[Federal Register Volume 60, Number 138 (Wednesday, July 19, 1995)]
[Rules and Regulations]
[Pages 36984-36986]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-16377]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-119-AD; Amendment 39-9303; AD 95-14-09]


Airworthiness Directives; Learjet Model 60 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Learjet Model 60 airplanes. This action 
requires inspection to detect bends in or damage to the fuel crossflow 
tube; inspection to determine clearance between the fuel crossflow tube 
and the flight control cables; and replacement or repair of the tube, 
if necessary. This amendment is prompted by reports of damage to the 
fuel crossflow tube and inadequate clearance between the fuel crossflow 
tube and the flight control cables due to bends in the fuel crossflow 
tube. The actions specified in this AD are intended to prevent chafing 
and eventual failure of the fuel crossflow tube due to inadequate 
clearance between the tube and the flight control cables; this 
condition 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: Effective August 3, 1995. -
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 3, 1995. -

[[Page 36985]]

    Comments for inclusion in the Rules Docket must be received on or 
before September 18, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-119-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. -
    The service information referenced in this AD may be obtained from 
Learjet, P.O. Box 7707, Wichita, Kansas 67277-7707. This information 
may be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Wichita Aircraft 
Certification Office, Small Airplane Directorate, 1801 Airport Road, 
Room 100, Mid-Continent Airport, Wichita, Kansas; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Charles D. Riddle, Aerospace Engineer, 
Propulsion Branch, ACE-117W, FAA, Wichita Aircraft Certification 
Office, Small Airplane Directorate, 1801 Airport Road, Room 100, Mid-
Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4144; fax 
(316) 946-4407.

SUPPLEMENTARY INFORMATION: Recently, the FAA has received reports from 
operators of Learjet Model 60 airplanes that the fuel crossflow tube in 
the underwing keelbeam area was bent slightly upward. In two instances, 
the fuel crossflow tube was found to be chafed by the flight control 
cables due to inadequate clearance between the flight control cables 
and the fuel crossflow tube. Investigation revealed that the tube was 
installed improperly. Chafing and eventual failure of the fuel 
crossflow tube due to inadequate clearance between the tube and the 
flight control cables, if not corrected, 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. -
    The FAA has reviewed and approved Learjet Alert Service Bulletin SB 
A60-28-3, dated May 12, 1995, which describes procedures for inspection 
to detect bends in or damage to the fuel crossflow tube, and 
replacement of bent or damaged tubes with new tubes; and inspection to 
determine the clearance between the fuel crossflow tube and the flight 
control cables, and replacement of tubes with new tubes if inadequate 
clearance exists. This alert service bulletin describes procedures for 
replacement of the fuel crossflow tube with a new tube for a certain 
group of airplanes. Replacement procedures for the remaining group of 
airplanes is described in Learjet Service Bulletin SB 60-28-4, dated 
May 12, 1995, which the FAA has reviewed and approved. -
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Learjet Model 60 airplanes of the same type 
design, this AD is being issued to prevent chafing and eventual failure 
of the fuel crossflow tube due to inadequate clearance between the tube 
and the flight control cables; this condition 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. 
This AD requires inspection to detect bends in or damage to the fuel 
crossflow tube, inspection to determine clearance between the fuel 
crossflow tube and the flight control cables, and replacement of tubes, 
if necessary. The actions are required to be accomplished in accordance 
with the service bulletins described previously. -
    This AD differs from the service bulletin in that the AD requires 
replacement of the tube if the tube is not bent or damaged and minimum 
clearance does not exist. This AD also requires the repair of certain 
fuel crossflow tubes in accordance with a method approved by the FAA. -
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been included in this rule to clarify this long-standing requirement. -
    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited -

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the Rules Docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed. -
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination by interested persons. A report that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket. -
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-119-AD.'' The postcard will be date stamped and 
returned to the commenter. -
    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment. -
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 

[[Page 36986]]
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39 -

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment -

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES -

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

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended] -

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:
95-14-09 Learjet: Amendment 39-9303. Docket 95-NM-119-AD. -
    Applicability: Model 60 airplanes having serial numbers 60-001 
through 60-058 inclusive, certificated in any category.

