What an Annual or 100-Hour Inspection Actually Covers

Direct Answer — What an Annual / 100-Hour Inspection Covers

An annual and a 100-hour inspection cover the same scope: the items listed in Appendix D to Part 43, as applicable to the particular aircraft. That scope spans ten groups — general preparation and cleaning (a); fuselage and hull (b); cabin and cockpit (c); engine and nacelle (d); landing gear (e); wing and center section (f); empennage (g); propeller (h); radio (i); and every other installed component not otherwise covered (j).

The performance rules in 14 CFR §43.15 then add three obligations: the person must inspect the aircraft to determine whether it meets all applicable airworthiness requirements (§43.15(a)(1)); must use a checklist that includes the scope and detail of Appendix D (§43.15(c)(1)); and must run the engine to verify satisfactory performance before approving the aircraft for return to service (§43.15(c)(2) reciprocating, (c)(3) turbine). The difference between the two inspections is the interval (12 calendar months vs 100 hours) and who may sign (an IA for the annual; an appropriately rated A&P for the 100-hour) — not what gets inspected.

Sources: Appendix D to Part 43, 14 CFR §43.15, 14 CFR §43.11 — eCFR.

The annual and 100-hour inspections are the backbone of light-aircraft and on-demand airworthiness. The requirement to have the inspection lives in 14 CFR §91.409; the scope and standard of the inspection live in Part 43 — specifically Appendix D and §43.15. This article is about the second half: what an inspector is actually obligated to look at, what the §43.15 performance rules add on top of the item list, and what the resulting maintenance record entry must contain to be defensible.

Why it matters for documentation: the inspection itself is the mechanic's job, but the proof that it happened — the §43.11 entry, the supporting airworthiness directive records, the life-limited parts status, and the current-status records under §91.417(a)(2) — is what an FAA inspector reviews. A perfectly performed annual with a defective record entry still produces a finding. FAA civil penalties for recordkeeping and airworthiness violations under 49 U.S.C. § 46301 reach $75,000 per violation (with a lower maximum of $1,875 per violation for an individual or small-business concern in certain cases) under 14 CFR §13.301 for violations occurring on or after December 30, 2024.

10 Item Groups

Appendix D scope groups (a)–(j), as applicable to the particular aircraft

Appendix D to 14 CFR Part 43

Engine Run-Up

Required before return to service — reciprocating (c)(2) and turbine (c)(3)

14 CFR §43.15(c)(2)–(3)

$75,000

Max FAA civil penalty per violation (lower for individual / small business)

14 CFR §13.301 (on/after Dec 30, 2024)

The Appendix D Scope — Group by Group

Appendix D to Part 43 sets the "scope and detail of items (as applicable to the particular aircraft) to be included in annual and 100-hour inspections." The phrase as applicable to the particular aircraft is load-bearing — a fixed-gear airplane has no retracting mechanism to inspect under (e), but every item that is installed must be covered. Each person must, where applicable, first remove or open inspection plates, access doors, fairing, and cowling, and thoroughly clean the aircraft and engine, then inspect the following.

(a)

General Preparation

Before the inspection, each person must (where applicable) remove or open all necessary inspection plates, access doors, fairing, and cowling, and thoroughly clean the aircraft and aircraft engine. Appendix D opens with preparation because items cannot be inspected through a closed cowling or under a layer of grime — incomplete opening-up is itself a scope gap.

(b)

Fuselage and Hull Group

Fabric and skin for deterioration, distortion, other evidence of failure, and defective or insecure attachment of fittings; systems and components for improper installation, apparent defects, and unsatisfactory operation; the envelope, gas bags, ballast tanks, and related parts for condition (on applicable aircraft).

(c)

Cabin and Cockpit Group

General cleanliness and loose equipment that might foul the controls; seats and safety belts for poor condition and apparent defects; windows and windshields for deterioration and breakage; instruments for poor condition, mounting, marking, and (where practicable) improper operation; flight and engine controls for improper installation and improper operation; batteries for improper installation and charge; and all systems for improper installation, poor general condition, apparent and obvious defects, and insecurity of attachment.

(d)

Engine and Nacelle Group

Engine section for visual evidence of excessive oil, fuel, or hydraulic leaks, and sources of such leaks; studs and nuts for improper torquing and obvious defects; internal engine for cylinder compression and for metal particles or foreign matter on screens and sump drain plugs (if cylinder compression is weak, internal condition and tolerances may be checked); engine mount for cracks, looseness of mounting, and looseness of engine to mount; flexible vibration dampeners for poor condition and deterioration; engine controls for defects, improper travel, and improper safetying; lines, hoses, and clamps for leaks, improper condition, and looseness; exhaust stacks for cracks, defects, and improper attachment; accessories for apparent defects in security of mounting; all systems for improper installation, poor general condition, defects, and insecure attachment; cowling for cracks and defects.

