[Federal Register Volume 63, Number 197 (Tuesday, October 13, 1998)]
[Proposed Rules]
[Pages 54635-54637]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-27326]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-CE-75-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Jetstream Model 3201 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to all British Aerospace Jetstream Model 3201 
airplanes. The proposed AD would require accomplishing both a routine 
visual inspection and either a detailed visual inspection or x-ray 
inspection of the main landing gear (MLG) bay auxiliary spar booms for 
cracks or fuel leaks on both the left and right sides of the airplane. 
The proposed AD would also require obtaining and incorporating repair 
procedures for the MLG bay auxiliary spar where fuel leaks or cracks 
are found. The proposed AD is the result of mandatory continuing 
airworthiness information (MCAI) issued by the airworthiness authority 
for the United Kingdom. The actions specified by the proposed AD are 
intended to prevent wing failure caused by cracks or fuel leaks in the 
area of the MLG bay auxiliary spar booms, which could result in loss of 
control of the airplane.

DATES: Comments must be received on or before November 13, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 98-CE-75-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106. Comments may be inspected at this location 
between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.
    Service information that applies to the proposed AD may be obtained 
from British Aerospace Regional Aircraft, Prestwick International 
Airport, Ayrshire, KA9 2RW, Scotland; telephone: (01292) 479888; 
facsimile: (01292) 479703. This information also may be examined at the 
Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. S.M. Nagarajan, Aerospace 
Engineer, FAA, Small Airplane Directorate, Aircraft Certification 
Service, 1201 Walnut, suite 900, Kansas City, Missouri 64106; 
telephone: (816) 426-6932; facsimile: (816) 426-2169.

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 should 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 that summarizes 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 No. 98-CE-75-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, Central Region, Office of the Regional Counsel, Attention: 
Rules Docket No. 98-CE-75-AD, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.

[[Page 54636]]

Discussion

    The Civil Airworthiness Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified the FAA that an 
unsafe condition may exist on all British Aerospace Jetstream Model 
3201 airplanes. The CAA reports that cracks were found on a MLG bay 
auxiliary spar lower boom on one of the above-referenced airplanes. 
Initial investigation indicates that the cracks were caused by residual 
stresses in the component originating from a manufacturing fault during 
the machining/heat treatment stages.
    This condition, if not detected and corrected, could result in wing 
failure with consequent loss of control of the airplane.

Relevant Service Information

    British Aerospace has issued Jetstream Alert Service Bulletin 57-A-
JA 980441, Original Issue: April 28, 1998, Revision No. 1: July 7, 
1998, which specifies procedures for accomplishing both a routine 
visual inspection and either a detailed visual inspection or x-ray 
inspection of the main landing gear (MLG) bay auxiliary spar booms for 
cracks or fuel leaks on both the left and right sides of the airplane. 
This service bulletin also specifies obtaining repair procedures for 
the MLG bay auxiliary spar where fuel leaks or cracks are found.
    The CAA classified this service bulletin as mandatory and issued 
British AD 001-04-98, dated May 7, 1998, in order to assure the 
continued airworthiness of these airplanes in the United Kingdom.

The FAA's Determination

    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, including the service information referenced 
above; and determined that AD action is necessary for products of this 
type design that are certificated for operation in the United States.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other British Aerospace Jetstream Model 3201 
airplanes of the same type design registered in the United States, the 
FAA is proposing AD action. The proposed AD would require accomplishing 
both a routine visual inspection and either a detailed visual 
inspection or x-ray inspection of the MLG bay auxiliary spar booms for 
cracks or fuel leaks on both the left and right sides of the airplane. 
The proposed AD would also require obtaining and incorporating repair 
procedures for the MLG bay auxiliary spar where fuel leaks or cracks 
are found. Accomplishment of the proposed actions would be in 
accordance with Jetstream Alert Service Bulletin 57-A-JA 980441, 
Original Issue: April 28, 1998, Revision No. 1: July 7, 1998.

Compliance Time of This AD

    Although the cracks on the MLG bay auxiliary spar booms could occur 
as a result of repetitive airplane operation, the FAA believes that the 
residual stresses in the component are originating from a manufacturing 
fault during the machining/heat treatment stages. The cracks could 
exist, but not be noticed, after just a few hours of airplane 
operation. The stress incurred during flight operations or temperature 
changes could then cause rapid crack growth. In order to assure that 
even very small cracks in the MLG bay auxiliary spar booms do not go 
undetected, the FAA is proposing a compliance based on calendar time.

