[Federal Register Volume 62, Number 41 (Monday, March 3, 1997)]
[Rules and Regulations]
[Pages 9359-9361]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-4947]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-NM-32-AD; Amendment 39-9952; AD 97-05-08]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 727 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to all Boeing Model 727 series airplanes. This action
requires repetitive pre-modification inspections to detect cracks in
the forward support fitting of the number 1 and number 3 engines; and
repair, if necessary. This AD also provides for an optional high
frequency eddy current (HFEC) inspection, and, if possible,
modification of the fastener holes; and various follow-on actions.
Accomplishment of these optional actions would constitute terminating
action for the repetitive pre-modification inspections. This amendment
is prompted by reports indicating that fatigue cracks were found in the
forward support fitting of the number 1 and number 3 engines. The
actions specified in this AD are intended to detect and correct such
fatigue cracking, which could result in failure of the support fitting
and consequent separation of the engine from the airplane.
DATES: Effective March 18, 1997.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 18, 1997.
Comments for inclusion in the Rules Docket must be received on or
before May 2, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 97-NM-32-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056.
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 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.
FOR FURTHER INFORMATION CONTACT: Walter Sippel, Aerospace Engineer,
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office,
1601 Lind Avenue, SW., Renton, Washington; telephone (206) 227-2774;
fax (206) 227-1181.
SUPPLEMENTARY INFORMATION: The FAA has received several reports of
cracks found in the forward support fitting of the number 1 and number
3 engines on Boeing Model 727 series airplanes. In two of these
incidents, the cracks emanated from the large fastener holes next to
the side of the fuselage. In a third incident, a fitting was cracked
almost completely through. In other incidents, cracks were found at a
small distance inboard from the fuselage side. The cracking has been
attributed to fatigue, which was caused by corrosion pitting damage on
the surfaces of the fastener holes in the fittings. These conditions,
if not detected and corrected in a timely manner, could result in
failure of the support fitting and consequent separation of the engine
from the airplane.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Service Bulletin 727-
54A0010, Revision 4, dated January 30, 1997, which describes the
following procedures:
1. Performing repetitive visual inspections to detect cracks of the
upper and lower flanges, and the vertical web of the forward support
fitting of the number 1 and number 3 engines;
2. Performing repetitive high frequency eddy current (HFEC)
inspections to detect cracks of the forward flange of the support
fitting adjacent to the collars of two fasteners of the number 1 and
number 3 engines;
3. Performing repetitive detail visual inspections to detect cracks
of the upper and lower flanges adjacent to six fasteners of the number
1 and number 3 engines;
4. Repairing the cracked forward support fitting; and
5. Performing a HFEC inspection to detect cracks of the fastener
holes in the forward support fitting of the number 1 and number 3
engines, and, if possible, modification of the fastener holes; and
various follow-on actions. (These follow-on actions include
installation of fasteners, repetitive HFEC inspections, and repair of
cracked forward support fittings.) The modification involves oversizing
the fastener holes until the HFEC does not detect any cracks.
Accomplishment of this HFEC inspection, modification, and follow-on
actions will eliminate the need for the repetitive pre-modification
inspections, as described in items 1 though 3.
Explanation of the Requirements of the Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other Boeing Model 727 series airplanes of the same
type design, this AD is being issued to detect and correct fatigue
cracking of the forward support fitting, which could result in failure
of the support fitting and consequent separation of the engine from the
airplane. This AD requires repetitive pre-modification inspections to
detect cracks of the forward support fitting of the number 1 and number
3 engines; and repair, if necessary. This AD also provides for an
optional HFEC inspection, and, if possible, modification of the
fastener holes; and various follow-on actions. Accomplishment of these
optional actions constitutes terminating action for the repetitive pre-
modification inspections. The actions are required to be accomplished
in accordance with the service bulletin described previously.
[[Page 9360]]
Differences Between the AD and the Relevant Service Information
Operators should note that, although the service bulletin specifies
that the manufacturer must be contacted for disposition of certain
conditions, this AD requires the repair of those conditions to be
accomplished in accordance with method approved by the FAA.
Interim Action
This AD is considered interim action. The FAA is considering
further rulemaking action to supersede this AD to require an HFEC
inspection to detect cracks of the fastener holes in the forward
support fitting of the number 1 and number 3 engines, and, if possible,
modification of the fastener holes; and various follow-on actions.
Accomplishment of these actions will constitute terminating action for
the repetitive pre-modification inspections required by this AD action.
However, the FAA's planned compliance time for these actions is
sufficiently long so that prior notice and time for public comment will
be practicable.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this rule by
submitting such written data, views, or arguments as they may desire.
