EASA Instrument Rating Theory: What the IR Exams Actually Test

The EASA IR(A) is examined in seven theoretical knowledge papers, each passed independently at 75%. It is a narrower syllabus than the ATPL and a far deeper one than the PPL, and it is built around a single question: can you fly an aeroplane safely in cloud, on instruments, to a runway you cannot see until the last few hundred feet? This guide covers the seven subjects, the deadlines that quietly destroy passes, the CB-IR route, and the handful of procedural topics that catch a disproportionate share of candidates out.

The seven papers, and how they are set

The IR(A) theoretical knowledge requirement is seven separate examination papers. Each is passed on its own merits at 75%. There is no averaging across subjects and no compensation for a weak paper by a strong one.

Two things surprise people arriving from the PPL. The first is what is absent. There is no General Navigation paper, no Principles of Flight, no Performance, no Mass and Balance, no Airframes/Systems/Powerplant and no Operational Procedures. The IR set examines what you need to fly in cloud and complete an approach, and deliberately nothing else. The second is where the weight sits: Meteorology and Radio Navigation are where most candidates report spending the bulk of their study hours, and they are the two subjects to start early rather than leave until last.

Questions come from the European Central Question Bank (ECQB), maintained by EASA and used by the national competent authorities. They are multiple choice, four options, one correct answer, and there is no negative marking — so a question left blank is simply a question thrown away.

Under FCL.025 you must take the complete set under the responsibility of one competent authority. You cannot sit Air Law with one member State's authority and Meteorology with another and expect them to be added together.

The five numbers that decide whether your passes survive

More IR candidates lose passes to a calendar than to a question bank. Five figures in Part-FCL govern the whole process.

The 18-month clock is the one people misread. It does not start on the day of your first exam — it starts at the end of that calendar month. Sit your first paper on 4 March 2026 and the clock runs from 31 March 2026, giving you until 30 September 2027 to have all seven in the bag.

A "sitting" is defined by your competent authority rather than by EASA — broadly, one scheduled examination session at which you may attempt one or more papers. Because the definition varies between States, so does how quickly you burn through your six. Ask before you start booking papers one at a time.

The 36-month clock is the one that bites IR candidates specifically

Passing the exams is not the end of it. Successful completion of the theoretical knowledge examinations is valid for 36 months for the issue of a CPL or an IR, counted from the day you complete the set. FCL.025 still names the EIR alongside them, but the EIR has not been issuable since 2021 — see the BIR below. Inside that window you must finish the flight instruction and pass the IR skill test.

Three years sounds generous. It stops sounding generous when a training aeroplane goes unserviceable for a season, a Class 1 medical renewal turns into a referral, or a European winter deletes four months of instrument training slots. Plenty of pilots have banked seven passes, then watched them expire while waiting on an examiner. Do the theory when you are ready to do the flying, not years ahead of it.

If you already hold ATPL theoretical knowledge

A completed ATPL(A) theoretical knowledge pass covers the IR(A) theoretical knowledge requirement — you do not sit the seven IR papers separately. That is the route most integrated and modular commercial students take by default — if a commercial licence is anywhere in your plans, weigh the seven IR papers against the CPL theory set before you book anything — and it is why the IR papers are mostly sat by pilots going straight from a PPL to an IR without commercial ambitions. Note the different clocks that then apply: the ATPL credit is valid for 36 months for the issue of a CPL or IR, and once an IR is entered in your licence the ATPL theoretical knowledge remains valid for the issue of an ATPL for seven years from the last validity date of that instrument rating.

How the IR syllabus differs from the PPL one

The PPL syllabus asks whether you can avoid the weather. The IR syllabus asks whether you can operate inside it. That single change of premise alters the character of every subject the two sets share.

Air Law stops being about where you may fly and becomes about what the system owes you. At PPL you learn that Class D exists. At IR you learn that in Class D an IFR flight is separated from other IFR flights and receives traffic information about VFR traffic, while in Class E it is separated from other IFR flights and receives traffic information about VFR traffic only as far as practicable — and VFR flights in Class E need no clearance and, in many States, no radio, so what is not practicable can be a great deal. That qualifier is precisely the sort of detail that decides whether you accept a clearance.

Meteorology stops being a forecast-reading exercise. The freezing level becomes an operational limit rather than a number, and you are expected to know why freezing rain implies a warmer layer above you, why the highest freezing level matters more than the lowest on a day with multiple inversions, and what a temperature and dew point converging to within a degree does to your alternate.

