[Federal Register Volume 62, Number 243 (Thursday, December 18, 1997)]
[Rules and Regulations]
[Pages 66264-66266]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-32610]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-222-AD; Amendment 39-10248; AD 97-26-05]
RIN 2120-AA64


Airworthiness Directives; British Aerospace (Jetstream) Model HS 
748 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all British Aerospace (Jetstream) Model HS 748 series 
airplanes. This action requires inspections of the inspection holes in 
all engine `W' frame socket fittings to determine if certain fasteners 
have been installed, or if the inspection holes have been reworked; and 
corrective action, if necessary. This amendment is prompted by issuance 
of mandatory continuing airworthiness information by a foreign civil 
airworthiness authority. The actions specified in this AD are intended 
to prevent fatigue cracking at the inspection hole locations, due to 
the installation of certain fasteners or hole enlargement, which could 
result in failure of the engine mount structure and consequent 
separation of the engine from the airplane.

DATES: Effective January 2, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director

[[Page 66265]]

of the Federal Register as of January 2, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before January 20, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-222-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this AD may be obtained from 
AI(R) American Support, Inc., 13850 Mclearen Road, Herndon, Virginia 
20171. 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: 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 (Jetstream) 
Model HS 748 series airplanes. The CAA advises that drive screws have 
been found installed in the inspection holes of engine `W' frame socket 
fittings, which resulted in fatigue cracks at the inspection holes. In 
addition, investigation revealed that, in some cases, the inspection 
holes had been enlarged beyond the original 0.125-inch diameter, which 
would reduce the structural strength of the fittings. Such fatigue 
cracking at the inspection hole locations, if not detected and 
corrected in a timely manner, could result in failure of the engine 
mount structure and consequent separation of the engine from the 
airplane.

Explanation of Relevant Service Information

    British Aerospace (Jetstream) has issued Viscount Preliminary 
Technical Leaflet (PTL) No. 501, Issue 2, dated June 1, 1994, including 
Appendix 1, dated January 1, 1994, which describes procedures for a 
detailed visual inspection of the inspection holes in all engine 'W' 
frame socket fittings to determine if drive screws, and/or blind rivets 
have been installed, or if the original 0.125-inch diameter hole size 
has been reworked. The PTL also describes procedures for reworking the 
inspection holes and/or replacement of the 'W' frame fitting, if 
necessary. The CAA classified this service information as mandatory and 
issued British airworthiness directive 002-09-94, dated September 1994, 
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 section 21.29 of the Federal Aviation Regulations (14 CFR 
21.19) 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 the 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 AD requires accomplishment of the actions 
specified in the PTL described previously, except as described below.

Differences Between This AD and the Service Information

    Operators should note that, unlike the procedures described in the 
referenced PTL and the British airworthiness directive, this AD will 
not permit further flight if drive screws, blind rivets, and/or 
reworked holes are found to exist at the inspection hole locations. The 
FAA has determined that, due to the safety implications and 
consequences associated with the installation of drive screws, blind 
rivets, and/or the existence of reworked holes at the inspection hole 
locations, corrective action must be accomplished prior to further 
flight.

Cost Impact

    None of the Jetstream Model HS 748 series airplanes affected by 
this action are on the U.S. Register. All airplanes included in the 
applicability of this rule currently are operated by non-U.S. operators 
under foreign registry; therefore, they are not directly affected by 
this AD action. However, the FAA considers that this rule is necessary 
to ensure that the unsafe condition is addressed in the event that any 
of these subject airplanes are imported and placed on the U.S. Register 
in the future.
    Should an affected airplane be imported and placed on the U.S. 
Register in the future, it would require approximately 13 work hours to 
accomplish the required actions, at an average labor charge of $60 per 
work hour. Based on these figures, the cost impact of this AD would be 
$780 per airplane.

Determination of Rule's Effective Date

    Since this AD action does not affect any airplane that is currently 
on the U.S. register, it has no adverse economic impact and imposes no 
additional burden on any person. Therefore, prior notice and public 
procedures hereon are unnecessary and the amendment may be made 
effective in less than 30 days after publication in the Federal 
Register.

Comments Invited

    Although this action is in the form of a final rule and was not 
preceded by notice and 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 
AD 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-222-AD.'' The postcard will be date stamped and 
returned to the commenter.

[[Page 66266]]

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.
    For the reasons discussed above, I certify that this action (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) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. 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:

97-26-05  British Aerospace Regional Aircraft [Formerly Jetstream 
Aircraft Limited, British Aerospace (Commercial Aircraft) Limited]: 
Amendment 39-10248. Docket 97-NM-222-AD.

    Applicability: All Model HS 748 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 
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 prevent fatigue cracking at the inspection hole locations, 
due to the installation of drive screws, and/or blind rivets, or 
hole enlargement, which could result in failure of the engine mount 
structure and consequent separation of the engine from the airplane, 
accomplish the following:
    (a) Within 12 months after the effective date of this AD, 
perform a detailed visual inspection of the inspection holes in all 
of the aft engine `W' frame socket fittings to determine if drive 
screws and/or blind rivets have been installed, and to determine if 
the inspection holes have been reworked, in accordance with PART ONE 
of the Accomplishment Instructions of British Aerospace (Jetstream) 
Viscount Preliminary Technical Leaflet (PTL) No. 501, Issue 2, dated 
June 1, 1994, including Appendix 1, dated January 1, 1994. If a 
drive screw or blind rivet is installed, or if any inspection hole 
has been reworked, prior to further flight, accomplish follow-on 
corrective actions, as applicable, in accordance with PART THREE of 
the Accomplishment Instructions of the PTL.
    (b) At the next engine `W' frame removal, or within 24 months 
after the effective date of this AD, whichever occurs first: Perform 
a detailed visual inspection of the inspection holes in all of the 
forward engine `W' frame socket fittings to determine if drive 
screws and/or blind rivets have been installed, and to determine if 
the inspection holes have been reworked, in accordance with PART TWO 
of the Accomplishment Instructions of British Aerospace (Jetstream) 
Viscount PTL No. 501, Issue 2, dated June 1, 1994, including 
Appendix 1, dated January 1, 1994. If a drive screw or blind rivet 
is installed, or if any inspection hole has been reworked, prior to 
further flight, accomplish follow-on corrective actions, as 
applicable, in accordance with PART THREE of the Accomplishment 
Instructions of the PTL.

    Note 2: Accomplishment of the inspections and/or corrective 
actions in accordance with Jetstream Service Bulletin HS748-71-33, 
dated September 2, 1994, is considered acceptable for showing 
compliance with the requirements of paragraphs (a) and (b) of this 
AD.

    (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, 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, International 
Branch, ANM-116.

    Note 3: 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 
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.
    (e) The actions shall be done in accordance with British 
Aerospace (Jetstream) Viscount Preliminary Technical Leaflet (PTL) 
No. 501, Issue 2, dated June 1, 1994, including Appendix 1, dated 
January 1, 1994. 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 AI(R) American 
Support, Inc., 13850 Mclearen Road, Herndon, Virginia 20171. 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 4: The subject of this AD is addressed in British 
airworthiness directive 002-09-94, dated September 1994.

    (f) This amendment becomes effective on January 2, 1998.

    Issued in Renton, Washington, on December 9, 1997.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-32610 Filed 12-17-97; 8:45 am]
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