RTCA/DO-160
EMC Requirements for Commercial Avionics
INTRODUCTION
- RTCA/DO-160G, Environmental Conditions and Test Procedures for Airborne Equipment.
- RTCA Special Committee 135.
- Covers procedures and environmental test criteria for testing airborne electrical and electronic equipment (avionics).
- Covers Federal Aviation Administration (FAA) or other international regulations for avionics equipment.
# AVIONICS
- We sometimes think of avionics as being the navigation and communications equipment, but it also includes:
- Engine controls
- Server motor controllers for control surfaces – ailerons, rudder, flaps
- Landing Gear control
- Radars
- WiFi
- Satellite TV and entertainment systems
RTCA DO-160
- RTCA is the Radio Technical Commission for Aeronautics
- Publishes DO-160
- DO-160F issued in December 2007
- Latest is DO-160G with a Section 22 User Guide released December 2010
- ≥ 5 years before next release
- DO-160 Section 22 is "Lightning Induced Transient Susceptibility" (indirect effects of lightning)
MIL-STD 461F
- Mil-Std-461(F) is used as a basis for environmental testing of military aircraft world-wide.
- It is planned that parts or all of DO-160 Section 22 will be incorporated in the next revision (Rev G) of Mil-Std-461 originally tentatively planned to start in 2012 and to be released in 2013/14.
# REQUIREMENTS SUMMARY
- Section 15: Magnetic Effect
- Section 16: Power Input
- Section 17: Voltage Spike
- Section 18: Audio Frequency Conducted Susceptibility – Power Inputs
- Section 19: Induced Signal Susceptibility
- Section 20: Radio Frequency Susceptibility (Radiated and Conducted)
- Section 21: Emission of Radio Frequency Energy
- Section 22: Lightning Induced Transient Susceptibility
- Section 23: Direct Lightning
- Section 25: Electrostatic Discharge
SECTION 15: MAGNETIC EFFECT
- This test is performed to determine how much the EUT will deflect a compass needle
- EUT is simply moved closer to the compass on an East-West line until one degree of deflection away from magnetic North is observed.
- Separation distance is then measured and the "Equipment Category" is determined.
SECTION 16: POWER INPUT
- This section is included here for two main reasons:
- Power Input/Quality tests are often performed in the EMC lab by the EMC test personnel.
- In the latest versions of DO-160, the frequency ranges for some of the tests fall well within the realm of typical EMC tests, and the test equipment used is similar to many other used in EMC Labs
- EUTs with both AC and/or DC power variations
- EUT does not have a negative influence on the aircraft power system
SECTION 16: CONT'D
- **Equipment categories**
- There are four Equipment Categories (A, B, D, or Z) that indicate the type of power used by the equipment and the type of AC and/or DC power source with which the equipment is compatible.
- For AC powered equipment, an additional designator, placed in parenthesis following the Category designator, is a two character code indicating that the equipment has been tested for use with Constant Frequency (CF), Narrow Variable Frequency (NF), or Wide Variable Frequency (WF).
SECTION 16: CONT'D
- **DO-160G Updates**
- Directions regarding the testing process for equipment with multiple power sources.
- The requirement to test all AC powered equipment
- Equipment uses "Narrow" or "Wide" Variable Frequency AC power
- Abnormal Surge test is now specified for each individual phase of 3 phase AC powered EUTs
- Tolerances for some test voltage levels have been added
SECTION 17:VOLTAGE SPIKE
- This test determines whether the EUT can operate as required during and/or after voltage spikes are applied to the AC and/or DC power input(s)
- Pulse produced duration at least 10 microseconds, a rise-time of less than 2 microseconds, and a source impedance of 50 ohms
- A minimum of 50 voltage spikes are applied within 1 min
- Test is very similar to MIL-STD-461F test method CS106
# SECTION 18: CONDUCTED SUSCEPTIBILITY
Audio frequency conducted susceptibility: Power inputs
- This test determines if EUT will operate as specified when audio frequency interference are coupled on AC and/or DC power inputs.
- Nearly identical to MIL-STD 461F test method CS101
- Test Level and Frequency range bit different from CS101
- The audio signal is transformer coupled onto each power input lead
- Test levels are up to 8% of the nominal AC input voltage
- Frequency range 10 Hz to 150 kHz
# SECTION 20: RADIO FREQUENCY
RADIO FREQUENCY SUSCEPTIBILITY
- Determines if EUT will operate as specified when exposed to RF interference.
- Continuous Wave (CW), Square Wave AM (SW), and Pulse Modulated (PM) RF signals are required.
- LISNs used with Power lines.
- Frequency range of 100 MHz to 18 GHz.
- Field strength significantly high.
SECTION 20: CONT'D
- **Equipment Categories**
- Equipment Category designation for Section 20 consists of two letters.
- Conducted susceptibility test levels are designated with the first category character and radiated susceptibility test levels with the second category character.
- 7 Equipment Categories for conducted susceptibility
- 10 Equipment Categories for radiated susceptibility.
- Category S is the least severe at 1 V/m, and Category L is the most severe, with test levels as high as 7200 V/m.
# SECTION 20: **CONT'D**
- **DO-160G Updates**
- Users Guide added.
- Wording updated to align Section 20 with the requirements of the new FAA HIRF Rule, FAA Advisory Circular 20-158, and SAE document ARP5583A (HIRF Users Guide).
- Requirement to test all faces of EUT with Anechoic Chamber method for RS.
- Clarification that the distance between the test antenna and the EUT must be the same for calibration and test.
