Which FAA written exam is actually the hardest?
The FAA passes almost every pilot it tests, and turns away a third of the mechanics. This index ranks all seven major knowledge tests on the numbers that matter to you, how many people pass, how well they score, and the exact topics they miss, using the FAA's own data from 2019 to 2025.
What the numbers say
Three things jump out of six years of FAA data, and they connect.
Test volume is up 64% since 2020, driven by drone pilots (Part 107 up 71%) and mechanics (A&P General up 118%). Most are first-timers.
Only 64% pass the A&P Powerplant, the lowest of any exam. Scores are sliding on exactly the fast-growing tracks, A&P and Part 107.
Private, Instrument, and Commercial pass rates barely move. The "pass rates are dropping" story is really about mechanics and drones, not pilots.
Every exam, ranked
A high pass rate is not the same as an easy test. Sort by whichever measure matters to you.
| Exam | Pass rate | Avg score | Volume (2024) | Threat |
|---|---|---|---|---|
| Aviation Mechanic Powerplant AMP · Aviation Maintenance (A&P) | 64.4% 1st hardest of 7 | 73.1% 1st lowest of 7 | 14,306 6th busiest of 7 | Severe |
| Aviation Mechanic General AMG · Aviation Maintenance (A&P) | 70.8% 2nd hardest of 7 | 74.3% 2nd lowest of 7 | 18,689 5th busiest of 7 | Severe |
| Aviation Mechanic Airframe AMA · Aviation Maintenance (A&P) | 72.6% 3rd hardest of 7 | 75.4% 3rd lowest of 7 | 14,213 7th busiest of 7 | Severe |
| Remote Pilot, Small UAS (Part 107) UAG · Remote Pilot (Part 107) | 84.2% 4th hardest of 7 | 80.0% 4th lowest of 7 | 67,576 1st busiest of 7 | Moderate |
| Private Pilot Airplane PAR · Airplane Pilot | 91.9% 5th hardest of 7 | 82.9% 5th lowest of 7 | 46,132 2nd busiest of 7 | Low |
| Instrument Rating Airplane IRA · Airplane Pilot | 94.2% 6th hardest of 7 | 85.6% 6th lowest of 7 | 25,647 3rd busiest of 7 | Low |
| Commercial Pilot Airplane CAX · Airplane Pilot | 99.3% 7th hardest of 7 | 91.0% 7th lowest of 7 | 18,840 4th busiest of 7 | Low |
Ranked hardest first by the most recent full-year (2024) pass rate. Sort by the chips above. Pass rate, average score, and volume are the FAA's figures; threat level is our reading of them.
How each exam is trending
One small chart per exam, each on its own scale, so you can see the shape of its trend at a glance. Flip between pass rate, score, and volume.
Each panel is one exam, scaled to its own history so you can see the shape of its trend. Bar color shows the exam's difficulty band (from its latest pass rate). Hollow bar is the preliminary 2025. The number at bottom right is the change from the first year in the data to the latest.
Do the hard exams also score lower?
Plot each exam's pass rate against its average score and they line up: the tests that stop the most people are the same ones where the people who take them score lowest. Difficulty is real, not a quirk of one number.
Each dot is one exam. Further right, more people pass; higher up, they score better. The dots climb from bottom-left to top-right, so the exams that stop the most candidates are also where scores run lowest. Hover a dot for its numbers.
The topics candidates miss most
The FAA publishes the single most-missed ACS code on each exam. These are the questions four candidates in five get wrong. Click any one for a plain-English breakdown and a sample question.
| Exam | Topic | Percent missed | Why people miss it | |
|---|---|---|---|---|
| CAX | Human factors: stress. CA.I.H.K1g | 83.6% | Underestimating how stress affects judgment | Deep dive → |
| PAR | Flight instruments: function and operation. PA.VIII.C.K1c | 80.7% | Misreading how the instrument works | Deep dive → |
| PAR | Documenting in-flight and postflight discrepancies. PA.XII.A.K2 | 80.7% | Getting the rule slightly wrong | Deep dive → |
| AMA | Special inspections. AM.II.D.K5 | 79.5% | Not knowing what triggers the inspection | Deep dive → |
| UAG | Declaration of Compliance (DoC). UA.I.E.K13 | 78.6% | Confusing which document is which | Deep dive → |
| AMG | Corrosion identification and inspection. AM.I.G.K6 | 78.5% | Mixing up which metal corrodes first | Deep dive → |
| CAX | What causes a spin, and how to identify the entry, incipient, and developed phases. CA.VII.E.K2 | 78% | Confusing the stages of a spin | Deep dive → |
| AMG | Electrostatic discharge. AM.I.A.K24 | 74.9% | Skipping a safe-handling step | Deep dive → |
| PAR | Airspeed, including airspeed limitations. PA.IX.A.K3 | 73.3% | Mixing up the V-speeds | Deep dive → |
Percent missed is the FAA Safety Analysis Branch's published figure for the most-missed ACS code per exam. The FAA publishes only its top code(s) per exam, so this is not an exhaustive ranking.
Why pilots and the data disagree
Ask around a hangar and most pilots will tell you the Private Pilot written is the hardest one. The data says otherwise: the three lowest pass rates all belong to the A&P mechanic tests, not to any flying exam. Both camps are right, and the reason is worth understanding before you open a study app.
Pilot writtens pass at 90 to 99% for two reasons. The people taking them are self-selected and already deep into flight training, and rote tools let many candidates memorize the question bank cold. That inflates the pass rate without saying much about how hard the material really is. The Private Pilot test feels like the hardest because it is your first, before you have learned how these exams are built.
The A&P tests have no shortcut and a much larger, more technical bank, which is why mechanics fail them far more often. Whatever you are sitting, remember that the written is only the first gate. Memorizing answers earns a passing score; understanding the material is what carries you through the oral and the checkride, where roughly one in four candidates still fails.
Sources & data notes
- FAA Airman Knowledge Test Statistics (hub)Annual and quarterly Airman Knowledge Test volume, pass rate, and average score by test code. Last verified Sep 15, 2026.
- Airman Knowledge Test annual statistics, 2019 to 2025Per-exam volume, pass rate, and average score. Calendar-year reports 2019 through 2025 (2025 preliminary). Last verified Sep 15, 2026.
- Frequently Missed Knowledge Test ACS CodesFAA Safety Analysis Branch quarterly report: the most-missed ACS code per test code, with percent missed. Last verified Sep 15, 2026.
- Airman Certification Standards (ACS) documentsPlain-English topic and Area/Task definitions for each ACS code (Private FAA-S-ACS-6, Commercial FAA-S-ACS-7, Aviation Mechanic FAA-S-ACS-1). Part 107 (UAG) follows the PSI UAG Applicant Information Bulletin, the current test blueprint that supersedes the FAA-S-ACS-10 blueprint. Last verified Sep 15, 2026.
- Pass rates, volumes, and average scores are the FAA's published figures. Difficulty rankings and threat levels are Aviator IQ's analysis of that public data, not official FAA ratings.
- Aviator IQ is not affiliated with, endorsed by, or associated with the Federal Aviation Administration.
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