DO-160 outlines current Radio Technical Commission for Aeronautics (RTCA) standards for the environmental testing of avionics hardware. The RTCA published the document’s most recent update, DO-160G, in 2010. Here’s a brief overview of some of its most important changes.Section 2: Revised Definitions of General Terms
In DO-160G, equipment tested and qualified to the environmental conditions of one category level are now auto-qualified to less severe categories of the same test.
This change excludes Category X, which remains reserved for cases where equipment does not fit into any other category.
Section 3: Revised Testing Conditions and Test Equipment Requirements
Section 3 of DO-160G aligns the minimum interconnecting cable lengths for radiated emissions testing with those listed in Section 21.
Section 3 also requires the use of special purpose software to place equipment in its most susceptible mode during environmental testing.
Section 16: Revised Power Input Requirements
DO-160G Section 16 contains an update to the control of inrush current for AC- and DC-powered systems that may introduce reactive loading to the airframe power distribution system.
Newly added test Category Z expands the list of allowed equipment to include those with different inrush requirements.
Section 16 also outlines normal steady-state voltage and frequency conditions for single- and three-phase powered equipment.
Category A(CF) equipment can now perform steady-state testing using the emergency condition levels while meeting the normal pass/fail criteria.
Section 18: Additional Information About Power Inputsand Audio Frequency Conducted Susceptibility Testing
In DO-160G, a maximum current allowance of 36A (peak-to-peak) replaces the 100-Watt test signal applied power limit.
As well, Appendix 18 now contains a user's guide with additional information.
Section 19: Revised Testing for Induced Signal Susceptibility
Section 19 of DOP-160G now includes electric field-induced testing in its list of requirements.
This requirement ensures that equipment will meet its specified level of operational performance when exposed to stray electric fields.
Section 20: New Radiated and Conducted Radio Frequency Susceptibility Testing Guidelines
In DO-160G, radiated susceptibility tests can now be used to evaluate transmitting portable electronic devices (TPEDs).
DO-160G allows the placement of radiating antennas farther than one meter away from the EUT.
A “Mode Stirring” technique replaces the “Mode Tuning” technique in the alternative reverberation chamber test method.
Section 20 now includes a user's guide on potential field stability issues.
Section 21: Revised Emission of Radio Frequency Energy Limits
Section 21 covers areas where equipment and its associated wiring may be near VHF and GPS radio receiver antennas, and other areas where little shielding is provided.
The applicable frequency range for the 100-kHz bandwidth is now 400 MHz – 960MHz, while that of the one MHz resolution is 960 MHz – six GHz.
Uncorrected 10 kHz bandwidth can no longer be used to measure Category M and H emission notches above 960 MHz. Instead, DO-160G now recommends the use of a low noise preamplifier.
Values for Category H and P limit notches at 152 MHz are changed from 27 dB to 27.5 dB.
