[Federal Register Volume 64, Number 78 (Friday, April 23, 1999)]
[Proposed Rules]
[Pages 19938-19940]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-10185]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-371-AD]
RIN 2120-AA64


Airworthiness Directives; Lockheed Model 382 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Lockheed Model 382 series 
airplanes. This proposal would require a one-time visual inspection of 
the under floor to ring fittings at fuselage station 817E to verify 
installation of the correct sized fasteners; and follow-on corrective 
actions, if necessary. This proposal is prompted by notification from 
the manufacturer indicating that during production incorrect sized 
fasteners were installed on the under floor to ring fittings at 
fuselage station 817E. The actions specified by the proposed AD are 
intended to prevent fatigue cracking of the fastener holes and adjacent 
fuselage structure due to installation of the incorrect sized 
fasteners, which could result in reduced structural integrity of the 
airplane.

DATES: Comments must be received by June 7, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-371-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from Lockheed Martin Aeronautical Systems Support Company 
(LMASSC), Field Support Department, Dept. 693, Zone

[[Page 19939]]

0755, 2251 Lake Park Drive, Smyrna, Georgia 30063. This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA, Small Airplane 
Directorate, Atlanta Aircraft Certification Office, One Crown Center, 
1895 Phoenix Boulevard, suite 450, Atlanta, Georgia.

FOR FURTHER INFORMATION CONTACT: Thomas Peters, Aerospace Engineer, 
Systems and Flight Test Branch, ACE-116A, FAA, Small Airplane 
Directorate, Atlanta Aircraft Certification Office, One Crown Center, 
1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone 
(770) 703-6063; fax (770) 703-6097.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-371-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules 
Docket No. 98-NM-371-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received notification from the manufacturer indicating 
that during production, incorrect sized fasteners were installed on 
Lockheed Martin Model 382 series airplanes. These fasteners are located 
on the under floor to ring fittings (aft ``pork chop'' fittings) at 
fuselage station 817E. The installation of \5/32\-inch diameter 
fasteners in lieu of the correct \3/16\-inch diameter fasteners could 
cause fatigue cracking of the fuselage structure by increasing the 
stress loads of the fuselage skin. Such cracking, if not detected and 
corrected, could result in reduced structural integrity of the 
airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Lockheed Hercules Alert Service 
Bulletin A382-53-57, Revision 1, dated January 30, 1997, which 
describes procedures for a one-time visual inspection of the under 
floor to ring fittings (aft ``pork chop'' fittings) at fuselage station 
817E to verify installation of the correct sized fasteners; and follow-
on corrective actions, if necessary. The follow-on corrective actions 
involve measurement of the distance between the incorrect sized 
fasteners, removal of discrepant fasteners, and a visual inspection of 
the fastener holes and surrounding areas to detect discrepancies 
(damage, corrosion, or misdrilled or elongated fastener holes). The 
alert service bulletin also describes procedures for redrilling the 
fastener holes at fuselage station 817E, visually inspecting the 
fastener holes to confirm damage removal, and installing new fasteners. 
Accomplishment of the actions specified in the alert service bulletin 
is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require accomplishment of the actions specified in 
the alert service bulletin described previously, except as discussed 
below.

Differences Between Proposed Rule and Service Bulletin

    Operators should note that the alert service bulletin specifies 
that visual inspection and/or rework of the under floor to ring 
fasteners at fuselage station 817E be accomplished upon receipt of the 
alert service bulletin, or an immediate cabin pressurization limit of 
8.75 in Hg (4.3 psi) is to be implemented. However, the FAA finds that 
a 30-day compliance time for accomplishment of the inspection and 
rework is adequate in that the FAA has determined that fatigue cracking 
originating at the fastener holes caused by the installation of 
incorrect size of fasteners could result in loss of pressurization, but 
not an ``explosive decompression'' or severe structural degradation. In 
light of this, the FAA finds that it is not necessary to implement an 
immediate cabin pressurization limit of 8.75 in Hg (4.3 psi) for 
affected airplanes to continue to operate without compromising safety.
    Operators also should note that, although the alert service 
bulletin specifies that the manufacturer may be contacted for 
disposition of certain repair conditions, this proposal would require 
the repair of those conditions to be accomplished in accordance with a 
method approved by the FAA.

