The gyroscopic instruments
The attitude indicator, heading indicator, and turn coordinator all exploit a spinning rotor — and the same properties that make them useful also make them drift.
14 min read · Flight instruments
After this lesson you can
- Explain rigidity in space and precession, and name which instrument relies on each.
- Read the attitude indicator's bank index and recognize its acceleration and deceleration errors.
- Realign the heading indicator correctly and explain why it drifts over time.
- Fly a coordinated standard-rate turn using the turn coordinator and the ball, and correct a slip or a skid.
Where the pitot-static instruments measure a pressure, the gyroscopic instruments exploit a spinning mass. Three instruments on the panel, the attitude indicator, the heading indicator, and the turn coordinator, all come from the same two physical properties of a fast-spinning rotor. Understand those two properties once, and all three instruments, and their errors, follow logically.
They are also mechanical parts that wear, drift, and fail slowly. A gyroscope rarely just stops; it degrades, and a degrading gyro keeps producing a plausible-looking, wrong indication for several minutes before anyone notices. Knowing what each instrument truly measures, and how to cross-check it against the others, is what turns a slow failure into a manageable one instead of a surprise.
The rest of this lesson
- 1.Rigidity in space and precession
- 2.The attitude indicator
- 3.The heading indicator
- 4.Turn indicators: turn-and-slip versus turn coordinator
- 5.The inclinometer: slip, skid, and coordination
These 5 sections, their figures, the checks along the way and the end-of-lesson quiz come with the PPL track. Paid once, yours for good.
Key terms
Try to recall each definition before turning the card.