. This technical standard order (TSO) is for manufacturers applying for a TSO
authorization (TSOA) or letter of TSO design approval (LODA). In it, we (the Federal Aviation
Administration, (FAA)) tell you what minimum performance standards (MPS) your FIS-B Data
Link Systems and Equipment must meet for approval and identification with the applicable TSO
marking.

This policy statement provides guidance to help applicants design fire detection,
suppression, and extinguishing systems in a manner that reduces the likelihood of
incorrectly connecting the system’s electrical wiring and plumbing components. This
policy provides design strategies to prevent misconnections from occurring and
impeding the function of these systems. The strategies in this guidance apply to the
approval of the electrical and plumbing connections for fire detection, suppression, and
extinguishing systems.

This order describes Federal Aviation Administration (FAA) policy
for carrying external loads on airplanes and is applicable to airplane external load operations
solely within the State of Alaska. This includes eligibility requirements for the airplane and the
operator, the steps for approving airplane external load operations under the provisions of
Title 14 of the Code of Federal Regulations (14 CFR) parts 21, 43, and 91, additional
requirements for operations conducted under 14 CFR part 135, as well as best practices for safe
airplane external load operations.

This advisory circular (AC) provides “best practices” for airborne electronic hardware
(AEH) design assurance and, is intended to be complementary information to
EUROCAE ED-80, Design Assurance Guidance for Airborne Electronic Hardware,
RTCA DO-254, Design Assurance Guidance for Airborne Electronic Hardware, and
AC 20-152A, Development Assurance for Airborne Electronic Hardware. This
document provides additional clarifications, explanatory text, or illustrations that could
be helpful when addressing some of the objectives of AC 20-152A. This document is
not intended to cover each section of AC 20-152A. The contents of this document do
not have the force and effect of law and are not meant to bind the public in any way.
This document is intended only to provide clarity to the public regarding existing
requirements under the law or agency policies.
Note: EUROCAE ED-80 is hereafter referred to as “ED”; RTCA DO-254 is hereafter
referred to as “DO.” Where the notation “ED-80/DO-254” appears in this document,
the referenced documents are recognized as being equivalent.

This advisory circular (AC) describes an acceptable means, but not the only means, for
showing compliance with the applicable airworthiness regulations for the electronic
hardware aspects of airborne systems and equipment for type certification or Technical
Standard Order (TSO) authorization. The contents of this document do not have the
force and effect of law and are not meant to bind the public in any way. This document
is intended only to provide clarity to the public regarding existing requirements under
the law or agency policies. However, if you use the means described in the AC, you
should follow it in all applicable respects unless alternate means or deviations are
proposed and accepted by the FAA.
This AC recognizes EUROCAE ED-80, Design Assurance Guidance for Airborne
Electronic Hardware, dated April 2000, and RTCA DO-254, Design Assurance
Guidance for Airborne Electronic Hardware, dated April 19, 2000.
This AC describes when to apply EUROCAE ED-80/RTCA DO-254, and it
supplements EUROCAE ED-80/RTCA DO-254 with additional guidance and
clarification for the development of custom devices, including the use of commercial
off-the-shelf (COTS) intellectual property (IP), for the use of COTS devices, and for the
development of circuit board assemblies (CBA).
The additional guidance and clarification are provided in the form of objectives. The
applicant is expected to describe the process and activities to satisfy the objectives of
this AC.
Note: EUROCAE ED-80 is hereafter referred to as “ED”; RTCA DO-254 is hereafter
referred to as “DO.” Where the notation “ED-80/DO-254” appears in this document,
the referenced documents are recognized as being equivalent.
This AC does not address the Single Event Effects (SEE) aspects or the assessment of
the hardware susceptibility to SEE. However, the Plan for Hardware Aspects of
Certification may still be used to document the certification considerations for Single
Event Effects.