[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