FAA Instrument Rating Airplane (IRA) flashcards

The lowest published altitude that guarantees obstacle clearance for the entire route segment, but assures acceptable NAVAID signal coverage only within 22 NM of a VOR.

• MOCA is charted with a superscript asterisk on IFR en route charts
• Guarantees 1,000 ft (2,000 ft mountainous) obstacle clearance
• Signal reliability only assured within 22 NM of the VOR

Memory trick: MOCA: Obstacles always covered, signal only up close (22 NM).

The VSI's calibrated leak and diaphragm design inherently cause a brief lag or momentary reversed indication during rapid changes in pitch or vertical speed, before settling to the correct rate.

• Caused by the calibrated leak restricting airflow
• More pronounced during abrupt maneuvers
• Instantaneous VSI (IVSI) reduces this lag using accelerometers

Memory trick: The leak takes a breath before it tells the truth.

The flight director displays directive pitch/roll command bars that can be hand-flown or followed automatically by the autopilot once separately engaged; the two systems, though integrated, operate independently in terms of engagement.

• FD command bars show where to fly, not current attitude
• Autopilot servos must be separately engaged to fly the FD commands automatically
• FD can be used purely as a hand-flying aid

Memory trick: The FD is the 'coach' pointing the way; the autopilot is the 'player' that must be told to actually run.

Attitude and heading indicators are commonly vacuum-driven, while the turn coordinator is electric, making it a critical backup source for bank information during vacuum failures.

• Vacuum failure disables AI and HI in typical light aircraft
• Turn coordinator remains functional using aircraft electrical power
• Partial-panel scenarios require use of turn coordinator plus other cross-checks

Memory trick: Vacuum powers AI/HI; electricity powers the turn coordinator.

Additional instruments required for IFR flight beyond the day-VFR list, including a clock, attitude indicator, and directional gyro.

• Mnemonic GRABCARD covers IFR-added items
• Clock must display hours, minutes, seconds
• Attitude and directional gyros also IFR-only additions

Memory trick: GRABCARD — the clock ticks only when flying IFR.

When flying a back course approach with a standard (non-HSI, non-reverse-sensing) VOR/LOC indicator, CDI needle deflections are reversed compared to a front-course approach, requiring the pilot to turn away from the needle to correct.

• HSIs typically auto-correct for back course sensing
• Standard VOR/LOC indicators require manual reverse interpretation
• Turning toward the needle on a back course will worsen the deviation

Memory trick: Back course, backwards needle — fly away, not toward.

The ceiling is the height AGL of the lowest layer reported as broken (BKN) or overcast (OVC), or the vertical visibility if the sky is obscured.

• Sky cover codes: FEW, SCT, BKN, OVC, VV
• Cloud heights in METAR are reported in hundreds of feet AGL
• Only BKN, OVC, or VV layers count as a ceiling

Memory trick: Few Scattered Broken Overcast — only Broken and Overcast Block the sky enough to be a Ceiling

A vestibular illusion where an abrupt transition from climb to level flight creates a false sensation of tumbling backward, prompting the pilot to push the nose down.

• Triggered by sudden leveling off after a sustained climb
• Can cause a dangerous nose-down pitch input
• Countered by trusting the attitude indicator, not bodily sensations

Memory trick: Level off after a climb, feel like you flip

An airport lacking a published instrument approach may still be filed as an alternate if forecast weather permits descent from the MEA, approach, and landing under basic VFR minimums.

• Governed by 14 CFR 91.169(c)(2)
• Basic VFR minimums must be met at ETA
• This is an exception to needing a published approach for an alternate

Memory trick: No approach? No problem — if VFR skies will let you land anyway.

If required visual references are not visible at the Missed Approach Point, the pilot must immediately execute the published missed approach procedure.

• Governed by 14 CFR 91.175
• No descent below MDA/DA without visual contact
• Immediate action required, no loitering

Memory trick: No see, must flee (climb away immediately)

LNAV/VNAV minimums provide a decision altitude with vertical guidance and require WAAS or approved baro-VNAV equipment; LNAV minimums use only lateral GPS guidance to an MDA and require no vertical guidance system.

• LNAV/VNAV requires WAAS or certified baro-VNAV avionics
• LNAV minimums use MDA with no vertical path guidance required
• LNAV/VNAV typically has lower minimums than LNAV due to vertical guidance
• Equipment capability, not pilot choice, dictates eligible minimums line

Memory trick: No WAAS, no Vertical — stick with LNAV's level.

If a pilot loses two-way radio in IMC but later encounters VFR conditions, 91.185(b) requires continuing VFR and landing as soon as practicable rather than following IFR lost-comm routing/altitude rules.

• VFR encountered after failure overrides IFR lost-comm procedures
• 'Land as soon as practicable' is not the same as 'as soon as possible'—it allows reasonable judgment
• Applies regardless of whether the failure began in VFR or IMC

Memory trick: 'See sky, land nearby'

A holding pattern using right-hand turns; any pattern using left turns is nonstandard and must be specified.

• Standard = right turns
• Nonstandard must be charted or issued by ATC
• Leg timing: 1 min below 14,000 ft, 1.5 min above

Memory trick: 'Standard stays to the right.'

When no ODP or SID is issued, pilots remain responsible for obstacle clearance during departure until reaching the MEA, MOCA, or another altitude that guarantees standard clearance.

• ODPs are non-radar, obstacle-based procedures
• Pilots may fly an ODP without ATC clearance unless one is required by the chart
• Obstacle clearance responsibility rests with the pilot until reaching a safe charted altitude

Memory trick: No ODP? You own the sky until charted safety.

A defined area on an RNAV approach chart divided into sectors (straight-in, left base, right base) that provides minimum altitudes for transitioning from the en route structure to the IAF without radar vectors.

• TAA sectors are centered on the IAF
• Each sector has its own minimum altitude for obstacle clearance
• Eliminates need for a separate feeder route in many cases

Memory trick: TAA = Three Areas Assisting your transition in.

A blocked static port freezes the altimeter and VSI at the blockage altitude/zero, and causes ASI to under-read in a climb and over-read in a descent because the static reference no longer matches actual ambient pressure.

• Altimeter freezes at blockage altitude
• VSI reads zero regardless of actual climb/descent
• Alternate static source restores accuracy if available

Memory trick: Trapped static lags reality—climb makes ASI look slow.

Radiation fog forms over land on clear, calm nights when the ground cools by radiation, cooling the adjacent moist air to its dew point.

• Requires clear sky for radiational cooling
• Requires light or calm wind (too much wind mixes the air and prevents fog)
• Common in low-lying valleys where cool air settles
• Usually dissipates after sunrise as the ground warms

Memory trick: Radiation fog needs a Radiant clear night and Restful calm air

A charted radial on a DME arc approach indicating where a pilot should begin turning from the arc onto the final approach course to compensate for turn radius.

• Typically begin turn 2-5° before reaching the course radial depending on speed/bank
• Prevents overshooting the final approach course
• Found on approach charts using DME arc transitions

Memory trick: Lead early, roll out neatly onto final.

A defined point on the final approach course of a nonprecision approach from which a normal descent from the MDA to the runway touchdown point may be commenced, provided visual references are in sight.

• Charted as a 'V' on the profile view when published
• When absent, pilot must judge normal descent point manually
• Prevents excessively steep dives to the runway after reaching MDA late on final

Memory trick: No VDP? Judge it—only descend when it's a normal glide.

An AIRMET advising of moderate turbulence, sustained surface winds of 30 knots or more, and/or low-level wind shear.

• One of three AIRMET types: Sierra (IFR/mountain obscuration), Tango (turbulence/wind), Zulu (icing/freezing level)
• Valid for 6 hours with outlook
• Advises of hazards significant to light aircraft, not necessarily hazardous to all aircraft

Memory trick: Sierra=Sky (IFR), Tango=Turbulence, Zulu=ice — S-T-Z for AIRMETs.

Thunderstorms hidden within a layer of other clouds, making them undetectable by visual means alone.

• Cannot be seen and avoided visually
• Require radar/datalink for detection
• Just as hazardous as isolated storms

Memory trick: If you can't see it, radar must see it for you.

Off-Route Obstruction Clearance Altitude provides obstacle clearance for pilots operating off established airways or routes.

• 1,000 ft clearance in non-mountainous terrain
• 2,000 ft clearance in designated mountainous terrain
• Does not guarantee navigation signal or communication reception
• Found in the margins of en route low-altitude charts

Memory trick: OROCA: Obstacles cleared, but Reception Officially Cannot be Assured.

A physiological condition caused by insufficient oxygen reaching body tissues, often at altitude, characterized by early symptoms of euphoria, impaired judgment, and lack of self-awareness of the impairment.

• Time of useful consciousness decreases rapidly above 25,000 ft
• Symptoms are insidious—pilot often feels fine while performance degrades
• 14 CFR 91.211 requires supplemental oxygen for flight crew above 12,500 ft MSL for more than 30 minutes and continuously above 14,000 ft

Memory trick: High and happy but hazardously hindered

A safety pilot must hold at least a private pilot certificate with the appropriate category/class rating for the aircraft and must occupy a control seat with adequate visibility.

• No instrument rating required for the safety pilot
• Must hold appropriate category and class rating
• Aircraft must have functioning dual controls

Memory trick: 'See for me while I can't see' - safety pilot just needs private cert + ratings.

If the ILS glideslope fails during an approach, the pilot flies the approach to the localizer-only (LOC) minimums published on the same approach chart, which use an MDA instead of a DA.

• LOC-only minimums are always higher (or equal) than ILS DA minimums
• Approach becomes nonprecision; stepdown fixes and MDA apply
• Chart typically lists both S-ILS and S-LOC minima lines

Memory trick: No glide? Slide to LOC minimums, not below.

A spatial disorientation illusion caused by a sudden return to level flight after a gradual, undetected bank, producing a false sensation of banking in the opposite direction.

• Most common vestibular illusion in flight
• Caused by fluid equilibrium in semicircular canals during slow bank changes
• Pilot may physically lean to compensate for the false sensation

Memory trick: Slow bank sneaks in, fast fix leans you out.

On east or west headings, acceleration causes the compass to show an apparent turn toward North, and deceleration causes an apparent turn toward South.

• ANDS = Accelerate North, Decelerate South
• Error is maximum on E/W headings, zero on N/S headings
• Caused by pendulous mounting of the compass card reacting to inertial forces

Memory trick: ANDS: Accelerate North, Decelerate South.

If a pilot cannot identify a charted step-down fix on a nonprecision approach, the higher MDA applicable before that fix must be used for the remainder of the approach.

• Step-down fixes allow a lower MDA once safely identified
• Inability to identify the fix removes eligibility for the lower MDA
• Applies commonly when required DME or RNAV equipment is unavailable

Memory trick: Can't confirm the step? Stay up top

Structural icing occurs when an aircraft flies through visible moisture (clouds, rain) at temperatures at or below freezing.

• Requires both visible moisture and sub-freezing temperatures
• Freezing level marks the base of potential icing in clouds above it
• PIREPs and forecast freezing levels help pilots identify icing layers

Memory trick: Clouds + cold = ice — check the freezing level first.

A Convective SIGMET is issued for severe thunderstorms, embedded thunderstorms, lines of thunderstorms affecting 3,000+ square miles, or thunderstorms with surface winds ≥50 knots, hail ≥3/4 inch, or tornadoes.

• Valid for 2 hours, issued for the Eastern, Central, and Western U.S. regions plus outlooks
• Implies severe or greater turbulence, severe icing, and low-level wind shear
• Tornado, hail ≥3/4 inch, and wind gusts ≥50 knots are specific severe thresholds
• Issued hourly at 55 minutes past the hour, with unscheduled updates as needed

Memory trick: 3000 square miles, 50 knots, 3/4 inch hail — remember the 'severe three'

A holding entry technique where the aircraft flies outbound parallel to the inbound course on the nonholding side, then turns to rejoin the inbound course or fly a teardrop back to the fix.

