FAA IFR Written Exam Topic Breakdown
Core Subject Areas and Weightings
The IFR written exam content is structured to mirror the diverse challenges encountered during actual instrument flight. While the FAA does not publish an exact percentage for every sub-topic, the distribution generally prioritizes high-stakes areas such as instrument procedures, navigation, and weather. Approximately 25% of the exam focuses on Federal Aviation Regulations (FARs) and Air Traffic Control (ATC) procedures, ensuring pilots understand the legal boundaries of the IFR system. Another 30% is dedicated to instrument procedures, including the interpretation of approach plates and arrival/departure procedures. The remaining portions are split between navigation systems, aviation weather theory, and cross-country flight planning. Success on the exam depends on understanding the Airman Certification Standards (ACS), which define the specific knowledge tasks for the rating. Candidates must be prepared to transition quickly between calculating a descent gradient and determining the legality of a specific instrument approach based on reported visibility.
Regulations and ATC Procedures
This section of the IFR knowledge test subjects evaluates a pilot’s grasp of the operational rules found in 14 CFR Part 91. A significant focus is placed on the Instrument Flight Rules (IFR) that dictate when a flight plan is required and what equipment must be operational for flight into Instrument Meteorological Conditions (IMC). You will encounter questions regarding the "Three-P" model of risk management and the specific requirements for pilot currency, such as the 6-6-HIT rule (6 approaches, holding, intercepting, and tracking within 6 months). ATC procedures involve understanding the hierarchy of clearances and the mandatory reports required when not in radar contact. For example, pilots must know to report leaving a final approach fix or changing altitude when operating under a cruise clearance. The scoring system heavily penalizes misunderstandings of "Lost Communication" procedures, as these are critical safety-of-flight items governed by FAR 91.185.
Navigation Systems and Instrumentation
The FAA instrument rating curriculum requires a deep dive into both legacy and modern avionics. This includes the mechanical principles behind gyroscopic instruments—the Attitude Indicator, Heading Indicator, and Turn Coordinator—and the errors associated with them, such as precession. You must also understand the pitot-static system and the specific indications of a blocked pitot tube versus a blocked static port. In terms of ground-based navigation, the exam covers the service volumes of Very High Frequency Omnidirectional Range (VOR) stations and the nuances of the Instrument Landing System (ILS). Candidates are often tested on the Horizontal Situation Indicator (HSI) and how it simplifies the pilot's workload by combining heading and navigation data. Understanding the relationship between the Course Deviation Indicator (CDI) sensitivity and the distance from the station is a recurring theme, particularly regarding how full-scale deflection changes from enroute to approach phases.
IFR Regulations and Flight Rules Deep Dive
Part 91 IFR Operating Requirements
Federal Aviation Regulation Part 91 serves as the legal backbone for the FAA IFR written topics. Candidates must distinguish between the requirements for a standard VFR flight and the more stringent mandates for IFR operations. A primary focus is FAR 91.205, which outlines the required instruments for IFR flight, often remembered by the acronym GRABCARD (Generator/Alternator, Radios, Altimeter, Ball, Clock, Attitude Indicator, Rate-of-Turn Indicator, Directional Gyro). The exam tests your knowledge of inspection requirements, such as the 30-day VOR check and the 24-calendar-month altimeter and transponder inspections. You must also understand the "VFR-on-top" clearance, which allows an IFR-filed aircraft to operate at VFR altitudes in visual conditions, and the specific rules regarding oxygen use at high altitudes. These questions often present scenarios where a piece of equipment is inoperative, requiring the pilot to determine if the flight can legally continue under the provisions of a Minimum Equipment List (MEL).
ATC Clearances, Instructions, and Phraseology
Mastering the language of the IFR system is essential for passing the written exam and for safe cockpit operations. Questions in this category focus on the elements of a standard clearance (CRAFT: Clearance Limit, Route, Altitude, Frequency, Transponder) and the pilot's responsibility to read back specific instructions. You will be tested on the difference between "maintain" and "expect" altitudes, and the implications of a "cleared as filed" instruction. A critical concept is the DP (Departure Procedure) and STAR (Standard Terminal Arrival), which are designed to transition aircraft between the terminal environment and the enroute structure. The exam examines your ability to interpret the textual and graphical descriptions of these procedures, including altitude and speed restrictions. You must also understand the concept of "Pilot's Discretion" when descending, which allows the pilot to start the descent at any time and level off at intermediate altitudes, but prohibits returning to a previously vacated altitude.
IFR Takeoff, Landing, and Alternate Minimums
One of the most technical areas of the regulations involves the criteria for starting and ending an IFR flight. While Part 91 operators often have "zero-zero" takeoff privileges, the exam focuses on the standard takeoff minimums for commercial operations and the necessity of following non-standard minimums published in the Terminal Procedures Publication (TPP). A major portion of the test concerns the 1-2-3 Rule for filing an alternate: if from 1 hour before to 1 hour after the estimated time of arrival, the weather is forecast to be less than a 2,000-foot ceiling and 3 miles visibility, an alternate must be filed. Furthermore, the exam tests the standard alternate minimums—600-2 for precision approaches and 800-2 for non-precision. You must also know the specific visual references required by FAR 91.175 to descend below the Decision Altitude (DA) or Minimum Descent Altitude (MDA), such as the approach lighting system, the threshold, or the touchdown zone lights.
