Document ID: FAA-2013-0691-0001
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Learjet Inc. Airplanes
Posted Date: 2013-08-13T04:00Z

[Federal Register Volume 78, Number 156 (Tuesday, August 13, 2013)]
[Proposed Rules]
[Pages 49232-49235]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-19524]

-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0691; Directorate Identifier 2012-NM-170-AD]
RIN 2120-AA64

Airworthiness Directives; Learjet Inc. Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to supersede an existing airworthiness directive 
(AD) that applies to certain Learjet Inc. Model 60 airplanes. The 
existing AD currently requires determining if a certain fuel crossflow 
tube is installed; and follow-on/corrective actions, as applicable. 
Since we issued that AD, we have received a report that airplanes 
produced since 2003 might also be subject to the unsafe condition; and 
that the minimum allowable clearance is not established in the airplane 
maintenance information, and therefore, must be addressed by this 
proposed AD. This proposed AD would retain all actions in the previous 
AD, and would require determining if a certain fuel crossflow tube is 
installed, performing repetitive measurements of the fuel crossflow 
tube and surrounding valves and cables, and doing corrective actions if 
applicable. In addition, this proposed AD expands the applicability of 
the existing AD. We are proposing this AD to prevent chafing and 
consequent failure of the fuel crossflow tube due to inadequate 
clearance between the tube and the flight control cables, which could 
result in loss of fuel from one fuel tank during normal operating 
conditions or loss of fuel from both main fuel tanks during fuel cross-
feeding operations.

DATES: We must receive comments on this proposed AD by September 27, 
2013.

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 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 review copies of 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.

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 (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: Jeff Janusz, Aerospace Engineer, 
Propulsion Branch, ACE-116W, FAA, Wichita Aircraft Certification Office 
(ACO), 1801 Airport Road, Room 100, Wichita, Kansas 67209; phone: 316-
946-4148; fax: 316-946-4107; email: jeff.janusz@faa.gov.

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-2013-0691; 
Directorate Identifier 2012-NM-170-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

    On September 16, 2003, we issued AD 2003-19-11, Amendment 39-13314 
(68 FR 55812, September 29, 2003), for certain Learjet Inc. Model 60 
airplanes. That AD requires a review of airplane maintenance records or 
an inspection to determine if a fuel crossflow tube having a certain 
part number is installed; and follow-on/corrective actions, as 
applicable. That AD resulted from reports of chafing of the fuel 
crossflow tube by flight control cables. We issued that AD to prevent 
chafing and consequent failure of the fuel crossflow tube due to 
inadequate clearance between the tube and the flight control cables, 
which could result in loss of fuel from one fuel tank during normal 
operating conditions or loss of fuel from both main fuel tanks during 
fuel cross-feeding operations.

Actions Since Existing AD 2003-19-11, Amendment 39-13314 (68 FR 55812, 
September 29, 2003) Was Issued

    Since we issued AD 2003-19-11, Amendment 39-13314 (68 FR 55812, 
September 29, 2003), we have received a report that airplanes produced 
since 2003 might be subject to the unsafe condition; and that the 
minimum allowable clearance is not established in the airplane 
maintenance information, and therefore, must be addressed by this 
proposed AD.

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 the same type design.

Proposed AD Requirements

    This proposed AD would retain all requirements of AD 2003-19-11, 
Amendment 39-13314 (68 FR 55812, September 29, 2003). This proposed AD 
would retain all actions in the previous AD, and would require 
determining if a certain fuel crossflow tube is installed, performing 
repetitive measurements of the fuel crossflow tube and surrounding 
valve and cables, and doing corrective actions if applicable.

[[Page 49233]]

Differences Between the AD and the Service Information

    Although Bombardier Alert Service Bulletin A60-28-3, Revision 2, 
dated October 26, 1998, applies to Learjet Inc. Model 60 airplanes, 
serial numbers 60-001 through 60-145 inclusive, this AD applies to 
Learjet Inc. Model 60 airplanes, serial numbers 60-001 through 60-409 
inclusive. Airplanes having serial numbers 60-001 through 60-409 are 
subject to the unsafe condition. In addition, the minimum allowable 
clearance is not established in the airplane maintenance information, 
and therefore, a repetitive measurement is necessary. This difference 
has been coordinated with Learjet Inc.

