Exhaustive Airplane Instrument Rating Study Guide and Quick-Review Notes
AERONAUTICAL EXPERIENCE AND RATINGS REQUIREMENTS
To earn an Airplane Instrument Rating, a pilot must accumulate specific aeronautical experience as prescribed in §61.65. This includes 50 hours of Cross-Country flight time as Pilot-in-Command (PIC), of which at least 10 hours must be in airplanes. Additionally, 40 hours of actual or simulated instrument time are required, with 15 hours of that time being received from an authorized Flight Instructor with an Instrument Rating (CFII). Within this training, a student must complete one cross-country flight of at least 250 Nautical Miles (NM) along airways or by directed Air Traffic Control (ATC) routing. This flight must involve an instrument approach at each airport, use at least three different kinds of approaches utilizing navigation systems, and be conducted under a filed IFR flight plan. Furthermore, 3 hours of instrument flight training must be completed within the last 2 calendar months prior to the practical test.
Aeronautical experience can also be gained through training devices. If trained by an authorized instructor, a pilot may use an approved full flight simulator (FFS) or Flight Training Device (FTD). Under Part 142, a maximum of 30 hours can be credited, while 20 hours is the maximum if not completed under Part 142. For Aviation Training Devices (ATD), a maximum of 10 hours can be credited for Basic ATDs (BATD) and 20 hours for Advanced ATDs (AATD). In total, no more than 20 hours of instrument time can be credited from a combination of FFS, FTD, or ATD, unless the 30-hour exception under Part 142 applies.
PERSONAL DOCUMENTS AND RECENCY OF EXPERIENCE
Every pilot acting as Pilot-in-Command under IFR must possess a Pilot Certificate, a Medical Certificate (or U.S. Driver’s license as permitted by §61.113 and §61.23), and an authorized photo ID such as a passport or driver’s license. For flights conducted outside the United States, a Restricted Radiotelephone Operator Permit is also required. Recency of experience follows the "6 HITS" rule to act as PIC under IFR or in weather conditions below VFR minimums. Within the 6 calendar months preceding the month of flight, the pilot must have performed 6 instrument approaches, holding procedures and tasks, and intercepting and tracking courses through the use of navigational electronic systems. These can be completed in an aircraft or in a representational FFS, ATD, or FTD without an instructor, provided the device matches the aircraft category.
If a pilot is not current within the first 6 months, they have a 6-month grace period to log the "6 HITS" with a safety pilot under simulated conditions, an examiner, or an instructor. A safety pilot must hold at least a private pilot certificate with the appropriate category and class, have adequate vision in all directions, and the aircraft must have a dual control system. If the pilot remains not current after 12 months, an Instrument Proficiency Check (IPC) is mandatory. This check must be conducted by a CFII, an examiner, or another approved person, following the Airman Certification Standards (ACS) guidelines. To carry passengers, a PIC must have performed 3 takeoffs and landings in the same category, class, and type in the last 90 days (full stop at night from 1 hour after sunset to 1 hour before sunrise). A flight review is required every 24 calendar months to act as PIC.
LOGGING INSTRUMENT TIME AND AIRCRAFT DOCUMENTS
Instrument time may only be logged when a person operates an aircraft solely by reference to instruments under actual or simulated instrument flight conditions. A CFII may log instrument time when providing instruction in actual instrument flight conditions. Logbook entries for IFR recency must include the location and type of each instrument approach and the name of the safety pilot if applicable. When using training devices for experience or recency, the device type, time, and content must be logged, and for certificate training, an instructor must sign the logbook. Aircraft readiness is determined by the A.R.R.O.W. acronym: Airworthiness certificate, Registration certificate, Radio station license (for international flights), Operating limitations (found in the AFM), and Weight and Balance data.
AIRCRAFT MAINTENANCE AND PREFLIGHT ASSESSMENTS
Maintenance requirements for IFR are captured by the A.V.I.A.T.E. acronym. Every 12 calendar months, the aircraft must undergo an Annual inspection. For IFR flight, a VOR check must be performed every 30 days. If the aircraft is operated for hire, a 100-hour inspection is required. The Altimeter, automatic altitude reporting system, and static system must be checked every 24 calendar months for IFR in controlled airspace. The Transponder also requires a check every 24 calendar months. The Emergency Locator Transmitter (ELT) must be inspected every 12 months, with battery replacement required after 1 hour of cumulative use or when 50% of its useful life expires.