Instrumentation barely mentions the engine. PPL Aircraft General Knowledge is largely piston, propeller and airframe; IR subject 022 is pitot-static systems, gyroscopics, compasses, air data, autopilots, flight directors and the failure modes of each. If you have not looked at magnetic compass errors since your PPL, this is where they come back.

The genuine step change is Radio Navigation. There is no PPL equivalent — you are starting from a blank page and finishing with ILS beam geometry, GNSS error budgets and PBN navigation specifications. Budget for it accordingly.

The CB-IR route, and where the BIR fits

There are two modular training routes to an IR(A): the traditional modular IR, and the competency-based instrument rating — CB-IR, sometimes written CBIR. They differ enormously in the theoretical knowledge instruction they demand, while examining exactly the same seven subjects.

The CB-IR — officially the competency-based modular instrument rating — was introduced to make an instrument rating reachable for general aviation pilots who had accumulated real instrument time but could not face a 150-hour ground school and a full ATPL-style commitment. Its stated objective is to train PPL or CPL holders for instrument flight taking into account the instrument flight instruction they have previously received and their experience in that area. That principle applies to the flying as well as the ground school: prior instrument instruction and experience can reduce the flight training required, which is the whole point of the route.

What the CB-IR is not is an easier rating. The privileges are identical to those of an IR obtained the long way. The skill test is the same test. The seven exam subjects are the same subjects, examined against the same learning objectives at the same 75%. The reduction is in mandated instruction hours, not in the standard you are held to.

The BIR is a different rating, not a shortcut

The Basic Instrument Rating (FCL.835) has been available since 8 September 2021, when it replaced the En-route Instrument Rating. The EIR could no longer be issued after 7 September 2021 and its privileges ceased a year later, so any guide that still offers the EIR as an option is out of date.

The BIR is trained in modules and examined in three theoretical knowledge papers — one attached to each of the first three flight instruction modules, the fourth having none — rather than in the seven-paper ECQB set, and the candidate also demonstrates theoretical knowledge orally to the examiner during the skill test. That structure suits a pilot building instrument capability progressively. It is not, however, a lighter way of arriving at an IR: the privileges and the limitations are different. If you are weighing the two, read FCL.835 and Appendix 6 Section Aa side by side rather than relying on summaries.

Instrumentation and Radio Navigation: the technical core

022 — Aircraft General Knowledge: Instrumentation

This paper is about what each instrument tells you, how it derives that, and — the part that carries the marks — what it tells you when it is broken.

• Pitot-static systems. Know the failure cases cold. A blocked static with the pitot clear leaves the altimeter frozen at the blockage altitude, and because the trapped static pressure is too high in a climb, the airspeed indicator under-reads in the climb and over-reads in the descent. A fully blocked pitot turns the ASI into a crude altimeter: it over-reads as you climb and under-reads as you descend. Selecting alternate static air in an unpressurised aeroplane usually gives a slightly lower pressure than ambient, so the altimeter reads slightly high.
• Gyroscopics. Rigidity and precession; the difference between real and apparent wander. Apparent wander of a directional gyro due to Earth rotation is 15° per hour multiplied by the sine of the latitude — zero at the equator, maximum at the poles — which is why the latitude nut exists. Attitude indicator acceleration errors show an apparent pitch-up under acceleration and an apparent pitch-down under deceleration. A directional gyro has no north-seeking ability of its own, so it is realigned against a compass carrying errors of its own — if magnetic compass errors have faded since your PPL, rebuild them here.
• Air data and displays. Air data computers, altitude alerting, the radio altimeter (which measures height above the surface directly beneath you, not above the aerodrome), EFIS layouts, flight director logic and basic autopilot modes.
• Warning and surveillance systems. Stall warning, GPWS/TAWS and ACAS/TCAS logic, transponder modes and what each returns.

062 — Radio Navigation

The most technically demanding paper in the set, and the one with the least PPL foundation to build on.

