# AC 20-170: Integrated Modular Avionics Development, Verification, Integration, and Approval Using RTCA/DO-297 and Technical Standard Order-C153 - Type: Advisory circular (guidance, not mandatory unless a rule or AD requires it) - Status: Current - Approved: November 21, 2013 - Last reviewed: January 30, 2020 - Family: AC 20-170 - Cancels: [AC 20-145](https://openairdocs.org/ac/20-145) - 14 CFR parts: 21 - Pages: 66 - PDF: https://openairdocs.org/files/sha256/e2/d8/e2d8df928c79c4567ea800fa22e92457e8d6ec21703e7db9ab303e7920bdc0c9 - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FED2F4EB786B1639862577D10048AC1E.0001 - DRS record last changed: November 22, 2025 - Page: https://openairdocs.org/ac/20-170 ## Versions - [AC 20-170](https://openairdocs.org/ac/20-170) (Current), approved Nov 21, 2013, 66 pages ## Text Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 0 Advisory U.S. Department of Transportation Federal Aviation Administration Circular Subject: Integrated Modular Avionics Date: 11/21/2013 AC No: 20-170 Development, Verification, Integration, and Initiated by: AlR-120 Change: 1Approval Using RTCA/OO-297 and Technical Standard Order-Cl53 Purpose. This advisory circular (AC) sets forth an acceptable means ofcompliance for aircraft and engines that utilize Integrated Modular Avionics (IMA) systems. This AC calls out and supplements the guidance material ofRTCAID0-297, Integrated Modular Avionics (IMA) Development Guidance and Certificatitm Considerations, dated November 8, 2005. This AC incorporates pertinent guidance material and information from AC 20-145, Guidance.far Integrated Modular Ai·ionics (IMA) that Implement TSO-CJ53 Authorized Hardware Elements. AC 20-145 is now cancelled. Principal Changes. This change incorporates minor changes and updates, and a new appendix to AC 20-170. These changes are necessary in order to address incorrect references in RTCNDO-297 when using SAE ARP 4754, Rev. A, which is recognized by AC 20-174. Information regarding whom you may contact with questions regarding the information in this AC, and where you may obtain a copy, are also included. PAGE CONTROL Cl lART Remove Pa es Dated Insert P cs Dated Table of Contents. page 10/28/IO Table ofContents. page iv. ­ iv (12/28/I 0) Pages 3 through 4 10/28/10 Pages 3 through 4 Page 26 10/28/10 Page 26 Pages D-1 through D-3 10/20/10 Appendix D. pages 0-1 through D-3 Appendix H. page Il-1 ~ ~~ ~ f',;,J.. David W. I lempe Manager, Aircraft Engineering Division Aircraft Certification Division ### Page 2 AdvisoryU.S. Department of Transportation Federal viation Admini tration Circular Subject: Integrated M dular A ionics Date: I 0/28/ J o: 20-170 Development, Verificali n. Integration an Approval Using RTCA/OO -297 and Tecluucal Initiated by: AIR-120 Standard Order-Cl 53 Thi advi ory circular cts forth an acceptable mean f compliance for aircraft and engine s that utiliz [ntegrated Modular Avjonics (I.MA) ·ystems. This AC calls out and supplements the guidance materia] of RT A/DO-297 , Integrated Modular Avionics (IMA) Development Guidan e and Certification Consideration , dated November 2005. This A incorporates pertinent guidance material and infom1ati n from AC 20- l 45~ 01,idance for /11tegrated Modular Avio nics (JMA) that Implement TSO-CI 53 Authoriz.ed Hard ware Elements. AC 20-145 i now cancelled . h~ David W. Hempe Manager, Aircraft Engine ring Di isi n Aircraft Certifica tion Divi. i n ### Page 3 10/28/10 AC20- 170 Table of Contents Chapter 1 RTCA-0O-297 as an Acceptable Means of Compliance … 1 1-1. Purpose of this AC … 1 1-2. Whom this AC A ff~cts … l 1-3. Cancellation … 2 1-4. Using this AC and RTCA/ D O-297 … 2 1-5. App lying RTCAIDO-297 as an Acceptable Means of Comp liance … 2 1-6. What This AC Cove rs … 4 Chapter 2 Acceptance And Incremental Acceptance … 5 2-1. Compari son ofRTCAIDO 297 Acceptance and FAA Approval … 5 2-2. Major Benefits of Incremental Accepta nce … 6 2-3. IMA Module, Appli cation, S ystem, and Installation Acce ptan ce … 6 2-4. Documentation And Data Packaging … 7 Chapter 3 Obtaining an IMA Component Acceptance Letter … 8 3- 1. General Guidance Regar din g LM A Component Accep tance Letters … 8 3-2. Parts of the IMA Component Acceptance Letter … 9 3-3. Essen tial Elements of the IMA Compo nent Acceptance Cover Letter................... .......... I 0 3-4. Esse ntial Elements of the IMA Compone nt Accep tance Letter Data Sheet … 12 3-5. Acceptanc e Letter … 13 3-6. lMA Compon ent Accept anc e Letters For Revised IMA Component s … 13 3-7 . Cance lling an IMA Component