[Federal Register Volume 63, Number 63 (Thursday, April 2, 1998)]
[Rules and Regulations]
[Pages 16111-16114]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8538]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-321-AD; Amendment 39-10444]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Model Viscount 744, 
745, 745D, and 810 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Direct final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to all British Aerospace Model Viscount 744, 745, 745D, 
and 810 series airplanes. This amendment requires repetitive 
inspections to detect cracking and corrosion of components of the 
engine nacelle subframe structure, and corrective action, if necessary; 
and replacement of any component that has reached its life limit (safe 
life) with a new or serviceable component. This amendment is prompted 
by issuance of mandatory continuing airworthiness information by a 
foreign civil airworthiness authority. The actions specified in this 
amendment are intended to ensure periodic replacement of certain engine 
nacelle subframe components that have reached their maximum life 
limits. Cracking and

[[Page 16112]]

corrosion of these components, if not detected and corrected in a 
timely manner, could result in reduced structural integrity of the 
engine nacelle subframe structure, separation of the engine from the 
airframe, and reduced controllability of the airplane.

DATES: Effective July 1, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 1, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before May 4, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-321-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this amendment may be 
obtained from British Aerospace Regional Aircraft Limited, Chadderton 
Division, Engineering Support, Greengate, Middleton, Manchester M24 
1SA, England. 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: 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: The Civil Aviation Authority (CAA), which is 
the airworthiness authority for the United Kingdom, notified the FAA 
that an unsafe condition may exist on all British Aerospace Model 
Viscount 744, 745, 745D, and 810 series airplanes. The CAA advises that 
it has received reports of cracking, attributed to fatigue and stress 
corrosion, found in the engine nacelle subframe structure. Such 
cracking and corrosion, if not detected and corrected in a timely 
manner, could result in reduced structural integrity of the engine 
nacelle subframe structure, separation of the engine from the airframe, 
and reduced controllability of the airplane.

Explanation of Relevant Service Information

    British Aerospace has issued 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. This alert PTL describes procedures for the introduction of a 
program of inspections to detect cracking and corrosion of the 
components of the engine nacelle subframe structure. The program 
includes a schedule of the maximum inspection threshold or life limit 
(safe life), as applicable, for each component; and includes procedures 
for replacement of any component that has reached its life limit with a 
new or serviceable component. (A life limit is the operational limit 
allowed for a part before it must be replaced.) The CAA classified this 
alert PTL as mandatory and issued British airworthiness directive 008-
06-94 (undated) in order to assure the continued airworthiness of these 
airplanes in the United Kingdom.

FAA's Conclusions

    This airplane model is manufactured in the United Kingdom and is 
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 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, this amendment is being issued to prevent reduced 
structural integrity of the engine nacelle subframe structure, 
separation of the engine from the airframe, and reduced controllability 
of the airplane. This amendment requires the actions specified by the 
alert PTL described previously; except as discussed below.

Differences Between This Amendment and the Service Information

    Operators should note that, unlike the procedures described in the 
alert PTL, this amendment will not permit flight of any airplane having 
any strut that has exceeded its life limit after the initial inspection 
specified in the alert PTL. The FAA has determined that, because of the 
safety implications and consequences associated with exceeding the life 
of a life-limited part, any strut that is found to have exceeded its 
life limit must be replaced prior to further flight.
    In addition, while the alert PTL specifies that any discrepant part 
be replaced, this amendment allows operators the option to repair 
discrepant parts, in accordance with a method approved by the FAA. The 
FAA has included this option because small amounts of corrosion or 
fatigue damage may be repairable.

Cost Impact

    The FAA estimates that 29 airplanes of U.S. registry will be 
affected by this amendment.
    It would require approximately 200 work hours per airplane to 
replace all struts when they have reached their life limits, at an 
average labor rate of $60 per work hour. Required parts would cost 
approximately $30,000 per airplane. Based on these figures, the cost 
impact on U.S. operators of this action is estimated to be $1,218,000, 
or $42,000 per life limit cycle.
    Should an operator be required to perform the visual inspection, it 
would take approximately 2 work hours, at an average labor rate of $60 
per work hour. Based on these figures, the cost impact on U.S. 
operators of this action is estimated to be $120 per airplane, per 
visual inspection cycle.
    Should an operator be required to perform the eddy current 
inspection, it would take approximately 2 work hours, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact on U.S. operators of this action is estimated to be $120 per 
airplane, per eddy current inspection cycle.
    It would require approximately 200 work hours to perform the 
detailed inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact on U.S. operators of this 
action is estimated to be $348,000, or $12,000 per airplane, per 
inspection cycle.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this amendment were not adopted.

The Direct Final Rule Procedure

    The FAA anticipates that this regulation will not result in adverse 
or negative comment and therefore is issuing it as a direct final rule. 
The FAA does not anticipate receipt of adverse or negative comments, 
since the affected airplanes may not be operated in a manner that would 
require compliance with this amendment. In accordance with 14 CFR 
11.17, unless a written adverse or negative comment, or a written 
notice of intent to submit an

[[Page 16113]]

adverse or negative comment, is received within the comment period, the 
regulation will become effective on the date specified above. After the 
close of the comment period, the FAA will publish a document in the 
Federal Register indicating that no adverse or negative comments were 
received; at that time, the AD number will be specified, and the date 
on which the final rule will become effective will be confirmed. If the 
FAA does receive, within the comment period, a written adverse or 
negative comment, or written notice of intent to submit such a comment, 
a document withdrawing the direct final rule will be published in the 
Federal Register, and a notice of proposed rulemaking may be published 
with a new comment period.

