This section of the FEDERAL REGISTER

contains notices to the public of the proposed

issuance of rules and regulations. The

purpose of these notices is to give interested

persons an opportunity to participate in the

rule making prior to the adoption of the final

rules.

Proposed Rules Federal Register

16676 

Vol. 75, No. 63 

Friday, April 2, 2010 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Parts 23, 25, 27, and 29 

[Docket No. FAA–2010–0224; Notice No. 10– 

05] 

RIN 2120–AJ57 

Airworthiness Standards; Electrical 

and Electronic System Lightning 

Protection 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The Federal Aviation 

Administration (FAA) proposes to 

amend the lightning protection 

airworthiness standards by establishing 

new lightning protection regulations for 

electrical and electronic systems 

installed on aircraft certificated under 

parts 23, 27, and 29, and revising 

lightning protection regulations for 

electrical and electronic systems 

installed on airplanes certificated under 

part 25. The proposed rulemaking 

would establish two levels of lightning 

protection for aircraft systems based on 

consequences of system function failure: 

Catastrophic consequences which 

would prevent continued safe flight and 

landing and hazardous or major 

consequences which would reduce the 

capability of the aircraft or the ability of 

the flightcrew to respond to an adverse 

operating condition. The proposed 

rulemaking would also establish 

lightning protection for aircraft systems 

according to the aircraft’s potential for 

lightning exposure. Compliance with 

the new requirements would be based 

on demonstration of effective lightning 

protection for electrical and electronic 

systems. The proposed airworthiness 

standards would establish consistent 

lightning protection requirements for 

electrical and electronic systems. 

DATES: Send your comments on or 

before July 1, 2010. 

ADDRESSES: You may send comments 

identified by Docket Number [Insert 

docket number, for example, FAA– 

200X–XXXXX] using any of the 

following methods: 

• Federal eRulemaking Portal: Go to 

http://www.regulations.gov and follow 

the online instructions for sending your 

comments electronically. 

• Mail: Send comments to Docket 

Operations, M–30; U.S. Department of 

Transportation, 1200 New Jersey 

Avenue, SE., Room W12–140, West 

Building Ground Floor, Washington, DC 

20590–0001. 

• Hand Delivery or Courier: Take 

comments to Docket Operations in 

Room W12–140 of the West Building 

Ground Floor at 1200 New Jersey 

Avenue, SE., Washington, DC, between 

9 a.m. and 5 p.m., Monday through 

Friday, except Federal holidays. 

• Fax: Fax comments to Docket 

Operations at 202–493–2251. 

For more information on the rulemaking 

process, see the SUPPLEMENTARY

INFORMATION section of this document. 

Privacy: We will post all comments 

we receive, without change, to http:// 

www.regulations.gov, including any 

personal information you provide. 

Using the search function of our docket 

Web site, anyone can find and read the 

electronic form of all comments 

received into any of our dockets, 

including the name of the individual 

sending the comment (or signing the 

comment for an association, business, 

labor union, etc.). You may review 

DOT’s complete Privacy Act Statement 

in the Federal Register published on 

April 11, 2000 (65 FR 19477–78) or you 

may visit http://DocketsInfo.dot.gov. 

Docket: To read background 

documents or comments received, go to 

http://www.regulations.gov at any time 

and follow the online instructions for 

accessing the docket or Docket 

Operations in Room W12–140 of the 

West Building Ground Floor at 1200 

New Jersey Avenue, SE., Washington, 

DC, between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal holidays. 

FOR FURTHER INFORMATION CONTACT: For 

technical questions concerning this 

proposed rule contact Lee Nguyen, AIR– 

130, Federal Aviation Administration, 

Suite 4102, 470 L’Enfant Plaza, 

Washington, DC 20591; telephone (202) 

385–4676; facsimile (202) 385–4651, 

e-mail lee.nguyen@faa.gov. For legal 

questions concerning this proposed rule 

contact Viola Pando, AGC–220, Federal 

Aviation Administration, 800 

Independence Ave., SW., Washington, 

DC 20591; telephone (202) 493–5293; 

facsimile (202) 267–7971, e-mail 

viola.pando@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Later in this preamble under the 

Additional Information section, we 

discuss how you can comment on this 

proposal and how we will handle your 

comments. Included in this discussion 

is related information about the docket, 

privacy, and the handling of proprietary 

or confidential business information. 

We also discuss how you can get a copy 

of related rulemaking documents. 

Authority for This Rulemaking 

The FAA’s authority to issue rules on 

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 the effects of 

lightning, this regulation is within the 

scope of the Administrator’s authority. 

Background and History 

Existing regulations for lightning 

protection of electrical and electronic 

systems installed on aircraft certificated 

under 14 CFR parts 23, 27 and 29 

require the type certification applicant 

only to ‘‘consider’’ the effects of 

lightning. Unlike system lightning 

protection regulations for part 25 

airplanes, these regulations have not 

been significantly amended since they 

were first adopted, and do not reflect 

current advances in technology. 

A. History of Lightning Regulations 

In the 1960s, regulations applicable to 

lightning protection for aircraft design, 

construction, and fuel systems were 

adopted for aircraft certificated under 


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parts 23, 25, 27 and 29. The regulations 

required that the aircraft be protected 

against catastrophic effects of lightning, 

but did not have specific requirements 

for electrical and electronic system 

lightning protection. At the time, most 

aircraft were designed with mechanical 

systems, or simple electrical and 

electronic systems. Airframe 

components were made from aluminum 

materials, with high electrical 

conductivity, and offered good 

protection against lightning. 