Acceptance Letter … 14 Chapter 4 Reuse Of IMA Components … 15 4-1 . Reuse of an Accepted lMA Component. ...................... ...... ............................. ................. l 5 4-2. What Can Be Reused … 15 4-3. Reuse of Other Types of Comp liance Data ................................................. , … 16 4-4. Reuse of Previous ly Acce pted Software-O nl y or Hardware Componen t Contain ing Airborne Software … 17 4-5. Reuse of CEH or Hardware Component Containin g CEH … 17 4-6. Reuse OfSEH or Hardware Compo nent Containing SEH … J8 II ### Page 4 4-7. Reuse of EQT Data … 18 4-8. Data the Componen t Developer Owes to Lhe IMA Developer /System Integrator or Applicant … 19 4-9. Reuse of a Previous ly Accepted IMA Component That Wa.,., Revised … 19 4-10. Reuse of an fMA Component with a Previous TSO Authorization … 20 Chapter 5 Configuration Management of an IMA System … 21 5-1. IMA Configuration Management … 21 5-2. Automated, Robust Configuration Management ............... .......... ................. .................. .. 2 1 5-3. Non-Automated, Robust Configuration Management … 22 5-4. Software Loading Procedures … 22 5-5. Assurance Level of lMA Components Used in Configuration Management … 22 Chapter 6 IMA Recovery Features … 23 6-L Restarting Safety Critica l IMA Functions … 23 6-2. Restart Mechanism Implementation … 23 Chapter 7 Topics Not Covered by RTCA/DO-297 … 24 7-1. Electrical Power For IMA Systems … 24 7-2. Field Loadable Software … 24 7-3. Electronic Identification Guidance … 26 7-4. Aircraft System Lightning and HCRF Protection … 27 Chapter 8 Use Of TSO Authorized Components In IMA Systems … 29 8-1. IMA Syste.ms and TS Os … 29 8-2. TSO-C 153 Authorization for IMA Hardware Components … 29 8-3. FunctionaJ TSO Authorization … 30 8-4. EQT of IMA Components with TSO Authoriza tion … 30 8-5. lMA Compone nt TSO Part Marking … 31 8-6. Integration ofTSO Authorized Components in [MA Systems … 32 8-7. Aircraft Installation Approval of IM A Systems includin g TSO Autl1orized Components . . … 32 8-8. Roles and Responsibilities When TSO Authorized Components Are Used in IMA Systems … 32 Ill ### Page 5 Appendix A Environmental Qualification Guidance forTSO-C153 … A-1 Appendix B Sample IMA Component Acceptance Cover Letter … B-1 Appendix C Sample Acceptance Letter … C-1 Appendix D Related Documents And How To Get Them .•....•••...•...••...••.••• D-1 Appendix E Glossary … E-1 Appendix F Acronyms .............•..••..•••..••.......•..•....•..•......•.................•... F-1 Appendix G Partial List of Functional TSOs … G-1 Appendix H SAE ARP 4754 to ARP 4754A Cross-Reference Matrix ..• … H-1 iv ### Page 6 Chapter 1 RTCA-OQ ..297 as an Acceptable Means of Compliance. 1-l. Purpose of this AC. a. This advisory circular (AC) shows you 110w to obtain Federal Aviation Administration (FAA) airworthiness approva l for the devel opment. verification , and integration of an integrated modular avionics (IMA) system for installation into an aircraft or engine. We cite RTCA, Inc. document RTCA/DO-297 , Integrated Modular Avionics (IMA) Development Guidance and Certification Considerations , dated November 8, 2005 and supplement it with this text. This AC also provides guidance on how to show compliance with Technical Standard Order (TSO)-C15 3, integrated Modular Avionics Hardware Ele ments. b. This AC is not mandatory and does not constitute a regulation. In it, we describe an acceptable means , though it is not the only means, to obtain FAA approval of rMA systems. c. This AC uses the terminology "should'' when discussing compliance to the AC itself , as the AC represents one, but not the only, method of complying wiU1 the regulations. This AC uses the term ''must " when discussing compliance to the re_brtilations, as com pliance to a regulation is not optional ln these cases, the AC text supplies a reference to the specific rule(s) being discussed. 1-2. Whom this AC Affects. a. We wrote this AC for: (I) Applicants for type certificates (fC), amended TC (ATC), suppleme ntal TC (STC) , or amended STC (ASTC) of aircraft and aircraft engines implementing IMA systems and equipment , (2) Developer s of IMA systems, applications, and compo nents, (3) Applican ts for TSO-C153 , Integrated Modular Avionics Hardwar e Elements , and for functiona l TSOs as they apply to IMA systems, (4) Integrators of lMA systems, (5) Installer s of the lMA syste m into the aircraft, and (6) Those involved in the approval and continued airworthines s of IMA systems. b. When the term ..applicant'' is used in this AC, we are refening to the applicant for an aircraft or engine TC. STC , A TC. or ASTC . When this AC is referrin g to an applicant for a TSO authorizat ion (TSOA), the phrase "applicant for TSO authorization " or other similar phrase is ### Page 7 used. When this AC is referring to an applicant for an IMA Component Acceptance Letter, the phrase "applicant for fMA Component Acccptanc ,e Letter • or othe r similar phrase is used . 