• NDB/ADF. LF/MF band, dependent on the surface wave, and error-prone in exactly the conditions you would want it: night effect from sky wave interference around dawn and dusk, coastal refraction when crossing a coastline at a shallow angle, thunderstorm effect, station interference and mountain effect. Understand homing versus tracking, and why homing in a crosswind produces a curved path.
• VOR. The 108.00–117.975 MHz band, shared below 112 MHz with ILS localisers — VOR occupies the even first-decimal channels, localisers the odd ones. Know the cone of confusion overhead, where the signal is unusable and the TO/FROM flag swings, along with site error and scalloping, and why Doppler VOR was developed.
• DME. UHF, 962–1213 MHz, interrogation and reply pulse pairs. It gives slant range, not ground distance, and the error is worst when you are high and close — directly overhead, a DME reads roughly your height above the station in nautical miles.
• ILS. Localiser 108.10–111.95 MHz on odd first-decimal channels, glide path 328.6–335.4 MHz, paired. Full-scale deflection is a fixed angle, so the lateral distance it stands for shrinks as you close in: roughly 0.4 NM either side of the centreline at 10 NM, about 105 m either side at the threshold. That geometry, not the instrument, is why the needle wakes up on final. Against a VOR the localiser is also four times more sensitive at any given range — 2.5° full scale against 10° — but that ratio is a constant and says nothing about closing in. Treat the 2.5° as nominal: the course sector is adjusted to be 210 m wide at the threshold, so a long runway gives a narrower angular sector and a short one a wider, within limits of roughly 3–6° for the full sector. False glide paths exist above the true one, the first at approximately twice the nominal glide path angle, which is why you check your altitude against the published distance at the final approach fix on every single ILS.
• RNAV and GNSS. Performance-based navigation vocabulary: RNAV versus RNP (RNP adds on-board performance monitoring and alerting), and the navigation specifications you will actually be cleared for — RNAV 5 en route, RNAV 1 in the terminal area, RNP APCH with LNAV, LNAV/VNAV and LPV minima lines. Four satellites give a three-dimensional position; RAIM needs five for fault detection and six for fault detection and exclusion. Ionospheric propagation delay is the largest natural error source, and EGNOS is the European satellite-based augmentation system that makes LPV minima possible.

Flight planning, monitoring and IFR meteorology

033 — Flight Planning and Monitoring

This paper is the one that most resembles the job. It covers the IFR route structure, the ATS flight plan, fuel, alternates, and what you do when the plan stops matching the aeroplane's actual position and fuel state.

On the route side: airways and their designators, the significance of the Route Availability Document in European airspace, and the fact that an IFR flight plan filed in the EUROCONTROL area is validated automatically before anyone in an ATC unit sees it — a route that is legal on a chart can still be rejected. Expect questions on cruising levels, on the transition altitude, transition level and the layer between them, and on the vertical separation minima: 1 000 ft below FL290, and 2 000 ft above it unless RVSM applies, in which case 1 000 ft is used between FL290 and FL410 between approved aircraft.

On fuel, know which rule set you are being examined against. Under Part-NCO an aeroplane flown IFR must carry fuel to reach the aerodrome of intended landing, then the destination alternate where one is required, and then to fly for at least 45 minutes (NCO.OP.125). Commercial air transport uses a different scheme with taxi, trip, contingency, alternate and additional fuel, and a final reserve of 30 minutes for turbine-engined aeroplanes or 45 minutes for reciprocating-engined ones, holding at 1 500 ft above the destination alternate — or above the destination itself where no alternate is required — in ISA conditions.

050 — Meteorology

The IR Meteorology paper is the ATPL syllabus filtered for one question: will this weather stop me completing an instrument approach, and if so, where do I go instead?

• Icing. Where supercooled water lives, the difference between rime, clear and mixed ice and the conditions that produce each, and why freezing rain is a warning that there is warmer air above you. Piston pilots should also revisit carburettor icing, which does not need visible moisture or freezing temperatures.
• Freezing levels. Not one number. Know how to read multiple freezing levels off a forecast and why the highest one matters for a climb through a frontal zone.
• Products. METAR, SPECI, TAF and TREND decoding until it is automatic; SIGMET and AIRMET; significant weather charts; wind and temperature charts. Under exam pressure, decoding speed is worth marks.
• Thunderstorms. The life cycle, the hazards in each stage, and the avoidance distances. Embedded cumulonimbus is the specific IFR problem, because you cannot see what you are being vectored into.
• Visibility and fog. Radiation, advection, frontal and steam fog and the conditions each needs; the significance of a converging temperature and dew point in an evening TAF.

Nothing in this paper is harder than the ATPL meteorology material, but the operational framing is sharper. You are not asked to describe a warm front; you are asked what it does to your alternate.

Air Law, Human Performance and IFR Communications

010 — Air Law and IFR procedures

Half of this paper is SERA and the rules of the air as they apply to IFR; the other half is the logic of instrument procedure design from PANS-OPS. Expect the airspace classification table — which services and which separation each class provides to an IFR flight — the requirement for a flight plan, ATC clearances and readback, holding, expected approach times, and the structure of an instrument approach: arrival, initial, intermediate, final and missed approach segments.

