High-Intensity Radiated Fields (HIRF) Protection for Aircraft Electrical and Electronic Systems, 44016-44028 [E7-15195]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 72, Number 150 (Monday, August 6, 2007)]
[Rules and Regulations]
[Pages 44016-44028]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-15195]



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Part V





Department of Transportation





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Federal Aviation Administration



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14 CFR Parts 23, 25, 27 and 29



 High-Intensity Radiated Fields (HIRF) Protection for Aircraft 
Electrical and Electronic Systems; Final Rule

Federal Register / Vol. 72, No. 150 / Monday, August 6, 2007 / Rules 
and Regulations

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 23, 25, 27, and 29

[Docket No. FAA-2006-23657; Amendment Nos. 23-57, 25-122, 27-42, and 
29-49]
RIN 2120-AI06


High-Intensity Radiated Fields (HIRF) Protection for Aircraft 
Electrical and Electronic Systems

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: This final rule amends FAA regulations by adding airworthiness 
certification standards to protect aircraft electrical and electronic 
systems from high-intensity radiated fields (HIRF). This action is 
necessary due to the vulnerability of aircraft electrical and 
electronic systems and the increasing use of high-power radio frequency 
transmitters. This action is intended to create a safer operating 
environment for civil aviation by protecting aircraft and their systems 
from the adverse effects of HIRF.

DATES: These amendments become effective September 5, 2007.

FOR FURTHER INFORMATION CONTACT: Richard E. Jennings, Aircraft 
Certification Service, Aircraft Engineering Division, AIR-130, Federal 
Aviation Administration, 470 L'Enfant Plaza, Suite 4102, Washington, DC 
20024; telephone (202) 385-4562; e-mail Richard.Jennings@faa.gov.

SUPPLEMENTARY INFORMATION: 

Availability of Rulemaking Documents

    You can get an electronic copy of this final rule using the 
Internet by:
    (1) Searching the Department of Transportation's electronic Docket 
Management System (DMS) Web page (https://dms.dot.gov/search);
    (2) Visiting the FAA's Regulations and Policies Web page at https://
www.faa.gov/regulations_policies/; or
    (3) Accessing the Government Printing Office's Web page at https://
www.gpoaccess.gov/fr/.
    You can also get a copy by sending a request to the Federal 
Aviation Administration, Office of Rulemaking, ARM-1, 800 Independence 
Avenue SW., Washington, DC 20591, or by calling (202) 267-9680. Make 
sure to identify the amendment number or docket number of this 
rulemaking.

Small Business Regulatory Enforcement Fairness Act

    The Small Business Regulatory Enforcement Fairness Act (SBREFA) of 
1996 requires the FAA to comply with small entity requests for 
information or advice about compliance with statutes and regulations 
within its jurisdiction. If you are a small entity and you have a 
question regarding this document, you may contact a local FAA official 
or the person listed under FOR FURTHER INFORMATION CONTACT. You can 
find out more about SBREFA on the Internet at https://www.faa.gov/
regulations_policies/rulemaking/sbre_act/.

Authority for This Rulemaking

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. Subtitle I, Section 106 
describes the authority of the FAA Administrator. Subtitle VII, 
Aviation Programs, describes in more detail the scope of the agency's 
authority. This rulemaking is promulgated under the authority described 
in Subtitle VII, Part A, Subpart III, Section 44701(a)(1). Under that 
section, the FAA is charged with prescribing regulations to promote 
safe flight of civil aircraft in air commerce by prescribing minimum 
standards in the interest of safety for appliances and for the design, 
material, construction, quality of work, and performance of aircraft, 
aircraft engines, and propellers. By prescribing standards to protect 
aircraft electrical and electronic systems from high-intensity radiated 
fields, this regulation is within the scope of the Administrator's 
authority.

I. Background

    The electromagnetic HIRF environment results from the transmission 
of electromagnetic energy from radar, radio, television, and other 
ground-based, shipborne, or airborne radio frequency (RF) transmitters. 
This environment has the capability of adversely affecting the 
operation of aircraft electrical and electronic systems.
    Although the HIRF environment did not pose a significant threat to 
earlier generations of aircraft, in the late 1970s designs for civil 
aircraft were first proposed that included flight-critical electronic 
controls, electronic displays, and electronic engine controls, such as 
those used in military aircraft. These systems are more susceptible to 
the adverse effects of operation in the HIRF environment. Accidents and 
incidents involving civil aircraft with flight-critical electrical and 
electronic systems have also brought attention to the need to protect 
these critical systems from high-intensity radiated fields.
    Further, the need to protect these systems in aircraft has 
increased substantially in recent years because of--
    (1) A greater dependence on electrical and electronic systems 
performing functions required for the continued safe flight and landing 
of aircraft;
    (2) The reduced electromagnetic shielding afforded by some 
composite materials used in aircraft designs;
    (3) The increase in susceptibility of electrical and electronic 
systems to HIRF because of increased data bus or processor operating 
speeds, higher density integrated circuits and cards, and greater 
sensitivities of electronic equipment;
    (4) Expanded frequency usage, especially above 1 gigahertz (GHz);
    (5) The increased severity of the HIRF environment due to an 
increase in the number and power of RF transmitters; and
    (6) The adverse effects experienced by some aircraft when exposed 
to HIRF.
    Recognizing the need to address the vulnerability of aircraft 
electrical and electronic systems to HIRF, the FAA published a notice 
of proposed rulemaking (NPRM) on February 1, 2006 (71 FR 5553). The 
NPRM includes a description of the HIRF-related incidents that provided 
some of the impetus for this rulemaking. It also includes a description 
of the collaborative efforts the FAA undertook in developing these rule 
changes. We encourage interested readers to refer to the NPRM for 
additional information.
    The comment period for the NPRM closed on May 2, 2006. We received 
thirty comments from twelve commenters. The commenters include two 
aviation industry associations, two avionics equipment manufacturers, 
one engine manufacturer, two airplane manufacturers and five individual 
commenters.