Change to Existing AD 2003-19-11, Amendment 39-13314 (68 FR 55812, 
September 29, 2003)

    This proposed AD would retain all requirements of AD 2003-19-11, 
Amendment 39-13314 (68 FR 55812, September 29, 2003). Since AD 2003-19-
11 was issued, the AD format has been revised, and certain paragraphs 
have been rearranged. As a result, the corresponding paragraph 
identifiers have changed in this proposed AD, as listed in the 
following table:

                      Revised Paragraph Identifiers
------------------------------------------------------------------------
   Requirement in AD 2003-19-11,
 Amendment 39-13314 (68 FR 55812,     Corresponding requirement in this
        September 29, 2003)                      proposed AD
------------------------------------------------------------------------
 paragraph (a)                       paragraph (g)
 paragraph (b)                       paragraph (h)
 paragraph (c)                       paragraph (i)
 paragraph (d)                       paragraph (j)
------------------------------------------------------------------------

Costs of Compliance

    We estimate that this proposed AD affects 264 airplanes of U.S. 
registry.
    We estimate the following costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
               Action                        Labor cost           Parts cost        product         operators
----------------------------------------------------------------------------------------------------------------
Inspection [retained actions from AD  2 work-hours x $85 per               $2             $172          $45,408
 2003-19-11, Amendment 39-13314 (68    hour = $170.
 FR 55812, September 29, 2003)].
----------------------------------------------------------------------------------------------------------------

    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
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replacement..................................  4 work-hours x $85 per hour =               $20             $360
                                                $340.
----------------------------------------------------------------------------------------------------------------

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 proposed 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),
    (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 removing airworthiness directive (AD) 
2003-19-11, Amendment 39-13314 (68 FR 55812, September 29, 2003), and 
adding the following new AD:

Learjet Inc.: Docket No. FAA-2013-0691; Directorate Identifier 2012-
NM-170-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by September 27, 
2013.

(b) Affected ADs

    This AD supersedes AD 2003-19-11, Amendment 39-13314 (68 FR 
55812, September 29, 2003).

(c) Applicability

    This AD applies to Learjet Inc. Model 60 airplanes, certificated 
in any category, serial numbers 60-001 through 60-409 inclusive.

[[Page 49234]]

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 28, Fuel.

(e) Unsafe Condition

    This AD was prompted by reports of chafing of the fuel crossflow 
tube by flight control cables. We are issuing this AD to prevent 
chafing and consequent failure of the fuel crossflow tube due to 
inadequate clearance between the tube and the flight control cables, 
which could result in loss of fuel from one fuel tank during normal 
operating conditions or loss of fuel from both main fuel tanks 
during fuel cross-feeding operations.

(f) Compliance

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

(g) Retained Part Identification

    This paragraph restates the part identification required by 
paragraph (a) of AD 2003-19-11, Amendment 39-13314 (68 FR 55812, 
September 29, 2003). For serial numbers 60-001 through 60-145 
inclusive: Within 25 flight hours after November 3, 2003 (the 
effective date of AD 2003-19-11), inspect the fuel crossflow tube to 
determine whether part number (P/N) 6026020-005 is installed. 
Instead of inspecting the tube, a review of airplane maintenance 
records is acceptable if the P/N of the tube can be positively 
determined from that review.

(h) Retained Clearance Measurement and Corrective Action for Airplanes 
Having Serial Numbers 60-001 Through 60-145, With Revised Repair 
Language

    This paragraph restates the clearance measurement and corrective 
action required by paragraph (b) of AD 2003-19-11, Amendment 39-
13314 (68 FR 55812, September 29, 2003), with revised repair 
language. For Learjet Inc. Model 60 airplanes, serial numbers 60-001 
through 60-145 inclusive: If P/N 6026020-005 is found installed 
during the review or inspection required by paragraph (g) of this 
AD, before further flight, measure the clearance between the fuel 
crossflow tube and the flight control cables to determine if it is 
at least 0.35 inch, per paragraph 2.B.(8) of the Accomplishment 
Instructions of Bombardier Alert Service Bulletin A60-28-3, Revision 
2, dated October 26, 1998.
    (1) If the clearance is 0.35 inch or more, no further action is 
required by this paragraph.
    (2) If the clearance is less than 0.35 inch, before further 
flight, repair in accordance with a method approved by the Manager, 
Wichita Aircraft Certification Office (ACO), FAA. For a repair 
method to be approved by the Manager, Wichita ACO, as required by 
this paragraph, the Manager's approval letter must specifically 
refer to this AD.