You are also expected to know how aircraft categories are assigned for approach purposes, because they set your minima. Categories run from A to E on the basis of V_at at maximum certificated landing mass: Category A below 91 kt, B from 91 to 120 kt, C from 121 to 140 kt, D from 141 to 165 kt and E from 166 to 210 kt.

040 — Human Performance for single-pilot IFR

At PPL level this subject can feel like general knowledge. At IR level it has a specific target: the pilot flying in cloud with nobody in the other seat to catch the error.

The vestibular material is the core of it — the leans, the somatogravic illusion on a go-around, the Coriolis illusion when you move your head during a turn, and the graveyard spiral. All of it is treated in more detail in our guide to spatial disorientation and visual illusions. Alongside that sits the approach-specific visual material: the black-hole approach, the runway that looks wrong because it is narrower or wider than you expect, the up-sloping runway that makes you fly low.

Then the cognitive half: workload management and task saturation, attention narrowing under stress, automation dependency and mode confusion, fatigue, and decision-making models. Single-pilot IFR is the case where the error chain has no second link to break it, and the examiner knows it.

092 — IFR Communications

Standard phraseology, the transmission of levels and headings, and the items SERA.8015(e) requires to be read back: ATC route clearances; any clearance or instruction to enter, land on, take off from, hold short of, cross, taxi or backtrack on a runway; and the runway in use, altimeter settings, SSR codes, newly assigned communication channels, level instructions, heading and speed instructions and transition levels. Distress and urgency — MAYDAY and PAN PAN — and 121.5 MHz. In European airspace, 8.33 kHz channel spacing.

Five procedural topics that catch IR candidates

Failures cluster. In our instructors' experience these five procedural topics account for a disproportionate share of them — and all five matter more in the aeroplane than in the exam room. They are Air Law, PANS-OPS and operations material rather than Radio Navigation: Radio Navigation is the paper most candidates find hardest, but it is a whole subject rather than a topic, which is why it gets a section of its own above.

1. Cold-weather altimetry

A pressure altimeter is calibrated to the International Standard Atmosphere. In air colder than ISA, the pressure levels lie closer to the ground than the instrument assumes, so your true height is lower than the altimeter indicates — the altimeter over-reads, and the error is a percentage of your height above the altimeter setting source, not a fixed number of feet.

PANS-OPS gives an approximation of roughly 4% of that height for every 10°C below standard temperature at the altimeter setting source, which is close enough for aerodrome temperatures down to about −15°C. Colder than that, use the ICAO correction table. A worked example makes the size of it obvious. The aerodrome is at sea level and reporting −10°C, so the rule of thumb still applies; standard temperature there is +15°C, so you are 25°C below ISA — about 10%, or roughly 100 ft of error at 1 000 ft above the aerodrome. On a minimum sector altitude of 3 000 ft that is 300 ft of obstacle clearance you never had. We cover the mechanism in full in cold weather altimetry.

2. Minimum en-route altitudes

Candidates lose marks here by treating a family of similar acronyms as interchangeable. They are not, and each guarantees something different. This is Air Law material as much as flight planning, and it is examined in both.

• The SERA baseline. Where no minimum flight altitude has been established, SERA.5015 requires an IFR flight to be at least 300 m (1 000 ft) above the highest obstacle within 8 km of the aircraft's estimated position — and at least 600 m (2 000 ft) over high terrain or in mountainous areas.
• MEA — minimum en-route altitude. Guarantees obstacle clearance and usable navigation signal along the whole segment.
• MOCA — minimum obstacle clearance altitude. An ICAO term, defined in Doc 8168 (PANS-OPS) as the minimum altitude for a defined segment that provides the required obstacle clearance — 1 000 ft in the primary area en route, more over mountainous terrain. Unlike the MEA it guarantees nothing about navigation signal coverage along the whole segment, which is why it is lower than the MEA on the same segment. It is charted on Jeppesen and State en-route charts inside EASA-land as well as outside it, so an airway segment can carry an MEA and a lower MOCA side by side — and reading that chart extract is examinable in 033.
• MORA — minimum off-route altitude. On Jeppesen charts, grid MORA clears terrain and structures by 1 000 ft where the highest elevation in the grid is 5 000 ft or below, and by 2 000 ft where it is 5 001 ft or above. It says nothing about navigation coverage.
• MSA — minimum sector altitude. An emergency figure, giving at least 1 000 ft of obstacle clearance within 25 NM of the specified facility or point. It is not a routing altitude.
• MRVA/MVA — minimum radar vectoring altitude. The controller's figure, not published on your chart, which is exactly why an unexpected descent instruction deserves a moment's thought.