1-3. Cancellation. This AC cancels AC 20-145, Guidance/or Integrated Modular Avionics (IMAJ that Jmpleme11t TSO-C153 Authori=ed Hardware Elements. and incorpornte s all pertin ent information from it that is not covered by RTCA/DO-297. 1-4. Using this AC and RTCA/0O-297. a. The means in this AC are a complete method to sJ10w compliance and obtain approval of IMA components and systems for installatiou into an aircraft or engine. We intend that this AC be applied at the aircraft or engine level by the applicant for o TC, STC, A TC, or ASTC. That is, this AC is not intended as gujdance solely for an IMA developer, IMA system integrator , or lMA application/component supplier . b. If you are an appl icant for an authorizution for TSO-C 153, Integrated Modular Avionics Hardware Elements, you may use the guidance in this AC as one acceptable means of compliance to requirements defined in TSO-C153. See paragraph 8-7 and appendix A ofthi s AC for more information. c. We find that the objectives, processes, and activittes in RTCA/DO-297, plus the additional guidance material contained in this AC, constitute an acceptable means of compliance for the developm ent, integration, verification, and installation approval of1MA syste ms. If the applicant wants to propose an alternativ e means. including those from other industry documents refer enced by RTCA /DO-2 971 document those altemative means and secure FAA approval during yoUI project's planning stage. Prepare to use Issue Papers to document agreements reached. d. According to the definition of an lMA in Appendix E. Glossary , an [MA is a "shared set of flexible, reusable , and interoperable hardware and software resources that, when integrated, fonn a platform that provide s services.'' You should keep in mind that an IMA system is defined by the system architecture, not by the functionality the syst em provides . lMA systems may not always imp lement functions historically regarded as "avio nics", such as flight deck displays, navigation, communication, etc. IMA syste ms may also be used to implement other aircraft functionality, such as fly-by-wire flight controls, inertial reference/air data systems, or electrical power control systems. The re may be more than one IMA sys tem on an aircraft. An IMA system could feasibly be mounted within an engine assembly. 1-5. App lying RTCA/DO -297 as an Acceptable Means of Compliance. a. RTCNDO-297 des(..Tibes objectives. proce sses, and activities to incrementally accumulate design ass urance and accepta nce of IMA syste ms and components. RTCA/DO-297 refers to indu stry standar ds such as SAE Intemational' s Aerospace Recommended Practice (ARP) 4754, Certification Consideralio11sfor Highly Integrated or Complex Aircraft, Syste,ns, and SAE ARP 4761, Guidelines and Methods ofConducti11g the Safety Assessment Process 0 11 Civil Airborne Systems and Equipment. When RTCA/0O-297 invokes the processes and methods in specific 2 ### Page 8 sections of those industry standards as part of the IMA development. integration, verification, or approval process, you should consider those sections of the referenced industry standard (or other acceptable alternative means) to be part of the overall acceptable means of compliance as outlined in RTCA/DO-297. Note: SAE International updated their ARP 4754 to ARP 4754A, ··Guidelines.for Development ofCivil Aircraft and Systems"' in December 2010. AC 20-174. Development of Civil Aircrc!ff and Systems, dated September 30,2011, recognizes ARP 4754A as an acceptable means of compliance for development of aircraft systems. This revision A reflects a significant change to that document, including section and paragraph numbering from that used in the original release. As a result, several references to ARP 4754 by RTCA/DO-297 are incorrect when using SAE ARP 4754A. Please see appendix Hof this AC in order to cross reference ARP 4754 with ARP 4754A sections and paragraphs referenced by the original release ofRTCA/DO-297. b. You may use this AC as an acceptable means of compliance for a IMA systems that include TSO authorized articles. Although RTCA/DO-297 docs not