(e)

Landing Gear Group

All units for poor condition and insecurity of attachment; shock absorbing devices for improper oleo fluid level; linkages, trusses, and members for undue or excessive wear, fatigue, and distortion; retracting and locking mechanism for improper operation; hydraulic lines for leakage; electrical system for chafing and improper operation of switches; wheels for cracks, defects, and condition of bearings; tires for wear and cuts; brakes for improper adjustment; floats and skis for insecure attachment and obvious or apparent defects.

(f)

Wing and Center Section

All components of the wing and center section assembly for poor general condition, fabric or skin deterioration, distortion, evidence of failure, and insecurity of attachment.

(g)

Empennage Group

Fixed surfaces for damage or obvious defects, insecure attachment, and faulty operation; movable surfaces for damage or obvious defects, improper installation, and improper operation; fabric or skin for abrasion or tears, distortion, and other evidence of deterioration or failure.

(h)

Propeller Group

Propeller assembly for cracks, nicks, binds, and oil leakage; bolts for improper torquing and lack of safetying; anti-icing devices for improper operations and obvious defects; control mechanisms for improper operation, insecure mounting, and restricted travel.

(i)

Radio Group

Radio and electronic equipment for improper installation and insecure mounting; wiring and conduits for improper routing, insecure mounting, and obvious defects; bonding and shielding for improper installation and poor condition; antennas (including trailing antennas) for poor condition, insecure mounting, and improper operation.

(j)

All Other Components

Each installed miscellaneous item that is not otherwise covered by any of the preceding groups, for improper installation and improper operation. This catch-all means the inspection scope follows the aircraft — anything fitted to that airframe that has not been inspected under (a) through (i) is inspected here.

Appendix D is the minimum scope, not the ceiling

Appendix D defines what an annual or 100-hour inspection must include — but it does not displace manufacturer maintenance manual inspection requirements, airworthiness directives, or the standard of workmanship in §43.13. An inspector who covers every Appendix D group but misses a manufacturer-mandated inspection item or an overdue AD has still not established the aircraft is in airworthy condition. For altimeter and transponder system tests and similar recurring checks, the annual is the moment to confirm those separate records are current.

The §43.15 Performance Rules — Beyond the Item List

14 CFR §43.15 is titled "Additional performance rules for inspections." It applies on top of the Appendix D scope and adds the obligations that turn a walk-around into a legally sufficient inspection.

§43.15(a)(1) — Inspect to the airworthiness standard

Each person performing an inspection required by part 91, 125, or 135 must perform the inspection so as to determine whether the aircraft, or portion inspected, meets all applicable airworthiness requirements. This sets the purpose of the inspection — it is not a checklist tick exercise; it is a determination of airworthiness. Under §43.15(a)(2), for inspections performed under part 125, 135, or §91.409(e), the person must perform the inspection in accordance with the instructions and procedures set forth in the operator's inspection program.

§43.15(c)(1) — Use a checklist that includes Appendix D

Each person performing an annual or 100-hour inspection shall use a checklist while performing the inspection. The checklist may be of the person's own design, provided by the manufacturer, or obtained from another source — but it must include the scope and detail of the items contained in Appendix D and, for rotorcraft, paragraph (b) of §43.15. A checklist that quietly omits Appendix D items is non-compliant even if every item is in fact inspected, and working from memory is a §43.15 violation in its own right.

§43.15(c)(2) & (c)(3) — Run the engine before return to service

For a reciprocating-engine aircraft, before approving it for return to service the person must run the engine(s) to determine satisfactory performance in accordance with the manufacturer's recommendations of: power output (static and idle rpm), magnetos, fuel and oil pressure, and cylinder and oil temperature (§43.15(c)(2)). For a turbine-powered aircraft, the person must run the engine(s) to determine satisfactory performance in accordance with the manufacturer's recommendations (§43.15(c)(3)). The run-up is part of the inspection — a finding here can move an aircraft from approved to disapproved.

