- The CAX has 100 scored questions plus 5 unscored ones, covering all 11 ACS content areas.
- You need 70% to pass, and FAA-S-ACS-7B (effective May 31, 2024) is the current standard.
- Domain 10, Multiengine Operations, only applies if you're pursuing a multiengine rating alongside the CPL.
- A passing knowledge-test report stays valid for 24 calendar months before your practical test.
What the CAX Knowledge Test Actually Covers
The Commercial Pilot Airplane knowledge test, administered by the FAA through PSI Services LLC, isn't organized around random trivia. Every question maps back to one of 11 defined content areas published in the FAA's Airman Certification Standards. Understanding these 11 domains isn't optional trivia for test-takers - it's the actual blueprint examiners and question writers use to build the exam you'll sit for.
The test itself is computer-based: 100 scored multiple-choice questions plus 5 unscored validation questions (105 total), with 2 hours and 30 minutes on the clock. You need a 70% score to pass, and the fee is $175 plus applicable tax. In 2025, the CAX pass rate sat at 99.17% across 20,530 administered tests - a number that reflects how well-prepared most applicants are, not how easy the material is on its own.
If you haven't yet reviewed the mechanics of registration, timing, and eligibility, our CPL Study Guide 2026: How to Pass on Your First Attempt walks through the logistics in more depth. This article focuses specifically on what's inside the test: the 11 domains themselves.
The 11 CPL Content Areas Explained
Here's the full list of domains that make up the Commercial Pilot Airplane ACS, in the order the FAA presents them:
Domain 1: Preflight Preparation
Covers weather interpretation, performance and limitations, weight and balance, airworthiness requirements, and cross-country flight planning at a commercial level of precision.
- Expect scenario-based questions requiring you to interpret METARs, TAFs, and performance charts simultaneously.
Domain 2: Preflight Procedures
Focuses on cockpit management, engine starting, taxiing, and before-takeoff checks - the operational habits that separate commercial-level discipline from private pilot basics.
- Questions often test system knowledge specific to complex or high-performance aircraft.
Domain 3: Airport and Seaplane Base Operations
Tests your understanding of traffic patterns, runway incursion avoidance, and - for those pursuing seaplane privileges - water operations considerations.
- Airport signage, lighting, and communication procedures show up here repeatedly.
Domain 4: Takeoffs, Landings, and Go-Arounds
Covers normal, crosswind, short-field, and soft-field procedures, plus the decision-making behind go-around calls.
- Questions frequently combine performance data with procedural judgment.
These first four domains alone account for a substantial share of the knowledge base and are covered in dedicated deep-dives - see CPL Domain 1: Preflight Preparation - Complete Study Guide 2026, CPL Domain 2: Preflight Procedures - Complete Study Guide 2026, CPL Domain 3: Airport and Seaplane Base Operations - Complete Study Guide 2026, and CPL Domain 4: Takeoffs, Landings, and Go-Arounds - Complete Study Guide 2026 if you want a granular breakdown of each.
The remaining seven domains round out the certificate's scope:
- Domain 5: Performance Maneuvers and Ground Reference Maneuvers - chandelles, lazy eights, steep turns, and eights-on-pylons, plus wind-correction reasoning near the ground.
- Domain 6: Navigation - pilotage, dead reckoning, radio navigation, and diversion planning at a commercial precision standard.
- Domain 7: Slow Flight and Stalls - recognition and recovery across configurations, with heavy emphasis on aerodynamic understanding, not just rote procedure.
- Domain 8: High-Altitude Operations - supplemental oxygen requirements, pressurization concepts, and physiological effects of altitude.
- Domain 9: Emergency Operations - systems failures, emergency descents, and decision-making under abnormal conditions.
- Domain 10: Multiengine Operations - engine-out procedures, Vmc awareness, and asymmetric thrust handling for applicants adding a multiengine class rating.
- Domain 11: Postflight Procedures - after-landing, parking, and securing procedures, often the shortest domain but still testable.
Key Takeaway
Domain 10 only matters if your training path includes a multiengine airplane. Single-engine-only applicants should confirm with their ground school which domains actually apply to their test bank.
How Domains Are Weighted on Test Day
The FAA doesn't publish an exact question count per domain, and that ambiguity is exactly why so many applicants either over-study low-yield areas or skip domains they assume are minor. In practice, Preflight Preparation and Navigation tend to generate more questions because they involve dense subject matter - weather products, performance charts, airspace, and flight planning all overlap heavily. Domains like Postflight Procedures and Airport and Seaplane Base Operations typically generate fewer questions simply because there's less regulatory material to draw from.
That doesn't mean you can skip the smaller domains. Every scored question counts equally toward your 70% threshold, and the test includes 100 scored items pulled from all 11 areas plus 5 unscored questions used for future test development. You won't know which five are unscored, so every question deserves your full attention.
A Domain-by-Domain Study Timeline
Rather than studying domains in the order the FAA lists them, group your review by how heavily they interconnect. Weather and performance data (Domain 1) feed directly into takeoff and landing decisions (Domain 4), while navigation (Domain 6) and ground reference maneuvers (Domain 5) share wind-correction logic. A six-week cycle works well for most applicants balancing flight training with knowledge-test prep.
