Document ID: FAA-2014-0249-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Learjet, Inc. Airplanes
Posted Date: 2014-04-16T04:00Z

[Federal Register Volume 79, Number 73 (Wednesday, April 16, 2014)]
[Proposed Rules]
[Pages 21416-21418]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-08605]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2014-0249; Directorate Identifier 2012-NM-211-AD]
RIN 2120-AA64

Airworthiness Directives; Learjet Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Learjet Inc. Model 45 airplanes. This proposed AD was prompted 
by reports of non-conforming windshield supports (coupe rails). This 
proposed AD would require a general visual inspection to detect gouging 
and scratches and to determine if a radius has been removed; an 
ultrasound inspection to measure the dimensions of the lower coupe 
rails; an eddy current inspection to detect cracks of the lower coupe 
rails; replacement of the lower coupe rails if necessary; and revision 
of the maintenance or inspection program, as applicable. We are 
proposing this AD to detect and correct non-conforming windshield 
supports, which could result in uncontrolled cabin depressurization. 
Non-conforming windshield supports could also compromise the capability 
of the windshield to withstand a bird strike.

DATES: We must receive comments on this proposed AD by June 2, 2014.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, 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: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Learjet, Inc., One Learjet Way, Wichita, KS 67209-2942; telephone 316-
946-2000; fax 316-946-2220; email ac.ict@aero.bombardier.com; Internet 
http://www.bombardier.com. You may view this referenced service 
information at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue SW., Renton, WA. 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 by searching for and locating Docket No. FAA-2014-
0249; 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 (phone: 800-647-5527) is in the ADDRESSES section. Comments will 
be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Paul Chapman, Aerospace Engineer, 
Airframe Branch, FAA, Wichita Aircraft Certification Office, 1801 
Airport Road, Room 100, Wichita, KS, 67209; phone: 316-946-4152; fax: 
316-946-4152; email: paul.chapman@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2014-0249; 
Directorate Identifier 2012-NM-211-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 received reports of non-conforming windshield supports (coupe 
rails). Learjet Inc. identified windshield primary supports that do not 
meet their type design. The non-conforming windshield supports (coupe 
rails) might have been compromised during fuselage build or windshield 
installation. This condition, if not corrected, could result in 
uncontrolled cabin depressurization. Non-conforming windshield supports 
could also compromise the capability of the windshield to withstand a 
bird strike.

Relevant Service Information

    We reviewed the following service information. The service 
information describe procedures for a detailed visual inspection to 
detect gouging and scratches and to determine if a radius has been 
removed; an ultrasound inspection to measure the dimensions of the 
lower coupe rails; an eddy current inspection to detect cracks of the 
lower coupe rails, replacement of the lower coupe rails if necessary; 
and revision of the maintenance or inspection program, as applicable.
     Chapter 4, Airworthiness Limitations, of the Bombardier 
Learjet 45 Maintenance Manual MM-104, Revision 57, dated June 11, 2012.
     Chapter 4, Airworthiness Limitations, of the Bombardier 
Learjet 40 Maintenance Manual MM-105, Revision 25, dated June 11, 2012.
     Bombardier Recommended Service Bulletin 40-56-03, Revision 
1, dated October 15, 2012.
     Bombardier Recommended Service Bulletin 45-56-3, Revision 
1, dated October 15, 2012.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of these same type 
designs.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously.

Costs of Compliance

    We estimate that this proposed AD affects 351 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

[[Page 21417]]

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                   Labor cost          Parts cost       Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspection......................  40 work-hours x     $77...............  $3,477 per          $1,220,427 per
                                   $85 per hour =                          inspection cycle.   inspection cycle
                                   $3,400 per
                                   inspection cycle.
Maintenance or inspection         1 work hour x $85   None..............  $85...............  $29,835
 program revision.                 per hour = $85.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacement 
that would be required based on the results of the proposed inspection. 
We have no way of determining the number of aircraft that might need 
this replacement:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                Action                        Labor cost               Parts cost            Cost per product
----------------------------------------------------------------------------------------------------------------
Replacement..........................  500 work-hours (to       $15,000 (to replace      $57,500 (to replace
                                        replace both coupe       both coupe rails).       both coupe rails)
                                        rails) x $85 per hour
                                        = $42,500.
----------------------------------------------------------------------------------------------------------------

    According to the manufacturer, some of the costs of this proposed 
AD may be covered under warranty, thereby reducing the cost impact on 
affected individuals. We do not control warranty coverage for affected 
individuals. As a result, we have included all costs in our cost 
estimate.