address TSOs, you should apply the intent of its objectives in Annex A to IMA systems that include TSO authorization(s) in order to obtain IMA system approval. See chapter 8 of this AC for more information. c. If you choose to follow this AC to show compliance, apply the AC to your !MA development and approval process regardless of the complexity of the IMA system or business model under which it is developed and approved. RTCA/DO-297 is written primarily from the perspective of a complex IMA system developed and integrated by multiple organizations and companies (see RTCA/DO-297, subsection 2.4). Although the development, integration, verification. and approval of an IMA system developed by a single company are likely lo be less complex than for multiple companies. RTCA/DO-297 applies equally. This AC should be used as an acceptable means of compliance for IMA systems that: (I) Arc developed by a single company as well as those developed by multiple companies. lfa single company develops a complete IMA system, many of the separate roles defined in RTCA/DO-297 - such as !MA developer, application developer, and !MA integrator -- will be taken by this single company. (2) Are simple IMA systems as well as complex IMA systems. These terms are purposely left undefined. because it is difficult to make a clear distinction between them. The purpose of this item is to illustrate that this AC should be applied to IMA systems of all levels of complexity. (3) Are closed architecture as well as open architecture. (See Appendix E. Glossary.) ### Page 9 (4) Use TSO authorized components (that is, TSO-Cl53) and functional TSOs (such as TSO-C 113, Electronic Flight Displays and TSO-C9, Automatic Pilots) as well as IMA systems that do not use TSO authorized components. Note: Because of the variations described inc. above, not all aspects of RTCND0-297 or the additional guidance contained in this AC may apply to every IMA development program. We strongly recommend that any question regarding the application of this AC be discussed with us at the beginning of the certification program and the a!,>reements reached during those discussions be documented. The FAA may require an Issue Paper on these questions. d. Appendix A of this AC, Environmental Qualification Guidance for TSO-Cl 53, Integrated Modular Avionics Hardware Elements. shows applicants for TSO-C 153 authorization how to conduct environmental qualification testing (EQT) that ensures compliance to the minimum performance standard (MPS) ofTSO-Cl53. We do not require compliance to appendix A if you are not using TSO-C 153 authori,:cd hardware components. 1-6. What This AC Covers. This AC describes an acceptable means by which to apply RTCND0-297, along with the additional guidance material included in this AC, to an aircraft or engine certification program which uses an IMA system. We cover the following subjects in detail: -Acceptance and Incremental Acceptance (in chapter 2). - Getting An IMA Component Acceptance Letter (in chapter 3 ). - Reuse Of IMA Components (in chapter 4 ). - Configuration Management of an !MA System (in chapter 5). - IMA Recovery Features (in chapter 6). - Additional Topics Not Covered by RTCA/D0-297 (in chapter 7). - Use of TSO Authorized Components in !MA Systems (in chapter 8). ### Page 10 10/28/ lO AC 20-170 Chapter 2 Acceptance And Incremental Acceptance. 2-1. Comparison of RTCA/DO 297 Acceptance and FAA Approval. a. RTCA /DO-297 , paragraph 2.1.2, gjves the following definitions: (I) Acceptance -Acknowledgement by the FAA thal the moduJe1 application, or system comp lies with its defined requirem ents. Ac;ceptance is recognition by the FAA (typically in the form of a letter or stamped data sheet) signifying that the submission of data, justification, or claim of equivalence satisfies applicable guidance or requirements. The goal of acceptance is to achieve credit for future use in a certification project. (2) Incremental Acceptance - A process for obtaining credit toward approval and certification by accepting or finding that an IMA module. applicalion, and/or off-aircraft lMA syste m complies with specific requirement s. This incremental acceptance is divided into tasks. Credit granted for individual tasks contributes to the overall certification goal. Increm ental acceptance provides tbe ability to integrate and accept new applications and/or module s, in an IMA system, and maintain existing applications and/or modules , without the need for re-acceptance. b. We view acceptance, as defined above, as part of the