3. Holding entries

The entry sectors are defined by a line drawn through the holding fix at 70° to the inbound track, with a 5° tolerance either side of each boundary. That gives three sectors: direct entry, the 180° sector on the non-holding side of the inbound track; and, on the holding side, parallel entry covering 110° and offset (teardrop) entry covering the remaining 70° adjacent to the inbound track.

• Direct: on reaching the fix, turn to follow the pattern.
• Parallel: turn onto a heading parallel to the reciprocal of the inbound track on the non-holding side, fly outbound for the appropriate time, then turn towards the holding side to intercept the inbound track or return to the fix.
• Offset: turn onto a heading 30° from the reciprocal of the inbound track on the holding side, fly outbound for the appropriate time, then turn to intercept the inbound track.

If that ordering feels backwards, work an example. Right-hand hold, inbound track 360°, so the outbound leg is displaced to the east and the holding side is east. Arrive from the west, tracking 090° to the fix, and you cross the fix and turn right 90° onto the outbound — a direct entry, from the non-holding side. Arrive from the east, tracking 270° to the fix, and a direct entry would need a 270° turn, so you fly a parallel entry instead. Parallel and teardrop exist precisely to deal with arrivals from the holding side.

The numbers that go with them: outbound timing is one minute at or below 14 000 ft and one and a half minutes above it. Turns are made at 25° of bank or a rate of 3° per second, whichever requires the lesser bank. Maximum holding speeds in normal conditions are 230 kt up to and including 14 000 ft, 240 kt above 14 000 ft to 20 000 ft and 265 kt above 20 000 ft to 34 000 ft — with 170 kt applying where a holding pattern is restricted to Category A and B aeroplanes.

4. Approach minima

Three distinctions carry most of the marks. First, OCA/OCH is the output of procedure design — the obstacle clearance altitude or height — while DA/DH or MDA/MDH is your operational minimum, which may never be lower than the OCA/OCH.

Second, a decision altitude and a minimum descent altitude behave differently. At DA you make the decision at the altitude, and the aeroplane will descend below it during the go-around — that is designed in. At MDA you must not descend below it at all: you level off and fly to the missed approach point. Candidates who blur the two get the vertical profile of a 2D approach wrong every time.

Third, minima are driven by the quality of the guidance. System minima fall as guidance improves, with 200 ft being the floor for a Category I ILS or an LPV, and lateral-only procedures sitting appreciably higher. To continue below DH or MDH you need the required visual reference — approach lighting, the threshold or its markings and lights, the visual glide slope indicator, the touchdown zone or its markings and lights, or the runway edge lights — and the visibility must be at or above the minimum. In commercial air transport the approach ban then applies: below 1 000 ft above the aerodrome, the approach may not be continued if the controlling reported RVR is below the applicable minimum.

5. Alternate requirements

Under Part-NCO, an IFR flight in an aeroplane requires at least one destination alternate in the flight plan unless the place of intended landing is isolated with no adequate alternate, or the available current meteorological information indicates that the approach and landing may be made in visual meteorological conditions for the period from one hour before to one hour after the estimated time of arrival — or from actual departure to one hour after ETA, whichever is shorter (NCO.OP.140).

Selecting the alternate then has its own, deliberately more demanding, planning minima. The principle across the EASA rule sets is that you plan the alternate one step worse than you would fly it — with circling as the exception, where planning and operating minima are the same because there is no lower category to step down to. In commercial air transport (CAT.OP.MPA.185) the structure is:

Part-NCO carries its own equivalent in NCO.OP.143. Separately, in commercial air transport and in NCC and SPO operations (CAT.OP.MPA.180, NCC.OP.150, SPO.OP.151), a take-off alternate must be selected when the weather at the departure aerodrome is below the applicable landing minima, or when a return would be impossible for performance reasons — and it must lie within one hour's flight time at the one-engine-inoperative cruising speed for a two-engined aeroplane, two hours for a three- or four-engined one. Part-NCO imposes no take-off alternate requirement at all, which does not make departing into below-minima weather a good idea: if something goes wrong on departure, you cannot come back.