Decoding ACS

Understanding the Airman Certification Standards

FAA Safety Briefing
Cleared for Takeoff
7 min readSep 6


By James Williams, FAA Safety Briefing Magazine

The FAA’s Airman Certification Standards (ACS) project started in 2011–2012 with a simple idea: finding a logical, data-driven way to clean up outdated knowledge test questions. The result is a system that enables pilots and prospective pilots to be more prepared — and more comprehensively prepared — with less digging.

Photo of small airplane in flight.

In the Beginning

I have personal experience with the reasons for this project. While we generally referred to this part of the certification process as the “written” test, they were all computer-based tests by the time I took my first of many. But some of the questions were downright prehistoric. As the test taker, you just learned to memorize your way around those questions and move on. This represented a waste of both the applicant’s time and the FAA’s chance to measure the applicant’s knowledge — you know, the whole point of the exercise.

To ensure that we got it right, the FAA invited a number of aviation community experts to join a team (formally convened in an “Aviation Rulemaking Committee” and later in a series of Aviation Rulemaking Advisory Committee working groups) to share their expertise. It quickly became clear that “getting it right” required a systematic approach. In the “old” days, your exam consisted of three separate but interlocked activities, each handled somewhat differently: the knowledge (“written”) exam, the oral exam, and the practical exam. The knowledge test drew from a bank of test questions, and the oral and practical exams drew from the Practical Test Standards (PTS). Over time, these had become disconnected and effectively separate activities instead of being integrated to provide the best possible certification testing.

It would take more than five years for this government/industry effort to become the first integrated ACS, and you can read all about it in the article “The ABCs of ACS,” (see link in Learn More).

Photo of a pilot in the cockpit of a small airplane.

Enter the ACS

The ACS unifies knowledge and skill elements with risk management elements to create a one-stop solution for airman certification. The ACS sorts elements into three kinds of tasks — things the applicant must know, consider, and do. The know portion is derived from the aeronautical knowledge portion of each certificate. The consider portion allowed FAA to formally introduce risk management concepts like Aeronautical Decision Making (ADM) that are critically important, and to integrate them into specific tasks. The do portion largely consists of the traditional PTS tasks in the new format. You can find all the ACS documents and additional support at

There are current ACSs for private pilot, commercial pilot, airline transport pilot, instrument rating, remote pilot, and aviation maintenance technician (AMT). ACS now covers many more certificates than when it initially rolled out.

Photo of airplane cockpit.

The Flight Path Ahead

So what is the status now? Currently, there are 18 Practical Test Standards (PTS) in use today. An ongoing rulemaking effort will codify these 18 PTSs along with 15 ACS documents as listed in

“The ACS is a comprehensive testing approach that connects the standards for knowledge, risk management, and skills to the knowledge and practical test,” explains Daron Malmborg, an aviation safety inspector and expert in airman certification with the FAA’s Regulatory Support Division. “The FAA will continue to use the PTS for some certificates and ratings until the corresponding ACS is completed.”

“The future does hold some updates to the ACS that are already available. Due to the intended regulatory nature of the PTSs and ACSs, the FAA proposed and initiated action, via rulemaking, to Incorporate by Reference (IBR), into the Code of Federal Regulations (CFRs), the aforementioned PTSs and ACSs,” Malmborg said. “They contain requirements for pilots, flight instructors, flight engineers, aircraft dispatchers, and parachute riggers. This rulemaking can be viewed at: Once this rulemaking is final, the FAA intends to continue its collaborative work with the Aviation Rulemaking Advisory Committee (ARAC) ACS Workgroup (WG), to produce future ACS documents, from the remaining original IBR’d PTS documents.” He continued, “Each document will be required to progress through rulemaking in order to comply with the Administrative Procedure Act (APA), which allows public comments during rulemaking.”

This rulemaking can be viewed at by referencing Regulation Identifier Number (RIN) 2120-AL74.

Why does the FAA want to make this change?

“There are multiple reasons to codify the ACS and PTS documents,” Malmborg explained. “The first being that the PTS and the ACS impose requirements on all persons seeking an airman certificate or rating. The PTS and ACS require an applicant seeking a certificate or rating to complete specific tasks, which must be performed to a minimum standard, in order to obtain the applicable certificate or rating. As such, if an applicant does not perform a task in the PTS or ACS, to the prescribed standard, the applicant cannot obtain the applicable certificate or rating. Unsatisfactory performance results in a notice of disapproval and denial of the airman certificate.”

“Also, the FAA has recently determined these testing and certification standards are indirectly referenced in the regulations, particularly in parts 61, 63, and 65; and require compliance in order to successfully complete an FAA test and obtain an airman certificate or rating,” Malmborg added. “As such, the FAA discovered it had not consistently provided the regulated community with the notice or opportunity to comment as mandated by the APA, before the community was required to comply with the standards set forth in the PTS and ACS. As a result, the FAA initiated this rulemaking to bring the PTS and ACS documents into the FAA regulations through proper notice and comment procedures required by the APA.”

Another reason for codifying is the unique nature of the PTS and ACS documents. “They are lengthy and contain complex technical information and tables that may prove difficult and inefficient to be traditionally printed in the Federal Register and CFR,” said Malmborg. “As such, the FAA has identified the most efficient and effective way to integrate the required elements in the PTS/ACS into FAA regulations is through IBR. In other words, the FAA proposes to IBR these standards, rather than reproduce the documents in their entirety,” Malmborg concludes. “IBR is a mechanism allowing federal agencies to comply with the requirements of the APA by publishing rules, in the Federal Register and the CFR, and referring to material published elsewhere. Material incorporated by reference has the same legal status as if it were published, in full, in the Federal Register.”


As noted above, the ACS can be pretty lengthy. In fact, the Private Pilot Airplane ACS comes in at more than 100 pages. In addition, each element covered in the ACS has a code like this one: PA.I.D.K4. What does that mean? Here’s a quick guide.

ACS Coding: PA = Private Pilot Airplane (applicable ACS); I = Preflight Preparation (Area of Operation); D = Cross-Country Flight Planning (Task); K4 = Elements of a VFR Flight Plan (Task Element)

We now see that PA.I.D.K4 is Elements of a VFR Flight Plan. While that one is fairly self-explanatory, other tasks, especially the skill-based ones, will have additional criteria like the following for normal takeoffs: Establish a pitch attitude to maintain the manufacturer’s recommended speed or Vy, +10/-5 knots. This is your performance standard. The knowledge test report will generate codes for missed questions that will correlate to an element in the applicable ACS. These codes will help you focus on areas of weakness and better prepare for the oral exam.

While lengthy, each ACS is relatively easy to skim through to find specific tasks. This allows you to look through the ACS, find your weak spots, and determine what the examiner will be looking at and what you need to know, consider, or do. That way, you can focus on those areas with your instructor and make sure you are going to ACE your encounters with the ACS.

Learn More

This article was originally published in the September/October 2023 issue of FAA Safety Briefing magazine.



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