processes documented by Title 14 of the Code of Federal Regulations ( l 4 CFR.) and published FAA policy used to approve airborne systems during an aircraft or engine certification program. To obtain approval for installation on a certified aircraft or engine, applicants must show that the aircraft or engine system/ fwiction meets with the applicable regulatory requfrements. See§§ 2 l. l 7, 21.20, and 2Ll 15. Some of the regulatory requirem ents are accompanied by an AC (such as this one) that describes one, but not the only, possible means of complying with those regulations. c. The main differences between RTCA/DO-297 .. acceptance" and our current formal process of showing compliance in an aircraft certification program are 1) each stage of RTCA /OO-297 acceptance is accompanied by some fom1 of recogni tion, such as a "signed letter or stampe d data sheet" or <(accepted or approved comp liance data package,' ' and 2) a goal of acceptance, as defined by RTCA/DO-297 , is to "achieve credit for futur e use in a certification pro cess." Otherwise, the two concepts are very similar: data submission s and statements of compliance are used to show that an airborne system or component complies with all applicable requir ements and therefore can be approved for installation onto an aircraft or engine. d. "Acceptance" is a term often used during the approval of aircraft or engine systems, but its meaning may not be consistent throughout the certification process. The meaning of this word can depend on the conte xt. For example, the RTCA/OO-297's "acceptance" is very similar, but not identical , lo AC 20-148, Reusable Software Components. That AC states: "Acceptance is credit the FAA grants for fully or pruiially meeting RTCA/OO-178B objective s for an (Reusable Software Component) RSC. The FAA shows acceptance by issuing a RSC acceptance letter.'' Although the concept is similar between RTCA/DO-297 and AC 20-148, the specific definitions of "acceptance" are not identical. This examp le illu strates that the meaning 5 ### Page 11 of ''acce ptance" may vary, given 1ts context. Make sure you understand the context and meaning of this term when you encounter it. e. "Incremental acceptance", as defined in RTCA/ 00-297, takes the concept of acceptance further. lt divides acceptance into «certification tasks" accomplished during different points, or increments, in the certification program. Each task builds upon previous tasks. Incremental acceptance of IMA components is no1mally associated with the (MA Component Acceptance Letter process described by RTCA/00-297. See RTCA/ 00-297, Section 4 for more infom1ation. f. An applicant may use acceptance of components within the IMA to accumulate certification credit towa rd instaJlation approval of an I.MA system on an aircraft or engine. The concept of acceptance does not alter or replace FAA certificatio n processes. [nstead, acceptance is a means to recognize that a specific lMA component complies with all docwnented requirements and objectives. and that an accepted component can be used without detailed examination of the compliance data for that component - that is, is the component acceptable for use in an approved airborne system? IMA Component Acceptance Letters described in Chapter 3 of this AC are not required to accumulate cettification credit toward installation approval. 2-2. Major Benefits of Incremental Acceptance. a. The major bendit of using the incremental acceptance process, as defined in RTCA/D0­ 297, is that incrementa l acceptance provides the ability to integrate and accept new components in an IMA system and maintain existing components without the need for re-acceptance. This allows you to: (I) Reuse accepted lMA components in multiple applications in the same certification program by submitting certification data packages that have an established pedigree. This reduces certification effort of the current aircraft or engine program without compromising system safety. (2) Reuse accepted [MA components in future certification programs by submittin g certification data packages that have an established pedigree. This reduces follow-on certification effort without compromising system safety. b. The incremental acceptance -process defined in RTCA/00-297 shows how to package and docwnent the data and artifacts of a specific IMA component, so the previously accepted data and artifacts may easily be used in multiple concurrent or future programs. 