[Federal Register Volume 61, Number 56 (Thursday, March 21, 1996)]
[Rules and Regulations]
[Pages 11529-11533]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-6391]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 94-NM-179-AD; Amendment 39-9542; AD 96-06-05]
Airworthiness Directives; Boeing Model 727 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes two existing airworthiness
directives (AD), applicable to certain Boeing Model 727 series
airplanes, that currently require repetitive visual inspections to
detect cracks of the elevator rear spar, and repair, if necessary. This
amendment adds new inspections to detect cracks and loose brackets of
the elevator rear spar; adds a new terminating modification for the
inspections, and expands the applicability of the rules to include
additional airplanes. This amendment is prompted by reports of cracking
in the spar radii at the tab hinge location of the elevator rear spar
on certain airplanes. The actions specified by this AD are intended to
prevent cracking in elements of the elevator rear spar assembly, which
could result in excessive free play of the elevator control tab and
possible tab flutter.
DATES: Effective April 22, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of April 22, 1996.
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: Walter Sippel, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle
Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington
98055-4056; telephone (206) 227-2774; fax (206) 227-1181.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 84-22-02,
amendment 39-4951 (49 FR 45743, November 20, 1984), and AD 87-24-03,
amendment 39-5769 (52 FR 43742, November 16, 1987), both of which are
applicable to Boeing Model 727 series airplanes, was published in the
Federal Register as a supplemental notice of proposed rulemaking on
September 19, 1995 (60 FR 47896). The action proposed to require
repetitive visual inspections to detect cracks and loose brackets of
the elevator rear spar, and various follow-on actions. The supplemental
NPRM also proposed to require the installation of a modification of the
elevator rear spar that would constitute terminating action for the
repetitive inspections. Additionally, the supplemental NPRM proposed to
expand the applicability of the existing proposed rules to include
additional airplanes.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
One commenter supports the proposal.
A discussion of other comments received follows:
Requests to Withdraw the Proposal
Two commenters request that the FAA withdraw the proposal. These
commenters consider that the problem addressed is strictly a quality
control problem and is not associated with airplanes on a fleet-wide
basis.
The FAA does not concur. There have been at least 13 occurrences of
cracking found in modified elevator rear spars on in-service airplanes.
New information has revealed that the shear plate contacting the radius
of the rear spar is not the only problem that is creating the addressed
cracking. New data show that loose tee fittings attached to the rib may
also contribute to cracking in the rear spar. In light of this, the FAA
finds no reason to consider the unsafe condition to be limited to a few
airplanes, nor a single operator's quality program.
Request To Allow Inspections With the Elevator Tab Installed
One commenter requests that the proposed rule be revised to allow
the inspection of modified elevator rear spars to be accomplished with
the elevator tab installed. This commenter, an operator, states that it
has inspected all of its affected modified airplanes using this method
and have not found any cracking of rear spars.
The FAA cannot concur with this commenter's request since no
technical data were submitted that could demonstrate that this method
of inspection would provide an acceptable level of safety (compared to
the proposed inspection methods). Additionally, the reliability of the
inspection method suggested by the commenter is not clear. (For
example, would other operators obtain accurate results? Have the
results of inspections performed with elevator tabs installed been
compared those of inspections performed with elevator tabs not
installed?) The FAA suggests that this commenter submit justifying data
and apply for the approval of this inspection as an alternative method
of compliance with the AD, in accordance with the provisions of
paragraph (j) of the final rule.
Requests To Extend the Inspection Interval for Modified Airplanes
Several commenters request that the proposed rule be revised to
extend the compliance time for accomplishing the visual inspection of
modified airplanes. One commenter requests that it be extended from the
proposed 4,000 flight hours to 3,000 flight cycles after the effective
date of the final rule. This commenter, an operator, states that it
modified its fleet of affected airplanes (in accordance with AD 84-22-
02 and 87-24-03) between 1987 and 1992. This operator has been
inspecting the subject area on these modified airplanes at every ``C''
check (approximately every 3,000 flight cycles) and has found no
cracking to date. Other commenters request that the initial inspection
be required at the next regularly scheduled ``C'' check scheduled for
the airplane. These commenters assert that the work hours needed to
accomplish this inspection and the complexity of this inspection
require that it be accomplished at a main base facility and by
maintenance personnel specifically trained for this task.
