Airworthiness Directives; McDonnell Douglas Model DC-8 Series Airplanes

[Federal Register Volume 66, Number 247 (Wednesday, December 26, 2001)]
[Rules and Regulations]
[Pages 66296-66299]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-31553]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-283-AD; Amendment 39-12568; AD 2001-26-04]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-8 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain McDonnell Douglas Model DC-8 series airplanes 
that have been converted from a passenger-to a cargo-carrying 
(``freighter'') configuration, that requires, among other actions, 
modification of the main deck cargo door structure and fuselage 
structure; replacement of fasteners in the two door-side hinge 
elements; modification of the main deck cargo floor; and installation 
of a main deck cargo 9g crash barrier. The actions specified by this AD 
are intended to prevent opening of the cargo door while the airplane is 
in flight, and consequent rapid decompression of the airplane including 
possible loss of flight control or severe structural damage. These 
actions are intended to address the identified unsafe condition.

DATES: Effective January 30, 2002.

ADDRESSES: Information pertaining to this AD may be examined at the 
Federal Aviation Administration (FAA), Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles 
Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, 
California.

FOR FURTHER INFORMATION CONTACT: Michael E. O'Neil, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification 
Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 
telephone (562) 627-5320; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain McDonnell Douglas Model 
DC-8 series airplanes that have been converted from a passenger-to a 
cargo-carrying (``freighter'') configuration was published in the 
Federal Register on September 27, 2000 (65 FR 58203). That action 
proposed to require, among other actions, modification of the main deck 
cargo door structure and fuselage structure; replacement of fasteners 
in the two door-side hinge elements; modification of the main deck 
cargo floor; and installation of a main deck cargo 9g crash barrier.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Revise Compliance Times

    One commenter requests that the compliance times specified in 
paragraph (b) of the proposed AD be revised from ``Within 2 years or 
2,000 flight cycles after the effective date of this AD, whichever 
occurs first'' to ``within 3 years or 4,000 flight cycles after the 
effective date of this AD, whichever occurs first.'' The commenter 
contends that if the inspection and evaluation required by that 
paragraph reveals a discrepancy, the corrective modification will be 
extensive. The commenter states that such an extension would allow 
operators to correct discrepancies at one maintenance visit, and thus, 
minimize airplane downtime.
    The FAA agrees. Since issuance of the NPRM, we have gained a better 
understanding of the design feature of the original modification 
relative to the vertical side restraint installation and decompression 
venting. We have determined that the structure is sufficiently robust, 
and that accomplishing the required inspection, evaluation, and 
modification, if necessary, required by paragraph (b) of this AD 
``within 3 years or 4,000 flight hours after the effective date of this 
AD, whichever occurs first,'' will provide an acceptable level of 
safety. For the same reasons, we also find that the 2-year compliance 
time for the modification required by paragraph (e) of this AD can be 
extended to ``within 3 years or 4,000 flight hours after the effective 
date of this AD, whichever occurs first.'' Therefore, we have revised 
the compliance times of paragraphs (b) and (e) of the final rule 
accordingly.
    The same commenter requests that the compliance time specified in 
paragraph (f)(2) of the proposed AD be revised from ``Within 2 years or 
2,000 flight

[[Page 66297]]

hours after the effective date of this AD, whichever occurs first'' to 
``within 3 years or 4,000 flight cycles after the effective date of 
this AD, whichever occurs first.'' The commenter states that postponing 
the replacement for another year will not adversely affect safety, 
because incorporating inspections into the operator's FAA-approved 
maintenance or inspection program within 1 year, as required by 
paragraph (a)(1) of the proposed AD, will provide an acceptable level 
of safety. The commenter also states that a 3-year compliance time 
would allow it to perform the proposed replacement concurrently with 
the major rework on the door structure, and thus, reduce airplane 
downtime.
    Based on the commenter's reasons, the FAA agrees to extend the 
compliance time for the replacement required by paragraph (f)(2) of 
this AD. Extending the compliance time to ``within 3 years or 4,000 
flight cycles'' will not adversely affect safety and will allow the 
replacement to be performed at a base during regularly scheduled 
maintenance where special equipment and trained maintenance personnel 
will be available if necessary. We have revised paragraph (f)(2) of the 
final rule to specify a compliance time of ``within 3 years or 4,000 
flight cycles after the effective date of this AD, whichever occurs 
first.'' It should be noted that we inadvertently used ``flight hours'' 
instead of ``flight cycles'' in paragraphs (f)(1) and (f)(2) of the 
NPRM. Therefore, we have revised that term to read ``flight cycles'' in 
paragraphs (f)(1) and (f)(2) of the final rule, as was used in other 
paragraphs of the NPRM.

