Airworthiness Directives; Boeing Model 727 Series Airplanes

[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]
BILLING CODE 4910-13-U

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