The FAA does not concur with these commenters' request. The FAA has
received reports of cracking in rear spars on several modified
airplanes after approximately 4,000 flight hours (after
[[Page 11530]]
modification). In addition, a crack has been found on a new, modified
one-piece spar that had accumulated approximately 4,000 fight hours. In
light of these findings, the FAA has determined that the compliance
time of 4,000 flight hours represents the maximum interval of time
allowable for the affected airplanes to continue to operate prior to
accomplishing the required inspection without compromising safety. The
FAA does not consider a ``C'' check to be an appropriate inspection
interval, since maintenance schedules for ``C'' checks may vary from
operator to operator, and there would be no assurance that the
inspection would be accomplished during the maximum interval of 4,000
flight hours. Further, the FAA does not consider 3,000 flight cycles to
be an appropriate interval, since many fatigue cycles can occur per
flight and the subject cracking is associated with fatigue.
Consequently, an interval of ``3,000 flight cycles'' would result in a
much longer time period than data show is acceptable.
Requests To Delete Calendar Time From Inspection Intervals
Several commenters request that the proposed rule be revised to
delete the references to calendar time in the repetitive inspection
intervals for both modified and unmodified spars. The proposal would
require that, in those cases where no cracking is found, visual
inspections be conducted every ``1,600 flight hours or 18 months,
whichever occurs first.'' The commenters contend that calendar time as
an inspection interval is inappropriate in this case because the
subject cracking is related to fatigue (which is associated with flight
cycles or flight hours), and not to conditions such as corrosion (which
is associated with calendar time or environmental conditions). These
commenters request that the inspection interval be expressed only in
flight cycles or flight hours.
The FAA concurs. Since the cracking addressed by this AD is the
result of problems associated with fatigue, it is more appropriate that
structure be inspected at intervals related to flight hours rather than
calendar time. The final rule has been revised to delete the references
to ``18 months'' in the compliance times for the repetitive
inspections.
Requests To Delete Mandatory Terminating Action
Several commenters request that the proposed rule be revised to
delete the requirement to accomplish the terminating modification
within 5 years. These commenters contend that continuing repetitive
inspections of the area will provide an acceptable level of safety. One
of these commenters, an operator, states that its existing inspection
program, which has been carried out successfully in its fleet over the
past 10 years, is adequate for finding and repairing cracks prior to
the time that a serious cracking condition can develop. Another
commenter states that it has continued to inspect its airplanes that
previously have been modified and has not detected any cracking in the
modified structure.
The FAA concurs that installation of the terminating modification
need not be mandatory. The FAA has reconsidered the information it has
received concerning the subject cracks that have been found on in
service airplanes. This information indicates that cracking has been
found during the scheduled inspection periods, and before any cracking
was able to propagate to critical lengths. Additionally, the FAA finds
that inspections are easy to accomplish, since the area is easily
accessible, and they are effective in finding cracks. Moreover, the
cracking is easily detectable and the consequences of the cracking are
not likely to be catastrophic. In light of this, the FAA has determined
that continuing inspections will provide an acceptable level of safety,
and that the terminating modification need not be mandatory. The final
rule has been revised to provide for a program of repetitive
inspections, in lieu of installation of the terminating modification,
for airplanes on which no cracking is detected during the required
inspections. The terminating modification will be provided as an
optional installation for those airplanes.