Request To Provide an Alternate Means of Compliance

    The commenter also requests that paragraph (a)(2)(i) of the 
proposed AD be revised to include an option that states: ``Main deck 
zone loading can be limited as approved by manager LA ACO in such a 
manner that no modification is required for the main deck floor 
structure. This will eliminate the requirement for Alternate Means of 
Compliance.'' The commenter notes that under the heading ``3. 
Capability of the Unmodified Floor'' in the preamble of the proposed 
AD, it states ``It is also possible to limit the main deck zone loading 
to a level that the main deck cargo floor can be supported safely 
without modification.'' The commenter states that the analysis 
performed by the DC-8 Cargo Conversion Joint Task Force and FAA has 
shown that the main deck floor modified per Supplemental Type 
Certificate (STC) SA1802SO or SA421NW is capable of carrying the zone 
loads equivalent to Aeronavali modified airplanes.
    The FAA consulted with the commenter to clarify its reference to 
paragraph (a)(2)(i) of the proposed AD. The commenter meant to refer to 
paragraph (c) of the proposed AD. We do not agree with the commenter's 
request to revise paragraph (c) of the final rule. We find that the 
option suggested by the commenter would require operators to obtain a 
separate approval from the Manager of the Los Angeles Aircraft 
Certification Office (ACO). Adding the commenter's statement in the AD 
would not save us or the operators any resources, because, like the 
requirements of paragraph (c) of this AD, it also would require 
operators to submit a letter and substantiating data to us for review. 
The difference between the two letters would be in name only (i.e., 
alternate method of compliance vs. approved method of compliance). 
Therefore, no change to paragraph (c) of the final rule is necessary.

Approval of Supplemental Type Certificate (STC)

    Since issuance of the NPRM, the FAA has reviewed and approved STC 
ST01181LA (held by Structural Integrity Engineering (SIE)). We find 
that this STC provides an acceptable means of compliance with the 
requirements of paragraphs (a) through (g) of this AD. Therefore, we 
have revised the final rule to include a new Note 2 to reference the 
applicable STC as a source of service information for accomplishing the 
requirements of paragraphs (a) through (g) of this AD.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 32 Model DC-8 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 29 
airplanes of U.S. registry would be affected by this proposed AD. The 
following table shows the estimated cost impact for airplanes affected 
by this AD. The average labor rate is $60 per work hour. The estimated 
maximum total cost for all airplanes affected by this proposed AD is 
$6,718,140, or $231,660 per airplane.

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                                               Work hours      Parts cost
                   Action                      (estimated)     (estimated)          Total cost (estimated)
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Incorporation of inspections into                         8             N/A  $13,920, or $480 per airplane.
 maintenance or inspection program.
Modification of main deck cargo door                  1,420          $6,500  $2,659,300, or $91,700 per
 structure and fuselage structure.                                            airplane.
Inspection of exposed surfaces of main deck              16             N/A  $27,840, or $960 per airplane.
 cargo door hinge.
Replacement of the existing fasteners in                 60            $100  $107,300, or $3,700 per airplane.
 the two door-side hinge elements.
Inspection and evaluation of the cargo                   16             N/A  $27,840, or $960 per airplane.
 handling system.
Modification of main deck cargo floor......              40            $500  $84,100, or $2,900 per airplane.
Inspection and evaluation of the venting                 16             N/A  $27,840, or $960 per airplane.
 system.
Installation of main deck cargo 9g crash              1,500         $40,000  $3,770,000, or $130,000 per
 barrier.                                                                     airplane.
----------------------------------------------------------------------------------------------------------------

    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted. The cost impact figures discussed 
in AD rulemaking actions represent only the time

[[Page 66298]]

necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations adopted herein will 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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, 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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

2001-26-04 McDonnell Douglas: Amendment 39-12568. Docket 2000-NM-
283-AD.

    Applicability: Model DC-8 series airplanes that have been 
converted from a passenger-to a cargo-carrying (``freighter'') 
configuration in accordance with Supplemental Type Certificate (STC) 
SA1802SO or SA421NW; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 (h) 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.

    Note 2: Installation of Structural Integrity Engineering (SIE) 
STC ST01181LA, is an approved means of compliance with the 
requirements of paragraphs (a) through (g) of this AD.

