What drives the six instruments?
They fall into two groups. Three are worked by air pressure, through the pitot tube and the static port. The other three are gyroscopes, spinning wheels that hold their direction while the aircraft moves around them.
| Instrument | Driven by | Shows |
|---|---|---|
| Airspeed indicator | Pitot tube and static port | Speed through the air, in knots |
| Altimeter | Static port | Height above sea level, in feet |
| Vertical speed indicator | Static port | Climb or descent, in feet per minute |
| Attitude indicator | Gyro, usually vacuum | Pitch and bank against the horizon |
| Heading indicator | Gyro, usually vacuum | Which way the nose points |
| Turn coordinator | Gyro, usually electric | Rate of turn, and balance (the ball) |
Because the groups work in different ways, a fault in one group leaves the other working. Pilots cross-check them all the time: if the attitude indicator and the turn coordinator disagree, one of them is wrong.
How to use these pages
- Open an instrument and read the two-sentence answer at the top.
- Move the controls under the live instrument and watch what changes.
- Read how each marking works, then the common mistakes.
- Look up any word you do not know in the glossary.
Questions
What are the six basic flight instruments?
The airspeed indicator, attitude indicator, altimeter, turn coordinator, heading indicator and vertical speed indicator.
Why are they called the six-pack?
Because they sit in two rows of three in front of the pilot, like a six-pack.
Which instruments use the pitot-static system?
The airspeed indicator, the altimeter and the vertical speed indicator. Only the airspeed indicator uses the pitot tube; all three use the static port.
Where do these facts come from?
From the FAA’s Pilot’s Handbook of Aeronautical Knowledge, chapter 8. The dial numbers come from the SkyDeck gauges, which are drawn to match the 172 in X-Plane 12.
Source
- Federal Aviation Administration, Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Chapter 8, Flight Instruments.