Requests for On-Going Repetitive Inspections in Lieu of Terminating
Action
Several commenters request that, if the proposed AD is revised to
delete the requirement that would mandate installation of the
terminating modification, then it should include a specific schedule of
repetitive inspections of the affected airplanes. These commenters
provide various suggestions for this inspection schedule:
1. One commenter requests that repetitive inspections of all
airplanes be allowed at intervals of 4,000 flight hours. This commenter
states that it is regularly conducting inspections of all of its
affected airplanes at approximately 4,000 flight hour intervals and has
found little cracking or other discrepancies.
2. Another commenter requests that continued repetitive inspections
of unmodified two-piece spars and all modified spars all be allowed to
be conducted at intervals of 4,000 flight hours. This commenter, an
operator, conducts inspections of airplanes with these configurations
in its fleet every 4,000 flight hours. In the last 18 months, 33
cracked spars have been found during 84 inspections of unmodified
spars, and 4 cracked spars have been found during 36 inspections of
modified spars. All cracks were found and repaired in a timely manner,
and no flutter of the flight control surface was experienced. Based on
this experience, this commenter considers 4,000-flight hour inspections
to be both effective and economical.
3. One commenter requests that the inspections of unmodified spars
(either one- or two-piece) be repeated at intervals of 1,600 flight
hours or 13 months, whichever occurs later. The commenter considers the
proposed inspection interval of ``1,600 flight hours or 18 months,
whichever occurs first'' is far too restrictive. This commenter, an
operator, states that its suggested interval would allow it to conduct
the inspections during its regularly scheduled maintenance periods,
without disrupting scheduling.
The FAA responds to these specific suggestions as follows:
As for Item 1, the FAA cannot concur with the suggestion that all
airplanes, whether modified or unmodified, be inspected at the same
interval, as one commenter suggested. Since reports indicate that
cracking has been found on modified one-piece spars within 4,000 flight
hours after modification, inspections every 4,000 flight hours are
appropriate for these spars. However, because modified spars have
certain reinforcements and less interference, they are less prone to
the subject cracking than are unmodified spars; therefore, cracking
could be expected to occur in unmodified spars earlier than it could
develop in the modified spars. In light of this, inspection intervals
of fewer flight hours will be more effective for detecting cracking in
unmodified one-piece spars in a timely manner.
As for Item 2, the FAA concurs that a repetitive inspection
interval of 4,000 flight hours for unmodified two-piece spars and all
modified spars is acceptable. In-service reports have shown that the
4,000 flight hour inspection interval is effective and appropriate for
detecting cracking in a timely manner.
As for Item 3, the FAA does not agree with the suggestion that an
inspection interval of 1,600 flight hours or 13
[[Page 11531]]
months, whichever is later, is appropriate for two-piece unmodified
spars. First, as discussed previously, a calendar time (i.e., ``13
months'') is inappropriate in addressing problems associated with
fatigue (such as the cracking addressed by this AD action). Second,
while 1,600 flight hours is appropriate for unmodified one-piece spars,
it is not appropriate for unmodified two-piece spars. The configuration
of two-piece spars makes them inherently less prone to cracking than
the one-piece spars, and the inspections that have been accomplished in
accordance with AD 87-24-03 at the 4,000 flight hour interval have been
shown to be effective in controlling cracking. Therefore, the FAA finds
that the 4,000-flight hour interval for inspections of the unmodified
two-piece spars is suitable.
In light of the information presented by commenters to this
supplemental NPRM, as well as the reports of inspection findings, the
FAA has determined that a different specific repetitive inspection
interval for each of the various configurations of spars is
appropriate. Taking this into account, the FAA has revised the final
rule as follows:
For airplanes equipped with unmodified one-piece spars: If no
cracking is found, the inspections are to be repeated every 1,600
flight hours. (This interval is unchanged from that previously required
by AD 84-22-02.)
For airplanes equipped with modified one-piece spars: If no
cracking is found, the inspections are to be repeated every 4,000 fight
hours.
For airplanes equipped with unmodified two-piece spars: If no
cracking is found, the inspections are to be repeated every 4,000
flight hours. (This interval is unchanged from that previously required
by AD 87-24-03.)