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 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 this 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),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, 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:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

Learjet Inc.: Docket No. FAA-2014-0249; Directorate Identifier 2012-
NM-211-AD.

(a) Comments Due Date

    We must receive comments by June 2, 2014.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Learjet Inc. Model 45 airplanes, certificated 
in any category, as identified in Bombardier Recommended Service 
Bulletin 40-56-03, Revision 1, dated October 15, 2012 (serial 
numbers (S/Ns) 45-2000 through 45-2120 inclusive, and S/Ns 45-2122 
through 45-2130 inclusive); and Bombardier Recommended Service 
Bulletin 45-56-3, Revision 1, dated October 15, 2012 (S/Ns 45-005 
through 45-427 inclusive).

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of non-conforming windshield 
supports (coupe rails). We are issuing this AD to detect and correct 
non-conforming windshield supports, which could result in 
uncontrolled cabin depressurization. Non-conforming windshield 
supports could also compromise the capability of the windshield to 
withstand a bird strike.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Inspections and Corrective Actions

    Within 600 flight hours or 36 months after the effective date of 
this AD, whichever occurs first: Do the inspections specified in 
paragraphs (g)(1) through (g)(3) of this AD. Do all inspections and 
corrective actions specified in paragraphs (g)(1) through (g)(3) of 
this AD, in accordance with the Accomplishment Instructions of 
Bombardier Recommended Service Bulletin 40-56-03, Revision 1, dated 
October 15, 2012 (for S/Ns 45-2000 through 45-2120 inclusive, and 
45-2122 through 45-2130 inclusive); or Bombardier Recommended 
Service Bulletin 45-56-3, Revision 1, dated October 15, 2012 (for S/
Ns 45-005 through 45-427 inclusive).
    (1) Do a general visual inspection of the coupe rails to detect 
gouging and scratches

[[Page 21418]]

and to determine whether a radius has been removed or damaged.
    (i) If gouging or scratches are found, before further flight, 
burnish or blend the gouges and scratches.
    (ii) If the radius has been removed or damaged, before further 
flight, restore the radius.
    (2) Do an ultrasound inspection to measure the dimensions of the 
lower coupe rails.
    (i) If the coupe rail has an ``X'' dimension of 0.246 (6.248 
millimeters (mm)) or greater, and a ``Y'' dimension of 0.148 (3.759 
mm) or greater, before further flight, identify the coupe rail, in 
accordance with table 1 of Bombardier Recommended Service Bulletin 
40-56-03, Revision 1, dated October 15, 2012 (for S/Ns 45-2000 
through 45-2120 inclusive, and S/Ns 45-2122 through 45-2130 
inclusive); or Bombardier Recommended Service Bulletin 45-56-3, 
Revision 1, dated October 15, 2012 (for S/Ns 45-005 through 45-427 
inclusive).
    (ii) If the coupe rail has an ``X'' dimension between 0.246 
(6.248 mm) and 0.166 (4.216 mm) or a ``Y'' dimension between 0.148 
(3.759 mm) and 0.134 (3.403 mm), before further flight, identify the 
coupe rail, in accordance with table 2 of Bombardier Recommended 
Service Bulletin 40-56-03, Revision 1, dated October 15, 2012 (for 
S/Ns 45-2000 through 45-2120 inclusive, and S/Ns 45-2122 through 45-
2130 inclusive); or Bombardier Recommended Service Bulletin 45-56-3, 
Revision 1, dated October 15, 2012 (for S/Ns 45-005 through 45-427 
inclusive).
    (iii) If any coupe rail ``X'' dimension is below 0.166 (4.216 
mm) or ``Y'' dimension is below 0.134 (3.403 mm), before further 
flight, replace that coupe rail with a new coupe rail.
    (3) Do a flange and radius eddy current inspection for cracks of 
the left-hand and right-hand lower coupe rails.
    (i) If no crack is found, before further flight, mark the new 
data plate.
    (ii) If any crack is found, before further flight, replace the 
coupe rail with a new coupe rail.