Pilots must perform a self-assessment using the I.M. S.A.F.E. checklist: Illness (symptoms), Medication (prescription/OTC), Stress (psychological pressure), Alcohol (8 hours "bottle to throttle" and <0.04% BAC), Fatigue (rested state), and Emotion (upset). Preflight information required for IFR involves N.W. K.R.A.F.T.: NOTAMs, Weather reports/forecasts, Known traffic delays, Runway lengths, Alternatives, Fuel requirements, and Takeoff/landing performance data. Risk management is guided by P.A.V.E. (Pilot, Aircraft, EnVironment, External pressure), while decision-making follows the D.E.C.I.D.E. model: Detect change, Estimate need, Choose outcome, Identify solution, Do action, and Evaluate effects.
BRIEFINGS AND IFR FLIGHT PLANNING
Passenger safety is managed through S.A.F.E.T.Y. briefings, covering Seat belts, Air vents, Fire extinguishers, Exit doors, Traffic/talking, and Your questions. Takeoff briefings follow D.E.P.A.R.T.S.: Departure review, Establish expectations, Plan/special considerations, Alternate plan, Runway conditions, Trouble/Tactics (rejected takeoff), and Speak up. For IFR operations in controlled airspace, a flight plan must be filed and ATC clearance received. While legal in Class G, entering controlled airspace requires a clearance. Filing can be done via FSS (1-800-WX-BRIEF), online (Leidos or FltPlan.com), EFB (ForeFlight), or radio/phone with ATC at least 30 minutes prior to departure (4 hours for non-scheduled flights above FL230). Flight plans are automatically cancelled at towered airports but must be manually cancelled by the pilot at non-towered airports.
Destination alternates are required unless the destination has a published instrument approach AND weather forecasts for 1 hour before to 1 hour after ETA show at least a 2000' ceiling and 3 SM visibility (the 1-2-3 rule). Minimum weather for an alternate shows precision approaches require 600' and 2 SM, while non-precision approaches require 800' and 2 SM. If no approach exists, the pilot must be able to descend from the Minimum Enroute Altitude (MEA) and land under VFR. Fuel requirements for IFR involve fuel from departure to destination, then to the most distant alternate (if required), plus 45 minutes at normal cruise speed.
IFR ALTITUDES AND EN ROUTE PROCEDURES
IFR cruising altitudes are based on the magnetic course: Odd thousands or Flight Levels (FL) for 0-179º and Even thousands/FL for 180-359º. Minimum IFR altitudes (MIA) mandate 2,000' above the highest obstacle within 4 NM in mountainous areas and 1,000' in non-mountainous areas. Key altitude definitions include: Decision Altitude (DA) for precision approaches, Minimum Descent Altitude (MDA) for non-precision approaches, Minimum Enroute Altitude (MEA) for signal coverage and obstacle clearance, and Minimum Obstruction Clearance Altitude (MOCA) for obstacle clearance and navigation within 22 NM of a VOR. Other altitudes include Maximum Authorized Altitude (MAA), Minimum Crossing Altitude (MCA), Minimum Reception Altitude (MRA), Minimum Turning Altitude (MTA), and Off Route Obstruction Clearance Altitude (OROCA).
Departure Procedures (DP) ensure obstacle clearance if the aircraft crosses the departure end at 35' AGL, reaches 400' AGL before turning, and climbs at 200 Feet per Nautical Mile (FPNM). Conversion to feet-per-minute uses: . DPs include Obstacle Departure Procedures (ODP) and Standard Instrument Departures (SID). IFR clearances use C.R.A.F.T.: Clearance limit, Route, Altitude, Frequency, and Transponder code. Standard Terminal Arrival (STAR) facilitates the transition from en route to an approach point.
FLIGHT INSTRUMENTS AND PITOT-STATIC SYSTEMS
Gyroscopic instruments operate on rigidity in space (Attitude Indicator, Heading Indicator) and precession (Turn Indicators). The Attitude Indicator shows pitch and bank and should be stable within 5 minutes of start. The altimeter is an aneroid barometer measuring height based on standard pressure lapse: 1000' per inch of mercury. Above 18,000' MSL, pilots set 29.92" Hg and operate in Flight Levels. Airspeed indicators measure dynamic pressure: .
