[Federal Register Volume 62, Number 29 (Wednesday, February 12, 1997)]
[Rules and Regulations]
[Pages 6455-6457]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-3027]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-226-AD; Amendment 39-9924; AD 97-03-19]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain Boeing Model 747 and 767 series airplanes, 
that currently requires inspection of the door opening thrusters and 
door opening/snubbing actuators for proper oil quantity, and 
modification of the off-wing compartment latching assemblies. This 
amendment adds a requirement for replacement of the currently installed 
door opening thrusters with new, improved thrusters for Model 747 
series airplanes. This amendment also removes Model 767 series 
airplanes from the applicability of the AD, since those airplanes are 
addressed currently in a separate AD. This amendment is prompted by 
reports indicating that the requirements of the existing AD do not 
adequately detect leakage of fluid from the actuators. The actions 
specified by this AD are intended to prevent such leakage, which could 
result in failure of the escape slide to deploy; such failure could 
delay and possibly jeopardize the successful emergency evacuation of an 
airplane.

DATES: Effective March 19, 1997.
    The incorporation by reference of Boeing Service Bulletin 747-25-
3073, dated September 21, 1995, as listed in the regulations, is 
approved by the Director of the Federal Register as of March 19, 1997.
    The incorporation by reference of certain other publications listed 
in the regulations was approved previously by the Director of the 
Federal Register as of November 25, 1992 (57 FR 47987, October 21, 
1992).

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207; and OEA Aerospace Inc., P.O. Box KK, Hwy. 12, 
Explosive Technology Road, Fairfield, California 94533-0659. This 
information may be examined at the Federal Aviation Administration 
(FAA), Transport Airplane Directorate, Rules 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: Gregory L. Schneider, Aerospace 
Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington; 
telephone (206) 227-2028; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 92-16-17, 
amendment 39-8327 (57 FR 47987, October 21, 1992), which is applicable 
to certain Boeing Model 747 and 767 series airplanes, was published in 
the Federal Register on June 26, 1996 (61 FR 33050). The action 
proposed to continue to require repetitive inspections of the door 
opening thrusters and door opening/snubbing actuators for proper oil 
quantity, and modification of the off-wing compartment latching 
assemblies for Model 747 series airplanes. For those airplanes, the 
action proposed to add a requirement for replacement of existing door 
opening thrusters with new, improved thrusters. Additionally, the 
action proposed to remove Model 767 series airplanes from the 
applicability of AD 92-16-17, since those airplanes are addressed 
currently by AD 95-08-11, amendment 39-9200 (60 FR 20013).
    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

    Two commenters support the proposed rule.

Request To Revise Description of Effect of Required Actions

    One commenter requests that Summary section of the preamble to the 
proposal be revised to replace the word ``preclude'' with the word 
``detect'' in the following sentence that appeared in that section: 
``This proposal is prompted by reports indicating that the requirements 
of the existing AD do not adequately preclude leakage of fluid from the 
actuators.'' The commenter indicates that the actions required by AD 
95-08-11 do not ``preclude'' fluid leakage; rather, they provide a 
means of detecting decreased fluid quantities in an effort to prevent 
failure of the escape slide to deploy.
    The FAA concurs with the commenter's request and justification, and 
has revised the Summary section of this final rule accordingly.

Request To Explain Removal of Certain Airplanes From Applicability

    The same commenter requests that the Summary section of the 
preamble to the proposal be revised to specify that the new AD action 
would remove Model 767 series airplanes from the applicability of AD 
92-16-17, since those airplanes are addressed currently by AD 95-08-11. 
The commenter notes that the existing AD is, in effect, being 
superseded by two AD's, one for each airplane model. The clarification 
will direct operators of Model 767 series airplanes to the appropriate 
AD.
    The FAA does not consider that additional clarification is 
necessary. This issue was discussed in detail elsewhere in the preamble 
to the proposal. Such detail is unnecessary in the Summary section to a 
rule, since that section is intended to provide only a synopsis of the 
proposed or required actions. Further, since operators of Model 767 
airplanes are no longer subject to this AD, there is no reason to 
address those operators further in this final rule.

Request To Remove Paragraph (d) From the Proposal

    The Air Transport Association (ATA) of America, on behalf of one of 
its members, requests that the FAA remove paragraph (d) from the 
proposal, which would require that all spare parts be modified as of 
the effective date of the final rule. The ATA states that inclusion of 
that paragraph would place an unnecessary burden on operators of Model 
747 series airplanes. The commenter points out that AD 95-08-11 
provides operators of Model 767 series airplanes an interval of two 
years to modify uninstalled actuators. The ATA maintains that there is 
no need to create different compliance periods between installed and 
uninstalled components, except where results of a risk assessment 
support two compliance periods. The commenter concludes that proposed 
paragraph (d) is unnecessary since paragraph (c) requires that all 
airworthy units, installed and uninstalled, be modified within two 
years.
    The FAA concurs partially. First, the FAA does not agree that 
paragraph (d) should be removed from this final rule altogether. The 
FAA finds that paragraph (d) must be included in the AD to ensure that 
only new, improved door opening thrusters (that are not fluid filled) 
are installed on the affected airplanes. However, upon reconsideration 
of the compliance time proposed in that paragraph, the FAA finds that 
it is appropriate to revise the

[[Page 6456]]

compliance time for paragraph (d) of this final rule so that is 
parallel to a similar paragraph in AD 95-08-11, which addresses these 
same components for Model 767 series airplanes. Accordingly, paragraph 
(d) of this final rule has been revised to specify that only new, 
improved door opening thrusters shall be installed on the affected 
airplanes as of two years after the effective date of this AD. This 
revision will also preclude the potential for any parts availability 
problem that may arise in the interim.
    Second, the FAA must clarify for this commenter that neither 
paragraph (c) nor paragraph (d) of this AD address ``uninstalled'' 
components. Part 39 of the Federal Aviation Regulations (14 CFR part 
39) precludes AD actions taken to address components that are not 
currently installed on the airplane (or product). Therefore, the FAA 
cannot require via an AD that operators inspect, repair, or modify a 
``spare part'' (i.e., currently in an operator's parts inventory). 
However, the FAA can ensure, via a requirement such as that specified 
in paragraph (d) of this AD, that any spare part is inspected, 
repaired, or modified prior to it being installed on an airplane. 
Accordingly, paragraphs (c) and (d) of this AD do not require that any 
action to be taken on ``uninstalled'' parts (spares). The requirements 
of those paragraphs only specify that, whenever a door opening thruster 
is to be installed on an airplane now or in the future, that thruster 
must be an improved model.

Request To Reference Additional Service Information

    One commenter requests that the proposal be revised to cite the 
following service bulletin revisions, which have been reviewed and 
approved by the FAA, as additional sources of appropriate service 
information:
    <bullet> Boeing Service Bulletin 747-25-3073, Revision 1, dated 
August 1, 1996.
    <bullet> Boeing Service Bulletin 747-25-2951, Revision 1, dated May 
13, 1993.
    <bullet> Boeing Service Bulletin 747-25-2951, Revision 2, dated 
September 30, 1993.
    <bullet> OEA Service Bulletin 2174200-25-013, Revision 1, dated 
September 14, 1993.
    <bullet> OEA Service Bulletin 2174200-25-013, Revision 2, dated 
November 1, 1993.
    <bullet> OEA Service Bulletin 2174200-25-013, Revision 3, dated 
January 13, 1994.
    The FAA agrees that the service bulletins listed above, with the 
exception of Boeing Service Bulletin 747-25-3073, Revision 1, dated 
August 1, 1996, should be referenced in the final rule. The FAA has 
confirmed that Boeing has not yet released Revision 1 of Service 
Bulletin 747-25-3073 due to changes in the engineering aspects prior to 
receipt of FAA approval of that service bulletin. However, Boeing 
advises that it plans to issue Revision 1 of that service bulletin in 
early 1997 and, subsequently, will request approval of it as an 
alternative method of compliance with this AD.
    The FAA has revised the final rule to add new NOTES 2 and 3, which 
specify that accomplishment of the actions required by this AD in 
accordance with the last five service bulletins listed above is 
acceptable for compliance with the requirements of this AD.