II. Discussion of the Rule

    This final rule amends the airworthiness standards for normal, 
utility, acrobatic, and commuter category airplanes certificated under 
part 23; transport category airplanes certificated under part 25; 
normal category rotorcraft certificated under part 27; and transport 
category rotorcraft certificated under part 29. Under the rule, 
applicants for certification of aircraft under these parts are required 
to demonstrate that any electrical and electronic system that performs 
a function whose failure would prevent the continued safe flight and 
landing of the aircraft must be designed and installed so that--
    (1) Each function is not adversely affected during and after the 
time the aircraft is exposed to a specifically

[[Page 44017]]

designated HIRF environment (HIRF environment I);
    (2) Each electrical and electronic system automatically recovers 
normal operation of that function, in a timely manner, after the 
aircraft is exposed to HIRF environment I, unless this conflicts with 
other operational or functional requirements of that system; and
    (3) Each electrical and electronic system is not adversely affected 
during and after the aircraft is exposed to a less severe, but more 
commonly encountered HIRF environment (HIRF environment II).
    HIRF environment I sets forth test and analysis levels that are 
used to demonstrate that an aircraft and its systems meet basic HIRF 
certification requirements. HIRF environment I represents the range of 
electromagnetic field strengths that an aircraft could encounter during 
its operational life. HIRF environment II is an estimate of the 
electromagnetic field strengths more likely to be encountered in the 
airspace above an airport or heliport at which routine departure and 
arrival operations take place.
    The rule also contains specific provisions for rotorcraft that 
differ from those applicable to airplanes. The rule requires rotorcraft 
to meet additional HIRF certification standards because rotorcraft 
operating under visual flight rules (VFR) do not have to comply with 
the same minimum safe altitude restrictions for airplanes specified in 
Sec.  91.119 and, therefore, may operate closer to RF transmitters. 
Accordingly, any electrical and electronic system that performs a 
function required during operation under VFR and whose failure would 
prevent the continued safe flight and landing of the rotorcraft must be 
designed and installed so that the function is not adversely affected 
during and after the time the rotorcraft is exposed to a specified HIRF 
environment unique to rotorcraft (HIRF environment III).
    HIRF environment III presents worst-case estimates of the 
electromagnetic field strength in the airspace in which VFR rotorcraft 
operations are permitted. Rotorcraft operating under instrument flight 
rules (IFR), however, normally have to comply with more restrictive 
altitude limitations and, therefore, electrical and electronic systems 
with functions required for IFR operations must not be adversely 
affected when the rotorcraft is exposed to HIRF environments I and II.
    This final rule also establishes equipment HIRF test levels for 
electrical and electronic systems. It requires each electrical and 
electronic system that performs a function whose failure would 
significantly reduce the capability of the aircraft or the ability of 
the flightcrew to respond to an adverse operating condition to be 
designed and installed such that it is not affected adversely when the 
equipment providing the function is exposed to equipment HIRF test 
level 1 or 2. HIRF test level 1 allows an applicant to use an industry 
standard test method for compliance. HIRF test level 2 allows an 
applicant to use equipment test levels developed for the specific 
aircraft being certificated. Either of these test levels may be used to 
demonstrate HIRF protection.
    Additionally, the final rule requires each electrical and 
electronic system that performs a function whose failure would reduce 
(but not significantly) the capability of the aircraft or the ability 
of the flightcrew to respond to an adverse operating condition to be 
designed and installed such that it is not affected adversely when the 
equipment providing these functions is exposed to equipment HIRF test 
level 3. HIRF test level 3, like HIRF test level 1, allows an applicant 
to use an industry standard test method for compliance that is not as 
rigorous as that specified by HIRF test levels 1 or 2. HIRF 
environments I, II, and III, and equipment HIRF test levels 1, 2, and 3 
are found in the appendices to the parts revised by this rule.
    The rule also includes provisions that provide relief from the new 
testing requirements for equipment previously certificated under HIRF 
special conditions issued in accordance with Sec.  21.16. These 
provisions permit the installation of an electrical or electronic 
system that performs a function whose failure would prevent the 
continued safe flight and landing of the aircraft, if an applicant can 
show that the system continues to comply with previously issued HIRF 
special conditions. This relief, however, will only be available for a 
five-year period and will only apply to equipment certificated under 
HIRF special conditions issued before December 1, 2007. To obtain this 
relief an applicant must be able to--
    (1) Provide evidence that the system was the subject of HIRF 
special conditions issued before December 1, 2007;
    (2) Show that there have been no system design changes that would 
invalidate the HIRF immunity characteristics originally demonstrated 
under the previously issued HIRF special conditions; and
    (3) Provide the data used to demonstrate compliance with the HIRF 
special conditions under which the system was previously approved.

Reference Material

    For further information on the development of the HIRF 
environments, consult the Naval Air Warfare Center Aircraft Division 
(NAWCAD) Technical Memorandum, Report No. NAWCADPAX-98-156-TM, High-
intensity Radiated Field External Environments for Civil Aircraft 
Operating in the United States of America (Unclassified), dated 
November 12, 1998. A copy of the NAWCAD Technical Memorandum is 
available in the docket for this final rule.

Related Activity

    When we published the HIRF NPRM on February 1, 2006, we also 
announced the availability of a draft Advisory Circular (describing a 
method for applicants to comply with the proposed HIRF standards (71 FR 
5570). We have revised the draft AC based on the comments we received. 
You can get copies of the final AC 20-158, ``The Certification of 
Aircraft Electrical and Electronic Systems for Operation in the High 
Intensity Radiated Fields (HIRF) Environment'', from the FAA's 
Regulatory and Guidance Library (RGL) at the Web site: https://
www.airweb.faa.gov/rgl. On the RGL Web site, click on ``Advisory 
Circulars.''

A. Revision of Proposed HIRF Test Levels

1. Deletion of Proposed HIRF Test Level 1
    In the NPRM, we proposed to include four specific equipment HIRF 
test levels for electrical and electronic systems. Each electrical and 
electronic system that performs a function whose failure would 
significantly reduce the capability of the aircraft or the ability of 
the flightcrew to respond to an adverse operating condition was 
required to be designed and installed so the system is not adversely 
affected when the equipment providing those functions is exposed to 
equipment HIRF test levels 1, 2, or 3. Additionally, we proposed that 
equipment be exposed to HIRF test level 4 for those functions that 
would cause any reduction in the capability of the aircraft or the 
ability of the flightcrew to respond to an adverse operating condition.
    RTCA, Inc. Special Committee 135, which develops HIRF test 
procedures for aircraft equipment, recommended deleting one of the 
proposed equipment HIRF test levels included in the appendices to the 
proposed regulations. Comments from Boeing, GAMA, and an individual 
commenter also supported this change.