The early 1980s ushered in part 25 

transport airplane designs that routinely 

included more complex electrical and 

electronic systems. Flight-critical 

electronic primary flight controls, 

electronic primary flight displays, and 

full-authority electronic engine controls 

became common on transport airplanes 

certificated under part 25. At this time, 

the FAA began to impose lightning 

protection requirements for critical and 

essential electrical and electronic 

systems through special conditions, 

when appropriate, for part 25 airplane 

certification projects. 

As electrical and electronic systems 

became more common on part 25 

airplanes, the FAA issued § 25.1316, 

specifically requiring protection for 

electrical and electronic systems on part 

25 transport category airplanes. The 

final rule was published on April 28, 

1994 (59 FR 22112). This regulation, in 

effect today, requires lightning 

protection for electrical and electronic 

systems based on the consequences of 

failure for functions these systems 

perform. The present regulation 

provides specific considerations that the 

applicant must design for to validate 

that the electrical and electronic 

systems and functions are protected 

from the effects of lightning strikes. 

B. Related Rulemaking Activity 

The FAA tasked the Aviation 

Rulemaking Advisory Committee 

(ARAC) on Transport Airplane and 

Engine Issues (57 FR 58843; December 

11, 1992) to develop recommendations 

for specific electrical and electronic 

systems lightning protection 

requirements for aircraft certificated 

under parts 23, 27, and 29 standards. 

The ARAC submitted 

recommendations to the FAA in 

November 1998. The recommendations 

included lightning protection 

requirements, based on the 

consequences of the failure of system 

functions, similar to the requirements in 

§ 25.1316. The ARAC also 

recommended changes to § 25.1316 

consistent with its recommendations for 

classification of the failure conditions 

for parts 23, 27, and 29. ARAC 

recommended the same requirements 

for all four parts. 

The FAA considered the ARAC 

recommendations in developing this 

notice of proposed rulemaking (NPRM) 

and agrees with these recommendations, 

with one exception. After careful 

consideration, the FAA is unable to 

endorse the ARAC recommendation to 

provide an exception to the requirement 

for automatic and timely recovery of a 

system that performs a function for 

which failure is catastrophic. ARAC 

recommended an exception to recovery 

of such a system in instances where the 

recovery of the system would conflict 

with other operational or functional 

requirements of the system. We are 

unable to identify a situation where 

such an exception would be 

appropriate, nor could we justify the 

need for such an exception and propose 

requirements that could ensure an 

equivalent level of safety. 

The recommendations of the ARAC 

are available at the following Web 

address: http://www.faa.gov/ 

regulations_policies/rulemaking/ 

committees/arac/issue_areas/tae/eeh/. 

C. Advisory Material 

In the absence of performance 

standards for protection of electrical and 

electronic systems from lightning 

effects, the FAA has issued Advisory 

Circular (AC) 20–136A, ‘‘Protection of 

Aircraft Electrical/Electronic System 

against the Indirect Effects of 

Lightning.’’ Since advisory circulars are 

not mandatory, a type certificate 

applicant may elect to ignore or deviate 

from the guidance therein, while still 

satisfying the requirement to ‘‘consider’’ 

lightning. The lack of specific 

performance standards has resulted in a 

variety of different interpretations and 

means of compliance for system 

lightning protection. 

General Discussion of the Proposal 

The proposed rulemaking would 

establish type certification standards for 

lightning protection of electrical and 

electronic systems for aircraft 

certificated under parts 23, 27 and 29. 

This action also proposes to revise 

§ 25.1316 for transport category 

airplanes to be consistent in format with 

the proposed regulations applicable to 

other aircraft. 

This rulemaking reflects a change in 

our approach to achieving lightning 

protection for aircraft by protecting 

functions of electrical and electronic 

systems. The current part 25 regulation 

for lightning protection focuses on 

protection of electrical and electronic 

systems that perform critical and 

essential functions and are no longer 

compatible or consistent with the latest 

classification concepts, terminology, 

and practices. Parts 23, 27 and 29 

regulations for lightning protection are 

less precise, and require the applicant 

only to ‘‘consider’’ lightning. While the 

focus on protection of electrical and 

electronic systems that perform critical 

or essential functions was fundamental 

to the wording of earlier airworthiness 

standards regarding systems, and 

associated advisory circulars, this 

proposal focuses on the effects that 

failure conditions would have on 

aircraft safety. The FAA proposes that 

lightning protection design required for 

each aircraft would be determined by 

the type of electrical and electronic 

systems installed on the aircraft, and 

how critical the system or function is to 

either continued flight and landing, or 

the aircraft capability and flightcrew’s 

ability to respond to adverse operating 

conditions. 

In aircraft, the term ‘‘electrical and 

electronic system’’ refers to the electrical 

and electronic equipment, associated 

software, and interconnecting wires 

installed on aircraft to perform one or 

more functions. The term ‘‘function’’ 

refers to the action that the system 

performs. An aircraft system may 

perform multiple functions with 

different failure conditions. For 

example, an engine control system may 

perform the function of the engine 

thrust control—for which failure could 

have catastrophic effects on the 

continued safe flight and landing of the 

aircraft. The engine control system may 

also perform the function of engine 

condition monitoring—for which failure 

could have hazardous or major effects 

on continued safe operation of the 

aircraft. A function may also be 

performed by multiple systems or 

subsystems. For example, the function 

of controlling engine thrust may be 

provided by an electronic engine control 

subsystem, with a separate backup 

mechanical control subsystem. 

A. Proposed Performance Standards 

The proposed regulations would 

establish consistent performance 

standards to design lightning protection 

for those aircraft electrical and 

electronic systems that provide: 

1. Functions for which failure would 

prevent the continued safe flight and 

landing of the aircraft: Failure of these 

functions could result in catastrophic 

consequences such as loss of life and 

loss of the aircraft; 

2. Functions for which failure would 

reduce the capability of the aircraft or 

the ability of the flightcrew to cope with 

adverse operating conditions: Failure of 


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these functions could have hazardous or 

major consequences. 