Blockages affect instruments differently. If the static port is blocked, the altimeter freezes, the VSI freezes at zero, and the airspeed indicator reads low at higher altitudes and high at lower altitudes. If the pitot tube's ram air inlet is clogged while the drain is open, airspeed drops to zero; if both are clogged, the indicator acts like an altimeter. Advanced cockpits utilize Air Data Computers (ADC) and Attitude Heading Reference Systems (AHRS) to replace mechanical instruments. Required IFR equipment includes G.R.A.B.C.A.R.D.: Generator, Radios, Altimeter (sensitive), Ball (slip-skid), Clock (seconds required), Attitude indicator, Rate-of-turn indicator, and Directional gyro.
RADIO NAVIGATION AND GPS
Navigation aids include VOR (108.0-117.95 MHz), NDB (190-535 kHz), and DME (962-1213 MHz). VOR checks involve VOT (±4º), Repair Station (±4º), Ground checkpoint (±4º), or Airborne (±6º). Global Positioning System (GPS) utilizes a constellation of at least 24 satellites. 2D position requires 3 satellites, 3D requires 4, and Receiver Autonomous Integrity Monitoring (RAIM) requires 5 satellites (or 4 with baro-aiding).
Augmentation systems like WAAS (Wide Area Augmentation System) provide corrections for higher accuracy, enabling LPV and LNAV/VNAV approaches. Ground Based Augmentation System (GBAS) provides even higher accuracy for GLS DA minima. Required Navigation Performance (RNP) standards dictate accuracy requirements: RNP 2.0 for en route, RNP 1.0 for terminal, and RNP 0.3 for final approach.
INSTRUMENT APPROACH SYSTEMS AND HOLDING
Instrument Landing Systems (ILS) provide lateral guidance (Localizer, 108.1-111.95 MHz) and vertical guidance (Glide Slope, 329.3-335 MHz). Approach Light Systems (ALS) facilitate the transition to visual landing. Marker Beacons provide range: Outer (Blue, 4-7 miles), Middle (Amber, 3500'), and Inner (White, DH point). For non-precision approaches, a Visual Descent Point (VDP) is used, calculated as .
Mandatory IFR reports include MARVELOUS VFR C.500: Missed approach, Airspeed (±10 kts/5%), Reaching hold fix, VFR on top altitude change, ETA change (±3 min), Leaving hold fix, Outer marker, Unforecasted weather, Safety of flight, Vacating altitude, Final approach fix, Radio/Nav failure, and 500 fpm climb/descent inability. Holding patterns use standard right turns. Maximum speeds are 200 kts (below 6,000'), 230 kts (6,001-14,000'), and 265 kts (above 14,001'). Holding entries are Direct, Parallel, or Teardrop.
LOST COMMUNICATIONS AND VISUAL REQUIREMENTS
In the event of lost communications under IFR, fly the highest altitude of MEA: Minimum IFR, Expected, or Assigned. Fly the route in the order of AVEF: Assigned, Vectored, Expected, or Filed. If the clearance limit is an approach fix, begin the approach at the EFC or ETA.
Descent below MDA or DA is permitted only if the aircraft is in a position to land using normal maneuvers, the flight visibility is not less than the required minimum, and the runway environment is in sight. These references include the approach lights (down to 100' above TDZE unless red bars are visible), threshold, runway markings, or the touchdown zone.
AEROMEDICAL AND WEATHER HAZARDS
Pilots must manage hypoxia types: Hypoxic (altitude), Hypemic (blood/CO), Histotoxic (alcohol/drugs), and Stagnant (circulation). Supplemental oxygen is required for crew above 12,500' MSL for >30 minutes and the entire time above 14,000' MSL; all occupants must have oxygen above 15,000' MSL. Spatial disorientation involves vestibular illusions like "The Leans," "Coriolis Illusion," and "Graveyard Spiral," or optical illusions like "Black Hole Approach" and "False Horizon."
