[Federal Register Volume 64, Number 2 (Tuesday, January 5, 1999)]
[Proposed Rules]
[Pages 435-438]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-49]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-47-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Model BAC 1-11 200 
and 400 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain British Aerospace 
Model BAC 1-11 200 and 400 series airplanes. That AD currently limits 
the number of operations at increased cabin pressure differential, and 
requires repetitive structural inspections for cracking of the 
fuselage, and repair or replacement of parts, if necessary. This action 
would require additional repetitive inspections for cracking of the 
fuselage. This proposal is prompted by the determination that airplanes 
operating at increased cabin pressure differential are more likely to 
develop fatigue cracking earlier in their service lives than those 
airplanes operating at normal cabin differential pressures. The actions 
specified by the proposed AD are intended to detect and correct fatigue 
cracking of the airplane fuselage, which could result in reduced 
structural integrity of the airplane.

DATES: Comments must be received by February 4, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-47-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, Service Support, Airbus Limited, P.O. 
Box 77, Bristol BS99 7AR, 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-47-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-47-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On August 14, 1989, the FAA issued AD 89-18-10, amendment 39-6310 
(54 FR 34768, August 22, 1989), applicable to certain British Aerospace 
Model BAC 1-11 200 and 400 series airplanes. That AD currently limits 
the number of operations at increased cabin pressure differential, and 
requires repetitive structural inspections for cracking of the 
fuselage, and repair or replacement of parts, if necessary. That action 
was prompted by the determination that airplanes operating at increased 
cabin pressure differential are more likely to develop fatigue cracking 
earlier in their service lives than those airplanes operating at normal 
cabin differential pressures. The requirements of that AD are intended 
to prevent inability of the

[[Page 436]]

airplane structure to carry required loads.

Actions Since Issuance of AD 89-18-10

    Since the issuance of AD 89-18-10, the Civil Aviation Authority 
(CAA), which is the airworthiness authority for the United Kingdom, 
advises that it has reviewed existing mandated supplemental fatigue 
inspections applied to older Model BAC 1-11 series airplanes. Following 
this review, additional routine visual inspections of the fuselage were 
recommended to improve the probability of the detection of fatigue 
cracking. Such fatigue cracking, if not corrected, could result in 
reduced structural integrity of the airplane.

Explanation of Relevant Service Information

    The manufacturer has issued British Aerospace Alert Service 
Bulletin 53-A-PM5922, Issue 2, dated April 27, 1995, which describes 
procedures for repetitive structural inspections for cracking of the 
fuselage. The procedures described in Issue 2 of the service bulletin 
are essentially identical to Issue 1, however, it adds additional areas 
to be inspected and revises certain inspection thresholds and 
intervals. The CAA classified this alert service bulletin as mandatory 
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 
21.29) 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 89-18-10 to 
continue to limit the number of operations at increased cabin pressure 
differential, and require repetitive structural inspections for 
cracking of the fuselage, and repair or replacement of parts, if 
necessary. The proposed AD would require additional repetitive 
structural inspections for cracking of the fuselage, revise certain 
inspection thresholds and intervals, and corrective actions, if 
necessary. The actions would be required to be accomplished in 
accordance with Issue 2 of the alert service bulletin described 
previously, except as discussed below.

Differences Between Proposed Rule and Alert Service Bulletin

    Operators should note that, although the alert service bulletin 
does not specify an initial compliance time for performing the 
additional visual inspections, the FAA has determined that a threshold 
of 3 months to accomplish those inspections would address the 
identified unsafe condition in a timely manner. In developing this 
compliance time, the FAA considered the degree of urgency associated 
with addressing the subject unsafe condition, the average utilization 
of the affected fleet, and the time necessary to perform the 
inspections. In light of all of these factors, the FAA finds that this 
compliance time represents an appropriate interval of time allowable 
for affected airplanes to continue to operate without compromising 
safety.