Cost Impact

    There are approximately 112 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 18 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
1 work hour per airplane to accomplish the proposed inspection, and 
that the average labor rate is $60 per work hour. Based on these 
figures, the cost impact of the inspection proposed by this AD on U.S. 
operators is estimated to be $1,080, or $60 per airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the proposed requirements of 
this AD action, and that no operator would accomplish those actions in 
the future if this AD were not adopted.

Regulatory Impact

    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that 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); 
and (3) if promulgated, 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. A copy of the draft

[[Page 19940]]

regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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. 106(g), 40113, 44701.

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Lockheed: Docket 98-NM-371-AD.

    Applicability: Model 382 series airplanes as listed in paragraph 
1.A.(1) (``Effectivity'') of Lockheed Hercules Alert Service 
Bulletin A382-53-57, Revision 1, dated January 30, 1997; 
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 request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent fatigue cracking of the fastener holes and adjacent 
fuselage structure due to installation of the incorrect sized 
fasteners, which could result in reduced structural integrity of the 
airplane, accomplish the following:
    (a) Within 30 days after the effective date of this AD, perform 
a one-time visual inspection of the under floor to ring fittings at 
fuselage station 817E to verify installation of the correct sized 
fasteners, in accordance with Lockheed Hercules Alert Service 
Bulletin A382-53-57, Revision 1, dated January 30, 1997.

    Note 2: Inspections, repairs, or replacements that have been 
accomplished prior to the effective date of this AD, in accordance 
with Lockheed Hercules Alert Service Bulletin A382-53-57, dated 
January 16, 1997, are considered acceptable for compliance with the 
applicable action specified by this AD.

    (1) If all fasteners are the correct size, no further action is 
required by this AD.
    (2) If any fastener is determined to be the incorrect size, 
prior to further flight, measure the distance between the fastener 
centers in accordance with the alert service bulletin.
    (i) If the distance between the fastener centers is less than 
0.57 inch, prior to further flight, repair in accordance with a 
method approved by the Manager, Atlanta Aircraft Certification 
Office (ACO), FAA, Small Airplane Directorate.
    (ii) If the distance between the fastener centers is greater 
than or equal to 0.57 inch, prior to further flight, accomplish the 
requirements of paragraph (b) of this AD.
    (b) For all airplanes on which the distance between the fastener 
centers is greater than or equal to 0.57 inch: Prior to further 
flight, remove any incorrect sized fastener and perform a one-time 
visual inspection of the fastener holes and adjacent fuselage 
structure to detect discrepancies (damage, corrosion, or misdrilled 
or elongated fastener holes) in accordance Lockheed Hercules Alert 
Service Bulletin A382-53-57, Revision 1, January 30, 1997.
    (1) If no discrepancy is detected, prior to further flight, 
redrill the fastener holes to the correct size and install correct 
sized fasteners in accordance with the alert service bulletin.
    (2) If any discrepancy is detected, prior to further flight, 
redrill the fastener holes to the correct size and perform an 
additional one-time visual inspection of the redrilled holes to 
detect remaining discrepancies (damage, corrosion, or misdrilled or 
elongated fastener holes) of the affected area, in accordance with 
the alert service bulletin.
    (i) If no remaining discrepancy is detected, prior to further 
flight, install the correct sized fasteners in accordance with the 
alert service bulletin.
    (ii) If any remaining discrepancy is detected, prior to further 
flight, repair in accordance with a method approved by the Manager, 
Atlanta ACO.

Alternative Methods of Compliance

    (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, Atlanta ACO. Operators shall submit 
their requests through an appropriate FAA Principal Maintenance 
Inspector, who may add comments and then send it to the Manager, 
Atlanta ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Atlanta ACO.

Special Flight Permits

    (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.

    Issued in Renton, Washington, on April 19, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-10185 Filed 4-22-99; 8:45 am]
BILLING CODE 4910-13-U