CAAB ATPL Theory common mistakes
CAAB ATPL Theory · Understand the traps and how to avoid them.
Answering Air Law questions from what happens at their own airline, flying club or from what an instructor once said, instead of from the wording of the regulation. Typical example: stating a licence validity, medical interval or document-carriage rule as it is done locally rather than as the Annex/CAAB rule states it.
Candidates build Air Law knowledge incidentally on the ramp and in the ops room, where local practice is often stricter or looser than the regulation and is repeated as fact. Local practice feels authoritative because it comes from people with experience.
What to do instead
For every Air Law topic, write the answer with its citation attached (Annex number and standard, or CAAB rule/number). When practising, cover the answer and recall the citation before the content. If you cannot name the source document, mark the item as not known rather than guessing from experience.
Learning aircraft systems as lists of components to be named ("the hydraulic system has pumps A and B, a reservoir and a filter") without being able to answer what the indications and consequences are when one part fails.
Systems are visually and verbally memorable as diagrams, so revision naturally drifts towards labelling rather than reasoning about function. Failure consequences are harder to revise and are postponed.
What to do instead
Convert every system into a failure card: for each major component write (a) what indication the crew sees, (b) what remains available, (c) what limitation or procedure applies. Revise by answering the failure case first and reconstructing the system from it.
Computing performance and fuel figures without tracking units and mass basis: mixing kg and lb, mixing litres and kg, using basic mass where dry operating mass is required, and applying fuel reserves in the wrong sequence.
Under time pressure the arithmetic becomes mechanical, and candidates pattern-match the numbers on a chart or in a table without re-checking which mass or unit the entry column requires.
What to do instead
Write the unit and the mass basis next to every number before doing arithmetic, and finish with two sanity checks: does the answer move in the expected direction if mass increases, and is it within the plausible band for that aircraft type. Build a fixed written sequence for fuel (taxi, trip, contingency, alternate, final reserve, extra) and always compute in that order.
Answering Human Performance questions from intuition or everyday psychology ('people just get used to night flying', 'you can tell when you are hypoxic') instead of from the defined model or the published figure.
The domain reads like common sense, so candidates do not realise it is a vocabulary-and-numbers subject in which SHELL, the Swiss cheese model, hypocoxia onset bands and time-of-useful-consciousness values are marked exactly.
What to do instead
Build a one-page numbers sheet (hypoxia onset by altitude, TUC at given altitudes, sensory thresholds, circadian low points) and a one-line definition for each model with an aviation example. Answer past-style items by naming the model or quoting the figure before choosing the option.
Misreading forecast change groups: treating a TEMPO or PROB group as a permanent change to the forecast conditions, treating BECMG as instantaneous, or ignoring the validity period attached to a group so the answer describes weather that never co-exists with the flight.
Candidates read TAFs as prose and scan for the worst weather mentioned, so the group indicator and its time window are skipped. The brain prioritises the hazardous value over the grammar of the forecast.
What to do instead
Before answering, rewrite the TAF into a timeline with the main period as baseline and every TEMPO/BECMG/PROB group drawn as a separate band with its start and end. Answer only from the timeline, and reject any option that mixes conditions from two non-overlapping bands.
Making sign and unit errors in the wind triangle: adding drift instead of subtracting it, using track where heading belongs, or mixing knots and minutes so the ground speed and time calculation disagrees with the plotted triangle.
The triangle is drawn quickly and small, with an arrowhead pointing the wrong way for the wind, and the arithmetic then runs consistently from a wrong diagram. Nobody goes back to re-check the diagram because the numbers look tidy.
What to do instead
Always draw the triangle large, with the wind vector drawn from the correct end and labelled in knots, then write the three knowns and the three unknowns beside it before computing. Keep all speeds in knots and all times in minutes over 60, and cross-check that a headwind component produces a ground speed lower than TAS.
Mixing up memory items and reference items, or quoting an operator-specific SOP as though it were the standard procedure, especially for engine failure, depressurisation, rejected take-off and fire.
Checklist layout differs between operators, and candidates who have seen one company's documents generalise them. Memory items are also easier to revise as a list of actions than as the trigger condition that makes them memory items.
What to do instead
Learn each abnormal situation as three layers: the recognition/trigger, the memory actions with their order and rationale, and the reference checklist that follows. Check every procedure against the ICAO/CAAB standard rather than a company document, and be able to say why each memory action is time-critical.
Giving absolute answers to 'which increases lift/stall speed/rate of climb' questions without stating the conditions held constant, and confusing indicated angle of attack with the geometric angle between chord and relative airflow.
Principles of Flight is taught with curves and relationships, so candidates remember that two variables are linked but lose the caveat 'at constant angle of attack' or 'at constant weight'. The qualifier is what the question is actually testing.
What to do instead
For each relationship, memorise it as a sentence with its conditions attached, e.g. 'lift increases with angle of attack up to the critical angle, at constant density, speed and area'. Before choosing an option, say out loud which variables the stem holds fixed and discard any option that only holds when something else is varied.
Using non-standard or misapplied phraseology: answering a clearance with 'roger' where a full readback is required, confusing 'wilco', 'affirm' and 'roger', using 'pan pan' for a distress situation, or reading back only the frequency and not the level.
In the aircraft, phraseology is heard far more often than it is spoken in full, and readbacks are often abbreviated in real traffic, so the candidate's model of a 'correct' response is built from imperfect exposure rather than from the standard.
What to do instead
Revise phraseology as call-and-response drills: write the controller transmission, then write the readback in full, including levels, headings, frequencies and the callsign at the point the standard requires. Separate the three response words into a table with a one-line rule each, and practise distress versus urgency with a single worked example of each.
Altimetry errors: using QFE where QNH is required, forgetting to reset the subscale at transition altitude or transition level, or computing the true altitude error for a temperature that is colder or warmer than ISA and applying the correction in the wrong direction.
Three pressure settings and one temperature correction are learned close together, so the labels blur. The correction direction is also counter-intuitive: candidates reason about pressure rather than about the density of the column of air beneath the aircraft.
What to do instead
Draw the altimeter as a diagram with three settings labelled by what they read on the ground, and memorise one sentence: 'cold air, low heights - the aircraft is lower than the altimeter says'. Practise by converting a single aerodrome example among QFE, QNH and QNE, then applying the temperature correction in both directions until the sign is automatic.