Becoming an FAA certificated Aviation Maintenance Technician (AMT) is a milestone that carries both meaningful authority and strict responsibility. Under 14 CFR Part 65, Subpart D, the FAA defines precisely what a certificated mechanic may — and may not — do when working on civil aircraft. Understanding these privileges and limitations is essential not only for the AMT knowledge test but for every day you spend in a maintenance hangar. A single misstep in exercising (or over-extending) these privileges can ground an aircraft, endanger lives, or cost you your certificate.
The FAA issues mechanic certificates with one or both ratings: Airframe and Powerplant. Each rating unlocks a specific set of privileges. Holding both is common and is informally called an A&P certificate, though the FAA documents them as a single certificate with two ratings. Let's walk through exactly what each rating authorizes, where the hard stops are, and the nuances that regularly appear on FAA knowledge tests.
Privileges by Rating
Under 14 CFR §65.81, a certificated mechanic may perform maintenance, preventive maintenance, and alterations on aircraft or aircraft engines, propellers, and appliances — but only within the scope of their rating(s). The specific work authorized breaks down as follows:
- Airframe rating: Authorizes maintenance, preventive maintenance, and alterations on the airframe of any aircraft for which the mechanic is rated. This includes the fuselage, wings, flight control surfaces, landing gear, and related systems such as hydraulics and pneumatics.
- Powerplant rating: Authorizes the same categories of work on aircraft engines, propellers, and all systems and components associated with powerplant operation — including fuel systems, exhaust, and engine-driven accessories.
- Both ratings combined: Together, the airframe and powerplant ratings effectively cover nearly the complete aircraft structure and propulsion system, though important exclusions still apply (discussed below).
A critical detail: the regulation uses the phrase "for which the mechanic is rated." This means an Airframe-only mechanic may not sign off powerplant work, and a Powerplant-only mechanic may not approve airframe repairs — even if they are physically capable of performing the task. The rating determines the legal authorization, period.
The Return-to-Service Approval: A Core Privilege
One of the most important privileges the Part 65 certificate grants is the authority to approve an aircraft for return to service after work the mechanic has performed or supervised. Per 14 CFR §65.81(a), a mechanic may approve and return to service any aircraft, aircraft engine, propeller, or appliance on which the mechanic has performed work — provided the work falls within the certificate's rating and the mechanic signs the maintenance record in accordance with 14 CFR §43.9 and §43.11.
This return-to-service signature is a legal attestation. It states that the work was performed in accordance with current, approved data and that the aircraft is airworthy for return to flight. The signature binds the mechanic legally and professionally. If the work is later found deficient, the record establishes accountability.
Limitations: What a Certificated Mechanic Cannot Do
The privileges sound broad, but 14 CFR §65.81(b) and related regulations impose explicit limitations. Understanding these is just as important as knowing the privileges themselves.
Cannot Approve Major Repairs or Major Alterations Without Supervision
A certificated mechanic may perform major repairs and major alterations, but may not approve the work for return to service without the involvement of an appropriately rated certificated mechanic or repairman who can supervise. In practice, major repairs and major alterations as defined in 14 CFR Part 43, Appendix A — such as welding on primary structural members or altering the basic flight characteristics of an aircraft — require sign-off by a mechanic who has demonstrated, through practical experience and appropriate authorization, the capability to assess that specific work. An Inspection Authorization (IA), issued under 14 CFR §65.91, is required to approve major repairs and major alterations for return to service on certificated aircraft.
Cannot Perform Annual Inspections Without an IA
This limitation trips up many test-takers. A certificated mechanic — even one holding both Airframe and Powerplant ratings — cannot conduct an annual inspection or return an aircraft to service following an annual inspection without holding a current Inspection Authorization. Annual inspections fall under 14 CFR §91.409, and only an IA holder or an appropriately certificated repair station may sign off an annual. A plain A&P mechanic may perform a progressive inspection if it has been established under an approved program, but the annual itself requires the IA. This is one of the most commonly tested distinctions in the AMT General knowledge exam.