2-3. IMA Mod ule, App lication , System, and Installation Acceptance. a. Acceptance at each stage of IMA development and verification, as described RTCA/00­ 297, subsection 4.2 (Task I - Module Acceptance), subsection 4.3 (Task 2 - Application Acceptance), subsection 4.4 (Task J - IMA System Acceptance), and subsection 4.5 (Task 4 ­ Aircraft integration oflMA System), is required for IMA system installation approval. We intend that a11 important aspects in RTCA/00-297 regarding IMA development, integration. ### Page 12 verification, and approval (Tasks 1 t11rougb 4) be fo11owed and you show that the IMA system complies with all object ives ofRTCA/00-297, Annex A, regardless of whether you request IMA Component Acceptance Letters. The IMA Component Acceptance Letter process covered in RTCA/D0-297, Section 4, and chapter 3 of this AC is optional. As an appl icant, IMA developer /system integrator. or IMA component supplier, you may decide whether or not to request an fMA Component Acceptance Letter. Note: RTCA/D0-297 , subsection 4.6 (Task 5) deals with change s to acce pted modules and subsection 4. 7 (Task 6) ---­ 6 7 7 l O 1 l 12 13 RTC /DO-l60F Section Title Temperature and Altitude ­ Temperature Temperature and Altitude ­ Altitude Temperature Variati n Humidity perational Shock and Crash afety - Operati nal Shock Operational Sh Safety - Crash plosion-pro fne Waterproofness Fluid Susceptibility and and Dust Fungus Resi tance Required for Required for TSO-Cl53 Functional TSO Nol tested Yes Ye Not tested Yes t tested Yes T 0- 153 quali ficati n data may be u ed by imilarity Yes Yes, TSO-C 1 5 qualificati n data may be u ed b similarity Yes y . Yes, TSO-C 153 qualification data may be u ed by similarity Yes Ye if appropriate Yes, TSO-Cl 53 qualification data may be u ed by similarity Yes, if appropriate Yes, TSO­ 153 qualification data may be u cd by similarity Ye if appropriate es TSO-Cl53 qualification data may be u ed by imilarity Yes, if appropri a le Yes, TSO- Cl 53 qualification data may be u ed by similarity Yes if appropriat Yes TSO-Cl53 qualification data may be u ed by similarity A-1 ### Page 43 10/20/ l0 Appendix A RTCA / DO-160F RTCA/DO-160F Section Section itle # ]4 Salt Spray Required for TSO-C153 Ye . if appropriate Required for Functional TSO - Yes, TSO-Cl 53 qualification data may be used by similarity 15 Magnetic Effect Yes - - Yes, TSO-Cl 53 qualification data may be used by similarity 16 Power Input Nolte ted Yes - 17 V ltage Spike Ye Yes TSO­ 153 qualification data may be u ed by similarity - 18 Audio Susceptibility - Power [nputs Ye Yes, TSO- data may b 153 qualification u ed by similarity 19 Induced Signal Su ceptibility Notte ted Yes - 20 Radio Frequenc y usceptibility N t tested Yes 21 Emissio ns of Radio Frequency Energy Not tested Yes ._ 22 Lightning Indu ed Transient Su ceptibility Not tested Yes 23 Lightning Direc Effects Not tested Yes 24 Icing Ys Yes, TSO-Cl 53 qualification data may be used by similarity 25 Electrostatic Di harge Ye Yes TSO-C153 qualification - - ~ata may be u ed by similarity -1 Note: RT A/DO-160Fl S ctions 20 and 22 may require additional te ting at aircraft in talla:tion. 3. Certain EQTs cannot e appropriately I erformed on th hardware element s part of TS ­ Cl53 . These EQTs can only be appropriate! pe1fonned when the IMA sy t m and hardware element ar arranged in the configuration spec ified for lhe applicable aircraft, as defined for the aircraft TC. STC, ATC, or ASTC. Also, lhe e EQ can nly be appropriately performed with the functional software in talled and operating. Therefore certain RTCNDO-160F EQTs are exclude from TSO-Cl53. You should addre s these EQ s as part of the functional T 0 compliance or a part f the TC/STC /ATC /ASTC environmental qualification. These te ts arc de crib d below: a. EQT for temperature (RTCNDO-l 60F, Section 4) and temperature variation (RTCA/DO­ 160F ection 5), Perfonn these with the cabinet or rack and modules in the hardware configuration intended for the functional T O authorization r the TC/STC/ATC /ASTC approval. For temperature and temperature arialion tests ti r the functional T O or A-2 ### Page 44 10/20/ 10 Appendix A TC/STC/ ATC/ ASTC, the hardware module urra11gement should represent the expected worst­ case temperatur e conditions. Alternately, applicants for the functional TSO or for aircraft/engine certification may perform engine ering analysis, using validated models, of the thermal characteristics of the expecte d cabinet or rack and module configuratio n variatio ns to determin e temperature test param eters that exceed the worst-case expected temperature conditions. These