A compliance testing certification should be available when using a rugged server or workstation. Rugged servers must undergo certification by an internal lab or compliance laboratory to ensure they can withstand and function as intended in harsh environments that would typically damage standard computers. These environments include desert conditions, submarine environments, or, as specified in DO-160, onboard aircraft.

Military and commercial testing standards such as DO-160 are frequently used to ruggedize and stress-test servers for usage in difficult locations. The purpose of the DO-160 tests is to evaluate robust computers that are intended to be used in or on supersonic transports, jumbo jets, helicopters, and general aviation aircraft.

By utilizing a robust server or workstation that holds DO-160 certification, you and your team can focus on your applications while airborne, free from concerns about potential breakdowns or malfunctions.

What is DO-160 testing?

DO-160 is a live document that contains environmental testing requirements for aerospace industry. The official title of the document is Environmental Conditions and Airborne Equipment Test Procedures, defining the conditions and test procedures for airborne equipment. The Radio Technical Commission for Aeronautics (RTCA) is responsible for maintaining and disseminating DO-160.

Since its first publication on February 28, 1975, certification authorities like EASA and the U.S. Federal Aviation Administration (FAA) have relied on DO-160 for airworthiness verification, despite it not being a government standard or rule.

According to an advisory circular published by the FAA in June 2011, RTCA / DO-160 has been used as an environmental testing standard and test procedures for airborne since 1958, when it was known as DO-130.

Introduced in December 2010, the latest iteration of DO-160, referred to as DO-160G, is the version the FAA encourages using for new articles and includes revisions related to test conditions, power input, and susceptibility to radio frequencies, among other factors. Although equipment installed on aircraft is not mandated to undergo DO-160 environmental testing, it has become widely accepted across the industry by equipment vendors, airlines, compliance testing institutions, and government agencies. This acknowledgment serves to establish a consensus regarding the quality and reliability standards used to validate the safety and reliability of avionics equipment and broader on board equipment in aviation environments. DO-160 covers dynamics, climatic, and EMI/EMC environments while supporting determining equipment compliance and evaluating equipment reliability.

Which environmental conditions and tests are under DO-160’s purview?

23 test standards are included in DO-160:

• Standard 4- Temperature and Altitude
• Standard 5-Temperature Variation
• Standard 6- Humidity
• Standard 7- Operational Shocks and Crash Safety
• Standard 8- Vibration
• Standard 9- Explosive Atmosphere Standard 10- Waterproofness
• Standard 11- Fluids Susceptibility
• Standard 12- Sand and Dust
• Standard 13-Fungus Resistance
• Standard 14- Salt Fog
• Standard 15- Magnetic Effect
• Standard 16- Power Input
• Standard 17- Voltage Spike
• Standard 18- Audio Frequency Conducted Susceptibility – Power Inputs
• Standard 19-Induced Signal Susceptibility
• Standard 20&21- Radio Frequency Susceptibility
• Standard 20&21- Radio Frequency Susceptibility (Radiated and Conducted)
• Standard 20&21- Emission of Radio Frequency Energy
• Standard 22&23- Lightning-Induced Transient Susceptibility
• Standard 22&23- Lightning Direct Effects
• Standard 24- Icing
• Standard 25- Electrostatic Discharge
• Standard 26- Fire and Flammability

Every portion of DO-160 is customized for each customer and specifically designed to fit the equipment or rugged computing system’s intended environment.

eInfochips has worked with the world’s top 10 commercial aircraft corporations. One of the eInfochips’ clients wanted to build an Electric Motor Control Unit (EMCU) for a leading aircraft program. Check out how eInfochips provided a DO-178B Motor Control for Horizontal Stabilizer System solution within a limited time window.

Let’s discuss some of the test procedures mentioned above:

Section 4 – Temperature and Altitude for airborne equipment

Assessing equipment’s performance characteristics under severe hot or cold conditions and at various altitudes is the goal of DO-160 temperature and altitude testing; these tests determine performance characteristics and verify equipment performance at temperature and altitude extremes. There are 20 categories in this technique that cover the whole spectrum of situations, including low operating temperature extremes, known to exist in the majority of aircraft types and installation sites.

Equipment is tested by placing it in a test chamber, observing its effects, and documenting the results to determine if it passed or failed. This helps reinforce general equipment performance under installed operating conditions.

Section 5 – Temperature Variation

The goal of the DO-160 temperature fluctuation test is to evaluate whether aircraft equipment can operate properly when the aircraft encounters sudden gusts and abrupt, severe temperature shifts. Five categories in this process deal with the rate of temperature change for equipment mounted externally or internally.

Similar to DO-160 Section 4, testing is carried out by putting the apparatus in an environmental testing room, keeping an eye on how the apparatus is affected, and documenting the results to decide if the apparatus passes or fails, including response to test variations in the rate of change across installation locations.