§43.15(b) — Rotorcraft: the additional powertrain items

Each person performing an inspection on a rotorcraft must inspect, in accordance with the maintenance manual or Instructions for Continued Airworthiness of the manufacturer: each part of the rotorcraft drive system in a manner prescribed by the manufacturer; the main rotor transmission gear box for obvious defects; the main rotor and center section (or the equivalent area); and the auxiliary rotor on helicopters. For Part 135 helicopter air ambulance operations, these rotorcraft-specific items are inspected on top of the full Appendix D scope, and the §43.15(c)(1) checklist must include paragraph (b).

A clean checklist is not the same as a clean determination

The §43.15 rules are written so the inspection produces an airworthiness determination, not just a completed form. An inspector who runs the checklist but does not actually run the engine, or who signs the airworthy statement while a manufacturer service-life limit or an applicable AD is overdue, has not met §43.15(a)(1) regardless of how complete the paperwork looks.

Annual vs 100-Hour — Same Scope, Different Trigger and Signature

Because the scope is identical, operators sometimes treat the two inspections interchangeably. They are not. The requirement to have each one comes from 14 CFR §91.409: §91.409(a) requires an annual inspection within the preceding 12 calendar months for any aircraft operated; §91.409(b) additionally requires an annual or 100-hour inspection within the preceding 100 hours of time in service for an aircraft that carries any person (other than a crewmember) for hire, or that is given for flight instruction for hire. The distinctions that matter operationally:

Attribute	Annual Inspection	100-Hour Inspection
Scope	Appendix D to Part 43	Appendix D to Part 43 (identical)
Interval	Within preceding 12 calendar months	Within preceding 100 hours time in service
Applies to	Every aircraft operated (§91.409(a))	For-hire carriage / flight instruction for hire (§91.409(b))
Who may sign	Mechanic with Inspection Authorization (§65.95(a)(2))	Appropriately rated A&P — no IA (§65.85 / §65.87)
Overfly allowance	None	Up to 10 hrs en route to the shop, charged to next 100
Substitution	Always satisfies the 100-hour requirement	Does NOT satisfy the annual requirement

The 10-hour overfly, precisely

§91.409(b) allows the 100-hour limitation to be exceeded by not more than 10 hours while en route to reach a place where the inspection can be done — and the excess time used to reach that place must be included in computing the next 100 hours of time in service. It is a borrow against the next interval, only for repositioning to maintenance, and only up to 10 hours.

Who holds the authority

Only a mechanic holding an Inspection Authorization may perform an annual and approve the aircraft for return to service (§65.95(a)(2)). A 100-hour may be performed and signed by an appropriately rated A&P (§65.85 for airframe, §65.87 for powerplant). A Part 145 repair station may perform either within the scope of its ratings. See our IA renewal requirements post for how that authorization is kept current.

For operators flying under an approved inspection program — Part 135, Part 125, or the §91.409(e)/(f) options — the annual/100-hour framework is generally replaced by that program, and the inspection is performed to the program's instructions per §43.15(a)(2). If you operate on demand, the parallel records live in what records a Part 135 operator must keep and the CAMP maintenance recordkeeping requirements rather than in §91.409.

See whether your annual records would survive a ramp check

FileFlo classifies aviation maintenance documents against the governing CFR — including §43.11 inspection-entry completeness, AD current-status, and the §91.417(a)(2) records an IA needs at the annual — and assembles an inspector-format binder on demand. See the full Aviation compliance coverage.

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The Inspection Record Entry — §43.11, Not §43.9

The entry that documents an annual or 100-hour inspection is governed by 14 CFR §43.11, not §43.9. This trips people up because §43.9 is the general maintenance-entry rule — but §43.9 expressly excludes inspections performed under part 91, part 125, §135.411(a)(1), and §135.419. Those inspection entries live entirely in §43.11. Our §43.9 entry-requirements post covers the separate repair entries; this section covers the inspection sign-off itself. A §43.11(a) entry must contain:

§43.11(a)(1)–(2) — Type, extent, date, and total time

The type of inspection and a brief description of the extent of the inspection; and the date of the inspection and the aircraft total time in service. The aircraft total time in service is the element most often left out of an annual entry — and it is exactly what feeds the §91.417(a)(2) life-of-aircraft records.

§43.11(a)(3) — Signature, certificate number, kind of certificate

The signature, the certificate number, and the kind of certificate held by the person approving or disapproving the aircraft for return to service. For an annual, the "kind of certificate" is a mechanic certificate with an Inspection Authorization. A signature without the certificate number is a defective entry.