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    The commenters noted that proposed Sec.  23.1308(b) would require 
each electrical and electronic system that performs a function whose 
failure would significantly reduce the capability of the airplane or 
the ability of the flightcrew to respond to an adverse operating 
condition to be designed and installed so the system is not adversely 
affected when the equipment providing the function is exposed to 
equipment HIRF test level 1, 2, or 3. Proposed Sec. Sec.  25.1317(b), 
27.1317(b), and 29.1317(b) also contained corresponding provisions.
    The commenters noted that the amplitudes and modulations defined in 
equipment HIRF test levels 1 and 2 were similar, but not identical. 
HIRF test level 1 specified the use of a pulse modulated waveform with 
150 volts per meter (V/m) amplitude and 0.1 percent duty cycle, along 
with a square wave modulated waveform with 28 V/m amplitude and 50 
percent duty cycle, for frequencies from 400 megahertz (MHz) to 8GHz. 
Test level 2 used a pulse modulated waveform 150 V/m amplitude and 4 
percent duty cycle, but no square wave modulated waveform in the same 
frequency range. The commenters also noted that compliance with 
proposed Sec.  23.1308(b) and corresponding provisions would be more 
consistent if only one of the two definitions of test amplitude and 
modulation were included in the regulations. RTCA, Inc. Special 
Committee 135 also noted that eliminating one equipment test level 
would help standardize equipment tests and minimize confusion in 
selecting the appropriate equipment test level. Both RTCA and an 
individual commenter recommend that this single test level conform to 
the proposed requirements in equipment HIRF test level 2.
    The FAA agrees with these comments and has eliminated proposed 
equipment HIRF test level 1 from the appendices to parts 23, 25, 27, 
and 29. We have renumbered the remaining test levels accordingly in the 
final rule. Equipment HIRF test levels 2, 3, and 4 in the proposed rule 
have therefore become test levels 1, 2, and 3, respectively, in the 
final rule. We have also revised Sec. Sec.  23.1308(b), 25.1317(b), 
27.1317(b), and 29.1317(b) to refer to equipment HIRF test levels 1 and 
2. Additionally, we have revised Sec. Sec.  23.1308(c), 25.1317(c), 
27.1317(c), and 29.1317(c) to refer to equipment HIRF test level 3. 
Equipment HIRF test levels are specified in paragraphs (c), (d), and 
(e) of Appendix J to Part 23; paragraphs (c), (d), and (e) of Appendix 
L to Part 25; paragraphs (d), (e), and (f) of Appendix D to Part 27; 
and paragraphs (d), (e), and (f) of Appendix E to Part 29.
2. Revision of Conducted Current Susceptibility Test Requirements
    RTCA, Inc. Special Committee 135 also recommended changes to the 
conducted current susceptibility test requirements in proposed 
equipment HIRF test levels 1, 2, and 4. These equipment HIRF test 
requirements define the amplitude and modulation of radio frequency 
current that equipment and its wiring must be exposed to in a 
laboratory to demonstrate that equipment is immune to HIRF.
    RTCA, Inc. Special Committee 135 stated that it has worked with the 
Aviation Rulemaking Advisory Committee (ARAC) Electromagnetic Effects 
Harmonization Working Group (EEHWG) to define equipment HIRF test 
requirements. The Special Committee stated that the changes it proposes 
would modify conducted radio frequency current amplitude to make the 
conducted radio frequency current decrease linearly with frequency so 
that the radio frequency current at 400 MHz would be one tenth the 
current at 30 MHz. The Special Committee asserted that this change 
would make the test levels more consistent with values measured on 
aircraft. HIRF tests on aircraft show that the conducted radio 
frequency current decreases above a certain frequency, and that this 
frequency depends on the size of the aircraft.
    The FAA generally agrees with RTCA's comment, however, data used to 
develop the HIRF AC shows the current decreases logarithmically with 
frequency. Therefore, the FAA has changed the conducted current 
amplitude in proposed equipment HIRF test levels 2 and 4 (test levels 1 
and 3 in the final rule) so that the conducted current decreases at 20 
decibel (dB) per frequency decade starting at 40 MHz and continuing to 
400 MHz. This change results in a current at 400 MHz that is one tenth 
the current at 40 MHz and simplifies the procedures necessary to show 
compliance with equipment HIRF test levels. Since the FAA is not 
adopting proposed HIRF test level 1 (as discussed earlier in this 
preamble), no additional changes have been made to the final rule in 
response to this comment.

B. Effect of the Rule on Systems That Have Demonstrated Compliance With 
Previously Issued HIRF Special Conditions

    In the NPRM, the FAA proposed that the HIRF certification 
requirements would apply to all electrical and electronic systems 
designed and installed in an aircraft for which the new rules 
constitute part of its certification basis. In their comments, the 
General Aviation Manufacturers Association (GAMA) and Rockwell Collins 
expressed general support for the rule yet stated that a number of 
systems have been installed on aircraft that have demonstrated 
compliance with HIRF special conditions issued pursuant to Sec.  21.16. 
The commenters assert that when application is made for certification 
of equipment in an aircraft and that same equipment has already been 
found to be in compliance with HIRF special conditions issued for 
another aircraft, the test requirements set forth in the proposal would 
impose significant costs with little additional safety benefit. Another 
commenter, Meggitt/S-TEC, expressed similar concerns.
    The commenters recommend that systems previously installed on an 
aircraft should be considered compliant with the HIRF protection 
requirements of the rule if those systems have been found to meet 
existing HIRF special conditions when installed on another aircraft.
    The FAA agrees that there are a number of systems installed under 
HIRF special conditions that have a proven service history and that 
compliance with the rule, as originally proposed, would require 
additional testing and costs. In an effort to address this concern, the 
FAA has revised the rule to permit the installation of an electrical or 
electronic system that performs a function whose failure would prevent 
the continued safe flight and landing of the aircraft, if it can be 
shown that the system to be installed continues to comply with HIRF 
special conditions issued before December 1, 2007. This relief is 
contained in paragraph (d) of each section of the rule and is limited 
to a five-year period.
    To utilize this relief from the general requirements of the rule, 
an applicant must: (1) Provide evidence that the system was the subject 
of previously issued HIRF special conditions; (2) show that there have 
been no system design changes that would invalidate the HIRF immunity 
characteristics originally demonstrated under the previously issued 
HIRF special conditions; and (3) provide the data used to demonstrate 
compliance with the HIRF special conditions under which the system was 
previously approved.
    Upon issuance of this rule, the FAA does not foresee the need to 
issue special conditions, like those previously issued for HIRF, to 
include special

[[Page 44019]]