• One of three standard entries: direct, teardrop, parallel
• Used when approaching from the nonholding side of the pattern
• After outbound leg, turn back to intercept inbound course

Memory trick: Parallel park, then turn back to the holding lane.

When both the pitot ram air inlet and drain hole are blocked but static ports remain open, trapped pitot pressure stays constant, causing the airspeed indicator to act like an altimeter (increasing in climbs, decreasing in descents).

• Differs from partial blockage (drain open), which causes ASI to act like altimeter in reverse pattern
• Static pressure continues functioning normally
• Cross-check with altimeter and VSI trends to identify this failure

Memory trick: Trapped air plus falling outside pressure equals a rising 'fake' airspeed.

Hail forms in strong thunderstorm updrafts that repeatedly loft water droplets above the freezing level, building ice layers until the stone falls.

• Requires strong, sustained updrafts
• Larger hail = stronger updrafts
• Associated with severe turbulence

Memory trick: Big hail = big updraft.

A solid-state replacement for vacuum-driven gyros that uses laser or MEMS sensors and accelerometers to compute attitude and heading, offering greater reliability and faster alignment.

• No spinning mass or vacuum pump required
• Faster erection/alignment after power-up
• Feeds attitude/heading data to the PFD in glass cockpits

Memory trick: No spin, no wear, no vacuum — solid-state wins the reliability race.

91.185(c)(2) requires flying the highest of the last assigned altitude, the altitude ATC advised to expect, or the applicable MEA/MOCA, evaluated segment by segment along the route.

• MEA compliance is mandatory even if it exceeds the assigned or expected altitude
• Expected altitudes only take effect at/after the referenced fix
• Pilots must reassess the 'highest of three' comparison for each new route segment

Memory trick: 'Assigned, Expected, MEA — fly the highest, no delay'

Fog that forms when warm rain falls through cooler air near the surface, saturating it ahead of a warm front or stationary front.

• Common ahead of warm fronts
• Caused by evaporation of falling rain into cool air
• Can produce widespread low visibility over large areas

Memory trick: Rain falling into cold air breeds fog before the front arrives.

14 CFR 91.215 mandates an operating Mode C transponder with automatic altitude reporting in specified airspace, including Class B, Class C, above 10,000 ft MSL (with exceptions), and within the Class B 30-NM veil.

• Required in Class A, B, C airspace and above 10,000 ft MSL (excluding below 2,500 AGL)
• Also required within the lateral limits of a Class B 30-NM Mode C veil
• Separate from the general IFR instrument list in 91.205(d)

Memory trick: 'Big airspace, big blip — Mode C required'

Federal regulation prohibiting a person from acting as a crewmember within 8 hours after consuming alcohol, while under the influence, or with a blood alcohol concentration of 0.04 or greater.

• 8-hour rule: no alcohol consumption within 8 hours of flight
• BAC limit: must be below 0.04
• 'Under the influence' clause can apply even if both other conditions are met

Memory trick: 8 hours bottle to throttle, no matter the number

A hazardous attitude in which a pilot feels the need to act immediately without adequate reflection, thinking 'do something quickly' even when a pause for analysis would be safer.

• Antidote thought: 'Not so fast, think first'
• Often triggered by time pressure or perceived urgency
• One of the five classic hazardous attitudes along with anti-authority, invulnerability, macho, and resignation

Memory trick: Rushing without thinking is impulsivity striking

IFR flight under VOR navigation requires the VOR system be checked within the preceding 30 days using an approved method with specified tolerances.

• VOT or ground checkpoint: ±4° tolerance
• Airborne checkpoint or designated radial: ±6° tolerance
• Dual VOR receiver comparison: max 4° difference between receivers

Memory trick: 'Ground=4, Air=6, Dual diff=4' — remember the tolerance triangle.

A non-WAAS IFR GPS may be used for alternate planning only to LNAV or circling minimums; WAAS-only minima like LPV or LNAV/VNAV cannot be relied upon for alternate planning without WAAS avionics.