§43.11(a)(4) — The verbatim airworthy statement (if approved)

If the aircraft is approved for return to service, the entry must read, in substance, the statement the rule prescribes: "I certify that this aircraft has been inspected in accordance with (insert type) inspection and was determined to be in airworthy condition." The bracketed type is replaced with the actual inspection — for example, "an annual" or "a 100-hour."

§43.11(a)(5) — The disapproval statement + discrepancy list (if not approved)

If the aircraft is not approved for return to service because of needed maintenance, non-compliance with applicable specifications, ADs, or other approved data, the entry must state, in substance: "I certify that this aircraft has been inspected in accordance with (insert type) inspection and a list of discrepancies and unairworthy items dated (date) has been provided for the aircraft owner or operator." That signed and dated list must actually be furnished to the owner or lessee — the statement alone is not enough.

What a compliant annual approval entry looks like

[Date] June 11, 2026

[Aircraft total time in service] 4,182.6 hours

[Type + extent] Annual inspection performed in accordance with 14 CFR Part 43 Appendix D and the manufacturer's inspection program. Engine run-up performed per §43.15(c)(2); all parameters within limits.

[Certification] I certify that this aircraft has been inspected in accordance with an annual inspection and was determined to be in airworthy condition.

[Signature] D. Okafor

[Certificate No.] 3456789 IA

[Kind of certificate] Mechanic — Airframe & Powerplant with Inspection Authorization

Note the elements auditors check first: aircraft total time in service present, the verbatim airworthy language, the certificate number, and the IA designation. The phrasing above mirrors the §43.11(a)(4) statement; verify the current eCFR text before adopting a logbook stamp.

Related Part 43 / Part 91 records resources

Where the Inspection Is the Mechanic's Job — and the Proof Is Yours

The Appendix D scope and the §43.15 performance rules are obligations on the person performing the inspection. FileFlo does not perform inspections, hold a certificate, or replace an A&P or IA. What it does is govern the documentary aftermath — the records that prove the inspection happened, that the aircraft was airworthy, and that the supporting status records an IA relies on are complete and current.

Inspection entry completeness

FileFlo classifies an annual or 100-hour entry and surfaces whether the §43.11 elements are present — type and extent, aircraft total time in service, signature, certificate number, kind of certificate, and the return-to-service language — so a missing element is caught before, not during, an FAA review. It does not write the entry; it checks the document you uploaded against the rule.

Currency and the next-due picture

Tracking the 12-calendar-month annual due date and, for for-hire and instruction aircraft, the 100-hour interval — including the way the 10-hour overfly is charged against the next 100 — keeps the airworthiness window visible. Tie that to AD recurrence and altimeter/transponder test cycles so nothing lapses between annuals.

The §91.417(a)(2) records the IA needs assembled

Current AD status, life-limited parts status, time since overhaul of time-limited items, total times, and copies of the FAA Form 337 for major alterations are the records an IA reviews to certify airworthiness. FileFlo keeps that set indexed and current-status so the annual is not the moment those records are first reconstructed. For on-demand operators, the parallel set lives in Part 135 surveillance-audit preparation.

Frequently Asked Questions

What does an annual or 100-hour inspection actually cover under 14 CFR Part 43?

The scope is defined by Appendix D to Part 43, which lists the areas a person must inspect (as applicable to the particular aircraft) during an annual or 100-hour inspection: general preparation and cleaning (paragraph a), the fuselage and hull group (b), the cabin and cockpit group (c), the engine and nacelle group (d), the landing gear group (e), the wing and center section (f), the empennage assembly (g), the propeller group (h), the radio group (i), and all other systems and components not covered elsewhere (j). The performance rules in 14 CFR §43.15 then add three requirements: the person must perform the inspection so as to determine whether the aircraft meets all applicable airworthiness requirements (§43.15(a)(1)), must use a checklist that includes the scope and detail of the items in Appendix D (§43.15(c)(1)), and must run the engine to determine satisfactory performance before approving the aircraft for return to service (§43.15(c)(2) for reciprocating engines, (c)(3) for turbine engines). The annual and 100-hour inspections cover the same Appendix D scope — the difference is the interval and who may sign the aircraft off, not what gets inspected.

What is the difference between an annual and a 100-hour inspection?

