[Federal Register Volume 59, Number 249 (Thursday, December 29, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-32035]
[[Page Unknown]]
[Federal Register: December 29, 1994]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-NM-179-AD]
Airworthiness Directives; Boeing Model 727 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to certain Boeing Model 727
series airplanes, that currently requires repetitive visual inspections
to detect cracks of the elevator rear spar, and repair, if necessary.
It also provides for a terminating action for the repetitive
inspections. This action would add a one-time inspection to verify that
proper clearance exists between the shear plate and the radii of the
elevator rear spar on airplanes on which the terminating action has
been accomplished. This proposal would also provide for an improved
terminating action. This proposal 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 the proposed AD are
intended to prevent such cracking, which could result in excessive free
play of the elevator control tab and possible tab flutter.
DATES: Comments must be received by February 27, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-179-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule 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.
FOR FURTHER INFORMATION CONTACT: Walter Sippel, Aerospace Engineer,
Airframe Branch, ANM-121S, 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:
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.
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 94-NM-179-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. 94-NM-179-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion -
On October 31, 1984, the FAA issued AD 84-22-02, amendment 39-4951
(49 FR 45743, November 20, 1984), applicable to certain Boeing Model
727 series airplanes, to require repetitive visual inspections to
detect cracks of the elevator rear spar, and repair, if necessary. That
action was prompted by several reports of cracking in the rear spar
flange radii at the elevator tab hinge points. The requirements of that
AD are intended to prevent cracking in the elevator rear spar, which
could result in excessive free play of the elevator control tab and
possible tab flutter.
Since the issuance of that AD, there have been several reports of
cracking in the spar radii at the tab hinge location of the elevator
rear spar on airplanes that were modified in accordance with Boeing
Service Bulletin 727-55-0085, dated August 31, 1984. That modification
was considered to be terminating action for the repetitive inspection
requirements of AD 84-22-02. The manufacturer has advised that the
cause of this cracking has been attributed to continued contact between
the shear plate and the radii of the elevator rear spar. Cracking in
this area, if not corrected, could result in excessive free play of the
elevator control tab and possible tab flutter.
The FAA has reviewed and approved Boeing Service Bulletin 727-55-
0085, Revision 4, dated March 31, 1994, which describes procedures for
continued repetitive visual inspections to detect cracks of the
elevator rear spar, and repair, if necessary. For airplanes that have
been modified in accordance with previous revisions of Boeing Service
Bulletin 727-55-0085, the service bulletin describes procedures for an
additional one-time inspection to verify that proper clearance exists
between the shear plate and the radii of the elevator rear spar, and
repair, if necessary. Additionally, for all other airplanes, the
service bulletin provides instructions for accomplishing an improved
modification or repair that would eliminate the need for the repetitive
inspections.
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 supersede AD 84-22-02 to continue to require
repetitive visual inspections to detect cracks of the elevator rear
spar, and repair, if necessary. However, this proposal would add a one-
time inspection to verify that proper clearance exists between the
shear plate and the radii of the elevator rear spar on airplanes on
which the terminating action specified in AD 84-22-02 has been
accomplished. The proposed AD would also provide for an improved
modification or repair of the elevator rear spar, which, if
accomplished, would constitute terminating action for the repetitive
visual inspection requirements. 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 requirement.
There are approximately 100 Model 727 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 64
airplanes of U.S. registry would be affected by this proposed AD.
The inspections of the elevator rear spar that were previously
required by AD 84-22-02, and retained in this proposal, take
approximately 12 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the total cost
impact of this currently-required inspection requirement on U.S.
operators is estimated to be $46,080, or $720 per airplane, per
inspection cycle.
The one-time inspection of previously modified airplanes that would
be required by this proposal would take approximately 12 work hours per
airplane to accomplish, at an average labor rate of $60 per work hour.
Based on these figures, the total cost impact of the one-time
inspection requirement of this proposal on U.S. operators of previously
modified airplanes is estimated to be $720 per airplane.