temperature test paramet ers could be used instead of the standard RTCA/DO-160F , Sections 4 and 5, temperature conditions. b. EQT for operationa l shock (RTCA /DO-160F , Section 7) and vibration (RTCA/DO-160F, Section 8). Perform these with all cabinet/rack module posi tions occupied in the hardwar e con.figuration specified for the functional TSO or TC/STC/ ATC/ ASTC installation. Alternately , you could perform an engineering analysis, using validated models , of the characteristic s of the expected cabinet or rack and module con.figuration s to determine vibration and operational shock test param eters that exceed the worst expected conditions . These test parameter s could be use-d instead of the standard RTCA/DO-l60F , Sections 7 and 8 conJiti ons. c. EQT for induced transients {RTCA/DO-160F, Section 19), radio frequency {RF) susceptibilit y (RTCA/D O-160F , Section 20), RF emissions (RTCA/ DO-160F, Section 21 ), and lightni ng induced tran sients (RTCA /DO-160P, Section 22). These are most appropr iately perform ed with the functional hardware and software in the IMA system. This is becau se the response of the system may be highly dependen t on the functional softwa re and hardware . Therefore , perform these EQTs as part of the functional TSO comp liance or as part of the TC/STC/ATC/ASTC environmental qualifi cation. d. EQT for lightning and HlRF protection . Perfom1 these with the hardw are elements and softwa re components loaded in the configuration specified for the applicable aircraft, per the lightn ing regulations, ACs, and the HIRF policy. The interface wiring and connected equipment should represent the wiring and connected equipment installed in the aircraft. 4. You may use EQT performed for a single functional TSO authorization or aircraft TC/STC/ATC/ASTC to support other applications for functional TSOs or aircraft TC/STC/ ATC/ ASTCs with similar configurations . A TSO applicant may use similarity assessment and worst-case test conditions Lo minimize the EQT required for subsequent functional TSO applicatio ns or aircraft TC/STC/A TC/ ASTC. Your use of the environmental qualification data should be accom panied by a rational engineeri ng analysis of the difference s between hardware and softwa re configu ration used during the origina l environmental tests a11d the proposed new configuration. The engineeri ng analysis may consider worst-case environmental limit s developed above. 5. The functional TSO qualificatio n data sheet should state explicitly the RTCA/DO -l 60F test categorie s and tests performed in the functional TSO configuration and the test categories and tests perfom1ed in the TSO-C l 53 configuration . Includ e this information in the install ation instructions. A-3 ### Page 45 10/20/10 Appendix A 6. Hardware modules and software components providing a function that lacks an applicable functional TSO must meet the TC/STC/ATC/ ASTC environmental requirements. See § 2 1.3 1. 7. You must evaluate all hardware elements before installation lo ensure that the TC/STC/ A TC/ASTC environmenta l requireme nts have bee n sat isfied. See § 21.31. A-4 ### Page 46 10/20/ 10 ppendi B Appendix B Sample IMA Component Acceptance Cover Letter. Use the fi II wing a a guide for an IMA C mponent Acceptan Cover Letter. The format given h re does not need to be followed pre isely. It is imp rtant however that all the information be present, in ome form in the letter. Page l ofx AME COMP OMPA NY CONTA CT INFORMATION D ate f appl ication Unique identifier ]MA omponent Acceptance Cover LeUer General lnformation lMA comp nent name: Y ADDR E TMA componen t top level identification: (Must uniquely identify the componenz, including anv revision or modificatio n level. ) ame and c ntact information of company that develope the IMA component different than the applicant for the IMA mponent Ac· ptance Letter): Contact in ormation: (List the name(s) o[engin eri11g and/or mana gerial 1aff'to 1,vlzich the FAA and other companies involved in the u c a11d po sible {1.1t11r reu e o[Lhis component may corr espond. Include the person ·s posilio11 or title within th company, telephone number and, ii po sibl e, a stable e-mail addre .) FAA office to which the ap plicat ion for lM ompo nent acceptance is being made: Aircraft r engine erti-ficati n program in which TMA comp nent will b u. ed or initial acceptance including targ t ertification date: Name and identification of [MA system in whic h the IMA c mpo nent will be used for initial acceptance:--------- ----------------------­ B-1 ### Page 47 10/20/1 0 Appendix B Name and address of IMA system developer/ integrator (if different than the lMA componen t developer making this application): _____________________ _ Information Regarding Initial Use of IMA component Describe the airborne system and environment in which the JMA component will be operating, also referred lo as tile "usage domain. " This i1lormation may l'ary widely based on the type of component. b!