[Federal Register Volume 59, Number 177 (Wednesday, September 14, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-22672]
[[Page Unknown]]
[Federal Register: September 14, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-NM-104-AD]
Airworthiness Directives; British Aerospace Model Viscount 744,
745D, and 810 Series Airplanes
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 all British Aerospace Model
Viscount 744, 745D, and 810 series airplanes. This proposal would
require various inspections to detect damage, corrosion, or cracking of
certain taper plugs and split bushings of the engine mount, and
replacement of taper plugs or split bushings with serviceable parts, if
necessary. This proposal is prompted by a report of damage of the taper
plug and split bushing of the engine mount due to the effects of
corrosion. The actions specified by the proposed AD are intended to
prevent such damage, which could lead to failure of the engine mount
attachment assembly and consequent separation of the engine from the
airplane.
DATES: Comments must be received by October 24, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No.94-NM-104-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 British Aerospace Regional Aircraft Ltd., Engineering
Support Manager, Military Business Unit, Chadderton Works, Greengate,
Middleton, Manchester M24 1SA, England. This information may be
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,
SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer,
ANM-113, Standardization Branch, ANM-113, FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056;
telephone (206) 227-2148; fax (206) 227-1320.
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-104-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-104-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Civil Aviation Authority (CAA), which is the airworthiness
authority for United Kingdom, recently notified the FAA that an unsafe
condition may exist on all British Aerospace Model Viscount 744, 745D,
and 810 series airplanes. The CAA advises that it has received a report
of damage to the taper plug and split bushing (bush) of the engine
mount. Investigation revealed that the taper plug and split bushing had
corroded. The effects of such corrosion could lead to the failure of
the taper plug and split bushing, which consequently could lead to the
failure of the engine mount attachment assembly. This condition, if not
corrected, could result in separation of the engine from the airplane.
British Aerospace has issued Viscount Preliminary Technical Leaflet
(PTL) 200, Disc 9 Doc.5, dated December 6, 1991 (for Model Viscount 810
series airplanes), and Viscount PTL 329, Disc 9 Doc.2, dated April 1,
1992 (for Model Viscount 744 and 745D series airplanes). These service
documents describe procedures for performing detailed visual and
nondestructive test (NDT) inspections to detect damage, corrosion, or
cracking of taper plugs, having part number (P/N) 60216-1017, and split
bushings, having P/N 60216-1019, of the engine mount; and replacement
of discrepant parts. The CAA classified these PTL's as mandatory.
This airplane model is manufactured in the United Kingdom and is
type certificated for operation in the United States under the
provisions of section 21.29 of the Federal Aviation Regulations (14 CFR
21.29) and the applicable bilateral airworthiness agreement. Pursuant
to this bilateral airworthiness agreement, the CAA has kept the FAA
informed of the situation described above. The FAA has examined the
findings of the CAA, reviewed all available information, and determined
that AD action is necessary for products of this type design that are
certificated for operation in the United States.
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, the proposed AD would require detailed visual and
nondestructive test (NDT) inspections to detect damage, corrosion, or
cracking of certain taper plugs and split bushings of the engine mount;
and replacement of discrepant parts. The actions would be required to
be accomplished in accordance with the applicable PTL described
previously.
The FAA estimates that 25 Model Viscount 744 and 745D series
airplanes of U.S. registry would be affected by this proposed AD, that
it would take approximately 25 work hours per airplane to accomplish
the proposed actions, and that the average labor rate is $55 per work
hour. Based on these figures, the total cost impact of the proposed AD
on U.S. operators is estimated to be $34,375, or $1,375 per airplane.
The FAA estimates that 4 Model Viscount 810 series airplanes of
U.S. registry would be affected by this proposed AD, that it would take
approximately 25 work hours per airplane to accomplish the proposed
actions, and that the average labor rate is $55 per work hour. Based on
these figures, the total cost impact of the proposed AD on U.S.
operators is estimated to be $5,500, or $1,375 per airplane.
Based on the above figures, the total cost impact of the actions
proposed by this AD on U.S. operators is estimated to be $39,875, or
$1,375 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:
British Aerospace Regional Aircraft Limited (Formerly British
Aerospace Commercial Aircraft Limited, Vickers-Armstrongs Aircraft
Limited): Docket 94-NM-104-AD.
Applicability: All Model Viscount 744, 745D, and 810 series
airplanes, certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent separation of the engine from the airplane,
accomplish the following:
(a) At the next unscheduled engine removal, but no later than 12
months after the effective date of this AD, perform a detailed
visual inspection to detect damage, corrosion, or cracking of taper
plugs, having part number (P/N) 60216-1017, and split bushings
(bushes), having P/N 60216-1019, of the engine mount, in accordance
with British Aerospace Viscount Preliminary Technical Leaflet (PTL)
200, Disc 9 Doc.5, dated December 6, 1991 (for Model Viscount 810
series airplanes); or British Aerospace Viscount PTL 329, Disc. 9
Doc.2, dated April 1, 1992 (for Model Viscount 744 and 745D series
airplanes); as applicable.
(1) If no taper plugs or split bushings are damaged, corroded,
or cracked, repeat the inspection thereafter at each unscheduled
engine removal, but no later than 48 months after the last visual
inspection of the taper plugs and split bushings.
(2) If any taper plug or split bushing is damaged, corroded, or
cracked, prior to further flight, replace the taper plug or split
bushing with a serviceable part, in accordance with the applicable
PTL. Thereafter, repeat the inspection at each unscheduled engine
removal, but no later than 48 months after the last visual
inspection of the taper plugs and split bushings.-
(b) At the next scheduled engine removal, but no later than 12
months after the effective date of this AD, perform detailed visual
and nondestructive test (NDT) inspections to detect damage,
corrosion, or cracking of all taper plugs and split bushings of the
engine mount, in accordance with British Aerospace Viscount PTL 200,
Disc 9 Doc.5, dated December 6, 1991 (for Model Viscount 810 series
airplanes); or British Aerospace Viscount PTL 329, Disc. 9 Doc.2,
dated April 1, 1992 (for Model Viscount 744 and 745D series
airplanes); as applicable.
(1) If no taper plug or split bushing is damaged, corroded, or
cracked, repeat the visual and NDT inspections thereafter at each
scheduled engine removal, but no later than 48 months after the last
visual and NDT inspections of the taper plugs and split bushings.
(2) If any taper plug or split bushing is damaged, corroded, or
cracked, prior to further flight, replace the taper plug or split
bushing with a serviceable part, in accordance with the applicable
PTL. Thereafter, repeat the visual and NDT inspections at each
scheduled engine removal, but no later than 48 months after the last
visual and NDT inspections of the taper plugs and split bushings.
(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, Standardization Branch, ANM-113,
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,
Standardization Branch, ANM-113.
Note: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(d) Special flight permits may be issued in accordance with
Secs. 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 September 8, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-22672 Filed 9-13-94; 8:45 am]
BILLING CODE 4910-13-U
