AD 2001-02-07
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Boeing | 767 | Airworthiness Directives; Boeing Model 767 Series Airplanes Powered by Pratt & Whitney Engines |
| engine | Pratt & Whitney | engines | Airworthiness Directives; Boeing Model 767 Series Airplanes Powered by Pratt & Whitney Engines |
Unsafe Condition
Fatigue cracking in primary strut structure and consequent reduced structural integrity of the strut.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Modify the nacelle strut and wing structure as specified in the referenced service bulletins.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Before further flight if the conditions described in paragraphs 1 and 2 of Figure 1 have been met.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 767 series airplanes powered by Pratt & Whitney engines.
AI-generated summary from the source AD text. Verify against the official source before acting.
Federal Register Abstract
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes powered by Pratt & Whitney engines, that requires modification of the nacelle strut and wing structure. The actions specified by this AD are intended to prevent fatigue cracking in primary strut structure and consequent reduced structural integrity of the strut.
Document Text
Show stored source text (verify against official source)
[Federal Register Volume 66, Number 19 (Monday, January 29, 2001)]
[Rules and Regulations]
[Pages 8085-8089]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-1947]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-365-AD; Amendment 39-12091; AD 2001-02-07]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 767 Series Airplanes
Powered by Pratt & Whitney Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Boeing Model 767 series airplanes powered by
Pratt & Whitney engines, that requires modification of the nacelle
strut and wing structure. The actions specified by this AD are intended
to prevent fatigue cracking in primary strut structure and consequent
reduced structural integrity of the strut.
DATES: Effective March 5, 2001.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 5, 2001.
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
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: James Rehrl, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2783; 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 767 series
airplanes powered by Pratt & Whitney engines was published in the
Federal Register on July 10, 2000 (65 FR 42306). That action proposed
to require modification of the nacelle strut and wing structure.
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.
[[Page 8086]]
Change the Word ``Damage'' Used in Paragraph (c)
One commenter requests that the word ``damage'' specified in
paragraph (c) of the proposed rule be changed to ``cracking or
corrosion,'' to avoid unnecessary work and delays. The commenter states
that, during accomplishment of the repair specified in paragraph (c) of
the proposal, it encountered several conditions when approval was
required for using oversized fasteners, tooling damage, tolerance
changes, and minor trimming of parts.
The FAA concurs with the commenter's request. The definition of
``damage,'' as described in this AD, is cracking or corrosion. But,
with respect to the deviations specified, only the deviations that
exceed currently published limits (Structural Repair Manual, process
specifications defined in the service bulletin) would need an
alternative method of compliance (AMOC). Paragraph (c) of this AD has
been revised to add the words ``cracking or corrosion'' in parenthesis
after the word ``damage''.
Approval of Repairs by Designated Engineering Representative (DER)
One commenter requests that the proposal include a provision for
approval of AMOC's by a Boeing DER, instead of by the Manager of the
Seattle Aircraft Certification Office (ACO). The commenter states that
this provision will result in a more efficient and timely repair
approval process. The FAA partially concurs with the commenter's
request. Accomplishment of the repair in accordance with a method
approved by the Manager is still acceptable, but paragraph (c) of this
AD has been revised to add the DER approval as an option for
accomplishment of the repair.
Clarify Certain Wording in Paragraph (a)
One commenter notes that certain wording in paragraph (a) of the
proposal which states, in part, ``* * * the conditions described in
paragraphs 1 and 2 (interim inspection requirements) of page 67 have
been met.'' The commenter recommends that the additional interim
inspection requirements referred to in this paragraph be more apparent
in the proposed AD. The FAA infers that the commenter is questioning
what is meant by the term ``conditions'' as specified in paragraph (a)
of the final rule. For that reason, paragraph (a) of this AD has been
revised to define the word ``conditions'' as, ``* * * the corrosion
prevention and control program inspections as described in paragraphs 1
and 2 of Figure 1 have been met.''
Revise Paragraph (a) to Reference Figure 1
One commenter requests paragraph (a) of the proposal be revised to
reference Figure 1 of Boeing Service Bulletin 767-54-0080, dated
October 7, 1999, instead of page 67. The commenter states that this
change would prevent confusion if the service bulletin is revised in
the future. The FAA concurs, because Figure 1 is on page 67 and
includes the flight cycle threshold formula, paragraph (a) of the final
rule has been revised to specify Figure 1.