conditions permitting equipment evaluations in a laboratory environment 
using test levels of 100 V/m (200 V/m for VFR rotorcraft). Therefore, 
if an installation cannot meet the requirements of paragraph (d), the 
installation will need to comply with the HIRF certification 
requirements specified in paragraph (a).
    Paragraph (d)(1) requires an applicant to provide objective 
evidence that the system was the subject of HIRF special conditions 
that were issued before December 1, 2007. In meeting subparagraph 
(d)(1), it is not essential that the HIRF special conditions be issued 
for the same make and model of aircraft, but only that they were used 
as the basis for showing HIRF compliance for the electrical or 
electronic system intended for the specific installation. After the 
rule becomes effective, the FAA generally will no longer use special 
conditions as a means for an applicant to show protection from the HIRF 
environment for new equipment installation certifications. The date 
specified in paragraph (d)(1), however, provides a sufficient time 
period beyond the effective date of the rule to allow applicants to use 
HIRF special conditions that are currently being developed as part of a 
new installation's certification basis to be processed and issued.
    Paragraph (d)(2) requires the applicant to show that there have 
been no system design changes that would invalidate the HIRF immunity 
characteristics originally demonstrated under previously issued HIRF 
special conditions. If a change has been made to the system, and the 
change cannot be substantiated through analysis as having no impact on 
the previously demonstrated HIRF immunity characteristics, the system 
must comply with the general requirements of the rule as specified in 
paragraph (a) of each section.
    Paragraph (d)(3) requires the applicant to provide the data used to 
demonstrate compliance with HIRF special conditions. The term ``data'' 
includes, but is not limited to, items such as the HIRF certification/
qualification test report used to demonstrate compliance; installation 
instructions, as appropriate, to support HIRF immunity of the system; 
and instructions for continued airworthiness (ICA) to maintain the 
integrity of the system's demonstrated HIRF immunity. To assist 
prospective applicants, Appendix 2 of AC 20-158 provides guidance on 
one means, but not the only means, of complying with these provisions.
    Although these revisions will affect aircraft intended for 
certification under parts 23, 25, 27 and 29, the FAA believes that the 
changes will primarily afford relief to persons installing equipment in 
aircraft intended for certification under part 23. The FAA estimates 
that as many as 30-35% of the applicants that apply for installation of 
a Level A system in aircraft certificated under part 23 will be seeking 
approval of equipment that has been shown to comply with previously 
issued HIRF special conditions (a Level A system is a system that 
performs a function whose failure would prevent the continued safe 
flight and landing of an aircraft, such as a flight display system 
certificated for IFR operations or a full authority digital engine 
control (FADEC) system). Such systems have been shown to meet 
appropriate certification standards and, based on comments received, 
the FAA believes that the burden associated with re-testing this 
equipment to the new certification standards is not justified by a 
corresponding benefit.
    In determining the extent of the relief that could be provided, the 
FAA sought clarification of GAMA's earlier comment. GAMA noted that if 
the FAA were to accept its comment to consider equipment previously 
certified under HIRF special conditions as compliant with the proposed 
HIRF requirements, it may not be feasible for the FAA to make such a 
provision open-ended. GAMA stated that if the FAA were to establish a 
specific time period during which such equipment would be considered 
compliant, that determination should give full consideration to the 
technological life of the product. The FAA concurs with this 
recommendation. We have therefore provided applicants with a five-year 
period during which equipment shown to comply with previously issued 
HIRF special conditions will be considered to meet the requirements of 
this rule. This decision was based on a number of factors.
    Due to the dynamic and highly competitive nature of the current 
avionics industry, new avionics models are being rapidly introduced 
into the marketplace in response to public demand. As special 
conditions for HIRF generally will no longer be issued after the 
effective date of the rule, it will become increasingly difficult to 
find new equipment in compliance with previously issued HIRF special 
conditions. Equipment manufacturers will therefore not be able to take 
advantage of the provisions of new paragraph (d), and the equipment 
will have to meet the general requirements of the rule. The FAA also 
believes that major design changes will, in most cases, necessitate 
retesting of previously approved equipment in accordance with the 
general provisions of the rule, again significantly decreasing the 
number of systems that will be able to use the provisions of paragraph 
(d) within a short period of time.
    Additionally, avionics manufacturers now compete in a global 
marketplace. Many foreign civil aviation authorities are adopting 
airworthiness standards similar to those found in paragraphs (a), (b), 
and (c) of each section added by the rule, but are not adopting 
airworthiness standards which contain provisions similar to those 
contained in paragraph (d) of those sections. Manufacturers intending 
to market their equipment for installation on aircraft registered in 
countries other than the United States will therefore need to ensure 
compliance with the general provisions of the rule to export their 
products.
    Technological advances and the necessity for manufacturers to 
comply with standards established by foreign aviation authorities to 
globally market their products will require that newer systems comply 
with the general test standards established by the final rule. The FAA 
therefore believes that the relief permitted by the revision, while of 
immediate benefit to manufactures, will neither be practical nor 
warranted within five years after the effective date of the rule, and 
has limited the relief to that period accordingly.

C. Applicability of HIRF Requirements

1. Applicability of HIRF Requirements to Aircraft Certificated Under 
Part 23
    Thielert Aircraft engines commented on the HIRF Risk Analysis 
report used in the regulatory evaluation (DOT/FAA/AR-99/50). This risk 
analysis forms the basis of the benefits analysis in the FAA's 
regulatory evaluation. According to Thielert, a comparison of estimated 
HIRF risks for transport category airplanes (table 9 of the report) 
with estimated HIRF risks for non-transport category aircraft, 
including Part 23 small airplanes (table 10 of the report), shows that 
HIRF risks are higher for transport category airplanes. Thielert 
therefore believes the proposed HIRF protection requirements for small 
airplanes should not be the same as those proposed for transport 
category airplanes. Additionally, Thielert believes that table 10 of 
the report indicates the proposal provides a decreased level of safety 
for airplanes certificated under Part 23.
    The FAA does not agree with Thielert's contentions. The HIRF Risk 
Analysis report shows that the HIRF

[[Page 44020]]