This NPRM identifies system 

lightning performance standards for 

item 1 as ‘‘protection against 

catastrophic failure.’’ These standards 

are addressed by paragraph (a) of the 

proposed regulations. System lightning 

performance standards for item 2 will be 

referenced as ‘‘protection against 

hazardous or major failure.’’ These 

standards are addressed by paragraph 

(b) of the proposed regulations. 

The proposed standards for protection 

against catastrophic failure would 

require an applicant to show that the 

function would not be adversely 

affected during or after the time the 

aircraft is exposed to lightning. 

Compliance with the standard would 

depend on the specific aircraft function, 

the system that performs that function, 

and the effects of failure on the system 

and function. Further guidance on 

defining the adverse effects for specific 

aircraft system functions can be found 

in various FAA advisory materials. 

The system could be affected during 

lightning exposure because a backup 

system continues to provide the 

function, even though the function may 

not be adversely affected. Accordingly, 

the applicant would be required to show 

that the system would automatically 

recover normal operation after the 

lightning exposure in a timely manner. 

‘‘Normal operation’’ means the ability of 

the system to perform functions to the 

extent necessary to continue safe flight 

and landing. For systems that provide 

one or more functions, the proposal 

would require the system to 

automatically recover normal operations 

of those functions for which failure 

could be catastrophic. Other functions 

would not be required to return to 

normal operation. The FAA would 

determine what constitutes ‘‘timely’’ 

automatic recovery on a case-by-case 

evaluation, based on engineering 

judgment of the specific function and its 

failure effects. 

The aircraft engine thrust/power 

control is an example of a function for 

which failure would have catastrophic 

effects on the aircraft’s ability to 

continue safe flight and landing. A fullauthority electronic engine control 

system may provide this function, and 

perform aircraft engine thrust/power 

control by automatically regulating fuel 

flow and airflow to the engine(s). The 

loss or malfunction of this function 

could stop the engines or result in 

engine overspeed, which could result in 

a catastrophic failure condition. In this 

situation, the applicant would be 

required to ensure the aircraft engine 

thrust/power control function is not 

adversely affected during or after 

lightning exposure. 

The aircraft display is another 

function for which failure would have 

catastrophic effects on continued safe 

flight and landing. This function 

provides aircraft attitude, altitude, and 

airspeed information to the pilot, which 

are required for continued safe flight 

and landing of the aircraft. The aircraft 

display may be provided by two 

systems: An electronic primary display 

and an electromechanical standby 

display. In this situation, the primary 

display may momentarily blank while 

the aircraft is exposed to lightning, 

provided the information is available 

from a standby display. The applicant 

would be required to demonstrate that 

the primary display system 

automatically recovers normal operation 

in a timely manner with no adverse 

effect on providing the attitude, altitude, 

and airspeed information. 

The proposed requirements for 

protection against hazardous or major 

failure would require the applicant to 

show that the system would not be 

damaged, and the function would 

recover normal operation in a timely 

manner after the aircraft is exposed to 

lightning. This proposed requirement 

would primarily focus on the recovery 

of the function to normal operation. For 

these systems, ‘‘damaged’’ refers to the 

inability to recover. As with the 

proposed standard for protection against 

catastrophic failure, the FAA would 

determine what constitutes a ‘‘timely’’ 

recovery of normal function based on 

engineering judgment of the specific 

function and its failure effects upon the 

design submitted for certification. 

An example of a function for which 

failure could result in or have a 

hazardous or major effect on aircraft 

operation is voice communication 

provided by radio. Failure of this 

function would increase the flightcrew’s 

normal workload and affect their ability 

to maintain situational awareness, as the 

flightcrew would no longer be able to 

transmit or receive voice 

communication information with other 

pilots or air traffic control. As proposed, 

the applicant would be required to 

ensure the radio system is not damaged 

after lightning exposure and the voice 

communication function would recover 

in a timely manner. Recovery may 

require flightcrew interaction. 

B. Applicability of the Proposed 

Lightning Protection Requirements 

Application of the proposed standards 

for aircraft electrical and electronic 

system lightning protection would be 

based on the aircraft’s potential for 

lightning exposure and the 

consequences of system failure. The 

proposed requirements for parts 25 and 

29 would apply to all aircraft 

certificated under part 25 and part 29. 

The proposed requirements would also 

apply to part 23 and part 27 aircraft 

approved for operations under 

instrument flight rules (IFR). In 

addition, the proposed requirements 

would apply to part 23 airplanes and 

part 27 rotorcraft approved solely for 

operations under visual flight rules 

(VFR); for those electrical and electronic 

systems that perform functions for 

which failures would be catastrophic. 

Parts 25 and 29 Aircraft 

Parts 25 and 29 transport category 

aircraft are now routinely equipped 

with complex electrical and electronic 

systems. These systems are highly 

integrated, and provide a range of flightcritical functions. The FAA has 

tentatively determined that these 

transport category aircraft should be 

required to provide full protection for 

those systems that perform functions for 

which failure could result in both 

catastrophic and hazardous or major 

failure effects. 

Part 23 Airplanes 

Application of the proposed 

requirements for airplanes certificated 

to part 23 standards depends on 

whether the airplane is approved for IFR 

or VFR-only operations. This difference 

exists because, compared to part 23 

VFR-only airplanes, part 23 IFRapproved airplanes are more likely 

equipped with complex electrical and 

electronic systems that allow them to 

operate into instrument meteorological 

conditions (IMC), where lightning 

strikes are prevalent. As a result, part 23 

IFR-approved airplanes are designed for, 

and expected to operate into, weather 

conditions that present greater potential 

for exposure to lightning. 

