EAMAC Sélection CCA common mistakes
EAMAC Sélection CCA · Understand the traps and how to avoid them.
Converting between units (kt/km/h, ft/m, NM/km, hPa/inHg, °C/K) only at the end of a calculation, or skipping the conversion entirely and writing the answer in the wrong unit.
Candidates learn formulas in one unit system (often knots and feet) but exam items mix units deliberately; under time pressure the unit line is the first thing dropped, and mental arithmetic errors compound when several conversions are chained.
What to do instead
Write the unit next to every number as you copy it, convert to a single coherent system before calculating, and convert back as an explicit last line. Memorise the anchors: 1 NM = 1,852 km, 1 kt = 1,852 km/h, 1 ft = 0,3048 m, 1 hPa ≈ 30 ft, 1 inHg = 33,86 hPa. Drill 20 mixed-unit items per session until the conversion step becomes automatic.
Applying the semicircular rule and flight-level selection from memory of the cruise altitude rather than from the magnetic track actually flown, and forgetting the 0–179°/180–359° split or the IFR/VFR level differences.
The rule is taught as a table to memorise, so candidates recall 'odd/even' but lose the reference (magnetic track, not heading or true track) and the quadrant logic; items that give a track of 175° or 355° expose this immediately.
What to do instead
Reconstruct the rule each time: magnetic track 000–179° → odd levels, 180–359° → even levels, with the 1,000-ft VFR/2,000-ft IFR separation offset. Practise with tracks near the boundaries (179°/180°, 359°/000°) and with wind given, so you compute the track before selecting the level.
Reading a meteorological report or chart literally without decoding the trend, validity period, or change groups (BECMG, TEMPO, PROB30/PROB40, NOSIG), and treating a forecast as an observation.
METAR and TAF use dense coded syntax; candidates decode the wind and visibility correctly but skim the trend and validity, so they answer 'what is the weather' instead of 'what will it be during the flight'.
What to do instead
Decode every report in a fixed order: type and validity, wind, visibility, weather, cloud, temperature/dewpoint, pressure, then trend. For TAF, explicitly state the valid window and translate each BECMG/TEMPO/PROB group into a sentence with a time range. Do ten decodes per day and always answer the question 'at what time and with what probability'.
Confusing QNH, QFE and QNE, and mixing up transition altitude and transition level when computing the altimeter setting or the level to fly.
All three are pressure settings expressed in the same units, and the transition layer concept is abstract; candidates memorise 'QNH = altitude, QFE = height' but cannot apply it when the item gives an aerodrome elevation and a pressure different from standard.
What to do instead
Anchor each term to a physical reference: QNH referenced to mean sea level gives altitude, QFE referenced to the aerodrome gives height above the aerodrome, QNE (1 013,25 hPa) gives flight level. Draw the transition layer with transition altitude below and transition level above, and practise items that require going from QFE to QNH to flight level with a 1 hPa ≈ 30 ft approximation.
Answering radio-navigation questions by naming the system (VOR, DME, ILS, GNSS) instead of using its measured quantity - for example confusing radial with bearing, or treating DME slant range as ground distance.
The vocabulary is learned as labels rather than as geometry; a VOR radial is a line from the station, whereas a bearing is measured at the aircraft, and DME measures slant range, which differs from ground distance by a factor that grows with altitude and proximity.
What to do instead
For each aid, write down what it measures, from where, and in which reference (magnetic/true, slant/ground). Sketch the station, the aircraft and the radial/bearing before answering. For DME, remember slant range ≈ ground distance at long range but noticeably larger overhead; compute the overhead error for a few altitudes to internalise it.
Treating the traffic patterns, entry procedures, and radio calls as a script to recite, without checking the aircraft's position and category first, or applying the wrong entry to the circuit.
Procedures are learned as sequences, so candidates reproduce the phraseology but miss the conditions that select the procedure (position relative to the aerodrome, runway in use, aircraft category, controlled versus uncontrolled).
What to do instead
For every procedure question, first state the aircraft's position and category, then derive the entry or call from that. Rehearse with a simple diagram: overhead join, crosswind, downwind, base, final, and mark where each initial call is made. Learn the standard phraseology as complete readbacks, not isolated words.
Ignoring human-factors vocabulary and answering with everyday intuition - for example attributing an error to 'carelessness' instead of identifying the perceptual, decision, or skill-based failure, or missing the distinction between error and violation.
Human factors uses a precise taxonomy (skill-based slips and lapses, rule-based and knowledge-based mistakes, violations, situational awareness, workload, fatigue, communication loops) that candidates have not practised applying to scenarios.
What to do instead
Learn the taxonomy with one concrete aviation example each, then classify ten short scenarios aloud using the correct term. For communication items, always check the readback loop and the standard phraseology. For fatigue and workload, link the symptom to the countermeasure (rest, task-sharing, checklist, sterile cockpit).
Leaving English items unanswered or guessing from a single keyword, rather than reading the whole stem and the four options; also misreading standard phraseology as ordinary English.
Aviation English items often hinge on a modal verb or a preposition ('cleared to land' versus 'cleared for the approach'), and candidates whose first language is not English scan for a familiar word and stop there.
What to do instead
Read the full stem and all four options before choosing, and underline the operative word (cleared, hold short, expect, request, unable). Build a personal list of phraseology pairs that differ by one word and test yourself on them. Practise reading NOTAM-style and ATIS-style texts aloud to build speed without losing precision.
Answering aircraft-knowledge items from general impressions (which aircraft is faster, which engine is more efficient) without using the underlying relationships between lift, weight, thrust, drag, angle of attack and speed.
The subject rewards knowing that lift depends on angle of attack and the square of speed, that induced drag falls with speed while parasite drag rises, and that the stall is an angle-of-attack limit, not a speed limit; candidates memorise numbers instead of the relationship.
What to do instead
Learn the four forces and the lift/drag curves as graphs you can redraw from memory, then answer each item by locating the aircraft on those curves. For performance questions, check the units and the conditions (mass, altitude, temperature, wind) before computing. Test yourself by predicting the effect of one change (heavier, hotter, slower) on each phase.
Spending too long on one calculation or navigation item and then rushing the remaining questions, leaving easy regulation and culture items unanswered.
The exam mixes short factual items with multi-step calculations; candidates without a time budget sink into the first hard item and lose the easy marks later, and they do not return to flagged questions.
What to do instead
Adopt a two-pass strategy: answer every item you can in the first pass, flag the rest, and return with a fixed time budget per remaining item. Before the exam, time full mock papers and record which item types consume the most minutes; drill those specifically. Never leave a blank - eliminate options and commit to an answer before moving on.