requirements provide a substantial HIRF risk reduction for both 
transport category airplanes and non-transport category aircraft, 
including small airplanes certificated under Part 23, even when 
compared to existing HIRF special conditions (page 13 of the report).
    The FAA agrees, however, that both tables 9 and 10 of the report 
could be misconstrued. With regard to the data used to evaluate the 
HIRF risk to transport category airplanes, a crucial component 
affecting the risk analysis is the aircraft's position with respect to 
an emitter's location. HIRF protection requirements are predicated on 
various minimum (i.e., safe) distances between aircraft and emitters. 
Inconsistencies in the values for transport category aircraft in table 
9 noted by Thielert can be attributed to inaccuracies in recording 
aircraft position data due to the normal variability inherent in radar 
tracking. When the minimum distance assumptions on which the rule is 
based are taken into account, only a few flights in the analysis were 
exposed to field strengths that exceeded the rule's certification 
levels. As these discrepancies are likely the result of the normal 
variability inherent in determining an aircraft's position using radar, 
there was no evidence that HIRF certification levels were exceeded for 
flights involving transport category aircraft (in the Denver and 
Seattle study areas).
    The same positional inaccuracies are also the probable cause of the 
inconsistent results in table 10 of the analysis that were noted by the 
commenter. To account for this possible error, the FAA's benefits 
analysis was conducted using data from table 11 of the report to obtain 
the number of flights that exceeded the various protection (or 
comparison) levels. Similar to the results of the analysis for 
transport category aircraft, the risk analysis for part 23 aircraft 
shows that the HIRF requirements provide a substantial risk reduction 
compared to existing HIRF special conditions. The FAA's risk-avoidance 
analysis for part 23 airplanes does, however, differ from that for part 
25 airplanes in that it combines information from an actual HIRF 
incident with the theoretical analysis of the Risk Analysis study. That 
incident was the basis of the finding in the benefits analysis of 
greater risk for part 23 airplanes.
    The report also includes a detailed discussion of how to interpret 
the information presented in tables 9 and 10. It clearly states that 
the proposed HIRF requirements reduce the risk of HIRF-related 
accidents by a factor of 3.5 compared to the existing HIRF special 
conditions for non-transport category airplanes, which include small 
airplanes certificated under Part 23 (page 16). Thus, the report 
supports the benefits of the rule for non-transport category aircraft, 
which includes small airplanes certificated under Part 23.
2. Applicability of the Requirements to Airplane-Level Functions
    Boeing Commercial Airplanes requested a change to proposed Sec.  
25.1317(a)(1). The proposed section stated ``Each electrical and 
electronic system that performs a function whose failure would prevent 
the continued safe flight and landing of the airplane must be designed 
and installed so that the function is not adversely affected during and 
after the time the airplane is exposed to HIRF environment I . * * *'' 
(Emphasis added). In the commenter's view, the phrase ``the function'' 
should be changed to ``the airplane-level function'' since only top-
level functions may be observable in multi-system integrated avionics 
configurations where several systems can contribute to correct 
operation of an airplane-level function.
    The FAA disagrees with the comment. The wording of proposed Sec.  
25.1317(a)(1) is consistent with the wording of existing Sec.  25.1316, 
which governs system lightning protection. The FAA has taken a similar 
approach in addressing protection from lightning and HIRF as both 
constitute external environmental hazards to an aircraft. A failure of 
a system as a result of lightning or HIRF would have an identical 
effect on the operation of the aircraft, and the FAA believes that 
their failure effects should therefore be treated similarly. For this 
reason, we did not make the requested change to the final rule.
3. Limiting Sec.  25.1317(a)(2) and Corresponding Requirements to 
Functions, Rather Than Systems Whose Failure Would Prevent Safe Flight 
and Landing of the Aircraft
    Boeing Commercial Airplanes requested clarification of proposed 
Sec.  25.1317(a)(2) which states ``Each electrical and electronic 
system that performs a function whose failure would prevent the 
continued safe flight and landing of the airplane must be designed and 
installed so that the system automatically recovers normal operation, 
in a timely manner, after the airplane is exposed to HIRF environment I 
* * *.'' (Emphasis added). The commenter requested clarification that 
the expectation of automatic recovery of an electrical or electronic 
system is limited to functions whose failure would prevent safe flight 
and landing. Other functions may not be required to return to ``normal 
operation,'' which is interpreted to mean the ability to perform 
functions to the extent necessary to continue safe flight and landing, 
not necessarily full functional performance and redundancy.
    The FAA agrees with Boeing. The requested change clarifies the 
rule's intent that an automatic recovery of an electrical or electronic 
system be limited to those functions whose failure would prevent safe 
flight and landing. We have therefore changed the wording of final 
Sec.  25.1317(a)(2) to state that ``The system automatically recovers 
normal operations of that function, in a timely manner. * * *'' 
(Emphasis added). We have also made corresponding changes to final 
Sec. Sec.  23.1308(a)(2), 27.1317(a)(2), and 29.1317(a)(2).
4. Expanding the Scope of the HIRF Protection Requirements to Equipment 
Whose Failure Does Not Have Safety Consequences
    An individual commenter recommended that equipment required by FAA 
certification or operating regulations should be subject to this 
rulemaking even though failure of that equipment would not have safety 
consequences.
    The FAA does not agree with the commenter. The FAA's general 
approach to system safety is to define requirements based on the hazard 
consequences of system failures. This rulemaking follows the FAA's 
longstanding system safety approach to aircraft design and defines 
requirements based on their impact on overall aircraft safety. For 
example, this approach is followed in 14 CFR 25.1309, which provides 
general aircraft equipment, systems, and installation safety 
requirements. The EEHWG, which developed the recommendations upon which 
the NPRM is based, specifically recommended that the rule apply only to 
systems with failure classifications that are major, hazardous, or 
catastrophic. The FAA notes that this final rule does not preclude any 
aircraft or avionics manufacturer or supplier from testing equipment 
not subject to the rule for susceptibility to HIRF effects using the 
standards contained in the rule.

D. Continued Airworthiness Requirements

    One individual commenter expressed general support for the NPRM, 
but was concerned that the cost of maintaining aircraft airworthiness 
after aircraft

[[Page 44021]]

delivery should be considered in the regulatory evaluation for the 
rulemaking.
    The FAA agrees with the commenter. The regulatory evaluation 
includes costs for both designing and installing HIRF protection, as 
well as costs for maintaining this protection over the service life of 
the aircraft. The EEHWG collected this cost data from aircraft and 
avionics manufacturers and provided this information to the FAA for 
inclusion in the regulatory evaluation. We believe the commenter's 
concerns have been addressed in the rulemaking process.

E. Concerns Regarding the Ability of the HIRF Certification Standards 
To Afford Adequate Protection of Aircraft

    An individual commenter expressed general support for the proposal, 
but had a concern about ``a flight that went down off Long Island a few 
years back.'' The commenter questioned whether the proposed standards 
will sufficiently protect aircraft. Two commenters urged the FAA to 
include standards in this final rule to protect aircraft from an 
electromagnetic pulse (EMP) generated by a nuclear weapon or some other 
EMP-based disabling device.
    We believe the first commenter is referring to the crash of TWA 
Flight 800, which broke up in flight off Long Island, New York on July 
17, 1996. The investigation of the accident was conducted by the 
National Transportation Safety Board (NTSB). The NTSB in its Aircraft 
Accident Report (NTSB/AAR-00/03) did not find that the probable cause 
of the accident was related to HIRF effects. As discussed in the 
notice, the FAA has worked extensively with aircraft and equipment 
manufacturers, foreign civil aviation authorities and engineers who 
have an extensive knowledge of the HIRF environment in its efforts to 
develop the protection regulations for the HIRF environment found in 
this rule. This rule is based to a significant degree upon their 
detailed recommendations and for these reasons, the FAA believes that 
the commenter's concern is not warranted.
    In response to concerns regarding EMP protection, the FAA notes 
that the EEHWG participants who assisted the agency in developing the 
HIRF NPRM were familiar with issues related to EMP. The aircraft 
protection requirements for lightning and HIRF provide some inherent 
protection from EMP. However, EMP generated from a nuclear or other 
device is not part of the normal HIRF environment. The FAA considers 
protection of aircraft from the hazards of EMP generated by such 
devices to be beyond the scope of this rulemaking effort.

