The Six Pack: Primary Flight Instruments

When it comes to aviation, a six-pack doesn’t refer to a pack of beer cans, or a ripped set of abs. In an aircraft, the six pack is the six primary flight instruments in the aircraft’s cockpit that relay the most critical pieces of information about flight characteristics. The six pack is broken into two categories: three instruments that rely on pitot static systems, and three gyroscopic systems.

The airspeed indicator is the first pitot static system instrument and measures the speed that the aircraft is traveling through the air, or to be more precise, the speed at which air is flowing over the aircraft. Airspeed is measured in knots, or nautical miles; however, the airspeed on the indicator is only the indicated airspeed. Small windows at the top and bottom of the indicator are used to determine the aircraft’s true airspeed.

The altimeter measures the altitude of the aircraft, or its height above sea level. It is important to remember that ground elevation can vary greatly, so the pilot must be aware of that variable to be able to calculate the aircraft’s distance from the ground. Altimeters have three hands, each of which moves at a different rate. The fastest hand reads for hundreds of feet, the second in thousands of feet, and the slowest hand reads in tens of thousands of feet.

Last of the pitot-static systems is the vertical speed indicator (VSI). The vertical speed indicator measures the aircraft’s rate of climb or descent in hundreds of feet, or FPM. The faster the speed, the greater the aircraft’s change in altitude. The VSI can also indicate if there is a steady loss or gain of altitude, allowing the pilot to adjust accordingly.

First of the gyroscopic instruments is the attitude indicator, also called the artificial horizon or gyro horizon. This instrument depicts the aircraft’s position in relation to the horizon. It communicates if the aircraft is flying level or if its wings are at an angle, if it is climbing or descending, or if it is flying in a straight path. Attitude indicators have a pair of wings to represent the attitude of the aircraft, and behind that a ball. The top of the ball is painted blue to represent the sky, and the bottom half painted brown or black to represent the ground. As the aircraft maneuvers and turns, the wings on the indicator represent the degree of bank and pitch attitude.

Next is the heading indicator. Sometimes called the directional gyro or heading gyro, it is the primary direction instrument used in flight. The heading indicator is gyroscopically stabilized, not a magnetic compass. However, the heading indicator is set according to the indication of the magnetic compass before takeoff and is regularly updated to match the compass during flight while the aircraft is steady and level. On the indicator itself, an outline of an aircraft is placed over a 360-degree scale with markings for north, south, east, and west, with markings between each cardinal direction at five- and ten-degree intervals.

Finally, the turn indicator is the last of the gyroscopic instruments, and the last of the six pack. The turn indicator gives information about the rate and direction of a turn. At the bottom of the instrument is a ball (or inclinometer) that will indicate if a turn is slipping or skidding during a turn.


January 18, 2021

Recent Twitter Posts

Semiconductor’s Certifications and Memberships

Thank You for Visiting!

Don’t forget That If You Need a Quote for A Part, You Can Get One Within Fifteen Minutes By Filling Out Or Instant RFQ form On the Homepage of This Website.

Request for Quote