RTCA/DO-160 (the civil aviation equivalent of EUROCAE/ED-14) governs environmental and EMC qualification testing for airborne equipment, and shares enough structural similarity with MIL-STD-461 — covered in our companion article — that it's tempting to treat the two as interchangeable. They aren't. DO-160's EMC sections cover broadly the same physical phenomena as MIL-STD-461's RE/RS/CE/CS methods, but the actual test setup geometry, frequency ranges, and equipment differ in ways that mean data from one standard generally can't be directly substituted for the other.
The Relevant Sections
DO-160's numbered sections cover environmental and EMC testing together — Section 19 covers induced signal susceptibility, Section 20 covers radio frequency susceptibility, Section 21 covers emission of RF energy, and Section 22 covers lightning-induced transient susceptibility.
| DO-160 Section | Covers | Roughly comparable MIL-STD-461 methods |
|---|---|---|
| Section 20 | RF susceptibility — radiated and conducted | CS114, RS103 |
| Section 21 | RF emissions — radiated and conducted | CE102, RE102 |
| Section 22 | Lightning-induced transient susceptibility | RS105 (loosely comparable) |
Why Test Setups Genuinely Differ From MIL-STD-461
Test distance. DO-160 typically specifies a 1m antenna-to-EUT test distance, compared to commercial EMC testing's more common 3m or 10m distances.
LISN value. DO-160 conducted testing uses a 5µH LISN, reflecting the relatively short cable runs typical of aircraft wiring.
Ground plane / table construction. DO-160 testing is performed on a conductive (metallic) bench.
Conducted emissions measurement principle. DO-160 Section 21 measures conducted RF current using clamp-on current probes, rather than the LISN-derived voltage measurement.
Radiated frequency range starting point. DO-160 Section 21 radiated emissions testing starts at 100 MHz, reflecting DO-160's focus on protecting aircraft-installed receivers.
Installation Categories Drive the Actual Limit
DO-160 doesn't apply a single universal emissions or susceptibility limit — equipment is assigned an installation category based on where it will physically sit on the aircraft and how close it is to sensitive receivers and antennas.
Reverberation Chamber vs Anechoic Method
Like MIL-STD-461 RS103, DO-160 Section 20 and Section 21 both explicitly permit a reverberation chamber as an alternative to the conventional anechoic-lined chamber (ALSE) method.
HIRF — A Related But Distinct Requirement
High Intensity Radiated Fields (HIRF) testing is a related but separate regulatory requirement, addressing aircraft systems' ability to continue safe operation when exposed to genuinely extreme electromagnetic environments.
Practical Comparison Summary
| Factor | MIL-STD-461 | RTCA/DO-160 |
|---|---|---|
| Governing domain | Military (DoD) | Civil aviation (FAA-aligned) |
| Test distance (typical) | Varies by method | 1m |
| Conducted emissions LISN | 50µH (general) | 5µH |
| Radiated emissions start frequency | 10 kHz (RE102) | 100 MHz (Section 21) |