    To prevent opening of the cargo door while the airplane is in 
flight or collapse of the main deck cargo floor, and consequent 
rapid decompression of the airplane including possible loss of 
flight control or severe structural damage, accomplish the 
following:

Actions Addressing the Main Deck Cargo Door and Associated Fuselage 
Structure

    (a) Accomplish the actions specified in paragraphs (a)(1) and 
(a)(2) of this AD in accordance with a method approved by the 
Manager, Los Angeles Aircraft Certification Office (ACO), FAA.
    (1) Within 1 year or 1,200 flight cycles after the effective 
date of this AD, whichever occurs first, incorporate inspections 
into the operator's FAA-approved maintenance or inspection program 
that ensure the continued operational safety of the airplane. These 
inspections should be based on a damage tolerance assessment that 
identifies any principal structural element (PSE) associated with 
the STC modification and should include associated inspection 
thresholds, inspection methods, and repetitive inspection intervals.
    (2) Within 3 years or 4,000 flight cycles after the effective 
date of this AD, whichever occurs first, accomplish the actions 
specified in paragraphs (a)(2)(i) and (a)(2)(ii) of this AD.
    (i) Modify the main deck cargo door structure and fuselage 
structure immediately surrounding the main deck cargo door to comply 
with the applicable requirements of Civil Air Regulations (CAR) part 
4b.
    (ii) Incorporate inspections into the operator's FAA-approved 
maintenance or inspection program that ensure the continued 
operational safety of the airplane. These inspections should be 
based on a damage tolerance assessment that identifies any PSE 
associated with the STC modification required by paragraph (a)(2)(i) 
of this AD and should include associated inspection thresholds, 
inspection methods, and repetitive inspection intervals.

Actions Addressing the Main Deck Cargo Floor

    (b) Within 3 years or 4,000 flight cycles after the effective 
date of this AD, whichever occurs first, perform an inspection and 
evaluation of the cargo handling system to determine if the side 
restraints provide the support required by the unit load devices 
(ULD), in accordance with a method approved by the Manager, Los 
Angeles ACO. If any vertical side restraint does not provide the 
required support, within 3 years or 4,000 flight cycles after the 
effective date of this AD, whichever occurs first, modify the 
vertical side restraint to provide the support appropriate to the 
ULD's compatible with the cargo handling system, in accordance with 
a method approved by the Manager, Los Angeles ACO.
    (c) Within 3 years or 4,000 flight cycles after the effective 
date of this AD, whichever occurs first, modify the main deck cargo 
floor to safely carry the applicable FAA-approved payload limits for 
above and below the main deck cargo floor. The modification and 
payload distribution shall be accomplished in accordance with a 
method approved by the Manager, Los Angeles ACO. The modification 
must comply with the applicable requirements of CAR part 4b for the 
FAA-approved payload distribution.
    (d) Except for those airplanes that have been modified in 
accordance with paragraph (c) of this AD, within 1 year or 1,000 
flight cycles after the effective date of this AD, whichever occurs 
first, perform an inspection and evaluation of the venting system of 
the main deck cargo floor to determine if the system limits 
decompression loads to a level that can be carried by the floor 
structure without failure, in accordance with a method approved by 
the Manager, Los Angeles ACO.
    (e) If, based on the evaluation required by paragraph (d) of 
this AD, the venting system does not limit decompression loads to a 
level that can be carried by the floor structure without failure, 
within 3 years or 4,000 flight cycles after the effective date of 
this AD, whichever occurs first, modify the venting system, as 
necessary, to limit the decompression loads to a level that can be 
supported successfully by the existing floor structure, in 
accordance with a method approved by the Manager, Los Angeles ACO.

Actions Addressing Main Deck Cargo Door Hinge

    (f) Accomplish the actions specified in paragraphs (f)(1) and 
(f)(2) of this AD in accordance with a method approved by the 
Manager, Los Angeles ACO.
    (1) Within 250 flight cycles after the effective date of this 
AD, perform a detailed visual inspection to detect cracks of the 
exposed surfaces of the main deck cargo door hinge (both fuselage 
and door-side hinge elements). If any crack is detected, prior to 
further flight, repair in accordance with a method approved by the 
Manager, Los Angeles ACO, or replace the cracked hinge element with 
a new, like part.

    Note 3: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or

[[Page 66299]]

irregularity. Available lighting is normally supplemented with a 
direct source of good lighting at intensity deemed appropriate by 
the inspector. Inspection aids such as mirror, magnifying lenses, 
etc., may be used. Surface cleaning and elaborate access procedures 
may be required.''

    (2) Within 3 years or 4,000 flight cycles after the effective 
date of this AD, whichever occurs first, replace the existing 
fasteners in the two door-side hinge elements at the forward and aft 
ends of the hinge with fasteners of acceptable strength.

Actions Addressing Main Deck Cargo 9g Crash Barrier

    (g) Within 3 years or 4,000 flight cycles after the effective 
date of this AD, whichever occurs first, install a main deck cargo 
9g crash barrier that complies with the applicable requirements of 
CAR part 4b, in accordance with a method approved by the Manager, 
Los Angeles ACO.

Alternative Methods of Compliance

    (h) 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, Los Angeles Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Los Angeles ACO.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

Special Flight Permits

    (i) 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.

Effective Date

    (j) This amendment becomes effective on January 30, 2002.


    Issued in Renton, Washington, on December 13, 2001.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-31553 Filed 12-21-01; 8:45 am]
BILLING CODE 4910-13-U

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