Airworthiness Directives; Boeing Model 747-400, -400D, and -400F Series Airplanes

[Federal Register Volume 64, Number 54 (Monday, March 22, 1999)]
[Rules and Regulations]
[Pages 13669-13671]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-6714]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-171-AD; Amendment 39-11082; AD 99-06-18]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400, -400D, and -400F 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Boeing Model 747-400, -400D, and -400F series 
airplanes, that requires modification of the P212 and P213 panels of 
the cabin pressure control system. For certain airplanes, this 
amendment also requires modification of the P5, P6, and P7 panels, and 
the W4701, W4703, and W4908 wire bundles, as applicable. This amendment 
is prompted by a report of in-flight loss of cabin pressurization 
control due to a single failure of the auxiliary power unit (APU) 
battery. The actions specified by this AD are intended to prevent loss 
of control of the cabin pressurization system, which could result in 
rapid depressurization of the airplane. Such rapid depressurization 
could result in deleterious physiological effects on the passengers and 
crew; and airplane diversions, which represent an increased risk to the 
airplane, passengers, and crew.

DATES: Effective April 26, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of April 26, 1999.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. This information may be examined at the Federal 
Aviation Administration (FAA), Transport Airplane Directorate, Rules

[[Page 13670]]

Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Clayton R. Morris, Jr., Aerospace 
Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington; 
telephone (425) 227-2794; fax (425) 227-1181.

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 Boeing Model 747-400, -
400D, and -400F series airplanes was published as a supplemental notice 
of proposed rulemaking (NPRM) in the Federal Register on May 12, 1998 
(63 FR 26100). That action proposed to require modification of the P212 
and P213 panels of the cabin pressure control system. For certain 
airplanes, that action also proposed to require modification of the P5, 
P6, and P7 panels, and the W4701, W4703, and W4908 wire bundles, as 
applicable.

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.

Support for the Proposal

    One commenter supports the proposed rule. Another commenter offers 
no comments to the proposed rule, because it does not own or operate 
the subject airplanes.

Requests To Extend Compliance Time

    One commenter requests that the FAA extend the proposed compliance 
time for the modification from 180 days after the effective date of 
this AD to 18 months after the effective date of this AD, to reduce the 
impact on its operations and the cost associated with accomplishment of 
the proposed actions. The commenter states that the proposed 180-day 
compliance time would make it necessary to schedule approximately five 
of its airplanes for special maintenance visits, which the commenter 
estimates would cost $60,000 per airplane. The commenter states that an 
18-month compliance time would allow the modifications proposed in the 
supplemental NPRM to be accomplished during a regularly scheduled ``C'' 
check.
    The FAA partially concurs with the commenter's request to extend 
the compliance time. The FAA has determined that the compliance time 
may be extended somewhat. The FAA finds that extending the compliance 
time from 180 days after the effective date of this AD to 12 months 
after the effective date of this AD will not adversely affect safety 
and will allow the modifications to be performed, in the majority of 
cases, during a regularly scheduled maintenance visit. Therefore, 
paragraphs (a) and (b) of the final rule have been revised to specify a 
compliance time of 12 months after the effective date of this AD. 
However, with regard to the commenter's cost estimate, the FAA points 
out that operators may take advantage of special maintenance visits to 
accomplish other deferred maintenance tasks, which would reduce the 
time necessary to accomplish those deferred tasks during regularly 
scheduled checks. The commenter's estimate of additional costs 
associated with special visits does not take this into account.
    Another commenter also requests that the FAA extend the proposed 
compliance time for accomplishment of the actions to 18 months after 
the effective date of this AD. The commenter states that Boeing Service 
Bulletin 747-21-2268 should be accomplished prior to the accomplishment 
of Boeing Alert Service Bulletin 747-21A2381, dated June 27, 1996 
(which was referenced as an appropriate source of service information 
in the supplemental NPRM). The commenter states that Boeing Alert 
Service Bulletin 747-21A2381 can be accomplished within the 180-day 
compliance time proposed in the supplemental NPRM only if Boeing 
Service Bulletin 747-21-2268 has already been accomplished. The 
commenter requests that the compliance time be extended to provide for 
accomplishment of both Boeing Service Bulletin 747-21-2268 and Boeing 
Alert Service Bulletin 747-21A2381.
    The FAA does not concur that Boeing Service Bulletin 747-21-2268 
must be accomplished prior to accomplishment of Boeing Alert Service 
Bulletin 747-21A2381. The FAA has determined that Boeing Alert Service 
Bulletin 747-21A2381 provides specific instructions on how to 
accomplish the actions specified in the alert service bulletin both 
with and without prior incorporation of the actions specified in Boeing 
Service Bulletin 747-21-2268. In addition, the FAA does not require 
accomplishment of Boeing Service Bulletin 747-21-2268. Therefore, the 
FAA finds that it is not necessary to extend the compliance time to 
allow for accomplishment of Boeing Service Bulletin 747-21-2268. 
However, as stated previously, the compliance time for the actions 
required by this final rule has been extended to 12 months after the 
effective date of this AD to allow for accomplishment of the required 
actions during regularly scheduled maintenance visits.

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 described 
previously. 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 351 Model 747-400, -400D, and -400F series 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 43 airplanes of U.S. registry will be affected by this 
AD.
    For all airplanes, it will take approximately 8 work hours per 
airplane to accomplish the required modification of the P212 and P213 
panels, at an average labor rate of $60 per work hour. Required parts 
will cost approximately $389 per airplane. Based on these figures, the 
cost impact of this modification required by this AD on U.S. operators 
is estimated to be $37,367, or $869 per airplane.
    For certain airplanes, it will take approximately 47 work hours per 
airplane to accomplish the required modification of the P5, P6, and P7 
panels, and the W4701, W4703, and W4908 wire bundles, at an average 
labor rate of $60 per work hour. Required parts will cost approximately 
$1,529 per airplane. Based on these figures, the cost impact of this 
modification required by this AD on U.S. operators is estimated to be 
$4,349 per 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.

Regulatory Impact

    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

[[Page 13671]]

implications to warrant the preparation of a Federalism Assessment.
    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, 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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

99-06-18  Boeing: Amendment 39-11082. Docket 96-NM-171-AD.

    Applicability: Model 747-400, -400D, and -400F series airplanes; 
as identified in Boeing Alert Service Bulletin 747-21A2381, dated 
June 27, 1996; 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 loss of control of the cabin pressurization system, 
which could result in rapid depressurization of the airplane and 
consequent deleterious physiological effects on the passengers and 
crew; and airplane diversions, which represent an increased risk to 
the airplane, passengers, and crew, accomplish the following:
    (a) Within 12 months after the effective date of this AD: Modify 
the P212 and P213 panels of the cabin pressure control system as 
specified in paragraph (a)(1) or (a)(2) of this AD, as applicable, 
in accordance with Boeing Alert Service Bulletin 747-21A2381, dated 
June 27, 1996.
    (1) For Groups 1 through 7 airplanes, as identified in the alert 
service bulletin: Change the wiring in the P212 and P213 panels; 
replace the existing two-pole relays with new four-pole relays; and 
perform a test of both panels.
    (2) For Group 8 airplanes, as identified in the alert service 
bulletin: Change the wiring in the P212 panel; replace the existing 
two-pole relays with new four-pole relays; replace the existing P213 
panel with a new P213 panel; and perform a test of both panels.
    (b) For airplanes having line positions 696 through 1021 
inclusive: Within 12 months after the effective date of this AD, 
accomplish paragraphs (b)(1) and (b)(2), as applicable, of this AD; 
in accordance with Boeing Service Bulletin 747-24-2193, dated 
January 26, 1995; as revised by Notices of Status Change (NSC) 747-
24-2193 NSC 1, dated April 13, 1995, 747-24-2193 NSC 2, dated 
October 5, 1995, 747-24-2193 NSC 3, dated November 22, 1995, 747-24-
2193 NSC 4, dated December 21, 1995, 747-24-2193 NSC 5, dated May 2, 
1996, and 747-24-2193 NSC 6, dated March 13, 1997; or Alert Service 
Bulletin 747-24A2193, Revision 1, dated June 19, 1997.
    (1) For all airplanes: Modify the wiring of the P5, P6, and P7 
panels; modify the wiring in the W4701 and W4908 wire bundles; and 
install diodes in the P6 panel.
    (2) For Groups 1 and 2 airplanes identified in paragraph I. of 
the Accomplishment Instructions of the service bulletin or alert 
service bulletin: Modify the wiring in the W4703 wire bundle.
    (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, Seattle Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle 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 actions shall be done in accordance with Boeing Alert 
Service Bulletin 747-21A2381, dated June 27, 1996; and Boeing 
Service Bulletin 747-24-2193, dated January 26, 1995; as revised by 
Notices of Status Change (NSC) 747-24-2193 NSC 1, dated April 13, 
1995, 747-24-2193 NSC 2, dated October 5, 1995, 747-24-2193 NSC 3, 
dated November 22, 1995, 747-24-2193 NSC 4, dated December 21, 1995, 
747-24-2193 NSC 5, dated May 2, 1996, and 747-24-2193 NSC 6, dated 
March 13, 1997; or Boeing Alert Service Bulletin 747-24A2193, 
Revision 1, dated June 19, 1997. 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 
Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 
98124-2207. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.
    (f) This amendment becomes effective on April 26, 1999.

    Issued in Renton, Washington, on March 12, 1999.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-6714 Filed 3-19-99; 8:45 am]
BILLING CODE 4910-13-P