Weather hazards include structural icing (Clear, Rime, Mixed), which requires visible moisture and temperatures below freezing. Thunderstorms require moisture, an unstable lapse rate, and a lifting force, progressing through Cumulus, Mature, and Dissipating stages. IFR weather conditions are defined as ceilings less than 1,000' AGL and/or visibility less than 3 SM. Special VFR permits operation at 1 SM and clear of clouds with ATC clearance.
QUESTIONS & DISCUSSION
In the context of the Passenger Briefing, the pilot must conclude with "Your questions? Speak up!" to ensure all occupants understand safety procedures and expectations for the flight. This includes clarifying seat belt operation, fire extinguisher location, exit procedures, and the sterile flight deck policy during critical phases of flight. The pilot serves as the final authority on aircraft safety and must address any concerns regarding passenger discomfort or emergency actions before taxiing for departure.
QUANTITATIVE DATA AND FORMULAS
fpm to FPNM conversion:
Standard Rate Turn Bank Angle:
Visual Descent Point (Distance):
Visual Descent Point (Time):
Rate of Descent for 3-degree Glide Path:
Top of Descent (TOD) for 3-degree Glide Path:
To earn an Airplane Instrument Rating, a pilot must accumulate specific aeronautical experience as prescribed in §61.65. This includes 50 hours of Cross-Country flight time as Pilot-in-Command (PIC), of which at least 10 hours must be in airplanes. Additionally, 40 hours of actual or simulated instrument time are required, with 15 hours of that time being received from an authorized Flight Instructor with an Instrument Rating (CFII). Within this training, a student must complete one cross-country flight of at least 250 Nautical Miles (NM) along airways or by directed Air Traffic Control (ATC) routing. This flight must involve an instrument approach at each airport, use at least three different kinds of approaches utilizing navigation systems, and be conducted under a filed IFR flight plan. Furthermore, 3 hours of instrument flight training must be completed within the last 2 calendar months prior to the practical test. Aeronautical experience can also be gained through training devices. If trained by an authorized instructor, a pilot may use an approved full flight simulator (FFS) or Flight Training Device (FTD). Under Part 142, a maximum of 30 hours can be credited, while 20 hours is the maximum if not completed under Part 142. For Aviation Training Devices (ATD), a maximum of 10 hours can be credited for Basic ATDs (BATD) and 20 hours for Advanced ATDs (AATD). In total, no more than 20 hours of instrument time can be credited from a combination of FFS, FTD, or ATD, unless the 30-hour exception under Part 142 applies.
Every pilot acting as Pilot-in-Command under IFR must possess a Pilot Certificate, a Medical Certificate (or U.S. Driver’s license as permitted by §61.113 and §61.23), and an authorized photo ID such as a passport or driver’s license. For flights conducted outside the United States, a Restricted Radiotelephone Operator Permit is also required. Recency of experience follows the "6 HITS" rule to act as PIC under IFR or in weather conditions below VFR minimums. Within the 6 calendar months preceding the month of flight, the pilot must have performed 6 instrument approaches, holding procedures and tasks, and intercepting and tracking courses through the use of navigational electronic systems. These can be completed in an aircraft or in a representational FFS, ATD, or FTD without an instructor, provided the device matches the aircraft category. If a pilot is not current within the first 6 months, they have a 6-month grace period to log the "6 HITS" with a safety pilot under simulated conditions, an examiner, or an instructor. A safety pilot must hold at least a private pilot certificate with the appropriate category and class, have adequate vision in all directions, and the aircraft must have a dual control system. If the pilot remains not current after 12 months, an Instrument Proficiency Check (IPC) is mandatory. This check must be conducted by a CFII, an examiner, or another approved person, following the Airman Certification Standards (ACS) guidelines. To carry passengers, a PIC must have performed 3 takeoffs and landings in the same category, class, and type in the last 90 days (full stop at night from 1 hour after sunset to 1 hour before sunrise). A flight review is required every 24 calendar months to act as PIC.
Instrument time may only be logged when a person operates an aircraft solely by reference to instruments under actual or simulated instrument flight conditions. A CFII may log instrument time when providing instruction in actual instrument flight conditions. Logbook entries for IFR recency must include the location and type of each instrument approach and the name of the safety pilot if applicable. When using training devices for experience or recency, the device type, time, and content must be logged, and for certificate training, an instructor must sign the logbook. Aircraft readiness is determined by the A.R.R.O.W. acronym: Airworthiness certificate, Registration certificate, Radio station license (for international flights), Operating limitations (found in the AFM), and Weight and Balance data.