For airplanes equipped with modified two piece spars: If no
cracking is found, the inspections are to be repeated every 4,000
flight hours.
For all configurations: If cracking is found during any inspection
and subsequently is stop-drilled, the inspection is repeated within
1,600 flight hours after stop-drilling, and the terminating
modification is required to be accomplished within 3,200 flight hours
after stop-drilling. (This provision is not changed from what was
proposed in the notice.)
The FAA has determined that this change--providing for continuing
inspections in lieu of mandatory terminating action--will not
compromise safety, since the quality and timeliness of the repeated
inspections will ensure that cracking will be detected before it can
propagate to critical levels. Additionally, the FAA has determined that
this change represents merely an optional method of compliance with the
rule as it was originally proposed. The optional procedures will not
impose an additional burden on any operator. They are a logical
outgrowth of the notice that do not necessitate providing an additional
opportunity for public comment.
Correction of Typographical Errors
The FAA has been advised that, in certain sections of the notice,
the numbers of the applicable service bulletins were incorrectly cited.
The FAA acknowledges these typographical errors and has revised the
final rule to specify the correct Boeing Service Bulletin numbers of:
727-55-0087 and 727-55-0089.
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 1,631 Model 727 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 1,166
airplanes of U.S. registry will be affected by this proposed AD.
The inspections will take approximately 17 work hours per airplane
to accomplish (this includes the time required to gain access, remove
parts, inspect, install, and perform functional testing), at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the inspection requirements of this AD on U.S. operators is
estimated to be $1,189,320, or $1,020 per airplane, per inspection
cycle.
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.
For operators who elect to install the optional terminating
modification, it will take approximately 430 work hours per airplane to
accomplish, at an average labor rate of $60 per work hours. Required
parts will cost approximately $8,580 per airplane. Based on these
figures, the cost impact of the optional modification is estimated to
be $34,380 per airplane.
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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-4951 (59 FR
45743, November 20, 1984), and amendment 39-5769 (52 FR 43742, November
16, 1987), and by adding a new airworthiness directive (AD), amendment
39-9542, to read as follows:
96-06-05 Boeing: Amendment 39-9542. Docket 94-NM-179-AD. Supersedes
AD 84-22-02, amendment 39-4951; and AD 87-24-03, amendment 39-5769.
Applicability: Model 727 series airplanes, line numbers 1
through 1832 inclusive; certificated in any category.
[[Page 11532]]
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 (j) 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 excessive free play of the elevator control tab and
possible tab flutter, accomplish the following:
(a) For airplanes on which the modification or repair described
in Boeing Service Bulletin 727-55-0085, dated August 31, 1984
(specified as terminating action in AD 84-22-02, amendment 39-4951),
has not been accomplished and the repetitive inspections required by
AD 84-22-02 have not been initiated: Prior to the accumulation of
8,000 total flight hours since date of manufacture, or within 300
flight hours after the effective date of this AD, whichever occurs
later, perform a visual inspection to detect cracks and loose hinge
brackets of the elevator rear spar in the area along the upper and
lower edges at the shear plate, in accordance with Boeing Service
Bulletin 727-55-0089, dated June 29, 1995. Then accomplish the
follow-on actions (i.e., repetitive inspections, stop-drilling,
modification) in accordance with that service bulletin, at the times
specified as follows .
Note 2: AD 84-22-02 pertains to the one-piece elevator rear
spar.
(1) Repeat the visual inspection thereafter at intervals not to
exceed 1,600 flight hours.
(2) If any crack is detected and stop-drilled as a result of any
inspection required by this paragraph, accomplish the requirements
of paragraph (g) of this AD at the times specified in that
paragraph.
(b) For airplanes on which the modification or repair described
in Boeing Service Bulletin 727-55-0085, dated August 31, 1984
(specified as terminating action in AD 84-22-02, amendment 39-4951),
has not been accomplished and the repetitive inspections required by
AD 84-22-02 have been initiated: Accomplish either paragraph (b)(1)
or (b)(2) of this AD, as applicable.
