[Federal Register Volume 60, Number 85 (Wednesday, May 3, 1995)]
[Proposed Rules]
[Pages 21774-21776]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-10829]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-35-AD]


Airworthiness Directives; Boeing Model 727-100 and -200 Series 
Airplanes Equipped With an Engine Nose Cowl Installed in Accordance 
With Supplemental Type Certificate (STC) SA4363NM

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 727-100 and -
200 series airplanes. This proposal would require replacing the 
attachin-nutplates on certain engine nose cowls with washers and self-
locking nuts. This proposal is prompted by reports indicating that nose 
cowls separated (or nearly separated) from the engines of certain 
airplanes following failure of the engine fan blade and subsequent 
vibration of the engine, which caused loosening of the attach bolts on 
the nose cowl of the engine. The actions specified by the proposed AD 
are intended to prevent the attach bolts from becoming loose, which 
could result in subsequent separation of the nose cowl from the engine.

DATES: Comments must be received by June 12, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-35-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9 a.m. and 3 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from VALSAN Partnership Ltd., Aviation Products Management, 
Product Support Office, 39450 Third Street East, suite 121, Palmdale, 
California 93550. This information may be examined at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Phil Forde, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle 
Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 
98055-4056; telephone (206) 227-2771; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed 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 above. All 
communications received on or before the closing date for comments, 
specified above, will be considered before taking action on the 
proposed rule. The proposals contained in this notice may be changed in 
light of the comments received. [[Page 21775]] 
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 95-NM-35-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules 
Docket No. 95-NM-35-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA received reports from three operators of McDonnell Douglas 
Model DC-9-80 series airplanes indicating that a nose cowl separated 
from the engine of the airplane. In addition, the FAA received one 
report indicating that the nose cowl nearly separated from an airplane 
equipped with a Pratt & Whitney JT8D-200 series engine. These incidents 
occurred following severe vibration of the engine due to failure of the 
engine fan blade. Such vibration of the engine could cause the attach 
bolts on the nose cowl of the engine to become loose. This condition, 
if not corrected, could result in separation of the nose cowl from the 
engine of the airplane.
    On December 2, 1994, the FAA issued AD 94-25-06, amendment 39-9090 
(59 FR 64566, December 15, 1994), to address this unsafe condition on 
McDonnell Douglas Model DC-9-80 series airplanes and Model MC-88 
airplanes. Subsequently, the FAA has determined that certain Boeing 
Model 727-100 and -200 series airplanes are equipped with an engine 
nose cowl installed in accordance with Supplemental Type Certificate 
(STC) SA4363NM, which is identical to the engine nose cowl installed on 
the McDonnell Douglas airplanes affected by AD 94-25-06. Therefore, the 
FAA has determined that these Boeing Model 727-100 and -200 series 
airplanes also are subject to the addressed unsafe condition.
    The FAA has reviewed and approved VALSAN B727-RE Service Bulletin 
71-006, Revision 1, dated March 3, 1995, which describes procedures for 
replacing the attaching nutplates of the No. 1 and No. 3 engine nose 
cowls with washers and self-locking nuts. The replacement involves 
removing the attaching nutplates from the No. 1 and No. 3 engine nose 
cowls, reversing the installation direction of the attach bolt, 
installing washers and self-locking nuts in place of the removed 
nutplates, and increasing bolt torque values. Accomplishment of this 
replacement will minimize the possibility of the attach bolts becoming 
loose as a result of severe engine vibration, thereby minimizing the 
possibility of the nose cowl separating from the engine.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require replacing the attaching nutplates on certain 
engine nose cowls with washers and self-locking nuts. The actions would 
be required to be accomplished in accordance with the service bulletin 
described previously.
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been included in this notice to clarify this long-standing requirement.
    There are approximately 22 Model 727-100 and -200 series airplanes 
of the affected design in the worldwide fleet. The FAA estimates that 
19 airplanes of U.S. registry would be affected by this proposed AD, 
that it would take approximately 6 work hours per airplane to 
accomplish the proposed actions, and that the average labor rate is $60 
per work hour. The cost for required parts would be negligible. Based 
on these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $6,840, or $360 per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the proposed 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, 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 copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Boeing: Docket 95-NM-35-AD.

    Applicability: Model 727-100 and -200 series airplanes equipped 
with an engine nose cowl installed in accordance with Supplemental 
Type Certificate (STC) SA4363NM, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
[[Page 21776]] 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 use the authority 
provided in paragraph (c) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition; or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent the attach bolts on the nose cowl of the engine from 
becoming loose, and subsequent separation of the nose cowl from the 
engine, accomplish the following:
    (a) Within 12 months after the effective date of this AD, 
replace the attaching nutplates of the No. 1 and No. 3 engine nose 
cowls with washers and self-locking nuts in accordance with VALSAN 
B727-RE Service Bulletin 71-006, Revision 1, dated March 3, 1995.
    (b) As of the effective date of this AD, no person shall install 
a nose cowl having part number 259-0002-501 or 259-0002-503 on any 
airplane.
    (c) 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.

    (d) 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.

    Issued in Renton, Washington, on April 27, 1995.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-10829 Filed 5-2-95; 8:45 am]
BILLING CODE 4910-13-U