1. TCCA Aircraft Certification
EMI/EMC Requirements
for
Part 23/25 Airplanes
Jean Cartier
Avionics Workshop
TCCA Aircraft Certification
November 27, 2003

2. Avionics Modifications
AEA Item
EMI/EMC Testing of
Avionics Modifications

3. Statement of Issue
AEA recommends TCCA to provide guidance material to ensure EMI/EMC testing of avionics installations are conducted in a manner appropriate to the type and criticality of equipment being installed and its potential effects on the aircraft

4. AEA Issues
Level of EMC Testing for Non-required Equipment Installations
DO-160D Section 20/21 Test Category/Data for Criticality of Equipment and Functions
Compliance to HIRF Certification Standards
Requirements for EMC Test Plans
Acceptability of Equipment Test Data VS Installation Test Data

5. § 23.1431(b) Electronic Equipment
(b) Radio and electronic equipment, controls, and wiring must be installed so that operation of any unit or system of units will not adversely affect the simultaneous operation of any other radio or electronic unit, or system of units, required by this chapter.
§ (b) parallels the requirement of § (a)
The intent of § (b) is exactly the same as § (c) Issued 11/03/64 & CAR 4b.650, 31/12/53
Equipment required by this Chapter includes Parts 1 through 139
§ (b): requirement addressees the victim/source effects on installed equipment/systems
§ (a): Each item of equipment, each system, and each installation:
(1) When performing its intented function, may not adversely affect the response, operation, or accuracy of any (I) Equipment essential to safe operation; or…

6. Level of EMC Testing for NRE Installations
General guidelines for EMC are provided in: AC “Guidance for Installation of Miscellaneous, Non-required Electrical Equipment”
MIL-STD 464 “Electromagnetic Environmental Effects Requirements for Systems”
AC B “Guidance for Installation of Miscellaneous, Non-required Electrical Equipment” Chapter 11, Paragraphs 106/107
Ground Power may mask aircraft transient due to its large capacitive effect

7. Level of EMC Testing for NRE Installations (Cont’d)
The following factors should be addressed as part of the EMC requirements:
Verify by inspection that the installed equipment/system conforms to the specified installation drawings
Development of the source/victim operational check matrix should consider potential EMI conditions between transmission and harmonic frequencies of required equipment such as radios and navigation systems, Etc…
All reasonable combinations of control settings and operating modes should be assessed
Communications and navigation equipment should be operated on low, mid-band, and high frequencies

8. Level of EMC Testing for NRE Installations (Cont’d)
The following factors should be addressed as part of the EMC requirements (Cont’d):
All electrically operated equipment and systems must be fully functional
In-Flight EMC testing should be assessed to validate flight operated functions which cannot be assessed on-ground
On-Ground EMC testing should be conducted with the equipment powered by the airplanes’s electrical generating system

9. Level of EMC Testing for NRE Installations (Cont’d)
The following factors identify installation design considerations which may directly contribute to the quality of EMC between non-required and required A/C systems:
Equipment location and installation
Harness routing
Shielding integrity
Wiring segregation
Potential ground loops
Inter-channel communication interference
Antenna Radiation

10. Level of EMC Testing for NRE Installations (Cont’d)
The source/victim testing level for non-required equipment is the same as for required equipment. However, our concern is much less for the functionality of non-required equipment

11. RF Susceptibility (Radiated & Conducted)
DO-160D Section 20 Test Category/Data for Criticality of Equipment and Functions
RF Susceptibility (Radiated & Conducted)
The purpose of section 20 is to determine that the equipment functions will not be adversely affected when the equipment and its interconnecting wiring are exposed to specified HIRF levels
The declared equipment test category level should comply with the HIRF’s Special Condition (SC) requirements
Applicable to systems which perform critical functions
The test category levels is dependent upon the shielding effectiveness which is provided by the aircraft structural components.

