FAA Part 147 and ACS-based testing: what changed for AMT schools

FAA Part 147 schools are aviation maintenance technician schools (AMTS) certificated under Title 14 of the Code of Federal Regulations, part 147, to train students for the FAA mechanic certificate. Since the 2022 rewrite of part 147, each school must keep its curriculum aligned with the Mechanic Airman Certification Standards (ACS). Since August 1, 2023, the FAA has tested mechanic applicants against that same standard.

This post is for the people who run those schools: heads of training, quality managers, chief instructors and exam officers. Searches for “faa part 147 schools” also bring up prospective students looking for a school to attend, and this is not a school finder. As of October 2026, most pages that explain the rewrite describe the rule itself. This one adds three tools: a map from ACS element types to the evidence your own assessments should produce, a worked 60-day pass-rate calculation, and a table that separates what the rule sets from what your school decides.

This is general information, not legal or airworthiness advice. Confirm any point that affects your certificate with your FAA Flight Standards office.

Key takeaways

• The 2022 rewrite ended FAA approval of AMTS curricula and fixed curriculum hours. Under 14 CFR 147.17, each school must keep a curriculum designed to continually align with the Mechanic ACS.
• FAA mechanic tests have used the ACS since August 1, 2023, and every element has a code such as AM.I.A.K1. Tagging your own test items with the same codes shows what you teach and what you actually test.
• Under 14 CFR 147.25, at least 70 percent of students who test within 60 days of graduation must pass, measured over the most recent three years. Tests taken before graduation do not count.
• The rule does not say how a school assesses its own students, so item banks, mock tests and records are your decisions, made inside your quality control system.

What is a Part 147 school, and what did the 2022 rewrite change?

A Part 147 school is an FAA-certificated AMTS that holds an Airframe, Powerplant, or combined Airframe and Powerplant rating. It may issue a certificate of completion only for a curriculum its ratings authorize. The FAA replaced part 147 in an interim final rule effective September 21, 2022, then adopted it as final in 2023.

The preamble to the interim final rule (87 FR 31391, May 24, 2022) explains the main shift. The FAA stopped approving AMTS curricula, dropped the prescriptive curriculum-hour requirements from the old rule, and tied the curriculum to the Mechanic ACS instead. Earlier rulemaking material refers to national passing norms in the old section 147.37. The current rule sets one minimum passage rate instead.

The table lists the dates that matter for planning, with the source for each.

What must FAA Part 147 schools do about the ACS?

FAA Part 147 schools must keep a curriculum designed to continually align with the Mechanic ACS, as appropriate for the ratings held, and must ensure students are prepared to test under part 65, subpart D. The FAA no longer approves the curriculum, so the school holds the evidence of alignment.

The wording in 14 CFR part 147 is short. Section 147.17(a)(1) requires each school to: “Establish, maintain, and utilize a curriculum that is designed to continually align with the mechanic airman certification standards referenced in paragraph (b) of this section, as appropriate for the ratings held” (quoted). Paragraph (b) incorporates FAA-S-ACS-1, dated November 1, 2021, by reference.

Advisory Circular 147-3C (March 22, 2022) explains how a school might show alignment, though it is advisory and not legally binding. It suggests including the ACS high-level subjects with content items, concepts and practical projects under each (paragraph 2.7.2.2.1). It says ACS skill elements should appear as practical projects “with defined performance criteria and outcomes” (paragraph 2.7.2.2.3). It also says a school may teach more than the ACS requires, and that the curriculum must be revised no later than the effective date of any ACS change (paragraph 2.7.3.1).

According to the preamble, a school need not copy the whole ACS into its curriculum word for word. Nothing in section 147.17 tells a school how to test its own students, which is the gap the later sections address.

How does ACS-based FAA testing work, and what does it tell a school?

The Mechanic ACS has three sections (General, Airframe, Powerplant). Each is divided into subjects with coded knowledge, risk management and skill elements. Written tests draw on knowledge elements, oral tests on knowledge and risk management, and practical tests on risk management and skills. The knowledge test report lists the ACS code of each missed question.

Element codes have four parts. In AM.I.A.K1, AM is Aviation Mechanic, I is the General section, A is the subject (fundamentals of electricity and electronics) and K1 is the first knowledge element. The Mechanic ACS (FAA-S-ACS-1) lists twelve General subjects, A through L. Subject A alone has 27 knowledge, 4 risk management and 14 skill elements, so a single subject carries 45 elements.

The table shows how each FAA test uses the elements and what comes back to the applicant. The oral and practical figures come from FAA Notice N 8900.666, and the feedback column draws on the FAA’s companion guide, FAA-G-ACS-1.

The notice also says evaluators generate a unique test for each applicant through the Mechanic Test Generator, in person. It took effect August 1, 2023 and carried a cancellation date of August 1, 2024, so treat these counts as a snapshot and ask your Flight Standards office for current guidance.

How is the 70 percent pass rate under § 147.25 calculated?

Section 147.25 requires a school to maintain its pass rate for the most recent 3-year period. At least 70 percent of students who take an FAA mechanic test within 60 days after graduation must pass the written, oral or practical test, alone or in combination. A failure counts unless that same test is passed inside the 60-day window.

The regulation says “at least 70 percent of students must pass one of the following tests or any combination thereof” (quoted), and paragraph (c) tells a school to “count a failure on any one test as a student failure” unless “that failed test is subsequently passed within the 60-day window” (quoted). The FAA’s 2026 AMTS minimum passage rate report, created September 30, 2026, adds how it counts. It covers three years of tests, reports each school by section (General, Airframe, Powerplant), and says it does not itself state a threshold or decide any school’s compliance.

