Iran CAO CPL Theory common mistakes
Iran CAO CPL Theory · Understand the traps and how to avoid them.
Answers rules-of-the-air and licensing questions by recalling ICAO Annex values (e.g. VFR flight visibility and cloud distance minima, licence validity, medical intervals) and silently substitutes them for the values in the Iranian CAO regulations the question is actually testing.
ICAO Annexes are the most widely circulated documents, so candidates revise from them and assume the national rules are word-for-word identical. The exam deliberately tests the points where the national regulation differs.
What to do instead
Keep a two-column table: ICAO Annex reference vs. the corresponding national CAR/CAO article, listing every numeric limit you meet. On every practice question write the source article beside your chosen answer; if you cannot name the source, treat the question as unanswered and revise only from the national text.
On pitot-static failure questions, answers 'the ASI over-reads in the climb' irrespective of which port is blocked, and picks the direction of a gyro instrument's apparent drift from memory rather than from the mechanism.
The three blockage cases are memorised as a picture or a keyword association. Pitot blockage with a clear static port makes the ASI behave like an altimeter, which is the opposite of the static-blockage case candidates over-learn.
What to do instead
Re-derive the cases each revision session from first principles. Pitot blocked, static clear: trapped pitot pressure fixed, static pressure falls in the climb, so the ASI under-reads in the climb and over-reads in the descent. Static blocked: ASI over-reads in the climb and under-reads in the descent, altimeter frozen, VSI reads zero. Then state, in one sentence each, why each instrument behaves that way.
Computes the take-off CG only, loading the aircraft to MTOM and then declaring the loading acceptable, without recomputing the CG after fuel burn to check the landing case; also mixes arm values in inches from one chart with a metric datum from another.
The take-off case is the one practised, and the landing envelope is treated as automatically satisfied. Mixed units come from using whichever graph is nearest, without noting its datum and units.
What to do instead
Adopt a fixed template: index/arm, mass, moment for each item, then total; repeat the whole table for zero fuel, take-off and landing, and plot all three on the envelope. Write the datum and units at the top of every calculation before entering the first number.
Enters the take-off or landing chart at aerodrome elevation with the QNH instead of pressure altitude, and reads the chart at the exact given temperature without interpolating between the weight or wind lines.
Elevation and pressure altitude coincide only at 1013 hPa. Charts are drawn for discrete weights and wind components and candidates round to the nearest line rather than interpolate.
What to do instead
Convert first: pressure altitude = elevation + 30 ft per hPa by which QNH is below 1013 (subtract when above). Use pressure altitude and temperature to obtain density altitude, then read the chart between the bracketing lines and interpolate arithmetically. Always state the units and whether the wind component is head or tail before reading the factor.
Computes trip fuel once for a single cruise level and weight, then reuses that figure for a different level, a step climb or the return leg with a different wind, and treats contingency fuel as an optional addition.
Fuel figures are learned as one number per route rather than as a function of level, mass, temperature and wind, and the fuel policy is memorised as a list rather than as a sequence.
What to do instead
Build the fuel plan as an explicit stack: taxi, trip, contingency, alternate, final reserve, extra, total. Recompute trip fuel for the actual cruise level and estimated mass at top of climb. Check endurance against total fuel and confirm the landing mass is within MLW with the reserve still intact.
Decodes the four-figure visibility group in a METAR or TAF as kilometres (0800 read as 8 km), and treats the first wind group of a TAF as valid for the whole period, ignoring BECMG and TEMPO groups.
Visibility is written in metres with no unit, and everyday use of kilometres makes the conversion automatic and wrong. Trend groups are skimmed because the first line already looks complete.
What to do instead
Read every METAR and TAF aloud in full, group by group, converting 4-figure groups to metres and then to km only after writing the metres down. For TAFs, draw a simple timeline and place each BECMG (permanent change) and TEMPO (temporary fluctuation) on it, noting the times to which each applies.
Applies magnetic variation in the wrong direction when converting between true and magnetic, and measures track and distance on the chart with a plotter scaled in statute miles or a ruler read in centimetres.
The variation rule is recalled as a phrase rather than as a physical picture, and scale is assumed rather than checked against the chart's own scale bar.
What to do instead
Use one rule consistently and verify it with a known example: variation east, magnetic least (true 090 with 5E variation gives magnetic 085). Always derive distances from the chart's printed scale bar, never from a personal ruler, and keep one plotter marked in nautical miles only.
Answers operational questions from the ICAO or EU-OPS default (take-off alternate, approach minima, low-visibility procedures, commander's authority) instead of the Iranian rule, and ignores whether the question says 'shall' or 'should'.
Foreign study material dominates and the wording difference between a binding requirement and a recommendation is not noticed under time pressure.
What to do instead
For each operational topic, write the national requirement, then the ICAO/EU-OPS equivalent, then the difference in one line. When reading a question, underline the modal verb first; 'shall' and 'is required to' demand the mandatory value, 'should' and 'recommended' the advisory one.
Answers turn and load-factor questions using the load factor alone, without converting to stall speed via Vs times the square root of n, and describes induced drag as rising with speed rather than falling.
The load factor formula is well drilled but the stall-speed consequence is not linked to it, and the induced/parasite drag curves are memorised as two shapes without their physical cause.
What to do instead
For every turn question, write the chain explicitly: bank angle, load factor n = 1/cos(bank), stall speed = Vs times sqrt(n), then the answer. For drag, state the cause: induced drag falls as speed rises because lift is produced over a shorter time per unit distance; parasite drag rises with the square of speed; total drag is minimum where the two curves cross, which is Vx (and Vy is further up the back side of the curve).
Reads back a conditional clearance ('line up and wait', 'after the landing aircraft hold short runway 27') as if it were an immediate clearance, and omits readback of hold-short instructions and runway designators, replying 'roger' where a full readback is required.
Phraseology is learned as vocabulary rather than as a set of clearance types with mandatory readback content, and the conditional part is lost because attention goes to the action at the end.
What to do instead
Learn the mandatory-readback list as a checklist: runway holding point and hold-short instruction, runway designator, take-off, landing, line-up and crossing clearances, and any conditional element. Practise by repeating the conditional clause first, then the clearance, and never use 'roger' in place of a readback of a clearance to enter, cross or use a runway.