(i) Retained Part Replacement, Measurement, and Repair for Airplanes 
Having Serial Numbers 60-001 Through 60-055, With Revised Repair 
Language

    This paragraph restates the clearance measurement and corrective 
action required by paragraph (c) of AD 2003-19-11, Amendment 39-
13314 (68 FR 55812, September 29, 2003), with revised repair 
language. For airplanes having serial numbers 60-001 through 60-055: 
If P/N 6026020-005 is not found installed during the review or 
inspection required by paragraph (g) of this AD, within 90 days 
after accomplishing the review or inspection, replace the existing 
fuel crossflow tube with a new fuel crossflow tube having P/N 
6026020-005, and measure the clearance between the newly installed 
fuel crossflow tube and the flight control cables, per paragraph 
2.A. of the Accomplishment Instructions of Bombardier Service 
Bulletin 60-28-4, Revision 2, dated August 22, 2001.
    (1) If the clearance is 0.35 inch or more, no further action is 
required by this paragraph.
    (2) If the clearance is less than 0.35 inch, before further 
flight, repair in accordance with a method approved by the Manager, 
Wichita ACO, FAA. For a repair method to be approved by the Manager, 
Wichita ACO, as required by this paragraph, the Manager's approval 
letter must specifically refer to this AD.

(j) Retained Part Replacement, Measurement, and Repair for Airplanes 
Having Serial Numbers 60-056 Through 60-145, With Revised Repair 
Language

    This paragraph restates the clearance measurement and corrective 
action required by paragraph (d) of AD 2003-19-11, Amendment 39-
13314 (68 FR55812, September 29, 2003), with revised repair 
language. For airplanes having serial numbers 60-056 through 60-145: 
If P/N 6026020-005 is not found installed during the review or 
inspection required by paragraph (g) of this AD, within 90 days 
after accomplishing the review or inspection, replace the existing 
fuel crossflow tube with a new fuel crossflow tube having P/N 
6026020-005, and measure the clearance between the newly installed 
fuel crossflow tube and the flight control cables to determine if 
the clearance is at least 0.35 inch, per paragraph 2.B. of the 
Accomplishment Instructions of Bombardier Alert Service Bulletin 
A60-28-3, Revision 2, dated October 26, 1998.
    (1) If the clearance is 0.35 inch or more, no further action is 
required by this paragraph.
    (2) If the clearance is less than 0.35 inch, before further 
flight, repair in accordance with a method approved by the Manager, 
Wichita ACO, FAA. For a repair method to be approved by the Manager, 
Wichita ACO, as required by this paragraph, the Manager's approval 
letter must specifically refer to this AD.
    Note 1 to paragraphs (h) and (j) of this AD: Bombardier Alert 
Service Bulletin A60-28-3, Revision 2, dated October 26, 1998, 
Figure 1, Detail D, incorrectly identifies the fuel crossflow tube 
to be installed as P/N 6026020-001. The manufacturer is aware of 
this error and stated it plans to correct the part number in the 
next revision of the service information.

(k) New Part Identification

    For airplanes having serial numbers 60-001 through 60-409 
inclusive: Within 25 flight hours after the effective date of this 
AD, inspect the fuel crossflow tube to determine whether P/N 
6026020-005 is installed. In lieu of inspecting the tube, a review 
of airplane maintenance records is acceptable if the P/N of the tube 
can be positively determined from that review.

