Instrument and equipment failures
Recognizing which instrument lied to you, working the pitot-static and vacuum systems, and what a glass panel does when something dies.
15 min read · IFR emergencies
After this lesson you can
- Identify the indication pattern that points to a blocked pitot tube versus a blocked static port.
- Explain what the alternate static source, and breaking the VSI glass, do to your readings.
- Explain the difference between a vacuum failure and an electrical failure, and which instruments each one takes with it.
- Describe what a glass cockpit does in reversionary mode and how long its standby battery lasts.
Every instrument in the panel is fed by one of three systems: the pitot-static system, a vacuum or electric gyro system, or the electrical system itself. When one of those systems fails, it rarely takes down the whole panel at once. It takes down a predictable group of instruments, and the pattern of what still works and what does not is the fastest way to diagnose what actually broke.
This lesson works through the two failures you are most likely to see: a pitot-static problem, which corrupts your airspeed, altitude, and vertical speed readings, and a gyro or electrical problem, which takes your attitude and heading indicators. Later lessons cover how to fly once the instrument is gone; this one is about recognizing it fast, before it costs you.
The rest of this lesson
- 1.How the pitot-static system feeds three instruments
- 2.The alternate static source, and a last resort
- 3.Vacuum failure: the attitude and heading indicators go quiet
- 4.Electrical failure and the standby battery
- 5.Announce, then get help
- 6.Cross-check before you believe any one instrument
These 6 sections, their figures, the checks along the way and the end-of-lesson quiz come with the IFR track. Paid once, yours for good.
Key terms
Try to recall each definition before turning the card.