Comments Invited

    Although this action is in the form of a final rule and 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 
amendment 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-321-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 noncontroversial and 
unlikely to result in adverse or negative comments. For reasons 
discussed in the preamble, I certify that this regulation (1) is not a 
``significant regulatory action'' under Executive Order 12866; (2) is 
not a ``significant rule'' under 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 it 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:

British Aerospace Regional Aircraft Limited (Formerly British 
Aerospace Commercial Aircraft Limited, Vickers-Armstrongs Aircraft 
Limited): Amendment 39-10444. Docket 97-NM-321-AD.

    Applicability: All Model Viscount 744, 745, 745D, and 810 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 
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 (f) 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 prevent reduced structural integrity of the engine nacelle 
subframe structure, separation of the engine from the airframe, and 
reduced controllability of the airplane, accomplish the following:
    (a) Prior to the accumulation of the number of landings 
corresponding to a strut's life limit (safe life), as specified in 
the ``Inspection Threshold Landings'' column of Table One, Two, 
Three, Four, Five, or Six (hereinafter referred to as ``the 
applicable Table''), as applicable, provided in 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; or within 100 
flight hours after the effective date of this AD; whichever occurs 
later: Replace any strut that has reached its life limit, as 
specified in the applicable Table, with a serviceable strut, in 
accordance with the alert PTL. Thereafter, replace any strut before 
it exceeds its life limit with a serviceable strut in accordance 
with the alert PTL, until initiation of the replacement cycle for 
that strut, as specified in paragraph (d) of this AD.
    (b) Prior to the accumulation of the number of landings 
corresponding to a strut's inspection threshold, as specified in the 
``Inspection Period Landings'' column of the applicable Table 
provided in British Aerospace Alert Viscount PTL 500, dated January 
1, 1993, including Appendices 1 through 4 inclusive, dated November 
1992, and Appendix 5, dated October 1992; or within 100 flight hours 
after the effective date of this AD; whichever occurs later: Perform 
a visual inspection to detect cracking of the strut end fittings, in 
accordance with paragraph 2.1, Part One, Accomplishment 
Instructions, of the alert PTL. Repeat the inspection thereafter at 
intervals not to exceed 100 flight hours, until initiation of the 
inspection cycle for the respective component, as specified in 
paragraph (d) of this AD.
    (c) Prior to the accumulation of the number of landings 
corresponding to a strut's inspection threshold, as specified in the 
``Inspection Period Landings'' column in the applicable Table 
provided in British Aerospace Viscount Alert PTL 500, dated January 
1, 1993, including Appendices 1 through 4 inclusive, dated November 
1992, and Appendix 5, dated October 1992; or within 200 flight hours 
after the effective date of this AD; whichever occurs later: Perform 
an eddy current inspection to detect cracking of the strut end 
fittings, in accordance with paragraph 2.1, Part One, Accomplishment 
Instructions, of the alert

[[Page 16114]]

PTL. Repeat the inspection thereafter at intervals not to exceed 200 
flight hours, until initiation of the inspection cycle for the 
respective component, as specified in paragraph (d) of this AD.
    (d) Within 6 months after the effective date of this AD, perform 
an inspection (surface eddy scan, rotating eddy bore, internal 
surface eddy scan, or radiographic, as applicable) to detect 
cracking and corrosion of components of the engine nacelle subframe; 
and replace any component that has exceeded its life limit; in 
accordance with paragraph 2.2, Part Two, Accomplishment 
Instructions, of British Aerospace Viscount Alert PTL 500, dated 
January 1, 1993, including Appendices 1 through 4 inclusive, dated 
November 1992, and Appendix 5, dated October 1992. Repeat the 
inspection(s) and replacement(s) thereafter at intervals not to 
exceed the inspection threshold or safe life for the applicable 
component, as specified in the ``Inspection Period Landings'' or the 
``Inspection Threshold Landings'' column (respectively) of the 
applicable Table of the alert PTL. Accomplishment of the initial 
inspections/replacements for all struts as required by this 
paragraph constitutes terminating action for the inspection/
replacement requirements of paragraphs (a), (b), and (c) of this AD.
    (e) If any crack or corrosion is found during any inspection 
required by this AD: Prior to further flight, accomplish the actions 
required by either paragraph (e)(1) or (e)(2) of this AD, and 
continue to follow the inspection and replacement schedule in 
accordance with the applicable Table.
    (1) Replace the discrepant component with a serviceable 
component. Or
    (2) Repair the discrepant part in accordance with a method 
approved by the Manager, International Branch, ANM-116, FAA, 
Transport Airplane Directorate.
    (f) 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.

    (g) 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.
    (h) The actions shall be done in accordance with British 
Aerospace Alert Preliminary Technical Leaflet 500, dated January 1, 
1993; including Appendices 1 through 4 inclusive, dated November 
1992, and Appendix 5, dated October 1992. 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 British Aerospace Regional Aircraft Limited, 
Chadderton Division, Engineering Support, Greengate, Middleton, 
Manchester M24 1SA, England. 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., suite 700, Washington, DC.

    Note 3: The subject of this AD is addressed in British 
airworthiness directive 008-06-94 (undated).

    (i) This amendment becomes effective on July 1, 1998.

    Issued in Renton, Washington, on March 25, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8538 Filed 4-1-98; 8:45 am]
BILLING CODE 4910-13-U