- The Reverberation Chamber test method has been modified from a "Mode-Tuned" process to a "Mode-Stirred" process. This change has resulted in a major re-write of Section 20.6.
# REVERBERATION CHAMBER
- Incoming mains power filter
- Conductive support
- Volume of uniform field
- Tuner/Stirrer assembly
- Alternate position for Tuner/Stirrer
- Drive motor
- Tuner/Stirrer assembly
- EUT measurement instrumentation
- Field generation equipment
- Interconnection
- Chamber penetration cables
- Field generation antenna pointed into corner of chamber with tuner
PHYSICS CONT'D
A closed cavity has many propagating modes which form 3-dimensional standing wave patterns with a large number of resonant modes. This gives rise to regions where the field is small and others where it is large. Typical variations are of the order of 40 dB, making the perceived test field very strongly dependent on the exact locations inside the cavity. At sufficiently high frequencies, the coupling between an equipment and an antenna varies rapidly with position and frequency.
OPPORTUNITIES
1. Shielding Effectiveness (SE), IEC 61000-4-21
1. Cables
2. Materials
3. Absorbers
2. Mil/Avionics
1. MIL-STD-461E/F
2. RTCA DO-160E/F/G
3. HERO Testing
4. HIRF Testing
5. DEF STAN 59-41
6. EUROCADE ED90
3. Automotive
1. SAE J1113-4 & J1113/27
2. GMW3097GS
3. FORD ES-XW7T-1A278-AC
4. E-mark
DO-160 SECTION 22 TESTING
- **DO-160 Section 22 "Lightning Induced Transient Susceptibility"**
- Verifies equipment capability to withstand the induced effects of lightning (indirect effects).
- However, these tests may not cover all aspects of lightning induced interaction and effects on equipment.
# Who needs this testing?
- Airframe manufacturers (partial list)
- Brazil – Embraer
- Canada – Bombardier
- China – Shanghai Aircraft, Xian, ACAC
- France – Airbus, ATR, Eurocopter
- Germany – Airbus, Dornier, Fokker
- Italy – ATR, Alenia Aermacchi
- Japan – Kawasaki Heavy Industries
- Korea – Korea Aerospace Industries
- Russia – Anotov, Ilyushin
- Sweden – Saab
- USA – Aviat, Boeing, Cessna, Raytheon (Beechcraft), Gulfstream
Composite Materials
- Carbon laminate
- Carbon sandwich
- Other composites
- Aluminum
- Titanium
DO-160 Section 22 Testing Overview
- 7 Test Waveforms (1, 2, 3, 4, 5A, 5B, 6)
- 5 Test Levels (1, 2, 3, 4, 5)
- 2 Test Types (Pin Injection, Cable Bundle)
- 3 Test Methods (Direct, Cable Induction, Ground Injection)
- 3 Cable Bundle Test Applications (Single Stroke, Multiple Stroke, Multiple Burst)
- Test Category Designations (ex: B3G4L3, AZZ3XX)
- Test Procedures (General, Pin Injection, Cable Bundle)
DO-160 Section 22 Test Waveforms
- Waveform 1 - Current
- Double exponential 6.4 us x 69 us (to 50%)
- Waveform 2 – Voltage
- Double exponential 100 ns x 6.4 us (at zero crossing)
- Waveform 3 – Voltage
- Ringing wave, sine or cosine 1 MHz and 10 MHz
- Waveform 4 – Voltage
- Double Exponential 6.4 us x 69 us (to 50%)
- Waveform 5A – Current
- Double Exponential 40 us X 120 us (to 50%)
- Waveform 5B – Current
- Double Exponential 50 us X 500 us (to 50%)
- Waveform 6 – Current
- Double Exponential 250 ns X 4 us (to 50%)
Section 22 Test Levels
- **Level 1**
- Equipment and wiring are installed in a well protected environment
- **Level 2**
- Equipment and wiring are in a partially protected environment
- **Level 3**
- Equipment and wiring are in a moderately exposed environment
- **Level 4 and 5**
- Equipment and wiring are in severe electromagnetic environments (or Mission Critical, typically)
# Summary
- RTCA/DO-160, and its European twin, EUROCAE/ED-14, cover EMC requirements for aircraft electronic equipment.
- The test levels, requirements, and procedures are intended to reflect the "state-of-the-art" in aviation technology and EMC testing methodology.
- 7 Test Waveforms (1, 2, 3, 4, 5A, 5B, 6)
- 5 Test Levels (1, 2, 3, 4, 5)
- Test Category Designations (ex: B3G4L3, AZZ3XX)
- Test Procedures (General guidelines, Generator Verification, Pin Injection, Cable Bundle)
- Transient Amplitude Determination Guidelines
# How can SRC-TEST Assist?
- **Perform compliance assessment**
- Confirm regulatory requirements for target markets
- **Develop compliance strategy**
- Strategic plans for multiple markets
- Customize compliance around your needs
- **Execute compliance strategy**
- Project Management
- Testing, Certification (Marks, Certificates), Inspection, Documentation
- **Updates on evolving global compliance**
REFERENCES
- RTCA/DO-160G, "Environmental Conditions and Test Procedures for Airborne Equipment," RTCA, Inc., December 8, 2010.
- RTCA/DO-160F, "Environmental Conditions and Test Procedures for Airborne Equipment," RTCA, Inc., December , 2007.
- RTCA/DO-160D, "Environmental Conditions and Test Procedures for Airborne Equipment," RTCA, Inc., July 29, 1997.
- MIL-STD-461F, "Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment," Dept. of Defense Interface Standard, 10 December 2007
