The cognitive portion of the BU is a series of short, strictly timed subtests. Each one is simple to understand and hard to do fast — the difficulty comes from time pressure and sustained concentration across several hours of testing.
What is tested
Memory: short-term recall of visual and acoustic material — spoken sequences reproduced after a delay, and symbol-number pairs that must be held while new items interfere.
Mental arithmetic: rapid calculations without a calculator — and in the DLR's format the problems are dictated over headphones, so you hold every number in your head while you work.
Logical reasoning: figure series, analogies and matrix-style items solved under tight time limits.
Spatial orientation: rotating shapes, reading instruments, and keeping track of headings and positions — a core pilot aptitude the DLR weighs heavily.
Attention and concentration: long, monotonous scanning tasks that measure whether your accuracy holds up over time.
Technical comprehension: physics and mechanics fundamentals — forces, levers, gears, electricity and basic aerodynamics.
English: vocabulary, grammar and comprehension at the level expected of an international airline pilot — including listening comprehension, not only written items.
How to prepare
Train little and often: several short, focused sessions per week beat occasional marathon sessions, because the skill being built is speed-accuracy calibration under fatigue. Refresh secondary-school physics and practise mental arithmetic daily until common calculations are automatic — then switch to the Audio Math Test, which dictates the problems aloud exactly as the DLR does. On the practice page, Mental Math, Spatial Awareness, Technical Reasoning, the Vigilance Test, Sequences and Non-Verbal Reasoning are built around exactly these subtest formats, and a set of DLR-specific trainers goes deeper: Acoustic Memory for spoken sequences recalled after a delay, Associative Memory for symbol-number pairs, Visual N-Back for the visual working-memory subtest — shapes in colours where a match needs both, and the lag changes block to block — Cube Folding, Mental Rotation, Spatial Orientation and Instrument Comprehension for the spatial subtests, Figural Analogies and Letter Series for the reasoning items, Rule Application, Perceptual Speed and Processing Speed for the concentration block, Physics Knowledge and Electrical Comprehension for technical comprehension, and Aviation English — with its ATC listening mode — for the English test. Use your score trends to find and close your weakest areas before test day.