Take a moment to learn why arinc 429 has become the standard for transmitting data between components and systems in both commercial and military flight.

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 It is so crucial to have a universal and reliable way to convey information when you’re thousands of feet up in the air. Anyone who has ever piloted a plane or worked on aircraft knows that ARINC 429 is an integral component of airplane protocol. It is the technical standard for the most common avionics data bus used on most commercial aircraft in the skies today. People who deal with aircraft know it as the protocol that supports an aircraft's avionics local area network and main data bus. Take a moment to learn why this system has become the standard for transmitting data between components and systems in both commercial and military flight. 


ARINC 429 uses a self-clocking, self-synchronizing data bus protocol to transfer information. The wires used to create the physical connection are twisted pairs that carry balanced differential signaling. The data words carried by the bus are 32 bits in length. In addition, most messages only consist of one piece of data.

Conveying Messages

ARINC 429 is used to relay some extremely serious messages that have to do with airline protocol and air safety. Some of the critical messages that are conveyed using this protocol are:

  • Normal Operation (NO) indicates to the receiver that data in this word is considered to be correct data.
  • Functional Test (FT) indicates to the receiver that the data is being provided by a test source.
  • Failure Warning (FW) indicates to the receiver that a failure has occurred that has caused the data to appear to be missing or suspect.
  • No Computed Data (NCD) indicates to the receiver that data is missing or inaccurate for a reason other than failure. A common instance of this would occur when autopilot commands read as NCS because autopilot is not activated.

The Importance of Labels

One thing that makes ARINC 429 so crucial to flight is the fact that label guidelines for flight equipment are part of its specification. Each aircraft contains a number of different systems. This list of systems could include flight management computers, radios, GPS sensors and inertial reference systems. There is a high degree of uniformity among all manufactures and models to allow for cooperation and interchangeability between parts. ARINC 429 plays a role in ensuring that protocols stay consistent among all these parts that come from various sources. Click to read about arinc 429 labels list.

A Final Word on ARINC 429

Why is ARINC 429 such an important part of everyday flight for both commercial and military pilots? This protocol ensures that a uniform language exists between the countless components that go into creating safe and successful flights. This common language helps to eliminate both system error and human error.