)
Progressive inspections and inspection programs
Progressive 91.409(d)
- Owner submits a written request to the responsible Flight Standards office.
- Supervised or conducted by an IA, a certificated airframe repair station, or the aircraft manufacturer.
- Needs a current inspection procedures manual, schedule (incl. up to 10-hour en-route overrun), sample forms, housing/equipment and current technical information.
- Complete inspection of the aircraft within each 12 calendar months.
- If discontinued: notify the FSDO in writing; annual due within 12 calendar months and 100-hour within 100 hours of the last complete inspection.
- Start of program: inspect the aircraft completely; then routine (visual, no disassembly) and detailed (with disassembly) inspections per schedule. 43.15(d)(1)
Large & turbine aircraft 91.409(e)–(f)
Large airplanes (part 125 n/a), turbojet multiengine, turboprop multiengine and turbine rotorcraft must use a selected program, identified in the maintenance records:
- Continuous airworthiness inspection program (121/135 CAMP)
- Approved aircraft inspection program (AAIP) under 135.419
- Current program recommended by the manufacturer
- Owner/operator program approved by the FAA under 91.409(g)
Turbine rotorcraft operators may elect 91.409(a)–(d) instead.
Other recurring items a mechanic tracks
| Item | Interval / trigger | Who may do it | Cite |
|---|---|---|---|
| Altimeter, static system, altitude reporting | 24 calendar months — for airplanes/helicopters operated under IFR in controlled airspace; also after opening/closing the static system (except drains/alternate static) | Manufacturer; appropriately rated repair station; A-rated mechanic for static system tests only | 91.411; Part 43 App. E |
| ATC transponder | 24 calendar months; also after installation/maintenance that could introduce data-correspondence error | Rated repair station; CAMP holder; aircraft manufacturer (if it installed the transponder) | 91.413; Part 43 App. F |
| ELT inspection | Within 12 calendar months of last inspection: installation, battery corrosion, controls & crash sensor, radiated signal | — | 91.207(d) |
| ELT battery | Replace/recharge after more than 1 cumulative hour of use, or at 50% of useful life (of charge); new date marked outside the ELT and in the records | — | 91.207(c) |
| ELT removed | Aircraft may operate up to 90 days after initial removal with a records entry and an "ELT not installed" placard | — | 91.207(f)(10) |
| Airworthiness limitations | Mandatory replacement times / inspection intervals in the ALS of the manual or ICA | Per that section | 91.403(c); 43.16 |
| Airworthiness directives | Per each AD; operating a product that doesn't meet an applicable AD violates 39.7 each time | Per AD | 39.7; 39.9 |
Part 43 Appendix D — the minimum annual/100-hour scope
Before the inspection: remove or open all necessary inspection plates, access doors, fairings and cowling, and thoroughly clean the aircraft and engine. App. D(a) Then inspect, where applicable:
Fuselage & hull D(b)
- Fabric and skin — deterioration, distortion, failure, insecure fittings
- Systems and components — installation, defects, operation
- Envelope, gas bags, ballast tanks
Cabin & cockpit D(c)
- Uncleanliness, loose equipment that might foul controls
- Seats and safety belts
- Windows and windshields
- Instruments — condition, mounting, marking, operation
- Flight and engine controls
- Batteries — installation and charge
- All systems
Engine & nacelle D(d)
- Oil, fuel, hydraulic leaks and sources
- Studs and nuts — torquing, defects
- Internal — cylinder compression; metal particles on screens and sump drain plugs
- Engine mount — cracks, looseness
- Flexible vibration dampeners
- Engine controls — travel, safetying
- Lines, hoses, clamps
- Exhaust stacks — cracks, attachment
- Accessories; all systems; cowling
Landing gear D(e)
- All units — condition, attachment
- Shock absorbers — oleo fluid level
- Linkages, trusses, members — wear, fatigue, distortion
- Retracting and locking mechanism
- Hydraulic lines — leakage
- Electrical — chafing, switches
- Wheels — cracks, bearings
- Tires — wear and cuts
- Brakes — adjustment
- Floats and skis
Wing & center section D(f)
- General condition, fabric/skin deterioration, distortion, failure, attachment
Empennage D(g)
- All components and systems — condition, deterioration, distortion, attachment, installation, operation
Propeller D(h)
- Assembly — cracks, nicks, binds, oil leakage
- Bolts — torquing, safetying
- Anti-icing devices
- Control mechanisms — operation, mounting, travel
Radio D(i) & misc. D(j)
- Radio/electronic equipment — installation, mounting
- Wiring and conduits — routing, mounting
- Bonding and shielding
- Antennas incl. trailing
- Any other installed item not covered
Rotorcraft additionally: drive shafts, main rotor transmission gearbox, main rotor and center section, auxiliary rotor — per the manufacturer's manual. 14 CFR 43.15(b)