Cost Impact

    There are approximately 42 airplanes of U.S. registry that would be 
affected by this proposed AD.
    The actions that are currently required by AD 89-18-10, and 
retained in this proposed AD, take approximately 67 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 currently required 
actions on U.S. operators is estimated to be $168,840, or $4,020, per 
airplane.
    The new inspections that are proposed in this AD action would take 
approximately 29 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 new proposed requirements of this AD on U.S. operators is 
estimated to be $73,080, or $1,740 per airplane, per inspection cycle.
    The cost impact figures discussed above are 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 39-6310 (54 FR 
34768, August 22, 1989), and by adding a new airworthiness directive 
(AD), to read as follows:

British Aerospace Airbus Limited (Formerly British Aerospace 
Commercial Aircraft Limited, British Aerospace Aircraft Group): 
Docket 98-NM-47-AD. Supersedes AD 89-18-10, Amendment 39-6310.
    Applicability: Model BAC 1-11 200 and 400 series airplanes on 
which British Aerospace Modifications PM2840 and PM3187 have been 
accomplished; or on which British Aerospace Modification PM4886 has 
been accomplished; except for airplanes on which British Aerospace

[[Page 437]]

Modification PM5282 (cabin freight door) has been accomplished; and 
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 (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 detect and correct fatigue cracking of the airplane fuselage, 
which could result in reduced structural integrity of the airplane, 
accomplish the following:
    (a) Except as provided by paragraph (c) of this AD: For 
airplanes modified for operation to a maximum of 7.75 pounds per 
square inch (psi) cabin pressure differential, as specified in 
British Aerospace Alert Service Bulletin 53-A-PM5922, Issue 1, dated 
January 27, 1987, accomplish the requirements of paragraphs (a)(1) 
and (a)(2) of this AD.
    (1) At or prior to the accumulation of 55,000 total landings, or 
within 15 months after September 28, 1989 (the effective date of AD 
89-18-10, amendment 39-6310), whichever occurs later, perform the 
inspections specified in paragraph 2.1 of the alert service 
bulletin. Thereafter, repeat the inspections in accordance with 
paragraph 2.1.1 of the alert service bulletin at intervals shown in 
Table AA of the alert service bulletin.
    (2) At or prior to the accumulation of 60,000 total landings, or 
within 30 days after September 28, 1989, whichever occurs later, 
reduce the aircraft maximum cabin pressure differential to 7.5 psi 
by system modification, in accordance with a method approved by the 
Manager, International Branch, ANM-116, FAA, Transport Airplane 
Directorate.
    (b) Except as provided by paragraph (d) of this AD: For 
airplanes modified for operation at cabin pressure differentials 
above 7.75 psi up to a maximum of 8.2 psi, as specified in British 
Aerospace Alert Service Bulletin 53-A-PM5922, Issue 1, dated January 
27, 1987, accomplish the requirements of paragraph (b)(1) or (b)(2) 
of this AD, as applicable. Subsequently, accomplish the requirements 
of paragraphs (b)(3) and (b)(4), or paragraphs (b)(5) and (b)(6) of 
this AD, as applicable.
    (1) For airplanes originally manufactured for operation at cabin 
pressure differentials above 7.75 psi, at or prior to the 
accumulation of the number of landings shown for initial inspection 
in the ``NE period'' column of Table AA in the alert service 
bulletin, or within 15 months after September 28, 1989, whichever 
occurs later, perform inspections specified in paragraph 2.2.1 of 
the alert service bulletin and repeat the inspections as specified 
in paragraph 2.2.3 of the alert service bulletin at the intervals 
shown in Table AA of the alert service bulletin.
    (2) For airplanes modified for operation at cabin pressure 
differential above 7.75 psi after the airplane entered service, at 
or prior to the accumulation of the number of landings shown for 
initial inspection in the ``NE period'' column [obtained using the 
inspection adjustment graph (page 6) of the alert service bulletin], 
in Table AA of the alert service bulletin, or within 15 months after 
September 28, 1989, whichever occurs later, perform initial 
inspections specified in paragraph 2.2.2 of the alert service 
bulletin. Thereafter, repeat the inspections as specified in 
paragraph 2.2.3 of the alert service bulletin, at intervals shown in 
Table AA of the alert service bulletin.
    (3) At or prior to the accumulation of 55,000 total landings, or 
within 30 days after September 28, 1989, whichever occurs later, 
reduce the aircraft cabin maximum operating pressure differential to 
7.5 or 7.75 psi by modification as specified in paragraph 2.2.4 of 
the alert service bulletin, in accordance with a method approved by 
the Manager, International Branch, ANM-116.
    (4) For airplanes which have had the cabin pressure differential 
reduced from 8.2 psi to 7.75 psi as specified in paragraph 2.2.6 of 
the alert service bulletin, perform repetitive inspections at the 
intervals specified in the ``N.E. period'' column in Table AA of the 
alert service bulletin.
    (5) At or prior to the accumulation of 60,000 total landings, or 
within 30 days after September 28, 1989, whichever occurs later, the 
airplane cabin maximum operating pressure differential must be 
reduced to 7.5 psi by modification as specified in paragraph 2.2.7 
of the alert service bulletin, in accordance with a method approved 
by the Manager, International Branch, ANM-116.
    (6) For airplanes modified for 8.2 psi maximum cabin operating 
pressure differential and operated for a period in excess of any 
Table AA inspection threshold in the alert service bulletin, perform 
one additional inspection at or prior to the Table AA ``N.E. 
period'' column repeat interval after limiting operation to 7.5 psi, 
as specified in paragraph 2.2.5 of the alert service bulletin.
    (c) For airplanes modified for operation to a maximum of 7.75 
pounds per square inch (psi) cabin pressure differential, as 
specified in British Aerospace Alert Service Bulletin 53-A-PM5922, 
Issue 2, dated April 27, 1995: Prior to the accumulation of the 
number of landings specified in Table AA of the alert service 
bulletin, or within 3 months after the effective date of this AD, 
whichever occurs later, perform the inspections specified in 
paragraph 2.1 of the alert service bulletin. Thereafter, repeat the 
inspections in accordance with paragraph 2.1.1 of the alert service 
bulletin at the intervals shown in Table AA of the alert service 
bulletin. Accomplishment of the inspections required by this 
paragraph terminates the repetitive inspections required by 
paragraph (a)(1) of this AD.