The table walks through how the report’s counting rules treat five common situations.

Here is the arithmetic with invented numbers. If 30 graduates test inside their windows, 21 must pass to reach 70 percent. With 20 passes the rate is 66.7 percent. Nine failures is the limit, so every retest that turns a failure into a pass matters.

Pro tip: Start the Day-60 Clock at Graduation. Put the graduation date and the day-60 date on the same record as the section 147.21 certificate of completion. A retest normally needs a 30-day wait, or a signed statement of additional instruction under 14 CFR 65.19, so a graduate who first tests late in the window has little room to recover.

How can you map your own assessments to ACS codes?

Give every school test item, oral prompt and practical project exactly one ACS code, then count coverage by code. Knowledge elements become tagged items, risk management elements become scenario items or oral prompts, and skill elements become practical projects scored against written performance criteria.

The table shows what each element type needs from your own assessment and what to record.

A tagged record is simple. The item bank fields and tagging rules already cover learning objective and version, so the ACS code becomes the learning objective tag. This illustrative item is original, written for this post, and is not representative of any FAA test.

Once items carry codes, two checks follow. Count items per code and flag any code with none or one, which is a coverage gap. Then run item analysis for each cohort and read it by code, so weak spots show up by ACS element rather than by test.

Pro tip: Join Missed Codes to Your Bank. With each graduate’s permission, collect the ACS codes on their knowledge test report and count misses by code. A code that is missed often and has many items in your bank points to item quality or teaching. A code with no items points to a coverage gap.

Who decides what at FAA Part 147 schools: the rule, the FAA, or the school?

The regulation fixes the curriculum standard, the pass rate, the graduation document and the quality control topics. FAA guidance adds recommendations. Everything about how you run your own tests, which tool you use and how long you keep extra records is your school’s choice, subject to your quality control system.

The table separates the three levels. Each row cites the source reviewed, as of October 2026.

No source reviewed names an approved assessment tool. Part 147 and AC 147-3C describe procedures and records, not software, so be wary of any claim that a tool is “FAA approved” unless the FAA itself says so.

Is the Mechanic ACS about to change?

A change is proposed but not adopted. As of October 2026, the FAA’s testing page still lists FAA-S-ACS-1 from November 2021 with no change notices. A March 2026 webinar from ATEC (the Aviation Technical Education Council) described a plan to send the FAA a revision called ACS Rev 01 in April 2026.

ATEC’s slides say it “could be years before it’s promulgated” and promise “No changes to curriculum requirements until changes are promulgated” (quoted). The proposal is an industry recommendation, not FAA action, and it needs FAA review and rulemaking. Keep your coverage map easy to re-tag, because AC 147-3C expects curriculum updates by the effective date of any ACS change.

What should you do next?

Start with the curriculum gap analysis you already did for the 2022 rewrite. ATEC published a gap analysis form for that purpose. Extend it with one more column: for each ACS element, which school assessment tests it and how many items or projects cover it.

Then add the 60-day tracker to your graduate records and review it monthly. If you are choosing software for the item bank and records, test any platform with your own ACS code list first. The SimpliAssess features page names Item Banking, Tag Management and Analytics & Reporting but does not describe how they work or mention aviation. SimpliTrain, a separate training platform from the same company, has an aviation industry page that lists assessments, question banks and a certification tracker. It describes EASA Part-147 support and does not describe FAA Part 147 schools, so use it to prepare questions, not to answer them.

If your organization also teaches under EASA rules, read EASA Part-147 examinations and what your exam system must support, since the two rule sets differ.

Frequently asked questions

What is an FAA Part 147 school?

An FAA Part 147 school is an aviation maintenance technician school certificated by the FAA under 14 CFR part 147. It may hold an Airframe, Powerplant, or combined rating, and the rating shows which curriculum it may teach. It may issue a certificate of completion only on graduation from a specific curriculum, which helps a graduate show eligibility to test.

Does the FAA still approve a Part 147 school’s curriculum?

No. Under the 2022 rule, the FAA no longer approves AMTS curricula. Section 147.17 instead requires each school to maintain a curriculum designed to continually align with the Mechanic ACS, as appropriate for its ratings. The school must be able to show that alignment, and AC 147-3C describes ways to do so.

What pass rate must a Part 147 school maintain?

At least 70 percent. Section 147.25 requires that for students who take an FAA mechanic test within 60 days after graduation, at least 70 percent pass the written, oral or practical test, alone or in combination. The rate is measured over the most recent three years, and tests taken before graduation are excluded.

When did the Mechanic ACS become the FAA testing standard?

August 1, 2023. The FAA used the Mechanic Practical Test Standards through July 31, 2023, then switched to the ACS for written, oral and practical tests. Curriculum alignment began earlier, on September 21, 2022, when the rewritten part 147 took effect, and no transition period was provided.

Can students take FAA tests before they graduate?

Yes, in two cases. Under 14 CFR 65.75(c) and 147.31, a student may take the general written test early with an authenticated school document showing completion of the general curriculum. Under 14 CFR 65.80, a school can show satisfactory progress so a student takes oral and practical tests near the end. Neither counts in the pass rate.

Does a Part 147 school have to be accredited?

Not necessarily. Section 147.23 lets a school either be accredited within the meaning of 20 U.S.C. 1001(a)(5) or maintain a quality control system approved by the FAA. That system must provide procedures for recordkeeping, assessment, issuing credit, final grades, attendance, enough instructors, graduation documents and corrective action.