(ormation about hardwar e compon ents. such as their being install ed in a rotor cra/t or in an unpressuri zed location ofthe aircrafi structure, will be different than ifthe component is a software operating system. For hardware components. this description should be adequate to estimate the environmelllal qualification testing levels.for RTCA IDO-160F complianc e for the initial installation. Tllis section informs the FAA, as well as any potemial.future re-users ofthe accepted component, how the IMA component is being usedjor ils initial acceptance and what might need to be re­ examined during any future reuse. information may be at a high level, with more detailed i1?formation contained in the IMA Component Acceplance Leite r data sheet. lnformation Regarding Partitions (if any) and Assurance Levels within the IMA Component Describe all the various soft ware partiJiu11s (ifany) within the !MA compon ent. Identify the so.ftt-vare assurance level fo r each so.ftHw·e partition s. Justify at a high level why that assurance level is appropriat e. With hard ware compon ents.for which you are seeki ng acceptancefor compliance to RTCAIDO-254 , ident!/y u.nd describe each component along with the design assurance level (DAL) ofeach component and a justifi cation ofwhy this DAL is appropriate. If there are multipl e DALs 0 11 u single CEHISEH device, then addr ess each ofthose DALs. Include il!fonnalion regarding the separation ofthe multipl e DALs on a single device . This section informs the FAA. as well as any potential.future re-users ofthe accepted component, ofthe various assura nce levels (both hardwar e and soflll'are) wit/,;11 the £MA component and what might need to be re-examined during any f uture reuse. information may be at a high level, with more de/ailed informalion contained in the IMA Component Acceptance Letter data sheel. Statement of Full or Partial Complianc e to Industry Standards State for which indust, y standards RTCAIDO-1788.for airborn e software, RTCAIDO-254.for CEH, RTCA IDO- 160F for EQT) acceptan ce is being sought H•ith this IMA component. State whether you seek full or partial complian ce to these ~fandards. Your IMA Component Accepta nce Cover Letter does not need to explain. in detail. any partial compliance to Lhese sta ndards--inc/ud e that detailed informatio11 in t.he IMA cmnpon ent acceptance data sheet. The statement of/LIii or partial compliance in the IMA Component Acceprance Cover Lette r is on(v 8-2 ### Page 48 10/20/10 Appendix B an indicator to the FAA and any future re-user ofthis componenL that additional activity is needed to show full comp liance at the time ofinstallation approval ofthe IMA system. lfyou seek any compliance.for SEHfor the /MA component acceptance. this section should document that fact. Include the compliance data or refer e11ces to wher e the complianc e data may be found in the /MA compo nent acceptance data sheer. ffyou seek compliance to any other tec/,nical discipline, besides t/zose listed abov e with i/zis IMA compone nt acceptance . document it here. Include a high-level discussion ofthe requirements for which you seek compliance, and where rlze de/ailed requir ements are docum ented. Include more detailed i1?formation about the complian ce dala in the IMA Component Acceptance Letter dala shee t. Configuration Information of IMA component Include eno ugh if!formation to specf/y exactly the baseline configuration ofthe IMA component being accepted, including the development and verification environment. Include only a list of the documents names, numbers and revisio n levels. All other i,!(ormation concerning the configuration identification may be included in the IMA Component Acceptan ce Letter data sheet. This section makes clear the configuratfon ofthe IMA compo nent being accepted , Ifany oftlze docume111s identified in this secti on are revised, then write a new !MA component acceptance letter . Statement of compliance to the applicable requirement s Stare in the IMA Component Acceptance lette r that t/ze signatories al/est that the /MA component meets all the applicable requirements defined in th