The FAA Instrument Rating Airplane (IRA) knowledge test is 60 questions, 2.5 hours, 70% to pass. The question bank covers everything from holding-pattern entries to alternate weather minimums to MEA vs. MOCA — and the official FAA test is intentionally trickier than most home-study apps prepare you for.
This page gives you a serious framework for instrument written test practice: what's actually on the test, how to study it efficiently, and the specific regulations and ACS task elements you need cold before you walk into the testing center.
What's on the IRA Knowledge Test
The IRA test is built directly from the Instrument Rating – Airplane Airman Certification Standards (FAA-S-ACS-8). Every question maps to a knowledge code in one of these areas:
- Area I — Preflight Preparation (weather, NOTAMs, performance, FAR 91.103)
- Area II — Preflight Procedures (cockpit setup, instrument checks)
- Area III — Air Traffic Control Clearances and Procedures
- Area IV — Flight by Reference to Instruments (scan, unusual attitudes)
- Area V — Navigation Systems (VOR, GPS, RNAV, WAAS, DME)
- Area VI — Instrument Approach Procedures (precision, non-precision, circling)
- Area VII — Emergency Operations (loss of comm, partial panel, icing)
- Area VIII — Postflight Procedures
The weighting skews heavily toward weather interpretation, IFR regulations, approach charts, and navigation. Expect roughly:
| Topic Area | Approx. % of Questions |
|---|---|
| Weather services & interpretation | 20–25% |
| IFR regulations (Part 61, Part 91) | 15–20% |
| Approach procedures & charts | 15–20% |
| Enroute & departure procedures | 10–15% |
| Navigation systems | 10–15% |
| Aeromedical, aerodynamics, aircraft systems | 10–15% |
Eligibility to Take the Test
Before you sit for the IRA, FAR 61.65 requires that you:
- Hold at least a private pilot certificate (or be concurrently applying for one)
- Be able to read, speak, write, and understand English
- Have received ground training or completed a home-study course covering the aeronautical knowledge areas in 61.65(b)
- Obtain an endorsement from an authorized instructor certifying you're prepared for the test
The knowledge test is valid for 24 calendar months from the month you take it — you must complete the practical test (checkride) within that window or you'll need to retake the written.
The Regulations You Must Know Cold
Three FARs show up in the IRA test repeatedly in different disguises. Master these and you'll pick up easy points.
FAR 61.65 — Instrument Rating Requirements
Know the aeronautical experience requirements verbatim:
- 50 hours of cross-country PIC, of which at least 10 must be in airplanes (for the airplane rating)
- 40 hours of actual or simulated instrument time, including at least 15 hours with an authorized instrument flight instructor
- One cross-country flight under IFR of at least 250 NM along airways or ATC-directed routing, with instrument approaches at three different airports
- 3 hours of instrument training in an airplane within 2 calendar months before the practical test
Expect questions that test whether specific time counts (e.g., "does view-limiting device time with a safety pilot count?" — yes, when logged correctly under FAR 61.51).
FAR 91.169 — IFR Flight Plan Alternate Requirements
The "1-2-3 rule" is one of the most-tested concepts on the entire exam. You must file an alternate unless, at the destination airport, from 1 hour before to 1 hour after ETA, the weather is forecast to be at least 2,000 feet ceiling and 3 statute miles visibility.
For the alternate itself, standard alternate minimums are:
- Precision approach: 600-2 (600 ft ceiling, 2 SM visibility)
- Non-precision approach: 800-2
- No instrument approach available: weather must allow descent from MEA, approach, and landing under basic VFR
Fuel-wise, you must carry enough to fly to the destination, then to the alternate, then 45 minutes at normal cruise.
FAR 91.175 — Approach and Landing Operations
The descent-below-DA/MDA rule is fair game on every test. You may not descend below DA/MDA unless:
- The aircraft is continuously in a position from which a normal descent to landing can be made at a normal rate
- The flight visibility is at or above the published minimum
- At least one of the 10 specified visual references for the runway environment is distinctly visible (approach lights, threshold, REIL, VASI, runway markings, etc.)
Note the special approach light rule: with the approach light system in sight, you may descend to 100 feet above TDZE, but you must then see the red terminating bars or red side row bars to go lower.
Other high-yield FARs: FAR 91.171 (VOR check requirements — 30 days, 4°/6°), FAR 91.183 (IFR position reports), and FAR 61.57 (instrument currency — 6 approaches, holding, intercepting/tracking in the preceding 6 calendar months).
How to Actually Study for the IRA
Most students fail not because the material is hard but because they study passively. A test-prep app that just shuffles questions teaches you to recognize answer letters, not concepts. Here's a smarter sequence:
- Read the source first. Work through the Instrument Flying Handbook (FAA-H-8083-15) and the Instrument Procedures Handbook (FAA-H-8083-16) before touching practice questions. Two weeks, 1–2 hours/day.
- Drill by topic, not random. Take 50 weather questions in a row. Then 50 approach-chart questions. Mixed-mode practice belongs at the end of your prep.
- Review every wrong answer slowly. For each miss, find the FAR or handbook page that supports the right answer. If you can't, you don't actually understand it.
- Practice with current charts. The FAA updates approach plates every 28 days; old questions reference symbols that have changed. Use Jeppesen or current FAA chart supplements.
- Take 3 full-length mocks under timed conditions. 60 questions, 2.5 hours, no phone. If you're consistently scoring 85%+, you're ready.
Common Traps
- Holding pattern entries. Memorize the 70°/110° rule and practice drawing it. Test questions show you a hold from a fix and ask for the entry — picture it from the airplane's perspective, not the chart's.
- Compass errors. ANDS (Accelerate North, Decelerate South) and UNOS (Undershoot North, Overshoot South) are guaranteed points if you have them automatic.
- Cold-temperature corrections. When the reported temp is significantly below standard, true altitude is lower than indicated. Know which segments require correction at temperature-restricted airports.
- Lost comm procedures. FAR 91.185 — route is AVEF (Assigned, Vectored, Expected, Filed); altitude is MEA, Expected, or Assigned, whichever is highest for each segment.
How GroundScholar Helps with This
GroundScholar's instrument written test practice isn't a static question dump. The system adapts to your weak areas — if you're missing approach-chart questions, you get more approach-chart questions until your accuracy is solid, then it moves on. Every explanation is tied to a live citation from the current FAR/AIM, so you're not memorizing yesterday's regulation.
When you're ready, the mock checkride mode runs you through an oral-style examination with an AI examiner that asks follow-up questions exactly the way a DPE does. You get a pass-prediction score, a list of weak ACS task elements, and a study plan to close the gaps before test day.
Test-Day Logistics
- Cost: $175 at most PSI testing centers (varies slightly)
- Time: 2 hours 30 minutes
- Questions: 60 multiple choice
- Passing score: 70%
- Required to bring: government photo ID, instructor endorsement (paper or IACRA), authorization to test
- Allowed: non-programmable calculator, E6B, plotter, blank scratch paper provided
- Result: printed Airman Knowledge Test Report — keep this, your DPE needs it
Your score report lists the knowledge codes for every question you missed. Bring it to your CFII — they're required to review every missed area before signing you off for the practical test.
Ready to Start Drilling?
If you've done the reading and you want to know whether you'd actually pass today, the fastest signal is a full-length adaptive mock. GroundScholar gives you the IRA question bank, ACS-aligned explanations with verified FAR/AIM cites, and a mock checkride that pressure-tests your understanding the way the real test does.