    Note 2: Paragraph (a)(1) of this AD restates the requirement for 
an initial and repetitive inspections contained in paragraph A.1. of 
AD 89-18-10. Therefore, for operators who have previously 
accomplished at least the initial inspection in accordance with AD 
89-18-10, paragraph (c) of this AD requires that the next scheduled 
inspection be performed within the repetitive inspection interval 
specified in Table AA of Issue 2 of the alert service bulletin, 
after the last inspection performed in accordance with paragraph 
A.1. of AD 89-18-10.

    (d) For airplanes modified for operation at cabin pressure 
differentials above 7.75 psi up to a maximum of 8.2 psi, as 
specified in British Aerospace Alert Service Bulletin 53-A-PM5922, 
Issue 2, dated April 27, 1995: Prior to the accumulation of the 
number of landings specified in Table AA of the alert service 
bulletin, or within 3 months after the effective date of this AD, 
whichever occurs later, perform the inspections specified in 
paragraph 2.2.1 of the alert service bulletin. Thereafter, repeat 
the inspections in accordance with paragraph 2.2.3 of the alert 
service bulletin at the intervals shown in Table AA of the alert 
service bulletin. Accomplishment of the inspections required by this 
paragraph terminates the repetitive inspections required by 
paragraph (b)(1), (b)(2) or (b)(4) of this AD, as applicable.

    Note 3: Paragraph (b)(1) of this AD restates the requirement for 
an initial and repetitive inspections contained in paragraph B.1. of 
AD 89-18-10. Therefore, for operators who have previously 
accomplished at least the initial inspection in accordance with AD 
89-18-10, paragraph (d) of this AD requires that the next scheduled 
inspection be performed within the repetitive inspection interval 
specified in Table AA of Issue 2 of the alert service bulletin, 
after the last inspection performed in accordance with paragraph 
B.1. of AD 89-18-10.

    (e) If any defect is found during any inspection required by 
this AD, prior to further flight, accomplish paragraph (e)(1), 
(e)(2), or (e)(3) of this AD, as applicable.
    (1) Replace the defective part with a serviceable part of the 
same part number in accordance with the Structural Repair Manual; or
    (2) For damage within the limits specified in the BAC 1-11 
Structural Repair Manual, repair in accordance with the Structural 
Repair Manual; or
    (3) Repair in accordance with a method approved by the Manager, 
International Branch, ANM-116.
    (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 4: 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

[[Page 438]]

a location where the requirements of this AD can be accomplished.

    Issued in Renton, Washington, on December 28, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-49 Filed 1-4-99; 8:45 am]
BILLING CODE 4910-13-P