F. Use of Similar HIRF Protection Requirements for Systems With Major 
and Hazardous Failure Conditions

    An individual commenter recommends that the HIRF requirements for 
systems with major failure conditions should meet the same equipment 
HIRF test levels as systems with hazardous failure conditions. The 
commenter believes that this is the general practice of most aircraft 
manufacturers and that such a requirement would provide additional 
protection against the effects of portable electronic devices (PEDs) 
that may transmit during flight. These PEDs include mobile phones and 
two-way pagers.
    The FAA agrees, in part, with the commenter. Radiated emissions 
from PEDs on aircraft are a growing concern, and FAA has requested 
RTCA, Inc., through Special Committee 202 to investigate PED emissions 
(both intentional and unintentional emitters) and their possible impact 
on required aircraft electronic systems. However, the hazards related 
to radiated fields generated by PEDs are not considered part of the 
external HIRF environment encountered by an aircraft, and consideration 
of their effects is therefore beyond the scope of this rulemaking. Such 
effects would have to be addressed by a separate rulemaking activity 
when Special Committee 202 completes its assigned task. In addition, 
the FAA has reviewed certification plans that indicate many 
manufacturers do not require systems with major failure conditions to 
meet the same equipment HIRF test levels as systems with hazardous 
failure conditions. Therefore, we have not made any changes to this 
final rule based on the comment.

G. Harmonization of HIRF Certification Standards

    Thielert Aircraft Engines commented that the European Aviation 
Safety Agency (EASA) classified the consequence of a failure of their 
reciprocating engine as major or hazardous, while the FAA has required 
HIRF tests that assume the engine failures are catastrophic. Thielert 
commented that this decision has not fulfilled the intent to harmonize 
HIRF standards because the FAA requires more expensive HIRF tests on 
Thielert's FADEC systems than EASA does. Thielert states that the FAA 
HIRF compliance requirements are more expensive to comply with because 
the engine and engine electronic controls must be tested when they are 
installed on an airplane rather than prior to any installation. Based 
on these concerns, Thielert proposed changes to Sec.  23.1308(a) that 
would eliminate the need for the more expensive airplane tests.
    The FAA does not agree with the changes proposed by Thielert. The 
HIRF regulations neither define the specific failure classification for 
particular aircraft systems nor establish requirements used to classify 
any particular system. The failure classification must be established 
by the certification applicant and agreed on by the FAA for the 
specific aircraft and system being certified. Once a specific failure 
classification has been established, the HIRF regulations set forth in 
the final rule only specify those requirements that must be met for 
that specific failure classification. In fact, EASA currently issues 
HIRF Certification Review Items (CRI) (equivalent to the FAA's special 
conditions) that use the same approach as that generally set forth in 
the rule. The example provided by Thielert is not a consequence of the 
proposed HIRF regulations, but rather a difference in classification of 
failure severity.
    Additionally, this final rule, with the exception of the provisions 
contained in paragraph (d) of each section, is consistent with current 
EASA practices. The FAA, however, does recognize that for an aircraft 
to be exported it may not be acceptable to a foreign authority if a 
system installed on the aircraft has been certificated in accordance 
with the provisions of paragraph (d) of each section of the final rule.

H. Addition of Explanatory Note to HIRF Environment Tables

    A note was added to each HIRF Environment table in the appendices 
to this rule. The note states that, ``In this table, the higher field 
strength applies at the frequency band edges.'' Although not included 
in the proposal, this note was included in the draft AC that was the 
subject of a Notice of Availability published in the Federal Register 
(71 FR 5570) on February 1, 2006 concurrent with the notice for this 
rule. During the public comment period of the draft AC, we received no 
comments with regard to this note. The note was added to standardize 
testing and to remove any ambiguity when applying field strength values 
at frequency band edges.

III. Regulatory Notices and Analyses

Paperwork Reduction Act

    The Paperwork Reduction Act of 1995 (44 U.S.C. 3507(d)) requires 
that the

[[Page 44022]]

FAA consider the impact of paperwork and other information collection 
burdens imposed on the public. An agency may not collect or sponsor the 
collection of information, nor may it impose an information collection 
requirement unless it displays a currently valid Office of Management 
and Budget (OMB) control number. We have determined that there are no 
new information collection requirements associated with this amendment.

International Compatibility

    In keeping with U.S. obligations under the Convention on 
International Civil Aviation, it is FAA policy to comply with 
International Civil Aviation Organization (ICAO) Standards and 
Recommended Practices to the maximum extent practicable. The FAA has 
determined that there are no ICAO Standards and Recommended Practices 
that correspond to these regulations.

Economic Evaluation, Regulatory Flexibility Determination, 
International Trade Impact Assessment, and Unfunded Mandates Assessment

    Changes to Federal regulations must undergo several economic 
analyses. First, Executive Order 12866 directs that each Federal agency 
shall propose or adopt a regulation only upon a reasoned determination 
that the benefits of the intended regulation justify its costs. Second, 
the Regulatory Flexibility Act of 1980 (Pub. L. 96-354) requires 
agencies to analyze the economic impact of regulatory changes on small 
entities. Third, the Trade Agreements Act (Pub. L. 96-39) prohibits 
agencies from setting standards that create unnecessary obstacles to 
the foreign commerce of the United States. In developing U.S. 
standards, this Trade Act requires agencies to consider international 
standards and, where appropriate, that they be the basis of U.S. 
standards. Fourth, the Unfunded Mandates Reform Act of 1995 (Pub. L. 
104-4) requires agencies to prepare a written assessment of the costs, 
benefits, and other effects of proposed or final rules that include a 
Federal mandate likely to result in the expenditure by State, local, or 
tribal governments, in the aggregate, or by the private sector, of $100 
million or more annually (adjusted for inflation with base year of 
1995). This portion of the preamble summarizes the FAA's analysis of 
the economic impacts of this final rule. We suggest readers seeking 
greater detail read the full regulatory evaluation, a copy of which we 
have placed in the docket for this rulemaking.
    In conducting these analyses, FAA has determined that this final 
rule: (1) Has benefits that justify its costs; (2) is not an 
economically ``significant regulatory action'' as defined in section 
3(f) of Executive Order 12866; (3) is not ``significant'' as defined in 
DOT's Regulatory Policies and Procedures; (4) will not have a 
significant economic impact on a substantial number of small entities; 
(5) will not create unnecessary obstacles to the foreign commerce of 
the United States; and (6) will not impose an unfunded mandate on 
state, local, or tribal governments, or on the private sector by 
exceeding the threshold identified above. These analyses are summarized 
below.
Who Is Affected by This Rulemaking
    Manufacturers of transport category airplanes will incur no 
incremental costs; manufacturers of transport category rotorcraft and 
non-transport category aircraft will incur varying costs.
    Occupants in, and operators of, affected aircraft receive safety 
benefits.
Assumptions and Standard Values
     Discount rate: 7%.
     Period of analysis: Costs are based on a 10-year 
production period and benefits are based on 25-year operating lives of 
newly-certificated aircraft.
     Value of statistical fatality avoided: $3 million.
     Benefits/costs are evaluated from two perspectives: (1) 
The `base case'--a comparison of the costs and benefits concomitant 
with current industry practice to those associated with meeting the 
rule's requirements, and (2) the `regulatory case'--a comparison of the 
costs and benefits of complying with current U.S. special conditions to 
those associated with meeting the rule. Current industry practice for 
manufacturers of all airplanes certificated under part 25, for 
manufacturers of the majority of aircraft certificated under parts 23 
and 29, and for manufacturers of a sizeable minority of part 27 
rotorcraft, is to comply with the European Aviation Safety Agency's 
(i.e., EASA's, as noted earlier in this preamble) HIRF interim policy, 
which, with the exception of the provisions of paragraph (d) of each 
section, is equivalent to the rule. On the other hand, manufacturers of 
the remaining aircraft (some aircraft certificated under parts 23 and 
29 and most rotorcraft certificated under part 27) currently 
manufacture their aircraft to meet U.S. special conditions, which are 
not as stringent as the provisions in this final rule. These affected 
aircraft manufacturers will experience additional costs under the rule.
     The rule is assumed to be nearly 100 percent effective in 
preventing HIRF-related accidents.
Alternatives Considered
    Although earlier and current special condition levels of HIRF 
protection were considered, EASA's HIRF interim policy (formerly Joint 
Aviation Authorities (JAA) policy) was selected for this rule because 
of both the proven high levels of protection demonstrated and the 
potential cost savings associated with adoption of substantially 
harmonized U.S. and European HIRF-requirements.
Costs and Benefits of the Rule
Costs