Navigation Systems and Enroute Procedures
VOR, DME, and Conventional Navigation
Despite the rise of satellite technology, conventional navigation remains a core component of the IFR written exam content. You must demonstrate the ability to orient an aircraft using only a VOR head and a compass. This includes identifying the "TO/FROM" indication and determining the aircraft's position relative to a specific radial. Distance Measuring Equipment (DME) is another critical topic; the exam tests your understanding of Slant Range Error, which is most pronounced when the aircraft is at high altitudes directly over the station. You will be asked to calculate the time and distance to a station using speed and bearing change formulas. Additionally, the exam covers the different types of VORs (Terminal, Low, and High) and their respective service volumes. Understanding how to identify a station via its Morse code identifier and the implications of a failed signal or an "OFF" flag on the navigation instrument is a recurring theme in the test bank.
RNAV, GPS, and Satellite-Based Navigation
Modern flight relies heavily on Area Navigation (RNAV) and Global Positioning Systems (GPS). The FAA instrument rating curriculum includes detailed questions on the Global Navigation Satellite System (GNSS) and the requirement for Receiver Autonomous Integrity Monitoring (RAIM). You must know that RAIM requires at least five satellites (or four satellites plus a barometric altimeter) to detect a faulty satellite signal. The exam also covers the Wide Area Augmentation System (WAAS), which provides the accuracy necessary for Localizer Performance with Vertical Guidance (LPV) approaches. Candidates must understand the different GPS modes—Enroute, Terminal, and Approach—and the sensitivity of the CDI in each mode (typically 2.0 NM, 1.0 NM, and 0.3 NM, respectively). Questions may also address the legality of using a GPS database that is out of date for enroute navigation versus the absolute requirement for a current database when flying instrument approaches.
IFR Enroute Charts, Airways, and Reporting Points
The enroute phase of flight is managed using IFR Enroute Low Altitude Charts. The written exam tests your ability to read these charts with precision. Key concepts include the Minimum Enroute Altitude (MEA), which ensures both obstacle clearance and navigation signal reception, and the Minimum Obstruction Clearance Altitude (MOCA), which only guarantees navigation reception within 22 nautical miles of the station. You will be asked to identify Victor Airways, which are the highways of the sky based on VOR radials, and Tango routes, which are RNAV-based. The exam also covers the significance of different symbols, such as the brown vs. blue/green airport colors (indicating whether an airport has a published instrument approach) and the icons for compulsory vs. non-compulsory reporting points. Understanding the changeover point (COP) between two NAVAIDs is also essential for maintaining signal continuity on long airway segments.
Instrument Approaches and Terminal Procedures
Precision vs. Non-Precision Approach Concepts
A fundamental distinction in the IFR knowledge test subjects is the difference between precision and non-precision approaches. Precision approaches, like the ILS and some LPV procedures, provide both lateral and vertical guidance down to a Decision Altitude (DA). Non-precision approaches, such as VOR, NDB, or LNAV, provide only lateral guidance and require the pilot to descend to a Minimum Descent Altitude (MDA). The exam explores the components of an ILS, including the localizer, the glide slope, and the marker beacons. You must understand how the glide slope signal is formed by the intersection of 90 Hz and 150 Hz lobes. Furthermore, the test addresses the Visual Descent Point (VDP), a defined point on the final approach course of a non-precision straight-in approach from which a normal descent from the MDA to the runway touchdown point may be commenced, provided the runway environment is clearly visible.
Reading and Interpreting Instrument Approach Charts
The ability to extract information from an instrument approach plate is perhaps the most critical skill tested on the IFR written. You will be presented with several plates and asked to determine the minimums for various aircraft approach categories (A, B, C, and D), which are based on 1.3 times the stalling speed in the landing configuration (Vso). The exam covers the four segments of an approach: Initial, Intermediate, Final, and Missed. You must be able to identify the Final Approach Fix (FAF)—indicated by a lightning bolt for precision approaches and a Maltese cross for non-precision—and the Final Approach Point (FAP) for certain GPS procedures. Questions often involve interpreting complex notes on the chart, such as "Procedure NA at night" or requirements for specific equipment like DME or RADAR. Understanding the planview (overhead), profile view (side), and the minimums section of the chart is essential for answering these multi-step questions.
Missed Approach and Holding Procedures
When an approach cannot be completed, the pilot must execute a missed approach. The exam tests your knowledge of when a missed approach is mandatory, such as when the aircraft is not in a position to land using normal maneuvers or when the requirements of FAR 91.175 are not met. You must also be proficient in holding procedures, which are often used for traffic separation or as part of a missed approach. This includes determining the correct entry method—Teardrop, Parallel, or Direct—based on the aircraft's heading relative to the holding fix. The exam covers standard holding patterns (right turns) versus non-standard (left turns) and the standard timing for legs (1 minute at or below 14,000 feet MSL, and 1.5 minutes above 14,000 feet MSL). You must also know the maximum holding speeds for different altitude bands to ensure the aircraft remains within the protected airspace of the holding pattern template.