Maintenance requirements for IFR are captured by the A.V.I.A.T.E. acronym. Every 12 calendar months, the aircraft must undergo an Annual inspection. For IFR flight, a VOR check must be performed every 30 days. If the aircraft is operated for hire, a 100-hour inspection is required. The Altimeter, automatic altitude reporting system, and static system must be checked every 24 calendar months for IFR in controlled airspace. The Transponder also requires a check every 24 calendar months. The Emergency Locator Transmitter (ELT) must be inspected every 12 months, with battery replacement required after 1 hour of cumulative use or when 50% of its useful life expires. Pilots must perform a self-assessment using the I.M. S.A.F.E. checklist: Illness (symptoms), Medication (prescription/OTC), Stress (psychological pressure), Alcohol (8 hours “bottle to throttle” and <0.04% BAC), Fatigue (rested state), and Emotion (upset). Preflight information required for IFR involves N.W. K.R.A.F.T.: NOTAMs, Weather reports/forecasts, Known traffic delays, Runway lengths, Alternatives, Fuel requirements, Takeoff/landing performance data. Risk management is guided by P.A.V.E. (Pilot, Aircraft, EnVironment, External pressure), while decision-making follows the D.E.C.I.D.E. model: Detect change, Estimate need, Choose outcome, Identify solution, Do action, Evaluate effects.
Passenger safety is managed through S.A.F.E.T.Y. briefings, covering Seat belts, Air vents, Fire extinguishers, Exit doors, Traffic/talking, Your questions. Takeoff briefings follow D.E.P.A.R.T.S.: Departure review, Establish expectations, Plan/special considerations, Alternate plan, conditions, Trouble/Tactics (rejected takeoff), Speak up. For operations in controlled airspace, a flight plan must be filed and ATC clearance received. While legal in Class G, entering airspace requires clearance. Filing can be done via FSS (1-800-WX-BRIEF), online (Leidos or FltPlan.com), EFB (ForeFlight), or radio/phone with at least a few minutes prior to departure (4 hours for non-scheduled flights above FL230). Flight plans are automatically cancelled at towered airports but must be manually cancelled by the pilot at non-towered airports. Destination alternates are required unless the destination has a published instrument approach and the weather forecasts an hour before and after ETA show a 2000' ceiling and 3 SM visibility (the 1-2-3 rule). The minimum an alternate must show is precision approaches requiring 600' and 2 SM, non-precision requiring 800' and 2 SM. If no alternate exists, the pilot is able to descend from the Enroute Altitude (MEA) and land under VFR. The requirements involve fuel for destination, then the most distant if required, plus normal cruise speed.
Cruising altitudes are based on magnetic course: Odd thousands levels (FL 0-179°) and even thousands/FL (180-359°). The Minimum Inroute Altitude (MIA) mandates 2,000' above the highest obstacle within a nautical mile in mountainous areas, and 1,000' in non-mountainous areas. Key altitude definitions include: Decision (DA) approaches, Descent (MDA) signal coverage clearance, Obstruction Clearance (MOCA) navigation of VOR. Other altitude definitions include Maximum Authorized (MAA), Crossing (MCA), Reception (MRA), Turning (MTA), and Off Route (OROCA). Procedures (DP) ensure if an aircraft crosses the end of a runway 35' AGL, it reaches 400' AGL before turning, and climbs Feet per Nautical Mile (FPNM). Conversion feet-per-minute uses: . Departure Procedures Obstacle (ODP) and Standard Instrument Departures (SID) are also included. Clearances use C.R.A.F.T.: Clear limit, Route, Altitude, Frequency, Transponder code. Terminal Arrival (STAR) facilitates transition from en route to an arrival point.