                      Estimated Present Value Costs
                    [$millions over a 10-year period]
------------------------------------------------------------------------
                                              Current         Special
                                           practice  to   conditions  to
                                               rule            rule
------------------------------------------------------------------------
Part 23 certificated airplanes..........           $21.8           $72.8
Part 25 certificated airplanes..........               0           308.1
Part 27 certificated rotorcraft.........             1.5             2.0
Part 29 certificated rotorcraft.........             5.3            26.6
                                         -------------------------------
    Total estimated costs...............            28.6           409.5
------------------------------------------------------------------------


[[Page 44023]]

    In the first column (or, the base case, which reflects actual costs 
to industry), there are no additional HIRF-protection costs for 
manufacturers of airplanes certificated under part 25 and for 
manufacturers of the majority of aircraft certificated under parts 23 
and 29, since most U.S. large manufacturers have produced these 
aircraft to comply with current EASA HIRF interim policy standards 
(generally equivalent to the requirements in this final rule) to market 
their aircraft in Europe. There are moderate incremental costs for 
manufacturers of the remaining portion of aircraft certificated under 
parts 23 and 29 and relatively lower costs for the majority of 
rotorcraft certificated under part 27 that do not currently meet EASA's 
HIRF interim policy standards either because (1) their aircraft do not 
yet have complex electronic systems installed or (2) they have chosen 
not to market their aircraft outside the United States. This ``current 
practice to rule'' is the base perspective in this analysis. The total 
estimated ten-year costs of $28.6 million (the sum of column one) 
represent the true incremental impact on the industry.
    However, most manufacturers of aircraft certificated under parts 
23, 25, 27, and 29 believe that U.S. special conditions afford 
sufficient protection from HIRF. Therefore, in the second column (or, 
the regulatory case, ``special conditions to rule''), the FAA shows the 
incremental compliance costs between the current U.S. special 
conditions (essentially equivalent to industry's self-determined 
protection) and the rule's more stringent requirements. These 
regulatory costs equal $409.5 million, and represent the costs for more 
robust HIRF protection that industry would not have voluntarily 
incurred.
Benefits
    Estimated benefits of this rule are the accidents, incidents, and 
fatalities avoided as a result of increased protection from HIRF-
effects provided to electrical and electronic systems. Quantified 
benefits are partly based on a study titled ``High-Intensity Radiated 
Fields (HIRF) Risk Analysis,'' by EMA Electro Magnetic Applications, 
Inc. of Denver, CO. (DOT/FAA/AR-99/50, July 1999). The complete study 
is available in the docket for this rulemaking. Using the study's risk 
analysis results for airplanes certificated under parts 23 and 25 and 
FAA accident/incident data for rotorcraft certificated under parts 27 
and 29, the FAA calculated the difference between the expected number 
of accidents under the new standards versus those expected under 
current U.S. special conditions.

                    Estimated Present Value Benefits
                    [$millions over a 34-year period]
------------------------------------------------------------------------
                                              Current         Special
                                           practice  to   conditions  to
                                               rule            rule
------------------------------------------------------------------------
Part 23 certificated airplanes..........           $37.1          $123.5
Part 25 certificated airplanes..........               0         3,683.9
Part 27 certificated rotorcraft.........            33.3            44.4
Part 29 certificated rotorcraft.........            17.7            88.6
                                         -------------------------------
    Total estimated benefits............            88.1         3,940.4
------------------------------------------------------------------------

    Following FAA's rationale as stated in the cost section earlier, 
column one (the base case) in the benefits table above shows 
incremental benefits of $88.1 million resulting from averted accidents 
in future compliant parts 23, 27, and 29 aircraft. Part 25 airplanes 
already meet similar EASA standards, hence no additional benefits 
attributable to part 25 airplanes accrue to society. Column two in the 
table presents the regulatory case; it shows the additional benefits 
associated with going from industry's self-determined protection 
standards (or current special conditions) to the new HIRF standards. 
Total regulatory incremental benefits equal $3,940.4 million and 
represent the value of avoiding the following numbers of accidents over 
the 34-year analysis period:
    (1) Part 23 airplanes, 24 accidents; (2) part 25 airplanes, 22 
accidents; (3) part 27 rotorcraft, 41 accidents, and (4) part 29 
rotorcraft, 14 accidents. The FAA believes that, based on the 
aforementioned risk assessment, the predicted accidents could occur 
absent the new HIRF standards in this rule if manufacturers of all 
airplanes certificated under part 25, manufacturers of the majority of 
aircraft certificated under parts 23 and 29, and manufacturers of a 
sizeable minority of part 27 rotorcraft, choose in the future not to 
market their aircraft abroad and therefore no longer meet EASA's 
enhanced HIRF requirements (but rather meet only current less stringent 
U.S. special conditions).
Comments to the Docket on Costs and Benefits
    Although there were no comments directly criticizing FAA's cost 
estimates, GAMA, Rockwell Collins, and Meggitt/S-TEC were concerned 
that companies which previously installed electrical systems in 
aircraft pursuant to HIRF special conditions could experience 
significant additional testing costs, with little additional safety 
benefit, if those systems required re-certification before installation 
on other aircraft. A comment from Thielert questioned the efficacy of 
the risk analysis, which is the basis of the benefits analysis in FAA's 
regulatory evaluation. Thielert believes the HIRF requirements for 
small airplanes certificated under part 23 should not be the same as 
those for transport category airplanes certificated under part 25. The 
FAA's detailed response to these comments is discussed earlier in this 
preamble and in the full regulatory evaluation (available in the docket 
to this rulemaking). Although the FAA has revised the final rule in 
response to the comments, the benefit and cost estimates remain the 
same.
Summary of Costs and Benefits (at Present Value)
    For a ten-year period, the incremental costs of meeting the new 
requirements versus current industry practice equal $28.6 million and 
the associated benefits are $88.1 million, for a benefit-to-cost ratio 
of 3.1 to 1. Alternatively, the incremental costs of meeting the new 
requirements versus current U.S. special conditions equal $409.5 
million and the benefits are $3,940.4 million, for a benefit-to-cost 
ratio of 9.6 to 1. From either perspective, this rule is clearly cost-
beneficial.

[[Page 44024]]

Regulatory Flexibility Determination

    The Regulatory Flexibility Act of 1980 (Pub. L. 96-354) (RFA) 
establishes ``as a principle of regulatory issuance that agencies shall 
endeavor, consistent with the objective of the rule and of applicable 
statutes, to fit regulatory and informational requirements to the scale 
of the businesses, organizations, and governmental jurisdictions 
subject to regulation. To achieve this principle, agencies are required 
to solicit and consider flexible regulatory proposals and to explain 
the rationale for their actions to assure that such proposals are given 
serious consideration.'' The RFA covers a wide range of small entities, 
including small businesses, not-for-profit organizations and small 
governmental jurisdictions.
    Agencies must perform a review to determine whether a rulemaking 
action will have a significant economic impact on a substantial number 
of small entities. If an agency determines that it will, the agency 
must prepare a regulatory flexibility analysis as described in the RFA. 
However, if an agency determines that a proposed or final rule is not 
expected to have a significant economic impact on a substantial number 
of small entities, section 605(b) of the RFA provides that the head of 
the agency may so certify and a regulatory flexibility analysis is not 
required. The certification must include a statement providing the 
factual basis for this determination, and the reasoning should be 
clear.
    The FAA believes that this final rule will not have a significant 
economic impact on a substantial number of small entities for the 
following reasons:
    As noted in the regulatory evaluation and preamble to the NPRM, 
this rule will affect manufacturers of aircraft intended for 
certification under parts 23, 25, 27, and 29. For manufacturers, the 
RFA considers a small entity to be one with 1,500 or fewer employees. 
None of the part 25 or part 29 manufacturers has 1,500 or fewer 
employees; consequently, none is considered a small entity. There are, 
however, currently about four part 27 (utility rotorcraft) and ten part 
23 (small non-transport category airplanes) manufacturers, who have 
fewer than 1,500 employees and are considered small entities.
    Based on a sampling of the affected small manufacturers of parts 23 
and 27 aircraft, the incremental costs are expected to represent 
significantly less than one percent of the typical small manufacturer's 
annual revenues; these compliance costs do not constitute a significant 
economic impact. There were no comments to the docket disputing this 
finding.
    Therefore, as the FAA Administrator, I certify that this rule will 
not have a significant economic impact on a substantial number of small 
entities.

International Trade Impact Assessment

    The Trade Agreements Act of 1979 prohibits Federal agencies from 
engaging in any standards or related activities that create unnecessary 
obstacles to the foreign commerce of the United States. Legitimate 
domestic objectives, such as safety, are not considered unnecessary 
obstacles. The statute also requires consideration of international 
standards and where appropriate, that they be the basis for U.S. 
standards. The FAA has assessed the potential effect of this final rule 
and determined that it is in accord with the Trade Agreements Act in 
that it uses European standards as the basis for United States 
regulation.

Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-
4) requires each Federal agency to prepare a written statement 
assessing the effects of any Federal mandate in a proposed or final 
agency rule that may result in an expenditure of $100 million or more 
(adjusted annually for inflation since the base year 1995) in any one 
year by State, local, and tribal governments, in the aggregate, or by 
the private sector; such a mandate is deemed to be a ``significant 
regulatory action.'' The FAA currently uses an inflation-adjusted value 
of $128.1 million in lieu of $100 million. This final rule does not 
contain such a mandate. The requirements of Title II do not apply.

Executive Order 13132, Federalism

    The FAA has analyzed this final rule under the principles and 
criteria of Executive Order 13132, Federalism. We determined that this 
action will not have a substantial direct effect on the States, or the 
relationship between the national Government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government, and therefore does not have federalism implications.

Environmental Analysis

    FAA Order 1050.1E identifies FAA actions that are categorically 
excluded from preparation of an environmental assessment or 
environmental impact statement under the National Environmental Policy 
Act in the absence of extraordinary circumstances. The FAA has 
determined this rulemaking action qualifies for the categorical 
exclusion identified in paragraph 308(c)(1) and involves no 
extraordinary circumstances.

Regulations That Significantly Affect Energy Supply, Distribution, or 
Use

    The FAA has analyzed this final rule under Executive Order 13211, 
Actions Concerning Regulations that Significantly Affect Energy Supply, 
Distribution, or Use (66 FR 28355, May 18, 2001). We have determined 
that it is not a ``significant energy action'' under the executive 
order because it is not a ``significant regulatory action'' under 
Executive Order 12866, and it is not likely to have a significant 
adverse effect on the supply, distribution, or use of energy.

List of Subjects

14 CFR Part 23

    Air transportation, Aircraft, Aviation safety, Certification, 
Safety.

14 CFR Part 25

    Air transportation, Aircraft, Aviation safety, Certification, 
Safety.

14 CFR Part 27

    Air transportation, Aircraft, Aviation safety, Certification, 
Rotorcraft, Safety.

14 CFR Part 29

    Air transportation Aircraft, Aviation safety Certification, 
Rotorcraft, Safety.

The Amendment

0
In consideration of the foregoing, the Federal Aviation Administration 
amends Chapter I of Title 14, Code of Federal Regulations as follows:

PART 23--AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND 
COMMUTER CATEGORY AIRPLANES

0
1. The authority citation for part 23 continues to read as follows:

    Authority: 49 U.S.C. Sec. Sec.  106(g), 40113, 44701, 44702, and 
44704.


0
2. Add Sec.  23.1308 to subpart F to read as follows:


Sec.  23.1308  High-intensity Radiated Fields (HIRF) Protection.

    (a) Except as provided in paragraph (d) of this section, each 
electrical and electronic system that performs a function whose failure 
would prevent the continued safe flight and landing of