• Non-WAAS GPS limited to LNAV/circling minimums for alternates
• WAAS-equipped aircraft may use LPV/LNAV VNAV for alternate planning
• This distinction affects flight planning, not enroute nav which may still be fine

Memory trick: 'No WAAS? No vertical guidance for your alternate.'

Civil aircraft using VOR for IFR navigation above FL240 must be equipped with DME or a suitable RNAV system.

• Applies specifically above FL240
• DME or RNAV satisfies the requirement
• Reflects wider VOR station spacing at high altitude

Memory trick: Above 24,000 feet, VOR alone isn't enough — bring DME or RNAV.

Loss of vacuum causes the gyro-driven attitude indicator to slowly spin down, producing gradually increasing erroneous pitch/bank indications rather than an immediate failure.

• Vacuum gauge reading zero indicates pump failure
• Attitude indicator errors develop slowly and can be mistaken for real attitude changes
• Cross-check with electric turn coordinator to detect the failure

Memory trick: A dying vacuum pump makes the gyro 'die slowly,' not instantly.

Even a friction-free gyro appears to drift because its spin axis is fixed in inertial space while the Earth rotates beneath it, at a rate up to 15°/hour depending on latitude.

• Maximum apparent drift at the poles (15°/hr)
• Zero apparent drift at the equator
• Requires periodic realignment with the magnetic compass, separate from mechanical/friction precession

Memory trick: The Earth spins under a gyro that doesn't care — that's 'apparent' drift, not real error.

A triangle containing an 'A' on an approach chart indicating the airport has alternate minimums different from the standard 600-2 (precision) or 800-2 (nonprecision), requiring the pilot to consult published nonstandard minimums.

• Triangle 'A' = check nonstandard alternate minimums
• Triangle with 'NA' = approach not authorized as an alternate at all
• Standard alternate minimums: 600-1 precision / 800-2 nonprecision for civil airports (Part 91 default varies by AIM/IPH context)

Memory trick: Triangle A? Always check the chart's fine print.

A time by which a pilot must be airborne or the ATC clearance becomes void, often used at airports without direct radio/radar contact.

• Pilot must be off the ground before the void time
• If unable, must advise ATC by the specified time (or within 30 minutes if none given)
• Failure to advise may result in search and rescue procedures
• Common at non-towered airports with clearance delivery via phone

Memory trick: Void time voids your clearance — call ATC or become a search target.

A charted annotation on an instrument approach indicating that a course reversal is not required or authorized when arriving via a specific route or transition.

• Commonly charted on feeder routes or hold-in-lieu-of-PT arrivals
• Course reversal is skipped, proceeding directly on final approach course
• Executing a procedure turn when NoPT is charted may create traffic conflicts
• Different transitions to the same IAF may have different NoPT status

Memory trick: NoPT means No Pointless Turning — go straight in.

14 CFR 91.205(d) lists additional instruments and equipment required for IFR flight beyond the day/night VFR equipment lists in 91.205(a)-(c).

• Includes generator/alternator, gyroscopic rate-of-turn indicator, slip-skid indicator
• Requires a sensitive altimeter adjustable for barometric pressure and a clock with seconds
• Requires gyroscopic attitude and heading indicators plus appropriate radio/nav equipment

Memory trick: GRAB-C: Generator, Rate-of-turn, Attitude, Bank/slip, Clock

The accurate perception of aircraft position, state, and environment; loss of it through fixation on one task is called tunneling.

• Tunneling: excessive focus on one task at expense of overall picture
• Common cause of unnoticed heading, altitude, or airspeed deviations
• Combat by periodic instrument scan and cross-check habits

Memory trick: Don't stare at one gauge while the plane wanders.

The turn coordinator's gyro spin axis is canted upward relative to the longitudinal axis so the instrument responds to both roll rate and yaw rate, unlike the turn-and-slip indicator.

• Canted gimbal enables sensitivity to roll entry
• Electrically powered, providing backup if vacuum fails
• Turn-and-slip indicator only senses yaw (rate of turn)

Memory trick: Canted gimbal catches roll AND yaw.