     -Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must use the authority 
provided in paragraph (c) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

     -Compliance: Required as indicated, unless accomplished 
previously. -
    To prevent 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, due to chafing and eventual 
failure of the fuel crossflow tube, accomplish the following: -
    (a) Within 10 hours time-in-service after the effective date of 
this AD, perform a visual inspection to detect bends in or damage to 
the fuel crossflow tube, and perform an inspection to determine 
whether the clearance between the fuel crossflow tube and the flight 
control cables is at least 0.150 inch; in accordance with Learjet 
Alert Service Bulletin SB A60-28-3, dated May 12, 1995. -
    (1) If the tube is not found to be bent or damaged, and a 
minimum clearance of 0.150 inch exists, no further action is 
required by this AD. -
    (2) If the tube is not found to be bent or damaged, and a 
minimum clearance of 0.150 inch does not exist, within 10 hours 
time-in-service after the effective date of this AD, replace the 
tube with a new tube in accordance with either paragraph (a)(2)(i) 
or (a)(2)(ii) of this AD, as applicable. Prior to further flight 
following replacement of the tube, perform an inspection to 
determine whether the clearance between the fuel crossflow tube and 
the flight control cables is at least 0.150 inch, in accordance with 
Learjet Alert Service Bulletin SB A60-28-3, dated May 12, 1995. -
    (i) For airplanes having serial numbers 60-001 through 60-055, 
inclusive: Replace the fuel crossflow tube with a new tube in 
accordance with Learjet Service Bulletin SB 60-28-4, dated May 12, 
1995. -
    (ii) For airplanes having serial number 60-056 through 60-058, 
inclusive: Replace the fuel crossflow tube with a new tube in 
accordance with paragraph 2.B. of Learjet Alert Service Bulletin SB 
A60-28-3, dated May 12, 1995. -
    (3) If the tube is found to be bent or damaged, prior to further 
flight, replace the tube with a new tube in accordance with either 
paragraph (a)(3)(i) or (a)(3)(ii) of this AD, as applicable. Prior 
to further flight following replacement of the tube, perform an 
inspection to determine whether the clearance between the fuel 
crossflow tube and the flight control cables is at least 0.150 inch, 
in accordance with Learjet Alert Service Bulletin SB A60-28-3, dated 
May 12, 1995. -
    (i) For airplanes having serial numbers 60-001 through 60-055, 
inclusive: Replace the fuel crossflow tube with a new tube in 
accordance with Learjet Service Bulletin SB 60-28-4, dated May 12, 
1995.
    -(ii) For airplanes having serial number 60-056 through 60-058, 
inclusive: Replace the fuel crossflow tube with a new tube in 
accordance with paragraph 2.B. of Learjet Alert Service Bulletin SB 
A60-28-3, dated May 12, 1995. -
    (b) If a minimum clearance of 0.150 inch does not exist on the 
new fuel crossflow tube that was installed in accordance with the 
requirements of paragraph (a) of this AD, prior to further flight, 
repair in accordance with a method approved by the Manager, Wichita 
Aircraft Certification Office (ACO), FAA, Small Airplane 
Directorate. -
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Wichita ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Wichita ACO.

     -Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Wichita ACO. -
    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished. -
    (e) The inspections and certain replacements shall be done in 
accordance with Learjet Alert Service Bulletin SB A60-28-3, dated 
May 12, 1995; and certain other replacements shall be done in 
accordance with Learjet Service Bulletin SB 60-28-4, dated May 12, 
1995. This incorporation by reference was approved by the Director 
of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from Learjet, P.O. Box 7707, 
Wichita, Kansas 67277-7707. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the FAA, Wichita Aircraft Certification Office, 
Small Airplane Directorate, 1801 Airport Road, Room 100, Mid-
Continent Airport, Wichita, Kansas; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC. 
-
    (f) This amendment becomes effective on August 3, 1995.

    Issued in Renton, Washington, on June 28, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-16377 Filed 7-18-95; 8:45 am]
BILLING CODE 4910-13-U