[Federal Register Volume 63, Number 173 (Tuesday, September 8, 1998)]
[Proposed Rules]
[Pages 47440-47442]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-24064]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-217-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Model Viscount 744, 
745, 745D, and 810 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 all British Aerospace Model 
Viscount 700, 800, and 810 series airplanes, that currently requires 
repetitive inspections to detect cracks and corrosion in the inboard 
and outboard engine nacelle structures on the wings; replacement of any 
cracked fittings and mating struts; and treatment or replacement of any 
corroded fittings or struts. This action would require repetitive 
inspections to detect cracking or corrosion of the eye end fittings of 
the outboard engine lower support or of the bore of the taper pin 
holes, and repair, if necessary. This action also would limit the 
applicability of the existing AD. This proposal is prompted by reports 
of cracked and separated lower eye end fittings. The actions specified 
by the proposed AD are intended to detect and correct cracking of the 
eye end fittings of the outboard engine lower support, which could 
result in reduced structural integrity of the engine nacelle support 
structures.

DATES: Comments must be received by October 8, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-217-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 Limited, Chadderton 
Division, Engineering Support, Greengate,

[[Page 47441]]

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: Norman B. Martenson, Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2110; fax (425) 227-1149.

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 98-NM-217-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-114, Attention: Rules 
Docket No. 98-NM-217-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On September 10, 1990, the FAA issued AD 90-20-17, amendment 39-
6744 (55 FR 38539, September 19, 1990), applicable to all British 
Aerospace Model Viscount 700, 800, and 810 series airplanes, to require 
repetitive visual, x-ray, ultrasonic, and dye penetrant inspections to 
detect cracks and corrosion in the inboard and outboard engine nacelle 
structures on the left and right wings; replacement of any cracked 
fittings and mating struts; and treatment or replacement of any 
corroded fittings or struts. That action was prompted by reports 
indicating that nacelle lower eye end fittings had cracked and 
separated due to fatigue failure or stress corrosion. The requirements 
of that AD are intended to detect and correct fatigue or stress 
corrosion cracking of the nacelle lower eye end fittings, which could 
result in reduced structural integrity of the engine nacelle support 
structures.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 90-20-17, the Civil Aviation Authority 
(CAA), which is the airworthiness authority for the United Kingdom, has 
determined that long-term continued operational safety would be better 
assured by using eddy current inspections, rather than visual, x-ray, 
ultrasonic, and dye penetrant inspections, to detect cracking and 
corrosion in engine nacelle support structures. British Aerospace has 
issued new service information to reflect this determination.

Explanation of Relevant Service Information

    British Aerospace has issued Preliminary Technical Leaflet (PTL) 
No. 326, Issue 2, including Appendices 1 and 2, all dated December 1, 
1994 (for Model Viscount 744, 745, and 745D series airplanes). British 
Aerospace also has issued PTL 197, Issue 3, including Appendices 1 and 
2, all dated November 20, 1993 (for Model Viscount 810 series 
airplanes). Those PTL's describe procedures for repetitive eddy current 
inspections to detect cracking or corrosion of the eye end fittings of 
the outboard engine lower support and of the bore of the taper pin 
holes in the engine nacelle subframes, tubes, and fittings. The CAA 
classified these PTL's as mandatory in order to assure the continued 
airworthiness of these airplanes in the United Kingdom.

FAA's Conclusions

    These airplane models are manufactured in the United Kingdom and 
are type certificated for operation in the United States under the 
provisions of Sec. 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.

Explanation of Requirements of Proposed Rule

    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 supersede AD 90-20-17 to 
require new repetitive eddy current inspections to detect cracking or 
corrosion of the eye end fittings of the outboard engine lower support 
or of the bore of the taper pin holes, and repair, if necessary. The 
proposed AD also would limit the applicability of the existing AD. The 
actions would be required to be accomplished in accordance with the 
PTL's described previously, except as discussed below.

Differences Between Proposed Rule and Preliminary Technical 
Leaflets

    Operators should note that, although the PTL's specify that the 
manufacturer may be contacted for disposition of repair conditions, 
this proposal would require the repair of those conditions to be 
accomplished in accordance with a method approved by either the FAA, or 
the CAA (or its delegated agent). In light of the type of repair that 
would be required to address the identified unsafe condition, and in 
consonance with existing bilateral airworthiness agreements, the FAA 
has determined that, for this proposed AD, a repair approved by either 
the FAA or the CAA would be acceptable for compliance with this 
proposed AD.