(l) New Clearance Measurement

    If P/N 6026020-005 is found installed during the inspection 
required by paragraph (k) of this AD, before further flight, measure 
the clearance between the fuel crossflow tube and both elevator 
control cables to determine if it is 0.35 inches or more, in 
accordance with paragraph 2.A.(9) of the Accomplishment Instructions 
of Bombardier Optional Spares Service Bulletin 60-28-4, Revision 2, 
dated August 22, 2001.
    (1) If the clearance is 0.35 inch or more, no further action is 
required by this paragraph.
    (2) If the clearance is less than 0.35 inch, before further 
flight, adjust the fit of the P/N 6026020-005 tube to provide 0.35 
inch or more clearance to both elevator control cables, in 
accordance with paragraph 2.A.(9) of the Accomplishment Instructions 
of Bombardier Optional Spares Service Bulletin 60-28-4, Revision 2, 
dated August 22, 2001. If the tube shows any indication of chafing 
from the control cables, before further flight, replace the fuel 
cross flow tube with a new fuel cross flow tube, in accordance with 
paragraph 2.A.(9) of the Accomplishment Instructions of Bombardier 
Optional Spares Service Bulletin 60-28-4, Revision 2, dated August 
22, 2001.

(m) New Repetitive Measurements

    For all airplanes: As of the effective date of this AD and after 
accomplishing the inspection required by paragraph (g) or (k) of 
this AD, as applicable: Before further flight after removal, 
replacement, or adjustment of any crossflow tube, fuel cross flow 
drain valve, fuel cross flow valve or related plumbing and fittings, 
and elevator control cable, measure the clearance between the fuel 
crossflow tube and the flight control cables, in accordance with 
paragraph 2.A.(9) of the Accomplishment Instructions of Bombardier 
Optional Spares Service Bulletin 60-28-4, Revision 2, dated August 
22, 2001.
    (1) If the clearance is 0.35 inch or more, no further action is 
required by this paragraph.
    (2) If the clearance is less than 0.35 inch, before further 
flight, adjust the fit of the P/N 6026020-005 tube to provide 0.35 
inch or more clearance to both elevator control cables, in 
accordance with paragraph 2.A.(9) of the Accomplishment Instructions 
of Bombardier Optional Spares Service Bulletin 60-28-4, Revision 2, 
dated August 22, 2001.

(n) Reporting Requirement

    Submit a report of the findings of the initial measurement 
required by paragraph (l) of this AD to the Wichita Manufacturing 
Inspection District Office, 2204 S. Tyler Rd, Wichita, KS, 67209-
3001, at the applicable time specified in paragraph (n)(1) or (n)(2) 
of this AD. The report must include the airplane registration, 
serial number, the total time in service, and the measured clearance 
found between the fuel crossflow tube and the elevator control 
cables after the initial inspection. Under the provisions of the

[[Page 49235]]

Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of 
Management and Budget (OMB) has approved the information collection 
requirements contained in this AD and has assigned OMB Control 
Number 2120 0056.
    (1) If the inspection was done on or after the effective date of 
this AD: Submit the report within 30 days after the inspection.
    (2) If the inspection was done before the effective date of this 
AD: Submit the report within 30 days after the effective date of 
this AD.

(o) Part Installation Limitation

    As of the effective date of AD, only fuel crossflow tubes having 
P/N 6026020-005 may be installed on any airplane.

(p) Paperwork Reduction Act Burden Statement

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty 
for failure to comply with a collection of information subject to 
the requirements of the Paperwork Reduction Act unless that 
collection of information displays a current valid OMB Control 
Number. The OMB Control Number for this information collection is 
2120-0056. Public reporting for this collection of information is 
estimated to be approximately 5 minutes per response, including the 
time for reviewing instructions, completing and reviewing the 
collection of information. All responses to this collection of 
information are mandatory. Comments concerning the accuracy of this 
burden and suggestions for reducing the burden should be directed to 
the FAA at: 800 Independence Ave. SW., Washington, DC 20591, Attn: 
Information Collection Clearance Officer, AES-200.

(q) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Wichita 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 the 
Related Information section 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.

 (r) Related Information

    (1) For more information about this AD, contact Jeff Janusz, 
Aerospace Engineer, Propulsion Branch, ACE-116W, FAA, Wichita 
Aircraft Certification Office (ACO), 1801 Airport Road, Room 100, 
Wichita, Kansas 67209; phone: 316-946-4148; fax: 316-946-4107; 
email: jeff.janusz@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 review copies of 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 August 2, 2013.
Ross Landes,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-19524 Filed 8-12-13; 8:45 am]
BILLING CODE 4910-13-P