Request To Add Address To Obtain Service Information

    One commenter requests that the FAA revise the Addresses section of 
the preamble to the proposal to include the address for OEA Aerospace 
Inc., since an OEA service bulletin is cited in the proposal.
    The FAA concurs. The address for OEA was omitted inadvertently from 
the proposal, but has been included in this final rule.

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 400 Model 747 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 125 
airplanes of U.S. registry will be affected by this proposed AD.
    The actions that are currently required by AD 92-16-17 and retained 
in this new AD take approximately 12 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Required 
parts cost approximately $510 per airplane. Based on these figures, the 
cost impact on U.S. operators of the actions currently required is 
estimated to be $153,750, or $1,230 per airplane.
    The new actions that are required by this new AD will take 
approximately 2 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts will cost approximately 
$6,400 per airplane. Based on these figures, the cost impact on U.S. 
operators of the new requirements of this AD is estimated to be 
$815,000, or $6,520 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 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 removing amendment 39-8327 (57 FR 
47987, October 21, 1992), and by adding

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a new airworthiness directive (AD), amendment 39-9924, to read as 
follows:

97-03-19  BOEING: Amendment 39-9924. Docket 95-NM-226-AD. Supersedes 
AD 92-16-17, Amendment 39-8327.

    Applicability: Model 747-100, -200, and -300 series airplanes 
equipped with an off-wing, two-piece escape slide on Door 3; 
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 (e) 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 failure of the escape slide to deploy, which could 
delay and possibly jeopardize the successful emergency evacuation of 
an airplane, accomplish the following:
    (a) Within 18 months after November 25, 1992 (the effective date 
of AD92-16-17, amendment 39-8327), perform an inspection of the door 
opening thrusters of the escape system in accordance with OEA 
Service Bulletin 2174200-25-013, dated July 29, 1991. Repeat this 
inspection thereafter at intervals not to exceed 20 months until the 
replacement required by paragraph (c) of this AD is accomplished.

    Note 2: Inspections accomplished in accordance with OEA Service 
Bulletin 2174200-25-013, Revision 1, dated September 14, 1993; 
Revision 2, dated November 1, 1993; or Revision 3, dated January 13, 
1994; are considered acceptable for compliance with the inspections 
specified in paragraph (a) of this AD.

    (b) Within 18 months after November 25, 1992, inspect and modify 
the door latching mechanism of the escape slide compartment in 
accordance with Boeing Service Bulletin 747-25-2951, dated August 
15, 1991.

    Note 3: Inspections and modifications accomplished in accordance 
with Boeing Service Bulletin 747-25-2951, Revision 1, dated May 13, 
1993; or Revision 2, dated September 30, 1993; are considered 
acceptable for compliance with the applicable action specified in 
paragraph (b) of this AD.

    (c) Within 2 years after the effective date of this AD, replace 
the door opening thrusters having part number (P/N) 60B50077-14 or -
17 with new thrusters having P/N 60B50077-19 in accordance with 
Boeing Service Bulletin 747-25-3073, dated September 21, 1995. 
Accomplishment of this replacement terminates the repetitive 
inspections required by this AD.
    (d) As of 2 years after the effective date of this AD, only door 
opening thrusters having P/N 60B50077-19 shall be installed on any 
airplane.
    (e) 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 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (f) Special flight permits may be issued in accordance with 
Secs. 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.
    (g) The inspections and modification shall be done in accordance 
with OEA Service Bulletin 2174200-25-013, dated July 29, 1991; and 
Boeing Service Bulletin 747-25-2951, dated August 15, 1991. The 
incorporation by reference of those documents was approved 
previously by the Director of the Federal Register, in accordance 
with 5 U.S.C. 552(a) and 1 CFR part 51, as of November 25, 1992 (57 
FR 47987, October 21, 1992). The replacement shall be done in 
accordance with Boeing Service Bulletin 747-25-3073, dated September 
21, 1995. The incorporation by reference of that document 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; and OEA Aerospace Inc., P.O. Box KK, Hwy. 12, Explosive 
Technology Road, Fairfield, California 94533-0659. 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.
    (h) This amendment becomes effective on March 19, 1997.

    Issued in Renton, Washington, on January 31, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-3027 Filed 2-11-97; 8:45 am]
BILLING CODE 4910-13-U