GCAA Ghana CPL Theory Exam common mistakes
GCAA Ghana CPL Theory Exam · Understand the traps and how to avoid them.
Calculating a crosswind component by using the sine of the wind angle when the student has actually used the wind direction as given rather than the angle between wind and runway, so the answer is wrong by tens of degrees and the resulting component is either far too large or too small.
Candidates memorise 'use sine for crosswind, cosine for headwind' but then plug in the raw wind direction instead of first subtracting the runway heading. Under exam pressure the subtraction step is silently dropped, and because both sine and cosine of a wrong angle still produce plausible numbers, the error is never caught.
What to do instead
Write the angle between wind and runway in the margin before touching the calculator, and sanity-check with the 30/45/60 rule: 30 degrees gives half the wind speed as crosswind, 45 gives about 0.7, 60 gives about 0.87. If your computed crosswind exceeds the wind speed itself, you have used the wrong function or the wrong angle.
Treating pressure altitude and density altitude as interchangeable when computing take-off or landing distance, so the candidate uses the aerodrome elevation or QNH-derived altitude for a density-altitude-limited performance question.
Both are 'altitudes' derived from pressure, and many candidates conflate the two because they only ever see one chart at a time. The distinction only matters when temperature is non-standard, which is exactly the case the examiner sets up.
What to do instead
Force the two-step routine every time: pressure altitude from the altimeter subscale (1013 set, read altitude), then density altitude from pressure altitude plus the ISA temperature deviation. On the chart, enter at pressure altitude, move across for temperature, then down for weight and wind. If the chart has a temperature axis, you are working with density altitude and must not enter with pressure altitude alone.
Mixing up the privileges and validity conditions of the CPL, the instrument rating and the class ratings, for example stating that a CPL holder may fly as PIC on a commercial air transport flight without the appropriate type or class rating, or quoting the wrong revalidation period for the medical or the rating.
Air Law questions are written to test precise recall of numbers and conditions, and candidates study the broad privileges but skim the validity and revalidation paragraphs. The wording of the licence privileges and the rating validity are deliberately similar, so a partially learned answer feels correct.
What to do instead
Build a one-page table with columns for licence or rating, privileges, validity period, revalidation or renewal requirement, and the document that governs it. Recite the numbers aloud until they are automatic, and for every practice question identify which specific paragraph of the regulation the answer rests on rather than just recognising the right-sounding option.
Answering right-of-way and lights-and-shapes questions from memory of a diagram rather than from the rule, so the candidate gets the converging-head-on case right but fails the overtaking, landing, or converging-at-different-levels case, or misstates which aircraft shows which navigation lights.
These rules are usually learned visually from a single illustration, and the illustration only shows one geometry. The examiner tests the geometry the candidate did not visualise, and the candidate's mental picture cannot be rotated to fit.
What to do instead
Learn the rules as a decision hierarchy in words: head-on, converging at similar levels, overtaking, landing, and then the category exceptions (balloon, glider, airship, aircraft towing). For each, state who gives way and who maintains heading and speed. Then redraw the geometry from memory for each case and check the light and shape requirements separately for day and night, moving and stationary.
Computing a navigation leg by adding or subtracting the whole wind vector to the true airspeed instead of solving the wind triangle, producing a heading and groundspeed that do not correspond to the requested track and time.
The candidate knows the triangle exists but reduces it to 'add headwind, subtract tailwind' because that works for pure along-track wind. Any crosswind component makes the shortcut invalid, and the resulting groundspeed looks reasonable enough to pass unnoticed.
What to do instead
Always solve in the correct order: track and TAS give heading and groundspeed only after the wind vector is applied. Use the CRP-5 or the calculator method consistently, and verify with a rough sketch of the triangle drawn to scale in the margin. Check that groundspeed lies between TAS minus wind speed and TAS plus wind speed, and that the heading is on the upwind side of the track.
Reading a METAR or TAF and reporting the wrong trend or validity, for example quoting the TEMPO period as the whole forecast validity, treating BECMG as instantaneous, or missing that the wind group is in degrees true in a TAF and degrees magnetic in an ATIS or tower report.
The codes are learned as vocabulary rather than as a grammar, so candidates decode each group in isolation and never assemble the timeline. The true-versus-magnetic distinction is a classic trap that is not obvious from the text alone.
What to do instead
Practise by rewriting a full METAR and a full TAF into plain English sentences in chronological order, explicitly stating the start and end of each BECMG and TEMPO group and what changes. Keep a note that TAF and METAR winds are true, while ATIS, tower and approach reports are magnetic, and check the units and reference in every question before answering.
Applying a human performance concept by name without matching it to the scenario, for example labelling any error as a 'violation', calling all hypoxia 'hypoxic hypoxia', or attributing a pressurisation failure to 'stagnant hypoxia' when the cause is reduced oxygen partial pressure.
The four hypoxia types and the error taxonomy (slip, lapse, mistake, violation) are memorised as lists. Exam scenarios are written to test whether the candidate can classify a described situation, which requires understanding the mechanism, not the label.
What to do instead
For each hypoxia type, write the mechanism in one line (reduced oxygen availability, reduced oxygen-carrying capacity, reduced blood flow, or blocked tissue uptake) and one aviation cause. For errors, classify by intent and outcome: was the action intended and the outcome wrong (slip or lapse), or was the plan itself wrong (mistake), or was a rule deliberately broken (violation). Then answer the scenario by mechanism, not by keyword.
Mixing up the roles and readouts of ground-based and satellite navigation aids, for example treating a DME distance as a slant range equal to ground distance at all ranges, confusing a localiser and a glidepath frequency pairing, or misstating what an NDB or VOR radial actually tells the pilot.
Radio navigation is taught as a set of instruments rather than as a set of geometric measurements, so candidates learn what each aid is called but not what quantity it measures or in which reference frame.
What to do instead
For each aid write three lines: what it measures, in what reference (bearing to or from the station, slant or ground range, angular deviation), and its principal limitation. For DME, remember slant range equals ground range only at long range and overestimates it close in. For ILS, learn the paired frequencies and the fact that the localiser gives lateral guidance and the glidepath vertical, with the marker beacons or DME providing range.
Answering loading and mass-and-balance questions by checking only that the total mass is below the maximum, without verifying that the centre of gravity lies within the forward and aft limits for the actual zero-fuel and take-off configurations.
Candidates treat mass and balance as one check because the total mass is the easiest number to compute. The CG limits vary with mass and with fuel state, and a load can be within mass limits while the CG is outside the envelope, which is precisely what the examiner constructs.
What to do instead
Always compute the moment arms and the CG for at least two states: zero fuel and take-off. Plot or check both against the envelope at the relevant mass. If the CG is out, state the corrective action (move load, add ballast, redistribute fuel) rather than just declaring it out of limits. Carry units through every step and check the moment units match the arm units.
On operational procedures and communications, giving the correct-sounding phrase but omitting the mandatory elements of a readback or position report, for example reading back a clearance without the altimeter setting, or filing a position report without the next position and ETA.
Candidates learn phraseology by listening to it rather than by dissecting it, so the structure of a clearance or report is not explicit in their minds. Under time pressure they reproduce the gist and drop the items the examiner is counting.
What to do instead
Write out the template for each standard transmission (departure clearance, level clearance, position report, distress and urgency call) as an ordered list of elements, and practise reading back recorded or written clearances against the list. In the exam, tick off each required element in the question before choosing the option, and reject any option that omits a required item even if the rest sounds fluent.