Explanation of Revisions to Applicability

    The applicability of the proposed AD has been reduced to include 
only Model Viscount 744, 745, and 745D series airplanes on which 
British Aerospace Modification D3227 has not been accomplished, and 
Model Viscount 810 series airplanes, on which British Aerospace 
Modification FG 2103 has not been accomplished. This change is 
necessary to incorporate restrictions to the effectivity of the PTL's 
that are specified in the Compliance paragraph of each PTL.

Other Relevant Rulemaking

    The FAA previously has issued AD 98-12-17, amendment 39-10444 (63 
FR 31347, June 9, 1998), which is applicable to all British Aerospace 
Model Viscount 744, 745, 745D, and 810 series airplanes. That AD 
requires repetitive inspections to detect cracking

[[Page 47442]]

and corrosion of components of the engine nacelle subframe structure; 
corrective action, if any cracking or corrosion is found; and 
replacement of any component that has reached its life limit with a new 
or serviceable component. That AD references British Aerospace Viscount 
Alert Preliminary Technical Leaflet (PTL) 500, dated January 1, 1993; 
including Appendices 1 through 4 inclusive, dated November 1992, and 
Appendix 5, dated October 1992; as the appropriate sources of service 
information for accomplishment of the actions required by AD 98-12-17. 
PTL 500 superseded and canceled British Aerospace Viscount Alert PTL 
No. 122, Issue 4, and British Aerospace Viscount Alert PTL No. 258, 
Issue 4, which were referenced in AD 90-20-17 as appropriate sources of 
service information for accomplishment of certain actions required by 
that AD. For this reason, those actions would not be mandated by this 
new proposed AD.

Cost Impact

    There are approximately 29 airplanes of U.S. registry that would be 
affected by this proposed AD.
    The new eddy current inspections that are proposed in this AD 
action would take approximately 2 work hours per airplane to 
accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of the proposed requirements of this AD 
on U.S. operators is estimated to be $3,480, or $120 per airplane, per 
inspection cycle.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of 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.

Regulatory Impact

    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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-6744 (55 FR 
38539, September 19, 1990), and by adding a new airworthiness directive 
(AD), to read as follows:

British Aerospace Regional Aircraft Limited (Formerly British 
Aerospace Commercial Aircraft Limited, Vickers-Armstrongs Aircraft 
Limited): Docket 98-NM-217-AD. Supersedes AD 90-20-17, amendment 39-
6744.

    Applicability: Model Viscount 744, 745, and 745D series 
airplanes, on which British Aerospace Modification D3227 has not 
been accomplished; and Model Viscount 810 series airplanes, on which 
British Aerospace Modification FG 2103 has not been accomplished; 
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 (c) 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 cracking of the eye end fittings of the 
outboard engine lower support, which could result in reduced 
structural integrity of the engine nacelle support structures, 
accomplish the following:
    (a) Perform an eddy current inspection to detect cracking or 
corrosion of the eye end fittings of the outboard engine lower 
support, or of the bore of the taper pin holes, in accordance with 
the Accomplishment Instructions of British Aerospace Preliminary 
Technical Leaflet (PTL) No. 326, Issue 2, including Appendices 1 and 
2, all dated December 1, 1994 (for Model Viscount 744, 745, and 745D 
series airplanes); or PTL 197, Issue 3, including Appendices 1 and 
2, all dated November 20, 1993 (for Model Viscount 810 series 
airplanes); at the applicable time specified in either paragraph 
(a)(1) or (a)(2) of this AD. Thereafter, repeat the inspection at 
intervals not to exceed 900 landings.
    (1) For Model Viscount 744, 745, and 745D series airplanes: 
Inspect within 3 months after the effective date of this AD.
    (2) For Model Viscount 810 series airplanes: Inspect within 900 
landings after the last inspection performed in accordance with PTL 
197, Issue 2, dated July 10, 1992; or within 3 months after the 
effective date of this AD, whichever occurs later.
    (b) If any cracking is found during any inspection performed in 
accordance with paragraph (a) of this AD, prior to further flight, 
repair in accordance with a method approved by the Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate; 
or the Civil Aviation Authority (or its delegated agent).
    (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, International Branch, ANM-116. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, International Branch, ANM-116.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (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 1, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-24064 Filed 9-4-98; 8:45 am]
BILLING CODE 4910-13-U