Revise Service Information References
One commenter indicates the following:
(1) There is a typographical error in one of the service bulletin
numbers shown in the cost impact section and in paragraph (b) of the
proposal. The proposal refers to Boeing Service Bulletin 767-53-0069;
however, the number should be 767-54-0069;
(2) Boeing Service Bulletin 767-54-0069, Revision 2, dated August
31, 2000, is the latest revision of the service bulletin specified in
paragraph (b) of the proposal and should be referenced in the final
rule;
(3) Information notice (IN) 02, dated November 22, 1999, should be
included for Boeing Service Bulletin 767-57-0053, Revision 2, specified
in paragraph (b) of the proposal;
(4) Boeing Service Bulletin 767-57A0070, dated March 2, 2000,
should be added to the list of prior or concurrent service bulletins
referenced in paragraph (b) of the proposal. The commenter notes that
this service bulletin corrects a potential fatigue problem on certain
early-production airplanes by removing and replacing the wing front
spar outboard pitch load fitting with an improved design.
The FAA partially concurs with the commenter as follows:
(1) The FAA has verified that there is a typographical error in the
service bulletin number referenced in the proposal, as noted by the
commenter, and the number has been corrected in the final rule.
(2) Boeing Service Bulletin 767-54-0069, Revision 2, dated August
31, 2000, has been added to the final rule as an additional source of
service information for accomplishment of the applicable actions as
specified in the final rule. The actions described in Revision 2 are
essentially the same as those in Revision 1, which was referenced in
the proposal as the appropriate source of service information for
accomplishment of certain prior or concurrent actions.
(3) The FAA does not have a copy of IN 02, dated November 22, 1999,
to Boeing Service Bulletin 767-57-0053, Revision 2. The commenter can
provide this notice to the FAA with a request for an approval of an
alternative method of compliance per paragraph (d) of this final rule.
(4) The FAA has reviewed Boeing Alert Service Bulletin 767-57A0070,
dated March 2, 2000, and has determined that, although that service
bulletin specifies replacing the outboard pitch load fitting of the
wing front spar with an improved design, it is not directly related to
this final rule and will be addressed at a later time by a separate
rulemaking action.
Request To Extend Compliance Time
One commenter requests that the compliance time required by
paragraph (a) of the proposed AD be revised to allow for compliance at
the later of the times specified. The commenter states that there is a
concern with the threshold based on 20 years since the date of
manufacture or ``as defined by the flight cycle threshold formula'' in
paragraph (a) of the proposal, because the compliance time is
``whichever occurs first.'' The commenter adds that it has met the
requirements originally agreed upon and has planned accomplishment of
the Strut Improvement Program (SIP) based on the optional flight cycle
formula at the next (20C) maintenance check.
The FAA does not concur. In developing an appropriate compliance
time for the modification specified in paragraph (a) of this AD, the
FAA considered not only the degree of urgency associated with
addressing the subject unsafe condition, but accomplishment of the
required modification within an interval of time (the earlier of the
times specified) that parallels normal scheduled maintenance for the
majority of affected operators. However, under the provisions of
paragraph (d) of the final rule, the FAA may approve requests for
adjustments to the compliance time if data are submitted to
substantiate that such an adjustment would provide an acceptable level
of safety. No change to the final rule is necessary in this regard.
Recommendation To Add a Note
One commenter requests that the initial time of accomplishment for
the additional interim inspection service bulletins referred to in
paragraph (b) of the proposed rule be clarified. The commenter states
that, at the all-
[[Page 8087]]
operators' SIP meeting, held in November 1999, the manufacturer stated
that the interim inspection service bulletins were only required prior
to 20 years of age in-service, or within the individual service
bulletin limits, whichever occurs later, if the flight cycle formula
was used to exceed the 20-year calendar limit. The commenter further
states that this is acceptable since these inspections would not be
required on airplanes being modified at 20 years of age, and
accomplishment of these inspections after 20 years of age would ensure
continued safety. The commenter recommends a note be added after
paragraph (a) of the proposed rule, as follows: ``Note: If the flight
cycle formula is used to defer modification accomplishment of service
bulletin 767-54-0080 beyond 20 years of age, initial accomplishment of
the inspections per the service bulletins listed in paragraph 2 of
service bulletin 767-54-0080, Figure 1, must begin prior to 20 years of
age, or within the individual service bulletin limits, whichever occurs
later.''
The FAA does not concur with the commenter's recommendation.
