Understanding The Importance of ARINC 429 Standards In Avionics and Aircrafts

Electronics and ICT are the leading players in building avionics of aircraft and artificial satellites. The technology applied in avionics is highly advanced and highly reliable. Communication within the entire aircraft electronics requires a very efficient and robust network. ARINC 429 then comes in to support the avionics local area network of the aircraft by defining the standard for data transfer.


ARINC 429 is a technical data transfer standard for avionics data used in aircraft. It defines a data protocol to support an aircraft avionics LAN. ARINC 429 also sets standards for the physical and electrical interfaces of a two-wire data bus.

ARINC 429 specifies standards for two-wire data bus that avionics systems use to communicate within the aircraft.

ARINC is an acronym for Aeronautical Radio INC. ARINC 429 is also known as Mark 33 DITS (Digital Information Transfer Systems).

Benefits of ARINC 429

The standardization of aircraft systems through arinc 429 has benefited the industry in various ways.

1.      Ease of Gadget Communication

ARINC 429 specifies requirements for aviation communication lines such that gadgets can communicate with ease irrespective of the manufacturer. The specifications allow all avionic systems, from sensors to control systems, to share information easily since they are all compatible.

2.      Allows Parts from Different Manufacturers to Co-Exist

Since ARINC 429 protocols have set flawless standards and specifications, the parts and systems from different manufacturers can co-exist and operate together freely. Also, different avionics systems can interface and communicate with each other smoothly and efficiently.

Systems such as autopilot, climate control, computer systems, navigation, fuel management system, GPS, and cabinet oxygen control can talk with ease using standard data formats.

3.      Gives Freedom to Designers of Avionics to Develop Innovative Parts

ARINC 429 has well-set standards, which are physical, electrical, and protocol. Hence, different designers can use the ARINC 429 standards to make various avionics and aircraft parts.

4.      Makes It Easy to Upgrade Systems

The ARINC 429 standards are internationally recognized. Hence, replacing parts and systems is easy since all designers use the definitive specifications to develop the new designs. The ARINC standard also makes it easy to maintain and repair the systems.

Specifications of ARINC 429

ARINC 429 defines standard specifications for electrical, physical, and protocol.

·        Physical Standards

The standard uses a one-way simplex transmission two-channel twisted data bus with a resistance of 78 ohms. The 78 ohms cable with a shield must be grounded at every junction and at the end to prevent interference of radio frequencies.

·        Electrical Standards

The standard allows a potential difference of 10 volts, requiring up to -5 or +5 volts of the signal voltage. The voltage margin enables the system to communicate data even at a voltage lower by 5volts of the signal voltage, making it efficient during emergency operations.

Also, data transmission is tri-modulation consisting of high, low, and null.

·        Word Length

ARINC 429 unit of transmission is a word. The standard transmits data in a 32-bits word unit, information in a 24-bits portion, while the label that describes data uses the other 8-bits.

·        Data Speed

ARINC 429 allows only two types of data speed, a low frequency of 12.5khz and a higher frequency of 100khz. However, the standard allows only one speed in a bus.


ARINC 429 standard defines aircraft avionics’ data protocol, physical characteristics, and electrical characteristics. The ARINC standards allow parts and complex systems to communicate with each other with ease regardless of the manufacturer. Since the standard increases the level and efficiency of communication, it makes air travel safer and efficient.

Maxim Joy
the authorMaxim Joy