Cannot Exercise Privileges While Impaired
Under 14 CFR §65.23, a certificated mechanic may not exercise any certificate privilege while the person knows or has reason to know they are suffering from a physical or mental condition that would make the exercise of the privilege unsafe. Similarly, §65.23 prohibits acting as a mechanic while under the influence of alcohol, or within 8 hours after consuming alcohol, or with a blood alcohol concentration of 0.04 or greater. These rules mirror the alcohol provisions that apply to pilots and reflect the FAA's broad safety culture across all certificate holders.
Cannot Supervise Work Outside Their Rating
A mechanic rated only in Airframe cannot supervise or approve powerplant work, and vice versa. Supervision under the regulations only extends the mechanic's own legal authority — you cannot lend your certificate to authorize work that falls outside your rating's scope.
Preventive Maintenance: A Different Track
It is worth noting that preventive maintenance as defined in 14 CFR Part 43, Appendix A may be performed by certificated pilots (who own or operate aircraft not used for air carrier operations) — but the scope of that allowance is narrow. For certificated mechanics, preventive maintenance is simply a subset of what they are already authorized to do. The practical point is that preventive maintenance authority for pilots does not expand a mechanic's privileges; it merely creates a parallel, limited pathway for owner-pilots.
Certificate Duration and Surrender of Privileges
Unlike a pilot certificate, a mechanic certificate under Part 65 does not expire on a fixed schedule. However, 14 CFR §65.83 imposes a currency requirement: a mechanic must have been employed in an aviation maintenance capacity for at least 6 months of the preceding 24 months, or must pass a written or practical test, to exercise certificate privileges. Failure to meet this recency-of-experience standard does not invalidate the certificate — the certificate itself remains valid — but the mechanic legally cannot exercise its privileges until currency is re-established.
Why These Rules Matter
Aviation maintenance errors are a significant contributor to aircraft accidents. The FAA's privilege-and-limitation structure exists to ensure that only people with demonstrated, rated competency are signing off safety-critical work. The return-to-service signature is the mechanic's assertion that an aircraft is airworthy — and every person who boards that aircraft trusts that assertion implicitly. The IA requirement for annuals and major repairs creates a tiered system of oversight, where the most complex and consequential inspections receive an additional layer of qualification. These are not bureaucratic hurdles; they are the structural safeguards that make the general aviation maintenance system trustworthy.
Key Numbers and Rules
- 14 CFR §65.81: Core privileges — perform maintenance, preventive maintenance, and alterations within rating.
- 14 CFR §65.81(b): Cannot approve major repairs/alterations or annual inspections for return to service without an IA.
- 14 CFR §65.91: Inspection Authorization — required to approve annuals and major repairs/alterations.
- 14 CFR §65.83: Currency — 6 months of aviation maintenance experience within the preceding 24 months required to exercise privileges.
- 14 CFR §65.23: Alcohol — no exercise of privileges within 8 hours of alcohol consumption or with BAC ≥ 0.04.
- 14 CFR Part 43, Appendix A: Defines major repairs, major alterations, and preventive maintenance.
- Annual inspection sign-off: A&P alone is NOT sufficient — IA required.
Common Test Traps
- "A&P can sign off the annual." False. An A&P without an Inspection Authorization cannot approve an aircraft for return to service following an annual inspection. This is the single most frequently missed point on the AMT General exam.
- Confusing performing with approving. A mechanic may perform a major repair, but cannot approve it for return to service without an IA. The ability to do the work and the legal authority to certify the work are separate concepts.
- Assuming the certificate expires. A mechanic certificate does not expire, but the currency requirement (6 months in 24) must be met to exercise privileges legally. Don't confuse certificate validity with privilege currency.
- Rating scope errors. An Airframe-only mechanic signing a logbook entry for engine work is acting outside their rating. The FAA tests this directly with scenario-based questions about rating applicability.
- Alcohol timing. The 8-hour "bottle to throttle" equivalent for mechanics is often confused with the pilot rule. For mechanics, the standard is also 8 hours and BAC below 0.04 — the same thresholds, but students sometimes assume different numbers apply.