In contrast, part 23 VFR-only 

airplanes are prohibited by regulation 

from operating into IMC. Nevertheless, 

there is still some likelihood of the 

airplanes being exposed to lightning. 

Therefore, the FAA has determined that 

the resulting risk to part 23 VFR-only 

airplanes for which failure would be 

catastrophic may be sufficiently great to 

require lightning protection to prevent 

catastrophic failures. However, the FAA 

has tentatively determined that the 

resulting risk to part 23 VFR-only 

airplanes with electrical or electronic 

systems installed for which failure 

would be hazardous or major remains 

sufficiently low as to not require 

lightning protection. 


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Part 27 Rotorcraft 

Similar to the applicability of 

proposed changes to part 23, application 

of the proposed requirements for part 27 

would depend on whether the rotorcraft 

is approved for IFR or VFR-only 

operations. The proposed lightning 

protection requirements would apply to 

IFR-approved rotorcraft in the same 

way, and for the same reasons. 

Likewise, part 27 VFR-only rotorcraft 

would be required to protect those 

systems that perform functions where 

failure could have catastrophic effects. 

This requirement is intended to address 

the unique performance capabilities that 

make rotorcraft VFR operations 

vulnerable to lightning. Rotorcraft are 

inherently more maneuverable, and 

have more versatile landing capability 

than fixed wing aircraft. Accordingly, 

they are permitted to operate with low 

minimum altitude, low flight visibility, 

and nearer to clouds. Although 

prohibited from operating directly into 

IMC, part 27 VFR-only rotorcraft are 

able to operate close to meteorological 

conditions that have a high potential for 

lightning strikes. This means rotorcraft 

certificated to part 27 standards in VFRonly operations are likely to encounter 

lightning exposure. The FAA has 

determined that the resulting risk to part 

27 VFR-only rotorcraft systems for 

which failure would be catastrophic is 

sufficiently great to propose requiring 

lightning protection to prevent 

catastrophic failures. As with part 23 

VFR-only airplanes, the FAA has 

determined that the resulting risk to 

rotorcraft certificated to part 27 

standards that operate in VFR-only 

operations with electrical or electronic 

systems installed for which failure 

would be hazardous or major likely 

remains sufficiently low as to not 

require lightning protection. 

C. Specific Changes to Part 25 

The proposed changes to § 25.1316 

are intended to rephrase the existing 

regulation to clarify intent, to reformat 

it so that it is in keeping with the other 

three parts, and to delete § 25.1316(c) 

which sets forth specific requirements 

for compliance. If adopted, the proposal 

would not change the current part 25 

practices for lightning protection. 

Rather, the proposal would shift the 

emphasis placed on protecting functions 

of electrical and electronic systems, and 

focus on the effects that systems and 

equipment failure conditions have on 

aircraft safety. The most significant 

change would be to clearly set forth 

lightning protection performance 

standards for the function and the 

system, based on the failure effects of 

the function. 

Section 25.1316(a) currently requires 

those electrical and electronic systems 

that provide functions where failure 

would be catastrophic to be designed 

and installed so their operation and 

operational capabilities are not 

adversely affected when the airplane is 

exposed to lightning. Section 25.1316(b) 

requires that lightning protection for 

electrical and electronic systems that 

perform functions for which failure 

would be hazardous or major must be 

designed and installed to ensure that 

these functions can be timely recovered 

after exposure to lightning. 

The proposed regulation is 

distinguishable from existing § 25.1316 

in that it places the emphasis on the 

function and also sets forth specific 

standards for the function and the 

system respectively. By focusing on 

functions performed by systems, rather 

than the systems themselves, the 

proposed revision would allow the 

applicant to choose appropriate system 

configurations and designs to comply 

with this regulation, but would also 

require that the applicant demonstrate 

that the proposed configuration 

provides effective protection. 

Finally, the proposal would remove 

§ 25.1316(c), which contains specific 

step-by-step actions required to show 

compliance. The ARAC recommended 

removing § 25.1316(c) because this 

information is more appropriately 

addressed in guidance for means of 

compliance. Since § 25.1316 was 

adopted in 1994, significant guidance 

has been developed by the FAA and 

lightning technical committees. 

Advisory circulars 20–136A and 20–155 

provide much more comprehensive 

guidance on means of compliance with 

the lightning regulations. Removing 

§ 25.1316(c) allows for the use of means 

of compliance that achieve the intent of 

§ 25.1316(a) and (b) without the 

prescriptive list that is currently in 

§ 25.1316(c). The technology for 

showing compliance with § 25.1316(a) 

and (b) has progressed substantially 

since § 25.1316 was adopted in 1994, 

which makes the prescriptive list in 

§ 25.1316(c) obsolete. 

D. Miscellaneous Changes 

This rulemaking would remove 

§§ 27.1309(d) and 29.1309(h), and delete 

‘‘lightning and’’ from §§ 27.610(d)(4) and 

29.610(d)(4). Section 27.1309(d) 

currently governs lightning protection 

for part 27 electrical and electronic 

systems, and requires only that the 

applicant ‘‘consider’’ the effects of 

lightning according to § 27.610. Section 

29.1309(h) requires only that the 

applicant ‘‘consider’’ the effects of 

lightning. Sections 27.610(d)(4) and 

29.610(d)(4) both address general design 

requirements for electrical bonding and 

protection against lightning and static 

electricity. They require electrical 

bonding against lightning to reduce to 

an acceptable level the effects of 

lightning on the functioning of essential 

electrical and electronic equipment. 

Adoption of the proposed §§ 27.1316 

and 29.1316 would replace these 

references to lightning with specific 

performance standards for lightning 

protection of parts 27 and 29 electrical 

and electronic systems. 

Also, we propose to add a cross 

reference to § 27.1316 in Appendix B of 

Part 27 on electrical and electronic 

system lightning protection for 

rotorcraft approved for IFR operation. 

Paperwork Reduction Act 

The Paperwork Reduction Act of 1995 

(44 U.S.C. 3507(d)) requires that the 

FAA consider the impact of paperwork 

and other information collection 

burdens imposed on the public. We 

have determined that there is no new 

information collection requirement 

associated with this proposed rule. 

International Compatibility 

In keeping with U.S. obligations 

under the Convention on International 

Civil Aviation, it is FAA policy to 

conform to 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 proposed 

regulations. 

Regulatory 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 


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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 impact of the proposed rule. 

Department of Transportation Order 

DOT 2100.5 prescribes policies and 

procedures for simplification, analysis, 

and review of regulations. If the 

expected cost impact is so minimal that 

a proposed or final rule does not 

warrant a full evaluation, this order 

permits that a statement to that effect 

and the basis for it be included in the 

preamble. Such a determination has 

been made for this proposed rule. The 

reasoning for this determination 

follows: 

In a cost survey of industry conducted 

by the FAA, six of the seven replying 

firms reported no incremental cost from 

this proposed rule. One firm reported 

‘‘little or no cost.’’ The reason for little 

or no incremental cost is that these 

firms (six out of seven) reported usage 

of Advisory Circular (AC) 20–136A, 

‘‘Protection of Aircraft Electrical/ 

Electronic Systems Against the Indirect 

Effects of Lightning,’’ as guidance for 

demonstrating compliance with 

lightning requirements. Consequently, 

these firms are already in compliance 

with the proposed rule as it represents 

a codification of AC 20–136A. For 

manufacturers of Part 25 airplanes, cost 

changes should be minimal in any case, 

as the proposed changes in the rule are 

clarifying only. Moreover, four of the 

seven respondents reported at least 

some expected benefits from the 

proposed rule (See ‘‘Benefits’’ section 

below). The FAA therefore has 

determined that this proposed rule 

would have minimal costs with positive 

net benefits and does not warrant a full 

regulatory evaluation. The FAA requests 

comments with supporting justification 

on the FAA determination of minimal 

impact. Our analysis follows below. 

The FAA has also determined that 

this proposed rule is not a ‘‘significant 

regulatory action’’ as defined in section 

3(f) of Executive Order 12866, and is not 

‘‘significant’’ as defined in DOT’s 

Regulatory Policies and Procedures. 

Total Costs and Benefits of This 

Rulemaking 

As noted above, there are little or no 

expected costs for this proposed rule 

and some benefits. The benefits 

therefore justify the costs. See details in 

the separate costs and benefits sections 

below. 

Who Is Potentially Affected by This 

Rulemaking? 

Manufacturers of Parts 23, 25, 27, and 

29 aircraft and manufacturers of 

electrical and electronic systems for 

those aircraft. 

Assumptions and Sources of 

Information 

• We use a ten-year period of 

analysis, 2009–2018. 

• Data on costs of compliance and 

benefits of this rule were obtained from 

an FAA survey of industry. 

• Firms are defined as ‘‘small’’ or 

‘‘large’’ using Small Business 

Administration (SBA) size standards 

(U.S. SBA. Table of Small Business Size 

Standards Matched to North American 

Industry Classification System Codes, 

July 21, 2006). 

Costs of This Rulemaking 

On February 9, 2009, we sent a 

detailed cost survey to six 

manufacturers of Parts 23, 25, 27, and 

29 aircraft and three manufacturers of 

electrical and electronic systems for 

those aircraft. In addition to several 

detailed cost questions, the survey also 

asked one question about potential 

benefits from the proposed rule. We 

received four responses to this initial 

survey. On March 17, 2009, we 

resurveyed the five non-respondents 

and received three additional replies, 

although the last response came only on 

August 8, 2009. The seven responses we 

received were from manufacturers 

ranging from a small aircraft 

manufacturer (less than 1,500 

employees) to the largest U.S. aircraft 

manufacturer. As shown in the table 

below, the respondents indicated little 

or no cost from the proposed rule. 

Summary of Cost Survey Results 

Firm Type Products certified to: Costs Benefits 

A .................. Airplane manufacturer .. Part 23 .......................... No cost .......................... ‘‘The certification process will be less ambiguous and slightly streamlined by writing some 

of the AC 20–136A requirements directly into 

the regulations.’’ 

B .................. Airplane manufacturer .. Parts 23 & 25 ................ No cost .......................... ‘‘The commonality between parts and the ability 

to use the same substantiation across product 

lines is a very large benefit.’’ 

C .................. Airplane manufacturer .. Parts 23 & 25 ................ No cost .......................... ‘‘Harmonization of Part 23 and Part 25 rules will 

simplify our certification process as our internal procedures benefit from any similarity of 

the two Parts.’’ 

D .................. Airplane manufacturer .. Part 25 .......................... Little or no cost ............. No response to benefits question. 

E .................. Electrical/electronic systems manufacturer.Parts 23 & 25 ................ No cost .......................... ‘‘NA.’’ 

F .................. Electrical/electronic systems manufacturer.Parts 23, 25, 27, & 29 .. No cost .......................... ‘‘None.’’ 

G .................. Electrical/electronic systems manufacturer.Parts 23, 25, 27, & 29 .. No cost .......................... ‘‘Standardization of the rule across all aircraft 

types may simplify requirements capture resulting in some limit[ed] non-recurring cost reduction.’’ 

Benefits of This Rulemaking 

As supported by the responses to the 

benefits question, shown in the table, 

the proposed rule and the 

standardization of rule language would 

reduce firm costs by clarifying and 

simplifying the certification process. 

Regulatory Flexibility Determination 

The Regulatory Flexibility Act of 1980 

(Pub. L. 96–354) (RFA) establishes ‘‘as a 

principle of regulatory issuance that 


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Federal Register / Vol. 75, No. 63 / Friday, April 2, 2010 / Proposed Rules 16681 

agencies shall endeavor, consistent with 

the objectives 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-forprofit organizations, and small 

governmental jurisdictions. 

Agencies must perform a review to 

determine whether a rule will have a 

significant economic impact on a 

substantial number of small entities. If 

the 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 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. 

As noted above, in a cost survey of 

industry, the FAA found little or no 

expected costs from this proposed rule. 

The reason for this finding is that all but 

one respondent reported usage of AC 

20–136A, ‘‘Protection of Aircraft 

Electrical/Electronic Systems Against 

the Indirect Effects of Lightning,’’ as 

guidance for complying with system 

lightning requirements. Accordingly, 

this proposed rule represents current 

practice and imposes no more 

requirements than those previously 

recommended by AC 20–136A. 

Consequently, these firms are already in 

compliance with the proposed rule as it 

represents a codification of AC 20– 

136A. For manufacturers of Part 25 

airplanes, cost changes should, in any 

case, be minimal as the proposed 

changes in the rule are clarifying only. 

Therefore, the FAA certifies that this 

proposed rule would not have a 

significant economic impact on a 

substantial number of small entities. 

The FAA solicits comments regarding 

this determination. 

International Trade Impact Assessment 

The Trade Agreements Act of 1979 

(Pub. L. 96–39), as amended by the 

Uruguay Round Agreement Act (Pub. L. 

103–465), prohibits Federal agencies 

from establishing any standards or 

engaging in related activities that create 

unnecessary obstacles to the foreign 

commerce of the United States. 

Pursuant to these Acts, the 

establishment of standards is not 

considered not considered an 

unnecessary obstacle to the foreign 

commerce of the United States, so long 

as the standard have a legitimate 

domestic objective, such as the 

protection of safety, and do not operate 

in a manner that excludes imports that 

meet this objective. The statute also 

requires consideration of international 

standards and, where appropriate, that 

they be the basis for U.S. standards. The 

FAA notes the purpose is to ensure the 

safety of the American public, and has 

assessed the effect of this proposed rule 

to ensure that it does not exclude 

imports that meet this objective. As a 

result, this proposed rule is not 

considered as creating an unnecessary 

obstacle to foreign commerce because 

the FAA found little or no expected 

costs from this proposed rule. 

Unfunded Mandates Assessment 

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 (in 

1995 dollars) 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 

$136.1 million in lieu of $100 million. 

This proposed rule does not contain 

such a mandate. The requirements of 

Title II do not apply. 

Executive Order 13132, Federalism 

The FAA has analyzed this proposed 

rule under the principles and criteria of 

Executive Order 13132, Federalism. We 

determined that this action would not 

have a substantial direct effect on the 

States, on 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, 

would 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 proposed 

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 NPRM 

under Executive Order 13211, Actions 

Concerning Regulations that 

Significantly Affect Energy Supply, 

Distribution, or Use (May 18, 2001). We 

have determined that it is not a 

‘‘significant energy action’’ under the 

executive order, it is not a ‘‘significant 

regulatory action’’ under Executive 

Order 12866 and DOT’s Regulatory 

Policies and Procedures. 

Additional Information 

Comments Invited 

The FAA invites interested persons to 

participate in this rulemaking by 

submitting written comments, data, or 

views. We also invite comments relating 

to the economic, environmental, energy, 

or federalism impacts that might result 

from adopting the proposals in this 

document. The most helpful comments 

reference a specific portion of the 

proposal, explain the reason for any 

recommended change, and include 

supporting data. To ensure the docket 

does not contain duplicate comments, 

please send only one copy of written 

comments, or if you are filing comments 

electronically, please submit your 

comments only one time. 

We will file in the docket all 

comments we receive, as well as a 

report summarizing each substantive 

public contact with FAA personnel 

concerning this proposed rulemaking. 

Before acting on this proposal, we will 

consider all comments we receive on or 

before the closing date for comments. 

We will consider comments filed after 

the comment period has closed if it is 

possible to do so without incurring 

expense or delay. We may change this 

proposal in light of the comments we 

receive. 

Proprietary or Confidential Business 

Information 

Do not file in the docket information 

that you consider to be proprietary or 

confidential business information. Send 

or deliver this information directly to 

the person identified in the FOR FURTHER

INFORMATION CONTACT section of this 

document. You must mark the 

information that you consider 

proprietary or confidential. If you send 

the information on a disk or CD–ROM, 

mark the outside of the disk or CD–ROM 

and also identify electronically within 

the disk or CD–ROM the specific 

information that is proprietary or 

confidential. 


wwoods2 on DSK1DXX6B1PROD with PROPOSALS_PART 1
16682 Federal Register / Vol. 75, No. 63 / Friday, April 2, 2010 / Proposed Rules 

Under 14 CFR 11.35(b), when we are 

aware of proprietary information filed 

with a comment, we do not place it in 

the docket. We hold it in a separate file 

to which the public does not have 

access, and we place a note in the 

docket that we have received it. If we 

receive a request to examine or copy 

this information, we treat it as any other 

request under the Freedom of 

Information Act (5 U.S.C. 552). We 

process such a request under the DOT 

procedures found in 49 CFR part 7. 

Availability of Rulemaking Documents 

You can get an electronic copy of 

rulemaking documents using the 

Internet by— 

1. Searching the Federal eRulemaking 

Portal (http://www.regulations.gov); 

2. Visiting the FAA’s Regulations and 

Policies Web page at http:// 

www.faa.gov/regulations_policies or 

3. Accessing the Government Printing 

Office’s Web page at http:// 

www.gpoaccess.gov/fr/index.html. 

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 docket or notice number of 

this rulemaking. 

You may access all documents the 

FAA considered in developing this 

proposed rule, including economic 

analyses and technical reports, from the 

Internet through the Federal 

eRulemaking Portal referenced in 

paragraph (1). 

List of Subjects 

14 CFR Part 23 

Aircraft, Aviation safety, Signs and 

symbols. 

14 CFR Part 25 

Aircraft, Aviation safety, Reporting 

and recordkeeping requirements. 

14 CFR Part 27 

Aircraft, Aviation safety. 

14 CFR Part 29 

Aircraft, Aviation safety. 

The Proposed Amendment 

In consideration of the foregoing, the 

Federal Aviation Administration 

proposes to amend parts 23, 25, 27, and 

29 of Title 14, Code of Federal 

Regulations, as follows: 

PART 23—AIRWORTHINESS 

STANDARDS: NORMAL, UTILITY, 

ACROBATIC, AND COMMUTER 

CATEGORY AIRPLANES 

1. The authority citation for part 23 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701, 

44702, 44704. 

2. Add new § 23.1306 to read as 

follows: 

§ 23.1306 Electrical and electronic system 

lightning protection. 

(a) Each electrical and electronic 

system that performs a function, for 

which failure would prevent the 

continued safe flight and landing of the 

airplane, must be designed and installed 

so that— 

(1) The function is not adversely 

affected during and after the time the 

airplane is exposed to lightning; and 

(2) The system automatically recovers 

normal operation of that function in a 

timely manner after the airplane is 

exposed to lightning. 

(b) For airplanes approved for 

instrument flight rules operation, each 

electrical and electronic system that 

performs a function, for which failure 

would reduce the capability of the 

airplane or the ability of the flightcrew 

to respond to an adverse operating 

condition, must be designed and 

installed so that— 

(1) The system is not damaged after 

the airplane is exposed to lightning; and 

(2) The function recovers normal 

operation in a timely manner after the 

airplane is exposed to lightning. 

PART 25—AIRWORTHINESS 

STANDARDS: TRANSPORT 

CATEGORY AIRPLANES 

3. The authority citation for part 25 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701, 

44702, 44704. 

4. Revise § 25.1316 to read as follows: 

§ 25.1316 Electrical and electronic system 

lightning protection. 

(a) Each electrical and electronic 

system that performs a function, for 

which failure would prevent the 

continued safe flight and landing of the 

airplane, must be designed and installed 

so that— 

(1) The function is not adversely 

affected during and after the time the 

airplane is exposed to lightning; and 

(2) The system automatically recovers 

normal operation of that function in a 

timely manner after the airplane is 

exposed to lightning. 

(b) Each electrical and electronic 

system that performs a function, for 

which failure would reduce the 

capability of the airplane or the ability 

of the flightcrew to respond to an 

adverse operating condition, must be 

designed and installed so that— 

(1) The system is not damaged after 

the airplane is exposed to lightning; and 

(2) The function recovers normal 

operation in a timely manner after the 

airplane is exposed to lightning. 

PART 27—AIRWORTHINESS 

STANDARDS: NORMAL CATEGORY 

ROTORCRAFT 

5. The authority citation for part 27 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701, 

44702, 44704. 

6. Amend § 27.610 by revising 

paragraph (d)(4) to read as follows: 

§ 27.610 Lightning and static electricity 

protection. 

* * * * * 

(d) * * * 

(4) Reduce to an acceptable level the 

effects of static electricity on the 

functioning of essential electrical and 

electronic equipment. 

§ 27.1309 [Amended] 

7. Amend § 27.1309 by removing 

paragraph (d). 

8. Add a new § 27.1316 to read as 

follows: 

§ 27.1316 Electrical and electronic system 

lightning protection. 

(a) Each electrical and electronic 

system that performs a function, for 

which failure would prevent the 

continued safe flight and landing of the 

rotorcraft, must be designed and 

installed so that— 

(1) The function is not adversely 

affected during and after the time the 

rotorcraft is exposed to lightning; and 

(2) The system automatically recovers 

normal operation of that function in a 

timely manner after the rotorcraft is 

exposed to lightning. 

(b) For rotorcraft approved for 

instrument flight rules operation, each 

electrical and electronic system that 

performs a function, for which failure 

would reduce the capability of the 

rotorcraft or the ability of the flightcrew 

to respond to an adverse operating 

condition, must be designed and 

installed so that— 

(1) The system is not damaged after 

the rotorcraft is exposed to lightning; 

and 

(2) The function recovers normal 

operation in a timely manner after the 

rotorcraft is exposed to lightning. 

9. Add paragraph X. to Appendix B of 

part 27 to read as follows: 


wwoods2 on DSK1DXX6B1PROD with PROPOSALS_PART 1
Federal Register / Vol. 75, No. 63 / Friday, April 2, 2010 / Proposed Rules 16683 

Appendix B to Part 29—Airworthiness 

Criteria for Helicopter Instrument 

Flight 

* * * * * 

X. Electrical and electronic system 

lightning protection. For regulations 

concerning lightning protection for electrical 

and electronic systems, see § 27.1316. 

PART 29—AIRWORTHINESS 

STANDARDS: TRANSPORT 

CATEGORY ROTORCRAFT 

10. The authority citation for part 29 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701, 

44702, 44704. 

11. Amend § 29.610 by revising 

paragraph (d)(4) to read as follows: 

§ 29.610 Lightning and static electricity 

protection. 

* * * * * 

(d) * * * 

(4) Reduce to an acceptable level the 

effects of static electricity on the 

functioning of essential electrical and 

electronic equipment. 

§ 29.1309 [Amended] 

12. Amend § 29.1309 by removing 

paragraph (h). 

13. Add new § 29.1316 to read as 

follows: 

§ 29.1316 Electrical and electronic system 

lightning protection. 

(a) Each electrical and electronic 

system that performs a function, for 

which failure would prevent the 

continued safe flight and landing of the 

rotorcraft, must be designed and 

installed so that— 

(1) The function is not adversely 

affected during and after the time the 

rotorcraft is exposed to lightning; and 

(2) The system automatically recovers 

normal operation of that function in a 

timely manner after the rotorcraft is 

exposed to lightning. 

(b) Each electrical and electronic 

system that performs a function, for 

which failure would reduce the 

capability of the airplane or the ability 

of the flightcrew to respond to an 

adverse operating condition, must be 

designed and installed so that— 

(1) The system is not damaged after 

the rotorcraft is exposed to lightning; 

and 

(2) The function recovers normal 

operation in a timely manner after the 

rotorcraft is exposed to lightning. 

Issued in Washington, DC, on March 29, 

2010. 

Kalene C. Yanamura, 

Acting Director, Aircraft Certification Service. 

[FR Doc. 2010–7525 Filed 4–1–10; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2010–0280; Directorate 

Identifier 2009–NM–259–AD] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Model 777–200LR and 

–300ER Series Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: We propose to adopt a new 

airworthiness directive (AD) for certain 

Model 777–200LR and –300ER series 

airplanes. This proposed AD would 

require doing a high frequency eddy 

current inspection for cracking of the 

keyway of the fuel tank access door 

cutout on the left and right wings 

between wing rib numbers 8 (wing 

station 387) and 9 (wing station 414.5), 

and related investigative and corrective 

actions if necessary. This proposed AD 

results from reports of cracks emanating 

from the keyway of the fuel tank access 

door cutout of the lower wing skin 

between wing rib numbers 8 and 9. We 

are proposing this AD to prevent loss of 

the lower wing skin load path, which 

could cause catastrophic structural 

failure of the wing. 

DATES: We must receive comments on 

this proposed AD by May 17, 2010. 

ADDRESSES: You may send comments by 

any of the following methods: 

• Federal eRulemaking Portal: Go to 

http://www.regulations.gov. Follow the 

instructions for submitting comments. 

• Fax: 202–493–2251. 

• Mail: U.S. Department of 

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue, SE., 

Washington, DC 20590. 

• Hand Delivery: U.S. Department of 

Transportation, Docket Operations, M– 

30, West Building Ground Floor, Room 

W12–140, 1200 New Jersey Avenue, SE., 

Washington, DC 20590, between 9 a.m. 

and 5 p.m., Monday through Friday, 

except Federal holidays. 

For service information identified in 

this proposed AD, contact Boeing 

Commercial Airplanes, Attention: Data 

& Services Management, P.O. Box 3707, 

MC 2H–65, Seattle, Washington 98124– 

2207; telephone 206–544–5000, 

extension 1; fax 206–766–5680; e-mail 

me.boecom@boeing.com; Internet 

https://www.myboeingfleet.com. You 

may review copies of the referenced 

service information at the FAA, 

Transport Airplane Directorate, 1601 

Lind Avenue, SW., Renton, Washington. 

For information on the availability of 

this material at the FAA, call 425–227– 

1221. 

Examining the AD Docket 

You may examine the AD docket on 

the Internet at http:// 

www.regulations.gov; or in person at the 

Docket Management Facility between 9 

a.m. and 5 p.m., Monday through 

Friday, except Federal holidays. The AD 

docket contains this proposed AD, the 

regulatory evaluation, any comments 

received, and other information. The 

street address for the Docket Office 

(telephone 800–647–5527) is in the 

ADDRESSES section. Comments will be 

available in the AD docket shortly after 

receipt. 

FOR FURTHER INFORMATION CONTACT: 

Duong Tran, Aerospace Engineer, 

Airframe Branch, ANM–120S, FAA, 

Seattle Aircraft Certification Office, 

1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone 

(425) 917–6452; fax (425) 917–6590. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to send any written 

relevant data, views, or arguments about 

this proposed AD. Send your comments 

to an address listed under the 

ADDRESSES section. Include ‘‘Docket No. 

FAA–2010–0280; Directorate Identifier 

2009–NM–259–AD’’ at the beginning of 

your comments. We specifically invite 

comments on the overall regulatory, 

economic, environmental, and energy 

aspects of this proposed AD. We will 

consider all comments received by the 

closing date and may amend this 

proposed AD because of those 

comments. 

We will post all comments we 

receive, without change, to http:// 

www.regulations.gov, including any 

personal information you provide. We 

will also post a report summarizing each 

substantive verbal contact we receive 

about this proposed AD. 

Discussion 

We have received reports of cracks 

emanating from the keyway of the fuel 

tank access door cutout of the lower 

wing skin between wing rib numbers 8 

and 9. The keyway is found on Model 

777–200LR and 777–300ER airplanes at 

this location as the access door has a 

fuel measuring stick installed. The 

keyway is used to ensure that the fuel 

measuring stick is oriented properly in 

the access door cutout. The crack is the 

result of fatigue due to the position of 

the keyway. After the crack initiates, if 


wwoods2 on DSK1DXX6B1PROD with PROPOSALS_PART 1