What Does MEI Stand For?

The Short Answer: Multiengine Flight Instructor Rating

On this site, MEI stands for Multiengine Flight Instructor Rating. It is an added rating on a flight instructor certificate that authorizes a certificated flight instructor (CFI) to give instruction in multiengine airplanes. The Federal Aviation Administration governs it, and the standards a candidate is evaluated against are published in the Flight Instructor Airplane Airman Certification Standards.

If you landed here searching for the meaning of the letters, that is the full answer. The rest of this article explains what each word means in practice, how the rating is earned, what the evaluation covers, and where the rating is put to work. For a broader orientation, you may also want our companion explainers on what MEI is and the meaning of MEI.

Breaking Down Each Word in the Name

Multiengine

The airplane category and class distinction. A multiengine airplane has more than one engine, and flying one safely introduces problems that a single-engine airplane never presents: asymmetric thrust after an engine failure, critical-engine considerations, minimum control speed, feathering procedures, and a very different performance picture when one powerplant is inoperative. The instructor must understand and teach all of it.

Flight Instructor

This word is the part many candidates underestimate. The rating is not simply a multiengine pilot rating. It is an instructing privilege. The person being evaluated must show they can explain, demonstrate, and correct, not merely perform. That is why the standards open with fundamentals of instructing and technical subject areas before a single maneuver is flown.

Rating

In FAA terminology, a rating is an addition to an existing certificate. The MEI is added to a flight instructor certificate rather than standing alone. The holder is already an instructor in some capacity; the rating widens what that instructor may teach.

How the Rating Fits Into the FAA System

The rating sits inside a layered certification structure. A pilot first holds the underlying pilot qualifications, then a flight instructor certificate, and then adds ratings that extend instructional privileges. The multiengine instructor rating is one such addition. For the eligibility details, prerequisites, and how to qualify, see our guide to MEI requirements.

Two features of the FAA framework matter for understanding the name:

• The governing standard is the ACS. The Flight Instructor Airplane ACS, designated FAA-S-ACS-25, was published in November 2023 and became effective May 31, 2024. It defines the Areas of Operation, Tasks, and the knowledge, risk management, and skill elements an evaluator uses.
• Added-rating logic is built in. Because an MEI candidate usually already holds other instructor privileges, the ACS includes a table (on printed page 98) that determines which Tasks are required based on the ratings the applicant already holds.

The ACS and Its 14 Areas of Operation

The Flight Instructor Airplane ACS organizes its content into 14 Areas of Operation. These are the overarching headings under which Tasks are grouped. They are not percentage-weighted exam domains, and they should not be read as 14 equally scored sections of a single test. Our complete guide to all 14 content areas walks through each in more depth.

Multiengine Operations: The Heart of the Rating

Of the 14 Areas, Multiengine Operations is the one that most directly earns the rating its name. It is where a candidate demonstrates that they can teach the things that make a twin different from a single.

Because the instructor sits beside a student who may be learning engine-out handling for the first time, risk management is as much a part of this Area as technique. The ACS evaluates whether the candidate can recognize and manage instructional risk, including when to take the controls.

Several other Areas also acquire multiengine flavor when flown in a twin. Takeoffs, Landings, and Go-Arounds, Emergency Operations, and Slow Flight, Stalls, and Spins all carry airplane-specific considerations that an instructor must be prepared to teach correctly. For a quick-reference view of the facts that recur, see the MEI cheat sheet.

Knowledge Tests: AFA vs. FIA

Candidates frequently ask whether the multiengine instructor rating has its own written test. The answer requires care, and it is a place where much of the internet is imprecise.

The current FAA Testing Matrix (revised September 25, 2026) distinguishes two instructor knowledge tests:

Treat those figures as optional reference points, and read the applicability and exclusions in the Testing Matrix before relying on them. Several important qualifiers apply:

• The AFA is not a universal MEI knowledge test. Whether any knowledge test applies depends on the candidate's existing certificates and ratings.
• Glider-rated instructors adding airplane use the FIA.
• Added-rating tests are not available to sport-only instructor holders.
• Optional unscored validation questions are excluded from the listed question counts but are included in the testing time.
• 14 CFR 61.191(b) provides an exemption from the fundamentals-of-instructing test in certain circumstances. It is not a blanket exemption from every knowledge test.

Who Hires a Multiengine Instructor

The rating has practical value because multiengine training is a recurring need across aviation. Typical employers and settings include:

• Flight schools and Part 141/61 training operations that offer multiengine add-on courses, commercial multiengine, and instrument-multiengine work.
• Collegiate aviation programs that put students through multiengine training as part of a professional pilot curriculum.
• Airline pilot academies and cadet programs that need instructors who can move students into twins.
• Independent instructors and small operators who sell multiengine add-ons, recurrent training, and checkout flights to owners of light twins.
• Corporate and charter flight departments that use qualified instructors for in-house training and aircraft checkouts.

Specific compensation depends heavily on region, employer type, and hours flown, and we do not quote figures here that we cannot source. For analysis, see the MEI salary guide, the MEI jobs overview, and the ROI analysis.

Why the Acronym Causes Confusion

Three letters can mean many things, and a quick web search may surface unrelated credentials, organizations, or product categories that share the abbreviation. If you are an aviation candidate, the safeguard is simple: confirm that any source you read is discussing the FAA flight instructor rating, cites the Airman Certification Standards or 14 CFR Part 61, and talks about airplanes, engines, and instruction.

If a page quotes exam fees, domain percentages, pass rates, or salary numbers without citing the FAA or an aviation source, treat it with suspicion. The FAA ACS does not assign percentage weights to its 14 Areas, so any resource claiming otherwise is likely describing something else. Related explainers on our site include what a MEI is, what MEI means, and what MEI certification is.

Mapping Your Preparation to the Rating

Generic study advice is easy to find; what matters here is sequencing the Areas so that foundation topics precede the multiengine material. One reasonable ordering follows.

Pair this schedule with our MEI study guide, and use the practice test platform for knowledge-style questions. If you want to gauge how demanding the process is, read how hard the MEI exam is and the notes on pass rate data. For the financial side, see certification cost, and for hands-on preparation resources, our overview of MEI training. You can also explore more practice questions at any point.

Frequently Asked Questions