They cover the identical scope — Appendix D to Part 43 — but differ in interval, applicability, and who may approve the aircraft for return to service. Under 14 CFR §91.409(a), no person may operate an aircraft unless within the preceding 12 calendar months it has had an annual inspection approved for return to service per part 43. Under §91.409(b), an aircraft carrying any person (other than a crewmember) for hire, or given for flight instruction for hire, must additionally have had an annual or 100-hour inspection within the preceding 100 hours of time in service. The annual must be performed by, and approved for return to service by, a mechanic holding an Inspection Authorization (14 CFR §65.95(a)(2)). The 100-hour may be performed and approved by a certificated mechanic with the appropriate airframe and powerplant ratings — no IA is required (14 CFR §65.85 and §65.87). A current annual always satisfies the 100-hour requirement; the reverse is not true.

Can you fly past the 100-hour limit to reach a maintenance facility?

Yes, but narrowly. 14 CFR §91.409(b) provides that the 100-hour limitation may be exceeded by not more than 10 hours while en route to reach a place where the inspection can be done, and that the excess time used to reach that place must be included in computing the next 100 hours of time in service. So the 10 hours is borrowed, not free — if you fly 6 hours over the limit to reach the shop, the next inspection interval is reduced by those 6 hours. There is no comparable overfly allowance for the 12-calendar-month annual inspection under §91.409(a); once an annual lapses, the aircraft is not airworthy to operate until a new annual is signed off.

Is a checklist legally required for an annual or 100-hour inspection?

Yes. 14 CFR §43.15(c)(1) states that each person performing an annual or 100-hour inspection shall use a checklist while performing the inspection, and that the checklist may be of the person’s own design, one provided by the manufacturer, or one obtained from another source — but it must include the scope and detail of the items contained in Appendix D to Part 43 and, for rotorcraft, paragraph (b) of §43.15. Using a checklist that omits Appendix D items, or working from memory without a checklist at all, is a §43.15 performance-rule violation independent of whether the underlying inspection was thorough.

Does the engine have to be run during an annual or 100-hour inspection?

Yes, before the aircraft is approved for return to service. Under 14 CFR §43.15(c)(2), for an aircraft with a reciprocating engine, the person performing the inspection must run the aircraft engine or engines to determine satisfactory performance in accordance with the manufacturer’s recommendations of power output (static and idle rpm), magnetos, fuel and oil pressure, and cylinder and oil temperature. Under §43.15(c)(3), for a turbine-powered aircraft, the person must run the engine or engines to determine satisfactory performance in accordance with the manufacturer’s recommendations. The engine run-up is part of the inspection, not a separate operational test, and its results belong in the airworthiness picture the inspector relies on.

What must the inspection record entry say after an annual or 100-hour inspection?

The entry is governed by 14 CFR §43.11, not §43.9. It must include the type of inspection and a brief description of its extent; the date of the inspection and the aircraft total time in service; and the signature, certificate number, and kind of certificate held by the person approving or disapproving the aircraft for return to service. If the aircraft is approved, the entry must contain the language in §43.11(a)(4): "I certify that this aircraft has been inspected in accordance with (insert type) inspection and was determined to be in airworthy condition." If the aircraft is not approved, §43.11(a)(5) requires the entry to state that a list of discrepancies and unairworthy items dated (date) has been provided for the aircraft owner or operator, and that signed and dated list must actually be given to the owner or lessee. The verbatim approval language and the aircraft total time in service are the two elements most often missing from defective annual entries.

Who can sign off an annual versus a 100-hour inspection?

Per 14 CFR §65.95(a)(2), only a certificated mechanic who holds an Inspection Authorization may perform an annual inspection and approve the aircraft for return to service. A 100-hour inspection does not require an IA: under §65.85, a certificated mechanic with an airframe rating may perform the 100-hour inspection on an airframe and approve it for return to service, and under §65.87, a mechanic with a powerplant rating may do the same for powerplant and propeller items. A certificated repair station rated under Part 145 may also perform these inspections within the scope of its ratings. The practical effect: an A&P without an IA can keep a flight-school or charter aircraft current on 100-hour inspections, but the once-a-year annual must go to an IA.

Are airworthiness directives part of the annual inspection?

Determining whether the aircraft meets all applicable airworthiness requirements (§43.15(a)(1)) necessarily includes verifying that applicable airworthiness directives have been complied with, because an aircraft with an overdue AD is not in an airworthy condition. The AD compliance itself is documented separately — the corrective action for an AD is a maintenance event recorded under §43.9, and the current AD status is part of the §91.417(a)(2) records the owner keeps for the life of the aircraft. The annual inspection is where an IA confirms the AD record is complete and current before signing the airworthiness certification; it is not where the AD work is invented. FileFlo tracks AD applicability and recurrence so the current-status record an IA needs at the annual is already assembled.