(h) Maintenance/Inspection Program Revision

    Within 30 days after the effective date of this AD, revise the 
maintenance or inspection program, as applicable, by incorporating 
the applicable inspection reference number (IRN) tasks identified in 
table 1 to this paragraph, as specified in Chapter 4, Airworthiness 
Limitations, of the applicable maintenance manual specified in table 
1 to this paragraph. The initial task compliance time is the 
applicable initial compliance time specified in table 1 to this 
paragraph, or within 30 days after the effective date of this AD, 
whichever is later.

                             Table 1 to Paragraph (h) of This AD--IRN Task Revision
----------------------------------------------------------------------------------------------------------------
              Model--                       IRN--          Initial Compliance Time--        Chapter 4 of--
----------------------------------------------------------------------------------------------------------------
Model 40 airplanes.................  U5323167             Within 600 flight hours or  Bombardier Learjet 40
                                                           36 months, whichever        Maintenance Manual MM-
                                                           occurs first after the      105, Revision 25, dated
                                                           effective date of this AD.  June 11, 2012.
Model 40 airplanes.................  U5323168             Within 5,000 flight hours   Bombardier Learjet 40
                                                           after accomplishment of     Maintenance Manual MM-
                                                           Bombardier Recommended      105, Revision 25, dated
                                                           Service Bulletin 40-56-     June 11, 2012.
                                                           03, Revision 1, dated
                                                           October 15, 2012.
Model 45 airplanes.................  U5323167             Within 600 flight hours or  Bombardier Learjet 45
                                                           36 months, whichever        Maintenance Manual MM-
                                                           occurs first after the      104, Revision 57, dated
                                                           effective date of this AD.  June 11, 2012.
Model 45 airplanes.................  U5323168             Within 5,000 flight hours   Bombardier Learjet 45
                                                           after accomplishment of     Maintenance Manual MM-
                                                           Bombardier Recommended      104, Revision 57, dated
                                                           Service Bulletin 45-56-3,   June 11, 2012.
                                                           Revision 1, dated October
                                                           15, 2012.
----------------------------------------------------------------------------------------------------------------

(i) No Alternative Actions and Intervals

    After accomplishing the revision required by paragraph (h) of 
this AD, no alternative IRN task or interval may be used unless the 
IRN task or interval is approved as an alternative method of 
compliance (AMOC) in accordance with the procedures specified in 
paragraph (j) of this AD.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Wichita Aircraft Certification Office (ACO), 
FAA, has the authority to approve AMOCs for this AD, if requested 
using the procedures found in 14 CFR 39.19. In accordance with 14 
CFR 39.19, send your request to your principal inspector or local 
Flight Standards District Office, as appropriate. If sending 
information directly to the manager of the ACO, send it to the 
attention of the person identified in paragraph (k)(1) of this AD.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(k) Related Information

    (1) For more information about this AD, contact Paul Chapman, 
Aerospace Engineer, Airframe Branch, FAA, Wichita ACO, 1801 Airport 
Road, Room 100, Wichita, KS 67209; phone: 316-946-4152; fax: 316-
946-4152; email: paul.chapman@faa.gov.
    (2) For service information identified in this AD, contact 
Learjet, Inc., One Learjet Way, Wichita, KS 67209-2942; telephone 
316-946-2000; fax 316-946-2220; email ac.ict@aero.bombardier.com; 
Internet http://www.bombardier.com. You may view the referenced 
service information at the FAA, Transport Airplane Directorate, 1601 
Lind Avenue SW., Renton, WA. For information on the availability of 
this material at the FAA, call 425-227-1221.

    Issued in Renton, Washington, on April 1, 2014.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2014-08605 Filed 4-15-14; 8:45 am]
BILLING CODE 4910-13-P