12. Emission of RF Energy (Radiated & Conducted)
DO-160D Section 21 Test Category/Data for Criticality of Equipment and Functions
Emission of RF Energy (Radiated & Conducted)
The purpose of section 21 is to determine that the equipment does not emit undesired RF noise in excess of the specified test category level.
DO-160D section 21 provides guidance for selecting appropriate category levels
The test category levels are declared by the equipment manufacturer

13. DO-160D Section 21 Test Category/Data for Criticality of Equipment and Functions (Cont’d)
DO-160 provides guidance to assist the manufacture in selecting the appropriate test category. However, it is the responsibility of the installer to resolve any incompatibilities between the new installation and previously installed equipment
The test category levels is dependent upon the shielding effectiveness which is provided by the aircraft structural components.

14. Compliance to HIRF Certification Standards
The following are applicable guidance/advisory material:
FAA Notice N “Guidance for the Certification of Aircraft Operating in HIRF Environments” 4/2/98
AC/AMJ “The Certification of Aircraft Electrical and Electronic Systems for Operation in the HIRF Environment” – “Final Draft” March 1999
Users Guide for AC/AMJ “The Certification of Aircraft Electrical and Electronic Systems”
SAE ARP5583 “Guide to Certification of Aircraft in a HIRF Environment” January 2003
DO-160D Section 20 “RF Susceptibility (Radiated and Conducted)
14/12/00 Change No. 1

15. Compliance to HIRF Certification Standards (Cont’d)
The requirement for certification to HIRF is addressed by a Special Condition (SC), and is applicable to systems which perform critical (Level A) functions
Compliance to the HIRF SC requires that the applicant submit the following:
Compliance Plan outlining the method of compliance to HIRF
Aircraft Hazard/Safety Analysis (FHA) and a HIRF/Lightning Criticality Assessment to substantiate the systems/equipment criticality levels and test data
FHA: Functional Hazard Assessment
PSSA: Preliminary System Safety Assessment
(SAE ARP 4761)”Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment”
(Certification Environment for airplanes) (Severe Environment for rotorcraft)

16. Compliance to HIRF Certification Standards (Cont’d)
The FAA/TCCA HIRF SC requirements are applicable only to systems which perform critical functions (Level A)
The JAA HIRF SC requirements are applicable to systems which performs critical and essential functions (Levels A,B,C)
The test category levels is dependent upon the shielding effectiveness which is provided by the aircraft structural components.

17. Compliance to HIRF Certification Standards (Cont’d)
Also applicable to the HIRF SC is the requirement to provide Instructions for Continued Airworthiness (ICAW) in accordance with the requirement of §23/
The ICAW should include all necessary maintenance actions to assure that the continued integrity of structural shielding, wire shields, connectors, and equipment protection components are maintained
FHA: Functional Hazard Assessment
PSSA: Preliminary System Safety Assessment
(SAE ARP 4761)”Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment”
(Certification Environment for airplanes) (Severe Environment for rotorcraft)

18. Need for EMC Test Plans An EMC test plan is required to document:
The source/victim functional test matrix (Evaluation of all potential system victims must be assessed)
The equipment/system installation conformity (A/C equipment/system configuration must be representative; model and part number of the installed equipment should be identified)
The Pass/Fail criteria (as applicable)
All reasonable combinations of control settings and operating modes (All foreseeable EMC worst case conditions should be considered)

19. Need for EMC Test Plans (Cont’d)
An EMC test plan is required to document: (Cont’d)
Communication and navigation equipment operating frequencies
On-ground and In-flight test configurations
The test plan should provide adequate detail to assure repeatability

20. Acceptability of Equipment Test Data VS Installation Test Data
DO-160 Section 20 equipment test data would be acceptable providing that the test category levels comply with the HIRF SC requirements (Category W; 100V/M - 150mA)
DO-160 Section 21 equipment test data would not be sufficient (section 21 qualification test data provides some degree of confidence to the installer that the equipment will be compatible with installed systems) However, EMC A/C installation test data would be required to demonstrate compliance to §23/

21. Conclusion
All new installations must address the requirements of § (b)/§ (c)
Recommended guidance material is provided in AC 25-10, MIL-STD 464, AC B, and the HIRF users guide
TCCA intends to address EMI/EMC concerns at the internal TCCA workshop