(1) If no crack has been detected as a result of inspections
required by AD 84-22-02: Within 1,600 flight hours after the last
inspection required by that AD, perform a visual inspection to
detect cracks and loose brackets of the elevator rear spar in the
area along the upper and lower edges at the shear plate, in
accordance with the Boeing Service Bulletin 727-55-0089, dated June
29, 1995. Accomplish follow-on actions (i.e., repetitive inspection,
stop-drilling, modification) in accordance with that service
bulletin, at the times specified as follows:
(i) Repeat the visual inspection thereafter at intervals not to
exceed 1,600 flight hours.
(ii) If any crack is detected and stop-drilled as a result of
any inspection required by this paragraph, accomplish the
requirements of paragraph (g) of this AD at the times specified in
that paragraph.
(2) If any crack has been stop-drilled in accordance with AD 84-
22-02, accomplish the requirements of paragraph (g) of this AD at
the times specified in that paragraph.
(c) For airplanes on which the modification or repair described
in Boeing Service Bulletin 727-55-0085, dated August 31, 1984
(specified as terminating action in AD 84-22-02, amendment 39-4951),
has been accomplished: Within 4,000 flight hours after the effective
date of this AD, perform a visual inspection to detect cracks and
loose hinge brackets of the elevator rear spar in the area along the
upper and lower edges at the shear plate, in accordance with Boeing
Service Bulletin 727-55-0089, dated June 29, 1995. Accomplish
follow-on actions (i.e., repetitive inspections, stop-drilling,
modification) in accordance with that service bulletin, at the times
specified as follows:
(1) Repeat the visual inspection thereafter at intervals not to
exceed 4,000 flight hours.
(2) If any crack is detected and stop-drilled as a result of any
inspection required by this paragraph, accomplish the requirements
of paragraph (g) of this AD at the times specified in that
paragraph.
(d) For airplanes on which the modification or repair described
in Boeing Service Bulletin 727-55-087, dated June 20, 1986
(specified as terminating action in AD 87-24-03, amendment 39-5769),
has not been accomplished and the repetitive inspections required by
AD 87-24-03 have not been initiated: Accomplish the requirements of
paragraph (d)(1) of this AD at the earliest of the times specified
in paragraph (d)(2).
Note 3: AD 87-24-03 pertains to the two-piece elevator rear
spar.
(1) Perform a visual inspection to detect cracks and loose hinge
brackets of the elevator rear spar in the area along the upper and
lower edges at the shear plate, at the earliest of the times
specified in paragraph (d)(2) of this AD, and in accordance with
Boeing Service Bulletin 727-55-0089, dated June 29, 1995. Accomplish
follow-on actions (i.e., repetitive inspection, stop-drilling,
modification) in accordance with that service bulletin, at the times
specified as follows:
(i) Repeat the visual inspection thereafter at intervals not to
exceed 4,000 flight hours.
(ii) If any crack is detected and stop-drilled as a result of
any inspection required by this paragraph, accomplish the
requirements of paragraph (g) of this AD at the times specified in
that paragraph.
(2) Accomplish the initial visual inspection required by
paragraph (d)(1) of this AD at the earliest of the following times:
(i) Prior to the accumulation of 27,000 total flight hours since
date of manufacture, or within 4,000 flight hours after December 24,
1987 (the effective date of 87-24-03, amendment 39-5769), whichever
occurs later; or
(ii) Prior to the accumulation of 12,000 total flight hours
since date of manufacture, or within 4,000 flight hours after the
effective date of this AD, whichever occurs later; or
(iii) Prior to the accumulation of 27,300 total flight hours
since date of manufacture, or within 300 flight hours after the
effective date of this AD, whichever occurs later.