Cost Impact

    The FAA estimates that 124 airplanes in the U.S. registry would be 
affected by the proposed AD.
    Accomplishing the routine visual inspection proposed in this AD 
would take approximately 1 workhour per airplane, at an average labor 
rate of approximately $60 an hour. Based on these figures, the total 
cost impact of this proposed routine visual inspection on U.S. 
operators is estimated to be $7,440, or $60 per airplane.
    Accomplishing the detailed visual inspection proposed in this AD 
would take approximately 16 workhours per airplane, at an average labor 
rate of $60 per hour. Accomplishing the x-ray inspection proposed in 
this AD would take approximately 12 workhours per airplane, at an 
average labor rate of approximately $60 an hour. Based on these 
figures, the total cost impact of the proposed detailed inspection on 
U.S. operators is estimated to be $119,040, or $960 per airplane, and 
$89,280, or $720 per airplane for the proposed x-ray inspection.
    These figures only take into account the costs of inspections and 
do not take into account the costs for repairing any MLG bay auxiliary 
spar boom where fuel leaks or cracks are found during the proposed 
inspections.

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 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) 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 has been placed 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 adding a new airworthiness directive 
(AD) to read as follows:

British Aerospace: Docket No. 98-CE-75-AD.

    Applicability: Jetstream Model 3201 airplanes, all serial 
numbers, certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability

[[Page 54637]]

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 (d) 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 in the body of this AD, unless 
already accomplished.
    To prevent wing failure caused by cracks or fuel leaks in the 
area of the main landing gear (MLG) bay auxiliary spar booms, which 
could result in loss of control of the airplane, accomplish the 
following:
    (a) Within the next 45 calendar days after the effective date of 
this AD, accomplish the following:
    (1) Perform a routine visual inspection of the MLG bay auxiliary 
spar booms for cracks or fuel leaks on both the left and right sides 
of the airplane. Accomplish this inspection in accordance with Part 
1 of the Accomplishment Instructions section of Jetstream Alert 
Service Bulletin 57-A-JA 980441, Original Issue: April 28, 1998, 
Revision No. 1: July 7, 1998.
    (2) Perform either a detailed visual inspection or x-ray 
inspection of the MLG bay auxiliary spar booms for cracks or fuel 
leaks on both the left and right sides of the airplane. Accomplish 
this inspection in accordance with Part 2 of the Accomplishment 
Instructions section of Jetstream Alert Service Bulletin 57-A-JA 
980441, Original Issue: April 28, 1998, Revision No. 1: July 7, 
1998.
    (b) If cracks or leaks are found during any inspection required 
by paragraphs (a)(1) and (a)(2) of this AD, prior to further flight, 
accomplish the following:
    (1) Obtain repair instructions from the manufacturer through the 
FAA, Small Airplane Directorate, at the address specified in 
paragraph (d) of this AD; and
    (2) Incorporate these repair instructions.
    (c) 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.
    (d) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, Small Airplane Directorate, Aircraft 
Certification Service, 1201 Walnut, suite 900, Kansas City, Missouri 
64106. The request shall be forwarded through an appropriate FAA 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Small Airplane Directorate.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Small Airplane Directorate.

    (e) Questions or technical information related to British 
Aerospace Jetstream Alert Service Bulletin 57-A-JA 980441, Original 
Issue: April 28, 1998, Revision No. 1: July 7, 1998, should be 
directed to British Aerospace Regional Aircraft, Prestwick 
International Airport, Ayrshire, KA9 2RW, Scotland; telephone: 
(01292) 479888; facsimile: (01292) 479703. This service information 
may be examined at the FAA, Central Region, Office of the Regional 
Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

    Note 3: The subject of this AD is addressed in British AD 001-
04-98, dated May 7, 1998.

    Issued in Kansas City, Missouri, on October 6, 1998.
Carolanne L. Cabrini,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-27326 Filed 10-9-98; 8:45 am]
BILLING CODE 4910-13-U