During two-way radio failure, a pilot must fly the highest of the MEA, the expected altitude, or the last assigned altitude for each route segment.

• Applies per route segment, not the whole flight
• Mnemonic: MEA
• Ensures obstacle clearance and predictability for ATC

Memory trick: 'MEA' - Minimum, Expected, Assigned — fly the highest!

A personal self-assessment checklist pilots use before flight to evaluate fitness, standing for Illness, Medication, Stress, Alcohol, Fatigue, Eating/Emotion.

• Illness, Medication, Stress, Alcohol, Fatigue, Eating/Emotion
• Used for self-assessment of physical and mental readiness
• Should be applied before every flight, not just long trips

Memory trick: I'M SAFE to fly only if all six boxes check out.

Frozen precipitation formed when snow melts in a warm layer aloft and refreezes falling through a subfreezing layer near the surface.

• Indicates a warm layer aloft above a subfreezing surface layer
• Often signals nearby freezing rain conditions
• Reported as PL in METAR

Memory trick: Sleet bounces because it froze twice: melt then freeze.

PAR (Precision Approach Radar) provides azimuth and elevation guidance for a precision approach; ASR (Airport Surveillance Radar) provides azimuth guidance only, making it a nonprecision approach.

• PAR = precision, includes glide path
• ASR = nonprecision, azimuth only
• Both rely on controller radio guidance rather than onboard nav display

Memory trick: PAR = Precise All-Round; ASR = Azimuth-only Sideways guidance

91.167's requirement to carry fuel to an alternate applies only when an alternate is legally required under 91.169, not simply because one is listed on the flight plan.

• Minimum fuel = destination + 45 min if no alternate required
• Voluntary alternates don't change the regulatory minimum
• Pilots may carry extra fuel voluntarily beyond the minimum

Memory trick: Listing it on paper doesn't make it required — only the weather rule does.

Carburetor icing can form when moist air passes through the carburetor venturi, where pressure and temperature drops (due to fuel vaporization) can cause ice to form even when outside air temperatures are well above freezing, especially with high relative humidity.

• Can occur at OAT up to around 70°F (21°C) with high humidity
• Most likely at reduced power settings such as during descent
• Symptoms include rough engine and gradual RPM/manifold pressure loss
• Carburetor heat should be applied at first sign of icing or per POH guidance

Memory trick: Carb ice doesn't care about warm air — it cares about moist air and low power

Rapid linear acceleration (e.g., during takeoff roll) can cause the attitude indicator's erection mechanism to misread the resultant force as gravity, producing a temporary false pitch-up indication.

• Error is most pronounced during rapid acceleration/deceleration
• Self-corrects once acceleration stabilizes
• Similar principle to compass acceleration errors but affects the gyro's erecting system

Memory trick: Speeding up on the runway fools the gyro into thinking it's climbing.

In non-DME holding patterns, outbound leg timing is 1 minute at or below 14,000 feet MSL and 1.5 minutes above 14,000 feet MSL.

• Inbound leg is timed by design; outbound is adjusted to achieve it
• DME holding uses distance instead of time
• Wind correction is applied on the outbound leg to standardize the inbound leg

Memory trick: Below 14, one-minute gate; above, add a half

A six-step aeronautical decision-making process: Detect, Estimate, Choose (a course of action based on identified alternatives), Identify, Do, and Evaluate, used to systematically resolve in-flight problems.

• Detect: recognize a change requiring attention
• Estimate: determine significance of the change
• Identify/Choose: identify alternatives and choose the best action
• Do: implement the action; Evaluate: assess the outcome and repeat if needed

Memory trick: Detect, Estimate, Choose, Identify, Do, Evaluate—repeat as needed

An illusion caused by rapid acceleration or deceleration that creates a false sensation of pitch change, often leading to inappropriate control inputs.

• Rapid acceleration (e.g., takeoff, go-around) feels like nose-up pitch
• Rapid deceleration can feel like nose-down pitch
• Trust attitude indicator, not seat-of-the-pants sensations

Memory trick: Speed up, feel like you're climbing — check the gauge, not your gut.