Aviation Weather for Instrument Flight
IFR Weather Theory and Sources
Weather is the primary reason for the existence of the Instrument Rating, and the FAA IFR written topics reflect this importance. You must understand the fundamental cause of all weather: the uneven heating of the Earth’s surface. The exam covers the characteristics of stable vs. unstable air, including the types of clouds (stratus vs. cumulus) and the nature of precipitation associated with each. A key focus is the formation of fog, including radiation, advection, and upslope fog, and how each affects visibility. You will also be tested on the lifecycle of a thunderstorm and the hazards of the mature stage, such as microbursts and heavy precipitation. Understanding the Standard Atmosphere (29.92 inches of mercury and 15 degrees Celsius at sea level) is necessary for calculating pressure altitude and density altitude, which directly impact aircraft performance during the climb and approach phases of an IFR flight.
Weather Hazards: Icing, Thunderstorms, and Turbulence
Instrument pilots must be experts at identifying and avoiding hazardous weather. The exam focuses heavily on aircraft icing, distinguishing between structural icing (Rime, Clear, and Mixed) and induction icing. You must understand that Clear Ice is the most dangerous because it is heavy, difficult to see, and can significantly alter the airfoil's shape. The test also covers the conditions necessary for icing: visible moisture and temperatures at or below freezing at the point where the moisture impacts the airframe. Thunderstorm safety is another critical area; the FAA recommends staying at least 20 nautical miles away from severe cells. Questions will also address types of turbulence, such as Clear Air Turbulence (CAT) and wake turbulence. You must know the reporting criteria for turbulence (Light, Moderate, Severe, Extreme) and how to properly report these conditions to ATC using a PIREP (Pilot Report).
Obtaining and Using Aviation Weather Reports and Forecasts
Translating raw weather data into a go/no-go decision is a core competency. The exam requires the interpretation of METARs (Aviation Routine Weather Reports) and TAFs (Terminal Aerodrome Forecasts). You must be able to decode the string of text, including wind direction (given in degrees true), visibility, sky condition, and the remarks section. The IFR written exam content also includes graphical products like the Surface Analysis Chart, Constant Pressure Analysis Charts, and G-AIRMETs (Graphical Airman's Meteorological Information) for icing, turbulence, and IFR conditions. You must know the difference between an AIRMET and a SIGMET (Significant Meteorological Information), with the latter being issued for severe weather that affects all aircraft. The exam also covers the use of the Weather Depiction Chart to quickly identify areas of IFR (ceilings less than 1,000 feet and/or visibility less than 3 miles) and Marginal VFR (MVFR) conditions.
IFR Flight Planning and Cross-Country Considerations
Filing an IFR Flight Plan
The final stage of preparation involves the synthesis of all previous topics into a coherent flight plan. The exam tests your ability to complete an FAA or ICAO flight plan form. You must know when a flight plan is required (prior to entering controlled airspace in IFR) and how to close it (automatically by ATC at towered airports, or manually by the pilot at non-towered airports). Questions often involve calculating the Estimated Time Enroute (ETE) and the total fuel required. You must account for the time spent climbing to the initial cruising altitude and the fuel burn based on the aircraft's performance charts. The exam also emphasizes the importance of the "Remarks" section for notifying ATC of special equipment or navigation capabilities, such as being RVSM (Reduced Vertical Separation Minimum) compliant or having a functional GPS with WAAS.
Fuel Requirements and Alternate Airport Selection
Fuel management is a legal and safety priority under IFR. According to FAR 91.167, an aircraft must carry enough fuel to fly to the first airport of intended landing, then to the alternate (if required), and then for an additional 45 minutes at normal cruising speed. The IFR written exam content frequently presents scenarios where you must calculate the total fuel needed for a trip, including the reserve. This requires careful reading of the problem to determine if an alternate is required based on the weather forecast. When selecting an alternate, you must check the Chart Supplement to ensure the airport is available for use and that it has the necessary navigation facilities. If an airport has "A NA" (Alternate Not Authorized) listed on its approach plates, it cannot be filed as an alternate, regardless of the weather or the equipment on board the aircraft.
Using the Chart Supplement and NOTAMs
The Chart Supplement (formerly the Airport/Facility Directory) is an indispensable tool for the IFR pilot. The exam tests your ability to find information about runway lengths, lighting systems, and communication frequencies. It also covers the different types of NOTAMs (Notices to Air Missions). NOTAM(D)s cover information such as runway closures or navigation aid outages, while FDC NOTAMs (Flight Data Center) address regulatory changes, such as amendments to instrument approach procedures or Temporary Flight Restrictions (TFRs). You must understand that NOTAMs are essential for determining the actual status of the National Airspace System (NAS) at the time of your flight. For example, a published ILS approach might be unusable if the localizer is out of service for maintenance, a fact that would only be found in the NOTAMs. Mastering these final details ensures that the pilot is not only knowledgeable but also fully prepared for the realities of the IFR environment.