Section 6 – Humidity

This test is crucial because it examines how the equipment responds to variations in humidity and helps determine whether equipment material and protective finishes are adversely affected by moisture exposure. Humidity poses a gradual threat to materials and is detrimental to machinery. Three kinds of do 160 testing are conducted:

• Standard Humid Environment
• Severe Humid Environment
• External Humid Environment

Additionally, it says that this test shouldn’t be conducted before tests four and five (the order of the testing apparatus).

To qualify: Equipment should be designed to prevent vapor formation or, if it does occur, to ensure it does not affect the essential components of the equipment. Furthermore, it is crucial to protect the components with a suitable covering, while hermetically sealed equipment may already satisfy waterproofness-related moisture protection expectations.

When designing anything that can withstand high temperatures, protective coatings, painting, and other protective treatment processes must be considered to support applicable equipment performance standards.

The surface finish of coatings is important for vapor deposition, and it also affects the surfaces of moving components and boxes in line with applicable performance standards.

Section 7 – Operational Shocks & Crash Safety

• The goal of DO-160 shock testing, together with vibration evaluation, is to ensure crash safety by simulating operational stresses encountered in aviation while confirming that the equipment continues to operate within the specified performance criteria and still meets the applicable equipment performance standard. Another aspect of DO-160 Section 7 is the crash safety test, aimed at ensuring that specific equipment remains securely mounted and does not pose a hazard during emergency landings.DO-160 Section 7 has four categories for equipment testing: Standard Operational Shocks (Category A), Low-Frequency Operational Shock (Category D), and Standard Operational Shock and Crash Safety (Category B).
• An accelerometer is used to measure and regulate shock pulses when an apparatus is strapped to a shock table for testing, while verifying compliance with its performance specifications.

Section 8 – Vibration

When subjected to vibration levels unique to the installation, do 160 testing uses a battery of tests to support equipment qualification by proving that airborne equipment can endure the installation environment while meeting durability criteria and performance standards.

The following three tests are related to DO-160 vibration testing, and each has one or more categories: Standard (Category S), Robust (Categories R, U, and U2), and High-Level, Short-Duration (Categories H, Z).

For fixed-wing aircraft, the Standard Vibration Test (Category S) is used. Its goal is to ascertain whether the equipment works as required in the usual vibration environment experienced during routine aircraft operations, and pre-compliance testing can identify flaws before formal DO-160 testing starts.

The purpose of the Robust Vibration Test (Categories R, U, and U2) is to determine whether the equipment can withstand vibration exposure and continue to function even after being exposed to endurance vibration levels.

The Robust Vibration Test is defined by DO-160 as a combined evaluation used to monitor the structural integrity and operational performance of the equipment, with proper instrumentation used during testing to track equipment performance.

The Robust Vibration Test encompasses testing protocols for equipment installed in helicopters and is best suited for equipment subjected to prolonged vibration exposure.

The High-Level, Short-Duration Vibration Test is recommended for equipment where a loss of function could adversely impact the aircraft’s performance, and these tests determine structural and functional equipment performance under severe operational loads. This test is specifically designed to simulate vibration conditions following an engine fan blade failure.

Section 10 – Waterproofness

These tests ensure that the test object functions properly in settings where water is pouring or spraying. Waterproofness requirements may differ for externally mounted equipment. The equipment’s ability to withstand liquid entry is determined by the RTCA DO-160 waterproofness test standard. The liquid can enter the equipment in a few distinct ways. The most noticeable is the mist. Condensation and dripping liquid are the two other ways that water can enter the equipment.

Four main kinds of equipment are specified in the DO-160 Section 10 test standard, including equipment mounted externally where exposure is greater.

Category Y

Equipment placed in areas where it comes into contact with condensing water during routine airplane operations.

Category W

Equipment placed in areas where it occasionally gets exposed to falling water during routine aircraft operations (usually as a consequence of condensation).

Category R

Equipment placed in locations where it may be sprayed with water from all directions or exposed to a driving rainstorm.

Category S

Equipment placed in areas where it could be exposed to the forces of a strong stream of liquid, such as during cleaning, washing, or de-icing of aircraft.

Section 11 – Fluids Susceptibility

These tests establish whether fluid pollutants affect fuel systems or other equipment building components.

Testing for fluid susceptibility should only be done if the equipment is placed in locations where fluid contamination is likely to occur.

The fluids are typical and often utilized in both ground and aerial operations.

Conclusion

The extensive variety of environmental conditions and testing covered by the DO-160 standard helps accredited laboratories and manufacturers detect flaws in electronic equipment and correct them before the equipment is used onboard.

Since it is widely used in the aviation sector and has worldwide recognition, electronic equipment that complies with this standard is frequently accepted readily by certifying authorities and consumers.

eInfochips provides test engineering services for both software and hardware. We work with our clients throughout the whole process, from test planning (PSAC), test case generation, and test execution to certification utilizing Run For Score (RFS) test execution and SOI audit support capacity. We provide test engineering services for Environmental Test Procedures and EMI Test Procedure document development, RTCA DO-160F, DO-160G, and MIL-Standards. The engineering services provided by eInfochips comply with ARP4754, DO-178B/C, DO-160, and DO-254.