Airworthy Prep

Flight Instructor Airplane test code

AI.X.B.K5Slow flight, Stalls, and Spins: Demonstration of Flight Characteristics at Various Configurations and Airspeeds (ASEL and ASES)

Flight Instructor Airplane test standard, area of operation X, task B

Written as ai.x.b.k5 or AI.X.B.K5 on your score report.

The FAA's wording

Pitch, power, and trim control inputs that are required to operate the airplane in level flight, turns, climbs, and descents and how the control inputs change at various airspeeds between cruise airspeed and critically slow airspeeds.

FAA-S-ACS-25, Flight Instructor for Airplane Category ACS (November 2023, effective May 31, 2024), X. Slow flight, Stalls, and Spins, Task B. Demonstration of Flight Characteristics at Various Configurations and Airspeeds (ASEL and ASES)

What it means

AI.X.B.K5 is a knowledge element in the Slow flight, Stalls, and Spins area of operation of the Flight Instructor Airplane test standard. A knowledge element is something the FAA expects you to know, and the written test asks questions on it.

AI
Flight Instructor Airplane ACS
X
Area of operation X: Slow flight, Stalls, and Spins
B
Task B: Demonstration of Flight Characteristics at Various Configurations and Airspeeds (ASEL and ASES)
K5
Knowledge element 5

Seeing it on your score report

Your Airman Knowledge Test Report lists a code for each area where you missed a question. Seeing AI.X.B.K5 there means at least one of your wrong answers was on this element. If you are taking the practical test next, expect the examiner to ask about it. Retaking the written? Start with this code and the others on your report.

Sources: FAA-S-ACS-25, Flight Instructor for Airplane Category ACS (November 2023, effective May 31, 2024); FAA Airman Knowledge Testing Matrix (revised 9/25/26), p. 2.

Can be printed on 2 tests
  • Flight Instructor Airplane (Added Rating) (AFA)
  • Flight Instructor Airplane (FIA)

Got more than one code on your report?

Paste them all into the free study planner and it groups them by subject, most missed first.