 Cover of original 1975 issue | |
| Abbreviation |
|
|---|---|
| Status | Published |
| Year started | 1975 |
| Latest version | G December 2010 |
| Organization | |
| Committee | RTCA SC-135 EUROCAE WG-14 |
| Domain | Aviation |
| Website | rtca.org |
DO-160, Environmental Conditions and Test Procedures for Airborne Equipment is a standard for the environmental testing of avionics hardware. It is published by the Radio Technical Commission for Aeronautics (RTCA) and supersedes DO-138.
The DO-160 document was first published on February 28, 1975 to specify test conditions for the design of avionics electronic hardware in airborne systems. Since then the standard has undergone subsequent revisions up through Revision G.
This document outlines a set of minimal standard environmental test conditions (categories) and corresponding test procedures for airborne equipment for the entire spectrum of aircraft from light general aviation aircraft and helicopters through the jumbo jets and supersonic transport categories of aircraft. The purpose of these tests is to provide a controlled (laboratory) means of assuring the performance characteristics of airborne equipment in environmental conditions similar of those which may be encountered in airborne operation of the equipment. The standard environmental test conditions and test procedures contained within the standard, may be used in conjunction with applicable equipment performance standards, as a minimum specification under environmental conditions, which can ensure an adequate degree of confidence in performance during use aboard an air vehicle. The Standard Includes Sections on:
| Section | Name | Description |
|---|---|---|
| Standard conditions | ||
| 4.0 | Temperature | This checks the effects of temperature on the system. Condensation also can be a factor coming from cold temperatures. |
| Altitude | These tests check the effects (in terms of performance) of altitude, including loss of cabin pressure on the device/system/equipment. Factors tested include dielectric strength, cooling under low pressure, and resilience to rapid change in air pressure. The norm defines the different temperature profiles under which the equipment must be tested. Due to the variety of aircraft, the equipment are classified in categories. | |
| 5.0 | Temperature Variation | These tests exercise the assemblies capability of surviving extreme temperature changes and the effects of differing coefficients of thermal expansion. |
| 6.0 | Humidity | These tests under humidity check the effects of high concentrations of humidity and the articles ability to withstand moisture effects such as corrosion. Typically moisture sensitive devices have issues with this test and require conformal coat or other types of protection. |
| 7.0 | Shock & Crash safety | This aircraft type dependent test checks the effects of mechanical shock. Crash safety test insures the item does not become a projectile in a crash. The norm describes the test procedure for airborne equipment. |
| 8.0 | Vibration | Aircraft type dependent test checks the effects of vibration and the equipment's ability to operate during all vibration scenarios. |
| 9.0 | Explosion proofness | These tests subject the test article to an environment under vacuum, with a gaseous mixture of combustibles. The unit must operate and be subjected to any actuation including knob turns and button pushes and not ignite the environment. |
| 10.0 | Water proofness | These tests subject the test article to various scenarios of dripping water or pooled water to verify the unit will fully operate in the given condition. |
| 11.0 | Fluids susceptibility | Aviation related fluids susceptibility including a variety of fluids ranging from carbonated sugared beverage to various cleaners and solvents. |
| 12.0 | Sand & Dust | This test subjects the unit to an environment of blowing sand and dust of specific particle sizes in which the unit must operate at the end of exposures. |
| 13.0 | Fungus Resistance | These tests determine whether equipment material is adversely affected by fungi under conditions favorable for their development, namely, high humidity, warm atmosphere and presence of inorganic salts. |
| 14.0 | Salt & Fog | This test verifies the test articles ability to survive multiple exposures of salt fog and drying and the environment's ability to cause accelerated corrosion. |
| 15.0 | Magnetic effect | This test determines the magnetic effect of the equipment and ensures it can operate properly without interference which may affect the nearby equipment, particularly the aircraft's compass. |
| 16.0 | Power input | Input power conducted emissions and susceptibility, transients, drop-outs and hold-up. The power input tests simulate conditions of aircraft power from before engine start to after landing including emergencies. |
| 17.0 | Voltage spike | This test determines whether equipment can withstand the effects of voltage spikes arriving at the equipment on its power leads, either AC or DC. |
| 18.0 | Audio Frequency Conducted Susceptibility | This test determines whether the equipment will accept frequency components of a magnitude normally expected when the equipment is installed in the A/C. These frequency components are normally harmonically related to the power source fundamental frequency. |
| 19.0 | Induced Signal Susceptibility | This test determines whether the equipment interconnect circuit configuration will accept a level of induced voltages caused by the installation environment. This section relates specifically to interfering signals related to the power frequency and its harmonics, audio frequency signals, and electrical transients that are generated by other on-board equipment or systems and coupled to sensitive circuits within the EUT through its interconnecting wiring. |
| 20.0 and 21.0 | RF emission and susceptibility | Radio frequency energy: -- radiated emissions and radiated susceptibility (HIRF) via an (Electromagnetic reverberation chamber). |
| 22.0 and 23.0 | Lightning susceptibility | Direct and indirect effects depending on mounting location; includes induced transients into the airframe or wire bundle. |
| 24.0 | Icing | This test determine performance characteristics for equipment that must operate when exposed to icing conditions that would be encountered under conditions of rapid changes in temperature, altitude and humidity. |
| 25.0 | ESD | This checks for resilience vs ESD in handling and operation. |
| 26.0 | Flammability | This analysis and test verifies the assembly will not provide a source to fire. |
The user of the standard must also decide interdependently of the standard, how much additional test margin to allow for uncertainty of test conditions and measurement in each test.