Communications shall identify the Rules Docket number and be submitted
in triplicate to the address specified under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the rule. All comments submitted will be
available, both before and after the closing date for comments, in the
Rules Docket for examination by interested persons. A report that
summarizes each FAA-public contact concerned with the substance of this
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 97-NM-32-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, 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:
97-05-08 BOEING: Amendment 39-9952. Docket 97-NM-32-AD.
Applicability: All Model 727 series airplanes, certificated in
any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (e) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To detect and correct fatigue cracking, which could result in
failure of the support fitting and consequent separation of the
engine from the airplane, accomplish the following:
(a) Within 100 days or within 600 flight cycles after the
effective date of this AD, whichever occur first, accomplish
paragraph (a)(1), (a)(2), and (a)(3) of this AD, in accordance with
Boeing Service Bulletin 727-54A0010, Revision 4, dated January 30,
1997.
(1) Perform a visual inspection to detect cracks of the upper
and lower flanges, and the vertical web of the forward support
fitting of the number 1 and number 3 engines, in accordance with
Part 1--Pre-Modification Inspections of the Accomplishment
Instructions of the service bulletin.
(2) Perform a high frequency eddy current (HFEC) inspection to
detect cracks of the forward flange of the support fitting adjacent
to the collars of two fasteners of the number 1 and number 3
engines, in accordance with Part 1--Pre-Modification Inspections of
the Accomplishment Instructions of the service bulletin.
(3) Perform a detailed visual inspection to detect cracks of the
upper and lower flanges adjacent to six fasteners of the number 1
and number 3 engines, in accordance with Part 1--Pre-Modification
Inspections of the Accomplishment Instructions of the service
bulletin.
(b) If no crack is detected during the inspections required by
paragraph (a) of this AD, repeat those inspections thereafter at
intervals not to exceed 100 days or 600 flight cycles, whichever
occurs first.
(c) If any crack is detected during any inspection required by
paragraph (a) of this AD, prior to further flight, repair the
forward support fitting in accordance with a method approved by the
Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport
Airplane Directorate.
[[Page 9361]]
(d) Accomplishment of the actions specified in paragraphs (d)(1)
and (d)(2) of this AD in accordance with Boeing Service Bulletin
727-54A0010, Revision 4, dated January 30, 1997, constitutes
terminating action for the requirements of paragraphs (a) and (b) of
this AD.
(1) Perform a HFEC inspection to detect cracks of the fastener
holes in the forward support fitting of the number 1 and number 3
engines, and, if possible, modify the fastener holes, in accordance
with Part II--Fastener Hole Modification of the Accomplishment
Instructions of the service bulletin.
(i) If the modification (i.e., a fastener installed in a hole
with no cracks) was accomplished at all eight holes, no further
action is required by paragraph (d)(1) of this AD.
(ii) If the modification was not accomplished at all eight holes
because of the continued detection of cracking, prior to further
flight, repair the forward support fitting in accordance with a
method approved by the Manager, Seattle ACO.
(2) Prior to the accumulation of 3,000 flight cycles or 24
months, whichever occurs first, following accomplishment of
paragraph (d)(1) of this AD, perform a HFEC inspection to detect
corrosion or cracks of the modified forward support fitting of the
number 1 and number 3 engines, in accordance with Part III--Post-
Modification Inspections of the Accomplishment Instructions of the
service bulletin.
(i) If no crack or corrosion is detected, prior to further
flight, install the fasteners wet with a sealant in accordance with
the service bulletin. Repeat the HFEC inspection required by
paragraph (d)(2) of this AD thereafter at intervals not to exceed
3,000 flight cycles or 24 months, whichever occurs first.
(ii) If any crack or corrosion is detected, prior to further
flight, repair the forward support fitting in accordance with a
method approved by the Manager, Seattle ACO.
(e) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Seattle Aircraft Certification
Office (ACO), FAA, Transport Airplane Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Seattle ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(f) Special flight permits may be issued in accordance with
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.
(g) The inspections and modifications shall be done in
accordance with Boeing Service Bulletin 727-54A0010, Revision 4,
dated January 30, 1997. This incorporation by reference was approved
by the Director of the Federal Register in accordance with 5 U.S.C.
552(a) and 1 CFR part 51. Copies may be obtained from Boeing
Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-
2207. Copies may be inspected at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
Office of the Federal Register, 800 North Capitol Street, NW.,
suite700, Washington, DC.
(h) This amendment becomes effective on March 18, 1997.
Issued in Renton, Washington, on February 21, 1997.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-4947 Filed 2-28-97; 8:45 am]
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