Test guides / CAX
FAA KNOWLEDGE TEST GUIDE
Commercial Pilot written test (CAX)
The Commercial Pilot Airplane (CAX) knowledge test builds on private pilot knowledge with more depth on regulations, aerodynamics and performance. It is the longest of the common pilot written tests at 100 questions.
AT A GLANCE
- Test code
- CAX
- Questions
- 100 multiple choice (3 options each)
- Time allowed
- 2 hr 30 min
- Passing score
- 70% (70 of 100)
- Minimum age to test
- 16
- Results valid for
- 24 calendar months
- Where
- PSI testing centers (about $175)
What the CAX covers
- ▸Commercial privileges and limitations, Part 61, 91 and 119 basics
- ▸Advanced aerodynamics, load factor and maneuvers
- ▸Complex aircraft systems: constant-speed propellers, retractable gear, turbocharging
- ▸Performance and weight and balance calculations
- ▸Weather theory and weather products
- ▸Navigation, flight planning and flight operations
- ▸Aeromedical factors and decision-making
What you need to take it
- Authorization: A logbook endorsement or written statement from an authorized instructor, or a graduation certificate or statement of accomplishment from an FAA-certificated pilot school or qualifying program.
- ID: a government-issued photo ID with your date of birth, signature and address.
- FAA Tracking Number (FTN): create one in IACRA before you schedule with PSI.
How to prepare
- ✓Know exactly what a commercial pilot may and may not do for compensation or hire — it is heavily tested.
- ✓Practice performance and weight-and-balance problems with the testing supplement figures.
- ✓Pace yourself: 100 questions in 2.5 hours is about 90 seconds each.
Frequently asked questions
How many questions are on the Commercial Pilot written test?
The CAX test has 100 scored multiple-choice questions, each with three answer choices. A few extra unscored questions may be included; they don't count for or against you.
How long is the CAX test?
You have 2 hr 30 min, including time for any unscored questions.
What score do I need to pass the CAX?
70% — at least 70 of 100 correct.
How long are my CAX results valid?
A passing result is valid for 24 calendar months: you need to finish the practical test (checkride) within that window (14 CFR 61.39).
What do I need to bring to the testing center?
A government-issued photo ID showing your date of birth, signature and address, your FAA Tracking Number (FTN) from IACRA, and your test authorization: a logbook endorsement or written statement from an authorized instructor, or a graduation certificate or statement of accomplishment from an FAA-certificated pilot school or qualifying program.
What happens if I fail?
If you fail, you can retake the test after an authorized instructor gives you additional training in the areas you missed and signs a retest endorsement (14 CFR 61.49). There is no required waiting period, but you pay the test fee again.
How much does the test cost?
The FAA says knowledge test centers charge about $175. You book and pay through PSI, the FAA’s testing provider.
Study a little every day
AeroPrep gives you three FAA-style CAX practice questions a day for free, with explanations and FAA references, plus a Logbook that shows which topics need work. Pro ($9.99/month) adds unlimited practice and unlimited timed exams.
Start free practice →Test formats are from the FAA Airman Knowledge Testing Matrix and 14 CFR Part 61. The FAA updates these from time to time, so confirm details on the current matrix before you book. AeroPrep questions are written in the style of the FAA knowledge tests; they are not actual test questions. AeroPrep is not affiliated with the FAA.