The total cost impact figures, discussed above, are based on
assumptions that no operator has yet accomplished the current or
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 removing amendment 39-4951 (49 FR
45743, November 20, 1984), and by adding a new airworthiness directive
(AD), to read as follows:
Boeing: Docket 94-NM-179-AD. Supersedes AD 84-22-02, Amendment 39-
4951.
Applicability: Model 727 series airplanes, line numbers 1720
through 1831 inclusive, certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
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 (e) 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 excessive free play of the elevator control tab and
possible tab flutter, accomplish the following:
(a) For airplanes on which the modification 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: Within the next 300 flight hours after November 20,
1984 (the effective date of AD 84-22-02, amendment 4951), or prior
to the accumulation of 8,000 total flight hours, whichever occurs
later, perform a visual inspection to detect cracks of the elevator
rear spar, in accordance with Boeing Service Bulletin 727-55-0085,
dated August 31, 1984; Revision 1, dated November 16, 1984; Revision
2, dated December 21, 1984; Revision 3, dated July 26, 1985; or
Revision 4, dated March 31, 1994. Repeat the inspection thereafter
at intervals not to exceed 1,600 flight hours. After the effective
date of this AD, only Revision 4 of this service bulletin shall be
used.
(b) If any crack is found during any inspection required by
paragraph (a) of this AD, accomplish paragraphs (b)(1) and (b)(2) of
this AD in accordance with Boeing Service Bulletin 727-55-0085,
dated August 31, 1984; Revision 1, dated November 16, 1984; Revision
2, dated December 21, 1984; Revision 3, dated July 26, 1985; or
Revision 4, dated March 31, 1994. After the effective date of this
AD, only Revision 4 of this service bulletin shall be used.
(1) If any crack is found that is within the limits specified in
Part 1 of the Accomplishment Instructions of the service bulletin,
accomplish paragraphs (b)(1)(i) and (b)(1)(ii) of this AD.
(i) Prior to further flight, perform a time-limited repair by
stop drilling the crack in accordance with the service bulletin.
Within 1,600 flight hours after the repair, repeat the inspection
required by paragraph (a) of this AD.
(ii) Prior to the accumulation of 3,200 flight hours after stop
drilling the crack, repair the elevator rear spar in accordance with
Part III of the Accomplishment Instructions of the service bulletin.
(2) If any crack is found that is outside the limits specified
in Part 1 of the Accomplishment Instructions of the service
bulletin, prior to further flight, repair the elevator rear spar in
accordance with Part III of the Accomplishment Instructions of the
service bulletin.
(c) For airplanes on which the modification specified in Boeing
Service Bulletin 727-55-0085, dated August 13, 1984 (specified as
terminating action in AD 84-22-02, amendment 39-4951), has been
accomplished: Prior to the accumulation of 1,600 flight hours, or
within 12 months after the effective date of this AD, whichever
occurs later, perform an inspection to verify that proper clearance
exists between the shear plate and the radii of the elevator rear
spar, in accordance with Boeing Service Bulletin 727-55-0085,
Revision 4, dated March 31, 1994.
(1) If the clearance is within the limits specified in Part 1 of
the Accomplishment Instructions of the service bulletin, no further
action is required by this AD.
(2) If the clearance is outside the limits specified in Part 1
of the Accomplishment Instructions in the service bulletin, prior to
further flight, reaccomplish the modification in accordance with
Revision 4 of the service bulletin. After modification, no further
action is required by this AD.
(d) Modification or repair of the elevator rear spar, in
accordance with Part II or Part III of the Accomplishment
Instructions of Boeing Service Bulletin 727-55-0085, Revision 4,
dated March 31, 1994, constitutes terminating action for the
requirements of this AD.
(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.
Issued in Renton, Washington, on December 22, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-32035 Filed 12-28-94; 8:45 am]
BILLING CODE 4910-13-P