Gyroscopic instruments operate under rigidity in space (Attitude Indicator, Heading Indicator) and precession (Turn Indicators). The Attitude Indicator shows pitch and bank stability. The altimeter is an aneroid barometer that measures height and uses standard pressure lapse: 1000' per inch of mercury. Above 18,000' MSL, pilots set 29.92" Hg levels. Airspeed indicators measure dynamic pressure as . Blockages affect instruments differently. If the static port is blocked, the VSI freezes at zero, and the airspeed indicator reads low at higher altitudes and high at lower altitudes. If the pitot tube's ram air inlet is clogged but the drain is open, readings drop to zero; if both are clogged, it acts like an altimeter. Advanced cockpits utilize Data Computers (ADC) and Reference Systems (AHRS) to replace mechanical instruments. Required equipment includes G.R.A.B.C.A.R.D.: Generator, Radios, Altimeter (sensitive), Ball (slip-skid), Clock (seconds indicator), Rate-of-turn Directional gyro.
Radio navigation systems include VOR (108.0-117.95 MHz), NDB (190-535 kHz), and DME (962-1213 MHz). VOR checks must be performed and should be within ±4° for repair stations, ±6° airborne. The Global Positioning System (GPS) utilizes satellite constellations for position fixing. 2D position requires two satellites and 3D position requires four. The Receiver Autonomous Integrity Monitoring (RAIM) checks for accuracy, and augmentation systems like WAAS (Wide Area System) provide accuracy corrections, enabling LPV LNAV/VNAV approaches. Based systems (GBAS) provide even greater accuracy and GLS DA minima. Performance (RNP) standards dictate approach requirements: RNP 2.0 for routes, 1.0 for terminal, and 0.3 for final approach.
For instrument approaches, the ILS provides lateral guidance from the Localizer (108.1-111.95 MHz) and vertical guidance from the Glide Slope (329.3-335 MHz). Approach Light Systems (ALS) facilitate visual landing. Marker Beacons have ranges: Outer (Blue, 4-7 miles), Middle (Amber, 3500'), Inner (White, Decision Height). The Visual Descent Point (VDP) calculation is given by .
Mandatory reports use the acronym MARVELOUS VFR C.500: Missed approach, ±10 knots/5% airspeed change, Reaching hold fix, Top change ±3 minutes, Leaving marker, Unforecasted weather, Safety of flight, Vacating altitude, Final approach Radio/Nav failure, and abnormal climb/descent rate. Holding patterns utilize right turns, with entry speeds categorized below 6,000', from 6,001-14,000', and above 14,001'. Entries can be direct, parallel, or teardrop.
In the event of lost communications under IFR, pilots should fly to the Minimum Enroute Altitude (MEA): Expected or Assigned. They will need to remember AVEF: Assigned, Vectored, Filed and limit aim based on Estimated Time of Arrival (ETA). Below MDA, permission is required only using visual maneuvers, and not less than minimum, while maintaining sight of runway surroundings. The references include lights visible from down 100' TDZE red bars, threshold, markings, and the touchdown zone.
Pilots manage hypoxia types: Hypoxic (at high altitude), Hypemic (blood/CO), Histotoxic (alcohol/drugs), and Stagnant (poor circulation). Supplemental oxygen is required for crew above 12,500' MSL for more than 30 minutes and for the entire time above 14,000' MSL. All occupants must have oxygen above 15,000' MSL. Spatial disorientation can include vestibular illusions such as "The Leans," "Coriolis Illusion," and "Graveyard Spiral," or optical illusions like "Black Hole Approach" and "False Horizon." Weather hazards include structural icing (Clear, Rime, Mixed), which requires visible moisture and temperatures below freezing, and thunderstorms that require a combination of moisture, an unstable lapse rate, and a lifting force, progressing through Cumulus, Mature, and Dissipating stages. IFR weather conditions are defined as ceilings less than 1,000' AGL and/or visibility less than 3 SM. Special VFR permits operations at 1 SM and clear of clouds with ATC clearance.
In the context of the Passenger Briefing, the pilot must conclude with "Your questions? Speak up!" to ensure all occupants understand safety procedures and expectations for the flight. This includes clarifying seat belt operation, fire extinguisher location, exit procedures, and the sterile flight deck policy during critical phases of flight. The pilot serves as the final authority on aircraft safety and must address any concerns regarding passenger discomfort or emergency actions before taxiing for departure.
Quantitative data and formulas include the following conversions and calculations:
Standard Rate Turn Bank Angle:
Visual Descent Point (Distance):
Visual Descent Point (Time):
Rate of Descent for 3-degree Glide Path:
Top of Descent (TOD) for 3-degree Glide Path: