[Federal Register Volume 72, Number 116 (Monday, June 18, 2007)]
[Proposed Rules]
[Pages 33415-33417]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-11682]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25174; Directorate Identifier 2005-NM-007-AD]
RIN 2120-AA64


Airworthiness Directives; Learjet Model 45 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

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SUMMARY: The FAA is revising an earlier proposed airworthiness 
directive (AD) for certain Learjet Model 45 airplanes. The original 
NPRM would have required revising the Airworthiness Limitations section 
of the airplane maintenance manual to incorporate certain inspections 
and compliance times to detect fatigue cracking of certain principal 
structural elements (PSEs). The original NPRM resulted from new and 
more restrictive life limits and inspection intervals for certain PSEs. 
This action revises the original NPRM by changing the applicability to 
add certain airplanes. We are proposing this supplemental NPRM to 
ensure that fatigue cracking of various PSEs is detected and corrected; 
such fatigue cracking could adversely affect the structural integrity 
of these airplanes.

DATES: We must receive comments on this supplemental NPRM by July 13, 
2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this supplemental NPRM.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     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.
     Fax: (202) 493-2251.
     Hand Delivery: Room W12-140 on the ground floor of the 
West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Learjet, Inc., One Learjet Way, Wichita, Kansas 67209-2942, 
for service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Steve Litke, Aerospace Engineer, 
Airframe and Services Branch, ACE-118W, FAA, Wichita Aircraft 
Certification Office, 1801 Airport Road, Room 100, Mid-Continent 
Airport, Wichita, Kansas 67209; telephone (316) 946-4127; fax (316) 
946-4107.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this supplemental NPRM. Send your comments to an 
address listed in the ADDRESSES section. Include the docket number 
``Docket No. FAA-2006-25174; Directorate Identifier 2005-NM-007-AD'' at 
the beginning of your comments. We specifically invite comments on the 
overall regulatory, economic, environmental, and energy aspects of this 
supplemental NPRM. We will consider all comments received by the 
closing date and may amend this supplemental NPRM in light of those 
comments.
    We will post all comments submitted, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this supplemental NPRM. Using the search function 
of that web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Operations office between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The 
Docket Operations office (telephone (800) 647-5527) is located on the 
ground floor of the West Building at the street address stated in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after the Docket Management System receives them.

Discussion

    We proposed to amend 14 CFR part 39 with a notice of proposed 
rulemaking (NPRM) for an AD (the ``original NPRM'') for certain Learjet 
Model 45 airplanes. The original NPRM was published in the Federal 
Register on June 26, 2006 (71 FR 36255). The original NPRM proposed to 
require revising the Airworthiness Limitations section of the airplane 
maintenance manual to incorporate certain inspections and compliance 
times to detect fatigue cracking of certain principal structural 
elements (PSEs).

Actions Since Original NPRM Was Issued

    Since we issued the original NPRM, the manufacturer has informed us 
that the actions in the NPRM apply to serial numbers (S/Ns) 45-005 
through 45-302 inclusive, and 45-2001 through 45-2049 inclusive. We 
issued the original NPRM to apply to S/Ns 45-002 through 45-233 
inclusive, and S/Ns 45-2001 through 45-2031 inclusive. The supplemental 
NPRM includes this change in applicability.

[[Page 33416]]

Comments

    We have considered the following comments on the original NPRM.

Requests to Withdraw the NPRM

    Koch Business Holdings, LLC (Koch), asks if this proposed AD is 
necessary. Koch states that operators are already required to use the 
most up-to-date manuals, and wonders if it can expect to see an AD for 
every make and model of airplane for which a more restrictive change is 
made to the Airworthiness Limitations section of the airplane 
maintenance manual (AMM). Koch suggests that we streamline the 
paperwork instead of increasing the paperwork. Koch further states that 
the FAA cannot write an AD against a maintenance manual, and that this 
proposed AD merely adds a requirement to comply with a requirement (the 
maintenance manuals). Koch states that the proposed AD will not make 
certain that maintenance items are complied with. Koch suggests, 
instead of an AD, that we send out the information using advisory 
wires, service newsletters, and letters from the FAA to the operators. 
Koch states that it is 100 percent about safety, but believes that the 
proposed AD just distracts from safety.
    McWane, Inc., also states that the proposed AD is unnecessary 
because the regulatory requirement for complying with the Chapter 4 AMM 
revisions already exists. McWane explains that the Chapter 4 items are 
Airworthiness Limitations that are directly tied to the original type 
certificate; non-compliance places the aircraft outside the 
requirements of the original type design. McWane feels that using an AD 
in this case is overkill and an inappropriate use of rulemaking. McWane 
is primarily concerned that this action would set a precedent that 
would allow an original equipment manufacturer to let the FAA ``become 
their scapegoat'' instead of working with operators to ensure 
compliance with revised data. McWane suggests getting the information 
out using other means, and issuing an AD only against non-compliant 
airplanes.
    We infer that the commenters would like us to withdraw the original 
NPRM. We disagree. We have determined that an unsafe condition exists, 
and that the actions proposed in the original NPRM are necessary to 
ensure the continued operational safety of the affected fleet. 
Compliance with the terms of Airworthiness Limitations sections is 
required by Federal Aviation Regulations Sections 43.16 (for persons 
maintaining products) and 91.403 (for operators). Based on in-service 
data or post certification testing and evaluation, the manufacturer may 
revise the Airworthiness Limitations section to include new or more 
restrictive life limits and inspections. Or it may become necessary for 
the FAA to impose new or more restrictive life limits and structural 
inspections in order to ensure continued structural integrity and 
continued compliance with damage tolerance requirements. However, in 
order to require compliance with these new inspection requirements and 
life limits, the FAA must engage in rulemaking. Therefore, if we do not 
issue an AD, the revised limitations in the AMMs cannot be made 
mandatory. Because loss of structural integrity would constitute an 
unsafe condition, it is appropriate to impose these requirements 
through the AD process. We have not changed the supplemental NPRM in 
this regard.

Clarification of Alternative Method of Compliance (AMOC) Paragraph

    We have revised this action to clarify the appropriate procedure 
for notifying the principal inspector before using any approved AMOC on 
any airplane to which the AMOC applies.

Addition of Note To Clarify Requirements of Paragraph (f) of the 
Supplemental NPRM

    We have added Note 2 to the supplemental NPRM to clarify that after 
an operator complies with the requirements of paragraph (f) of the 
proposed AD, that paragraph does not require that operators 
subsequently record accomplishment of those requirements each time an 
action is accomplished according to that operator's FAA-approved 
maintenance inspection program.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

    The changes discussed in the section titled ``Actions since 
Original NPRM was Issued'' expand the scope of the original NPRM; 
therefore, we have determined that it is necessary to reopen the 
comment period to provide additional opportunity for public comment on 
this supplemental NPRM.

Costs of Compliance

    There are about 347 airplanes of the affected design in the 
worldwide fleet. This supplemental NPRM would affect about 258 
airplanes of U.S. registry. The proposed actions would take about 1 
work hour per airplane, at an average labor rate of $80 per work hour. 
Based on these figures, the estimated cost of this supplemental NPRM 
for U.S. operators is $20,640, or $80 per airplane.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. 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.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the proposed 
regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;
    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979); and
    3. Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this supplemental NPRM and placed it in the AD docket. See 
the ADDRESSES section for a location to examine the regulatory 
evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

[[Page 33417]]

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

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


Sec.  39.13  [Amended]

    2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

LEARJET: Docket No. FAA-2006-25174; Directorate Identifier 2005-NM-
007-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by July 13, 
2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Learjet Model 45 airplanes, certificated 
in any category; serial numbers (S/Ns) 45-002 through 45-302 
inclusive, and S/Ns 45-2001 through 45-2049 inclusive.

Unsafe Condition

    (d) This AD results from new and more restrictive life limits 
and inspection intervals for certain principal structural elements 
(PSEs). We are issuing this AD to ensure that fatigue cracking of 
various PSEs is detected and corrected; such fatigue cracking could 
adversely affect the structural integrity of these airplanes.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

    Note 1: This AD requires revisions to certain operator 
maintenance documents to include new inspections. Compliance with 
these inspections is required by 14 CFR 91.403(c). For airplanes 
that have been previously modified, altered, or repaired in the 
areas addressed by these inspections, the operator may not be able 
to accomplish the inspections described in the revisions. In this 
situation, to comply with 14 CFR 91.403(c), the operator must 
request approval for an alternative method of compliance (AMOC) 
according to paragraph (g) of this AD. The request should include a 
description of changes to the required inspections that will ensure 
the continued damage tolerance of the affected structure. The FAA 
has provided guidance for this determination in Advisory Circular 
(AC) 25-1529-1.

Revise the Airworthiness Limitations Section (ALS)

    (f) Within 30 days after the effective date of this AD, revise 
the ALS of the airplane maintenance manual (AMM) to include new life 
limits and inspection intervals according to a method approved by 
the Manager, Wichita Aircraft Certification Office (ACO), FAA. 
Incorporating the applicable chapters in paragraph (f)(1) or (f)(2) 
of this AD in the AMM is one approved method for doing the revision. 
Thereafter, except as provided in paragraph (g) of this AD, no 
alternative life limits or inspection intervals may be approved for 
the affected PSEs.
    (1) For Learjet Model 45 airplanes, S/Ns 45-002 through 45-302 
inclusive: Chapter 4 of the Learjet 45 Maintenance Manual, Revision 
38, dated April 24, 2006.
    (2) For Learjet Model 45 airplanes, S/Ns 45-2001 through 45-2049 
inclusive: Chapter 4 of the Learjet 40 Maintenance Manual, Revision 
6, dated April 24, 2006.

    Note 2: After an operator complies with the requirements of 
paragraph (f) of this AD, that paragraph does not require that 
operators subsequently record accomplishment of those requirements 
each time an action is accomplished according to that operator's 
FAA-approved maintenance inspection program.

AMOCs

    (g)(1) The Manager, Wichita ACO, has the authority to approve 
AMOCs for this AD, if requested in accordance with the procedures 
found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

    Issued in Renton, Washington, on June 8, 2007.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
 [FR Doc. E7-11682 Filed 6-15-07; 8:45 am]
BILLING CODE 4910-13-P