(e) For airplanes on which the modification or repair described
in Boeing Service Bulletin 727-55-087, dated June 20, 1986
(specified as terminating action in AD 87-24-03, amendment 39-5769),
has not been accomplished and the repetitive inspections required by
AD 87-24-03 have been initiated: Accomplish either paragraph (e)(1)
or (e)(2) of this AD, as applicable.
(1) If no crack has been detected as a result of inspections
required by AD 87-24-03: Within 4,000 flight hours after the last
inspection required by that AD, perform a visual inspection to
detect cracks and loose brackets of the elevator rear spar in the
area along the upper and lower edges at the shear plate, in
accordance with Boeing Service Bulletin 727-55-0089, dated June 29,
1995. Accomplish follow-on actions (i.e., repetitive inspection,
stop-drilling, modification) in accordance with that service
bulletin, at the times specified as follows:
(i) Repeat the visual inspection thereafter at intervals not to
exceed 4,000 flight hours.
(ii) If any crack is detected and stop-drilled as a result of
any inspection required by paragraph (e)(1) of this AD, accomplish
the requirements of paragraph (g) of this AD at the times specified
in that paragraph.
(2) If any crack has been detected and stop-drilled in
accordance with AD 87-24-03, accomplish the requirements of
paragraph (g) of this AD at the times specified in that paragraph.
(f) For airplanes on which the modification or repair described
in Boeing Service Bulletin 727-55-087, dated June 20, 1986
(specified as terminating action in AD 87-24-03, amendment 39-5769),
has been accomplished: Within 4,000 flight hours after the effective
date of this AD, perform a visual inspection to detect cracks and
loose hinge brackets of the elevator rear spar in the area along the
upper and lower edges at the shear plate, in accordance with Boeing
Service Bulletin 727-55-0089, dated June 29, 1995. Accomplish
follow-on actions (i.e., repetitive inspection, stop-drilling,
modification) in accordance with the service bulletin, at the times
specified as follows:
(1) Repeat the visual inspection thereafter at intervals not to
exceed 4,000 flight hours.
(2) If any crack is detected and stop-drilled as a result of any
inspection required by this paragraph, accomplish the requirements
of paragraph (g) of this AD at the times specified in that
paragraph.
(g) If any crack is detected and stop-drilled in accordance with
paragraph (a)(2), (b)(1)(ii), (b)(2), (c)(2), (d)(1)(ii),
(e)(1)(ii), (e)(2), or (f)(2) of this AD, accomplish the following:
(1) Within 1,600 flight hours after stop-drilling, perform a
visual inspection to detect cracks and loose hinge brackets of the
elevator rear spar in the area along the upper and lower edges at
the shear plate, and accomplish follow-on actions (i.e., stop-
drilling, modification) in accordance with the service bulletin. If
any crack growth is detected after stop-drilling, prior to further
flight, modify the elevator rear spar in accordance with Part II of
the
[[Page 11533]]
Accomplishment Instructions of Boeing Service Bulletin 727-55-0089,
dated June 29, 1995. Accomplishment of this modification constitutes
terminating action for the repetitive inspection requirements of
this AD.
(2) Within 3,200 flight hours after stop-drilling, modify the
elevator rear spar in accordance with Part II of the Accomplishment
Instructions of Boeing Service Bulletin 727-55-0089, dated June 29,
1995. Accomplishment of this modification constitutes terminating
action for the repetitive inspection requirements of this AD.
(h) Modification of the elevator rear spar in accordance with
Part II of the Accomplishment Instructions of Boeing Service
Bulletin 727-55-0089, dated June 29, 1995, constitutes terminating
action for the requirements of this AD.
(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.
(j) 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.
(k) The actions shall be done in accordance with Boeing Service
Bulletin 727-55-0089, dated June 29, 1995. 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.
(l) This amendment becomes effective on April 22, 1996.
Issued in Renton, Washington, on March 12, 1996.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-6391 Filed 3-20-96; 8:45 am]
BILLING CODE 4910-13-U