Foundational Planning Domains
- Domain 1: Preflight Preparation - weather products, performance charts, weight and balance
- Domain 2: Preflight Procedures - systems and cockpit checks
Ground and Pattern Operations
- Domain 3: Airport and Seaplane Base Operations
- Domain 11: Postflight Procedures
Takeoff, Landing, and Maneuver Precision
- Domain 4: Takeoffs, Landings, and Go-Arounds
- Domain 5: Performance Maneuvers and Ground Reference Maneuvers
Navigation and Aerodynamic Edge Cases
- Domain 6: Navigation
- Domain 7: Slow Flight and Stalls
Abnormal and Advanced Scenarios
- Domain 8: High-Altitude Operations
- Domain 9: Emergency Operations
- Domain 10: Multiengine Operations (if applicable)
Full-Length Review
- Cycle through practice questions covering all 11 domains
- Re-test weakest domains using targeted question banks
Spaced repetition across this six-week window works better than cramming because several domains overlap conceptually - reviewing Domain 1 weather concepts again during Domain 6 navigation review reinforces both without extra study time. Our main CPL practice test platform lets you filter questions by domain, which makes this kind of targeted review far more efficient than working through a single unsorted question bank.
Domain Difficulty and Focus Comparison
| Domain | Primary Focus | Common Challenge |
|---|---|---|
| 1. Preflight Preparation | Weather, performance, weight/balance | Chart interpretation under time pressure |
| 2. Preflight Procedures | Systems, cockpit management | Aircraft-specific system knowledge gaps |
| 3. Airport & Seaplane Base Operations | Traffic patterns, signage, water ops | Overlooked as "easy" and under-reviewed |
| 4. Takeoffs, Landings, Go-Arounds | Procedures across conditions | Distinguishing similar procedure variants |
| 5. Performance & Ground Reference Maneuvers | Chandelles, lazy eights, eights-on-pylons | Visualizing maneuver geometry from text |
| 6. Navigation | Pilotage, dead reckoning, radio nav | Multi-step flight planning problems |
| 7. Slow Flight and Stalls | Aerodynamics, recovery technique | Conceptual aerodynamic reasoning |
| 8. High-Altitude Operations | Oxygen, pressurization, physiology | Sparse study material, easy to skip |
| 9. Emergency Operations | System failures, abnormal procedures | Scenario-based judgment questions |
| 10. Multiengine Operations | Vmc, engine-out procedures | Only relevant to multiengine applicants |
| 11. Postflight Procedures | Securing and shutdown | Small domain, occasionally underprepared |
Why These Domains Matter for Hiring
Passing the CAX is just one requirement toward certificate issuance - you also need to be at least 18, demonstrate English proficiency, hold at least a private pilot certificate, complete required endorsements, log the aeronautical experience (generally 250 flight hours under Part 61), and pass a practical test. But the knowledge domains themselves carry weight beyond the exam room. Employers evaluating commercial pilot candidates - flight schools, charter operators, aerial survey companies, and regional carriers building hours toward airline minimums - expect fluency in exactly these 11 areas because they map directly to real operational judgment.
A candidate who can recite Domain 9 emergency procedures but struggles with Domain 1 performance calculations will still face scrutiny during checkouts and interviews. If you're weighing whether the certificate is worth the investment relative to the roles it opens up, our guides on CPL Jobs and Is the CPL Certification Worth It? Complete ROI Analysis 2026 go into the career-side reasoning, while CPL Salary Guide 2026: Complete Earnings Analysis covers compensation expectations across common CPL-holder roles.
It's also worth remembering that a passing knowledge-test report generally stays valid for 24 calendar months before your practical test, so timing your domain review around your flight training schedule - not just the exam date - matters. If your practical test gets delayed, you don't want your Domain 8 or Domain 9 knowledge to go stale before checkride day. For readers still getting oriented on the certificate itself, background pieces like What Is CPL?, CPL Meaning, and CPL Certification are useful starting points before diving into domain-level study.
Frequently Asked Questions
The FAA doesn't publish an official per-domain question count, but domains with more regulatory material - like Preflight Preparation and Navigation - tend to generate more questions than narrower domains like Postflight Procedures.
Multiengine Operations content applies specifically to applicants training toward a multiengine class rating. Single-engine-only candidates should confirm with their ground school or examiner whether this domain applies to their specific test.
The test has 100 scored multiple-choice questions plus 5 unscored validation questions, for 105 total, with 2 hours and 30 minutes allowed. You need 70% to pass.
Study from FAA-S-ACS-7B, effective May 31, 2024, which is the current standard covering all 11 commercial pilot airplane content areas.
A passing knowledge-test report is generally valid for 24 calendar months before you must complete your practical test, so plan your flight training timeline accordingly.
Mastering all 11 domains isn't about memorizing isolated facts - it's about building the same operational judgment examiners and employers expect from a working commercial pilot. Once you've reviewed each domain individually, running full-length practice sessions on our CPL practice test platform is the fastest way to confirm you're ready across the entire content area, not just the topics you find comfortable.