Operators that want to use the flight cycle threshold formula must
accomplish the referenced service bulletins prior to reaching 20 years
since date of manufacture of the airplane. This means that by 20 years,
the operator must have done either the terminating action in the
service bulletin, or it must have performed at least the first
recommended service bulletin inspection and the follow-on actions
described in the service bulletin. No change to the final rule is
necessary in this regard.
Request To Revise Cost Impact Information
Two commenters request the cost impact information in the proposal
be revised. One commenter states that the prior and concurrent service
bulletin requirements referenced in the proposal do not match the hours
specified in the cost impact section. The commenter adds that the cost
impact is significantly more than the cost estimate in the proposal or
the work hours in the service bulletins, which will be allocated for
warranty reimbursement given by the manufacturer. The commenter gave
cost estimate comparisons of the additional work hours for access and
close-up as specified in the service bulletins, and the costs it
incurred accomplishing the actions.
A second commenter states that the actual labor for accomplishment
of the actions specified in the proposal is significantly higher than
the estimate in the service bulletins. The commenter notes that it will
require a minimum of 2,978 work hours for its accomplishment of the
actions, and the estimate does not include non-routine labor.
The FAA does not concur with the commenters' request. The economic
analysis of the AD is limited only to the cost of actions actually
required by the rule. It does not consider the costs of ``on
condition'' actions, such as repairing damage to the airplane structure
detected during a required inspection (``repair, if necessary''). Such
``on-condition'' repair actions would be required to be accomplished--
regardless of AD direction--in order to correct an unsafe condition
identified in an airplane and to ensure operation of that airplane in
an airworthy condition, as required by the Federal Aviation
Regulations. In addition, the FAA recognizes that, in accomplishing the
requirements of any AD, operators may incur ``incidental'' costs in
addition to the ``direct'' costs. The cost analysis in AD rulemaking
actions, however, typically does not include incidental costs, such as
the time required to gain access and close up; planning time; or time
necessitated by other administrative actions. Because incidental costs
may vary significantly from operator to operator, they are almost
impossible to calculate. No change to the final rule is necessary in
this regard.
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 233 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 76 airplanes of U.S. registry
will be affected by this AD. It will take approximately 708 work hours
per airplane to accomplish the modification of the nacelle strut and
wing structure described in Boeing Service Bulletin 767-54-0080, at an
average labor rate of $60 per work hour. Required parts will be
provided at no cost by the airplane manufacturer. Based on these
figures, the cost impact of the modification required by this AD on
U.S. operators is estimated to be $3,228,480, or $42,480 per airplane.
It will take approximately 106 work hours per airplane to
accomplish the actions described in Boeing Service Bulletin 767-54-
0069, Revision 1 or Revision 2, at an average labor rate of $60 per
work hour. Required parts will be provided at no cost by the airplane
manufacturer. Based on these figures, the cost impact of these required
actions on U.S. operators is estimated to be $483,360, or $6,360 per
airplane.
It will take approximately 1 work hour per airplane to accomplish
the actions described in Boeing Service Bulletin 767-54-0083, at an
average labor rate of $60 per work hour. Required parts will be
provided at no cost by the airplane manufacturer. Based on these
figures, the cost impact of these required actions on U.S. operators is
estimated to be $4,560, or $60 per airplane.
It will take approximately 2 work hours per airplane to accomplish
the actions described in Boeing Service Bulletin 767-54-0088, Revision
1, at an average labor rate of $60 per work hour. Required parts will
be provided at no cost by the airplane manufacturer. Based on these
figures, the cost impact of these required actions on U.S. operators is
estimated to be $9,120, or $120 per airplane.
It will take approximately 20 work hours per airplane to accomplish
the actions described in Boeing Service Bulletin 767-54A0094, Revision
1, at an average labor rate of $60 per work hour. Required parts will
be provided at no cost by the airplane manufacturer. Based on these
figures, the cost impact of these required actions on U.S. operators is
estimated to be $91,200, or $1,200 per airplane.
It will take approximately 5 work hours per airplane to accomplish
the actions described in Boeing Service Bulletin 767-57-0053, Revision
2, at an average labor rate of $60 per work hour. Based on these
figures, the cost impact of these required actions on U.S. operators is
estimated to be $22,800, or $300 per airplane.
It will take approximately 16 work hours per airplane to accomplish
the actions described in Boeing Service Bulletin 767-29-0057, at an
average labor rate of $60 per work hour. Required parts will be
provided at no cost by the airplane manufacturer. Based on these
figures, the cost impact of these required actions on U.S. operators is
estimated to be $72,960, or $960 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of
[[Page 8088]]
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 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, 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:
2001-02-07 Boeing: Amendment 39-12091. Docket 99-NM-365-AD.
