How Instrument Comprehension works
Each question has two dials. On the left is the artificial horizon, or attitude indicator: a small fixed aircraft symbol in the centre, a heavy horizon line and shaded ground. It shows whether the aircraft is climbing or diving and whether it is banked. On the right is the compass, with an arrow showing the heading.
Below are four pictures of an aircraft. You choose the one that most nearly matches both dials. The rule that unlocks every question: you are always looking north, at the same altitude as the aircraft, with east to your right.
So an aircraft heading north shows you its tail, one heading south faces you, and one heading east is seen side on with its nose to your right. It counts towards the Pilot and Air Battle Manager composites.
Read the dials in this order
Three checks, each of which rules pictures out:
- Compass first. Decide whether the aircraft is going away from you, coming towards you, or crossing left or right, and cross off every picture facing the wrong way.
- Climb or dive next. If the aircraft symbol sits above the heavy horizon line, the aircraft is climbing; below it, diving; on it, level. The further from the line, the steeper.
- Bank last. The horizon line tilts against the bank. A level horizon line means wings level.
- Usually one picture survives all three checks. If two do, look again at the compass: a northeast heading and an east heading are easy to confuse.
Worked examples
The compass arrow points east. The aircraft symbol sits above the horizon line, and the line is level. East is to your right, so you see the aircraft side on with its nose to the right. Above the line means climbing, so the nose is raised. A level line means the wings are level. Choose the side view with the nose to the right and pointing up; a picture with the nose to the left is heading west and can be crossed off first.
The compass arrow points north, and the symbol sits on the horizon line. You are looking at the aircraft’s tail, flying level. Any picture showing the nose coming towards you is heading south, and any side view is east or west, so both are out before you think about bank.
Tips for the real subtest
- Say the heading to yourself as a direction of travel: “away and to the right” for northeast, “towards me and to the left” for southwest.
- Learn to read bank with the white pointer against the fixed black mark, as well as from the tilt of the line.
- Upper surfaces of the wings are drawn light and undersides dark, which tells you which way a banked aircraft is rolling.
- At 12 seconds a question, guess and move on rather than stall. There is no penalty.
- Practise on a computer. The real test is on a desktop screen with both dials and all four pictures visible at once.
Practise Instrument Comprehension on CogniPrep
Our Instrument Comprehension game is free. It gives you 25 questions in 5 minutes with an artificial horizon, a compass and four aircraft pictures, drawn by us to the published rules; they look different from the real pictures but are read the same way. You can move back and change answers until time runs out. Your result is the number right, split by heading (north and south, east and west, and the diagonals), compared with other CogniPrep users. On a narrow phone the last two pictures need a short scroll.