Avionics software is embedded software with legally mandated safety and reliability concerns used in avionics. The main difference between avionic software and conventional embedded software is that the development process is required by law and is optimized for safety. It is claimed that the process described below is only slightly slower and more costly than the normal ad hoc processes used for commercial software. Since most software fails because of mistakes, eliminating the mistakes at the earliest possible step is also a relatively inexpensive and reliable way to produce software. In some projects however, mistakes in the specifications may not be detected until deployment. At that point, they can be very expensive to fix.
DO-178B, Software Considerations in Airborne Systems and Equipment Certification is a guideline dealing with the safety of safety-critical software used in certain airborne systems. It was jointly developed by the safety-critical working group RTCA SC-167 of the Radio Technical Commission for Aeronautics (RTCA) and WG-12 of the European Organisation for Civil Aviation Equipment (EUROCAE). RTCA published the document as RTCA/DO-178B, while EUROCAE published the document as ED-12B. Although technically a guideline, it was a de facto standard for developing avionics software systems until it was replaced in 2012 by DO-178C.
A hazard analysis is used as the first step in a process used to assess risk. The result of a hazard analysis is the identification of different types of hazards. A hazard is a potential condition and exists or not. It may, in single existence or in combination with other hazards and conditions, become an actual Functional Failure or Accident (Mishap). The way this exactly happens in one particular sequence is called a scenario. This scenario has a probability of occurrence. Often a system has many potential failure scenarios. It also is assigned a classification, based on the worst case severity of the end condition. Risk is the combination of probability and severity. Preliminary risk levels can be provided in the hazard analysis. The validation, more precise prediction (verification) and acceptance of risk is determined in the risk assessment (analysis). The main goal of both is to provide the best selection of means of controlling or eliminating the risk. The term is used in several engineering specialties, including avionics, chemical process safety, safety engineering, reliability engineering and food safety.
ARP4761, Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment is an Aerospace Recommended Practice from SAE International. In conjunction with ARP4754, ARP4761 is used to demonstrate compliance with 14 CFR 25.1309 in the U.S. Federal Aviation Administration (FAA) airworthiness regulations for transport category aircraft, and also harmonized international airworthiness regulations such as European Aviation Safety Agency (EASA) CS–25.1309.
ARP4754, Aerospace Recommended Practice (ARP) ARP4754A, is a guideline from SAE International, dealing with the development processes which support certification of Aircraft systems, addressing "the complete aircraft development cycle, from systems requirements through systems verification." Revision A was released in December 2010. It was recognized by the FAA in AC 20-174 published November 2011. EUROCAE jointly issues the document as ED–79.
RTCA DO-254 / EUROCAE ED-80, Design Assurance Guidance for Airborne Electronic Hardware is a document providing guidance for the development of airborne electronic hardware, published by RTCA, Incorporated and EUROCAE. The DO-254/ED-80 standard was formally recognized by the FAA in 2005 via AC 20-152 as a means of compliance for the design assurance of electronic hardware in airborne systems. The guidance in this document is applicable, but not limited, to such electronic hardware items as
An electronic flight bag (EFB) is an electronic information management device that helps flight crews perform flight management tasks more easily and efficiently with less paper providing the reference material often found in the pilot's carry-on flight bag, including the flight-crew operating manual, navigational charts, etc. In addition, the EFB can host purpose-built software applications to automate other functions normally conducted by hand, such as take-off performance calculations. The EFB gets its name from the traditional pilot's flight bag, which is typically a heavy documents bag that pilots carry to the cockpit.
MIL-STD-810, U S Department of Defense Test Method Standard, Environmental Engineering Considerations and Laboratory Tests, is a United States Military Standard that emphasizes tailoring an equipment's environmental design and test limits to the conditions that it will experience throughout its service life, and establishing chamber test methods that replicate the effects of environments on the equipment rather than imitating the environments themselves. Although prepared specifically for U.S. military applications, the standard is often applied for commercial products as well.