Applicability: Model 767 series airplanes powered by Pratt &
Whitney engines, line numbers 1 through 663 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 request approval for an
alternative method of compliance in accordance with paragraph (d) 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 in primary strut structure and
consequent reduced structural integrity of the strut, accomplish the
following:
Modifications
(a) When the airplane has reached the flight cycle threshold as
defined by the flight cycle threshold formula described in Figure 1
of Boeing Service Bulletin 767-54-0080, dated October 7, 1999, or
within 20 years since the date of manufacture, whichever occurs
first: Modify the nacelle strut and wing structure on both the left
and right sides of the airplane, in accordance with the service
bulletin. Use of the flight cycle threshold formula described in
Figure 1 of the service bulletin is an acceptable alternative to the
20-year threshold, provided the corrosion prevention and control
program inspections, as described in paragraphs 1 and 2 of Figure 1,
have been met.
(b) Prior to or concurrently with the accomplishment of the
modification of the nacelle strut and wing structure required by
paragraph (a) of this AD; as specified in paragraph 1.D., Table 2,
on page 8 of Boeing Service Bulletin 767-54-0080, dated October 7,
1999; accomplish the actions specified in Boeing Service Bulletins
767-54-0069, Revision 1, dated January 29, 1998, or Revision 2,
dated August 31, 2000; 767-54-0083, dated September 17, 1998; 767-
54-0088, Revision 1, dated July 29, 1999; 767-54A0094, Revision 1,
dated September 16, 1999; 767-57-0053, Revision 2, dated September
23, 1999; and 767-29-0057, dated December 16, 1993, including Notice
of Status Change NSC 1, dated November 23, 1994; as applicable; in
accordance with those service bulletins. Accomplishment of this
paragraph constitutes terminating action for the repetitive
inspections required by AD 94-11-02, amendment 39-8918, and AD 99-
07-06, amendment 39-11091.
Note 2: Paragraph (b) of this AD specifies prior or concurrent
accomplishment of Boeing Service Bulletin 767-57-0053, Revision 2,
dated September 23, 1999; however, Table 2, on page 8 of Boeing
Service Bulletin 767-54-0080, dated October 7, 1999, specifies prior
or concurrent accomplishment of the original issue of the service
bulletin. Therefore, accomplishment of the applicable actions
specified in Boeing Service Bulletin 767-57-0053, dated June 27,
1996, or Revision 1, dated October 31, 1996, prior to the effective
date of this AD, is considered acceptable for compliance with the
actions required by paragraph (b) of this AD.
Repair
(c) If any damage (corrosion or cracking) to airplane structure
is found during the accomplishment of the modification required by
paragraph (a) of this AD; and the service bulletin specifies to
contact Boeing for appropriate action: Prior to further flight,
repair in accordance with a method approved by the Manager, Seattle
Aircraft Certification Office (ACO), FAA; or in accordance with data
meeting the type certification basis of the airplane approved by a
Boeing Company Designated Engineering Representative who has been
authorized by the FAA to make such findings. For a repair method to
be approved by the Manager, Seattle ACO, as required by this
paragraph, the Manager's approval letter must specifically reference
this AD.
Alternative Methods of Compliance
(d) 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 ACO. 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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
Special Flight Permits
(e) 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.
Incorporation by Reference
(f) Except as provided by paragraph (c) of this AD, the actions
shall be done in accordance with the following Boeing service
bulletins, as applicable:
----------------------------------------------------------------------------------------------------------------
Service bulletin No. Revision level Date
----------------------------------------------------------------------------------------------------------------
767-54-0080.............................. Original.................... October 7, 1999.
767-54-0069.............................. 1........................... January 29, 1998.
[[Page 8089]]
767-54-0069.............................. 2........................... August 31, 2000.
767-54-0083.............................. Original.................... September 17, 1998.
767-54-0088.............................. 1........................... July 29, 1999.
767-54A0094.............................. 1........................... September 16, 1999.
767-57-0053.............................. 2........................... September 23, 1999.
767-29-0057.............................. Original.................... December 16, 1993.
767-29-0057 NSC 1........................ Original.................... November 23, 1994.
----------------------------------------------------------------------------------------------------------------
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.
Effective Date
(g) This amendment becomes effective on March 5, 2001.
Issued in Renton, Washington, on January 17, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 01-1947 Filed 1-26-01; 8:45 am]
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