RTCA, Inc. is a United States non-profit organization that develops technical guidance for use by government regulatory authorities and by industry. It was founded in 1935 and was re-incorporated in 1991 as a private not-for-profit corporation. It has over 20 active committees with multiple working groups under each committee and develops industry standards in cooperation with aviation regulators from around the world including the FAA.
Integrated modular avionics (IMA) are real-time computer network airborne systems. This network consists of a number of computing modules capable of supporting numerous applications of differing criticality levels.
Environmental testing is the measurement of the performance of equipment under specified environmental conditions, such as:
Functional safety is the part of the overall safety of a system or piece of equipment that depends on automatic protection operating correctly in response to its inputs or failure in a predictable manner (fail-safe). The automatic protection system should be designed to properly handle likely human errors, systematic errors, hardware failures and operational/environmental stress.
FANS-1/A design is a range of Future Air Navigation System (FANS) products that allows aircraft to be seen by ATC in areas where radar is not practical so that aircraft separation can be maintained. FANS includes many components from human to avionics hardware and a dedicated network linking Air Traffic Control (ATC) to the flight crew via satellite and landlines. FANS 1/A consists of CPDLC and ADS-C. CPDLC allows communications between the pilot and ATC and ADS-C is an electronic contract, valid through the duration of time the aircraft is in FANS 1/A airspace, offered by ATC and accepted by the flight crew. ADS-C provides aircraft position information to ATC including heading, altitude, airspeed and position. The communications include air traffic control clearances, pilot requests, and position reporting. FANS-1 is Boeing's solution and FANS-A is the Airbus solution.
DO-178C, Software Considerations in Airborne Systems and Equipment Certification is the primary document by which the certification authorities such as FAA, EASA and Transport Canada approve all commercial software-based aerospace systems. The document is published by RTCA, Incorporated, in a joint effort with EUROCAE, and replaces DO-178B. The new document is called DO-178C/ED-12C and was completed in November 2011 and approved by the RTCA in December 2011. It became available for sale and use in January 2012.
IEC 60068 is an international standard for the environmental testing of electrotechnical products that is published by the International Electrotechnical Commission (IEC).
AC 25.1309–1 is an FAA Advisory Circular (AC) that identifies acceptable means for showing compliance with the airworthiness requirements of § 25.1309 of the Federal Aviation Regulations. Revision A was releases in 1988. In 2002, work was done on Revision B, but it was not formally released; the result is the Rulemaking Advisory Committee-recommended revision B-Arsenal Draft (2002). The Arsenal Draft is "considered to exist as a relatively mature draft". The FAA and EASA have subsequently accepted proposals by type certificate applicants to use the Arsenal Draft on development programs.
The Advisory Circular AC 20-115 , Airborne Software Development Assurance Using EUROCAE ED-12( ) and RTCA DO-178( ), identifies the RTCA published standard DO-178 as defining a suitable means for demonstrating compliance for the use of software within aircraft systems. The present revision D of the circular identifies ED-12/DO-178 Revision C as the active revision of that standard and particularly acknowledges the synchronization of ED-12 and DO-178 at that revision.
FAA Order 8110.105A, Simple and Complex Electronic Hardware Approval Guidance, supplements RTCA DO-254 by explaining how FAA aircraft certification staff can use that document "when working on certification projects" and is recommended as a reference for developers applying for certification under DO-254. A particular focus is on clarification of the application of DO-254 guidance to "simple" custom micro-coded components as opposed to the more rigorous assurance expected of complex custom micro-coded components. Micro-coded devices are typically presumed to be complex components that cannot be verified through testing alone; however, some applicants have proposed their specific micro-coded device applications as simple components.
DO-248C, Supporting Information for DO-178C and DO-278A, published by RTCA, Incorporated, is a collection of Frequently Asked Questions and Discussion Papers addressing applications of DO-178C and DO-278A in the safety assurance of software for aircraft and software for CNS/ATM systems, respectively. Like DO-178C and DO-278A, it is a joint RTCA undertaking with EUROCAE and the document is also published as ED-94C, Supporting Information for ED-12C and ED-109A. The publication does not provide any guidance additional to DO-178C or DO-278A; rather, it only provides clarification for the guidance established in those standards. The present revision is also expanded to include the "Rationale for DO-178C/DO-278A" section to document items that were considered when developing DO-178B and then DO-178C, DO-278A, and DO-330, as well as the supplements that accompany those publications.
The Certification Authorities Software Team (CAST) is an international group of aviation certification and regulatory authority representatives. The organization of has been a means of coordination among representatives from certification authorities in North and South America, Europe, and Asia, in particular, the FAA and EASA. The focus of the organization has been harmonization of Certification Authorities activities in part though clarification and improvement of the guidance provided by DO-178 and DO-254.