[Federal Register Volume 61, Number 2 (Wednesday, January 3, 1996)]
[Proposed Rules]
[Pages 131-133]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-45]



 ========================================================================
 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 61, No. 2 / Wednesday, January 3, 1996 / 
Proposed Rules  

[[Page 131]]


DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-164-AD]


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 all British Aerospace Model 
BAC 1-11 200 and 400 series airplanes, that currently requires visual 
inspections to detect cracks in the flight deck canopy area, and 
repair, if necessary. This action would reduce the inspection threshold 
and repetitive inspection interval, and would identify specific 
structural members to be inspected. This action also would require eddy 
current inspections to detect cracks of the top sill members at station 
82.5, and replacement of cracked parts with new parts, or repair of the 
top sill members. This proposal is prompted by reports of additional 
cracking found in the structural members in the flight deck canopy area 
of the affected airplanes. The actions specified by the proposed AD are 
intended to ensure that cracking in the flight deck canopy area is 
detected and corrected in a timely manner; such cracking could result 
in reduced structural integrity of the cockpit frame and the adjacent 
fuselage structure.

DATES: Comments must be received by February 7, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-164-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, 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: Tim Backman, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2797; fax (206) 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 94-NM-164-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-103, Attention: Rules 
Docket No. 94-NM-164-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 7, 1991, the FAA issued AD 91-02-12, amendment 39-6861 
(56 FR 1569, January 16, 1991), which is applicable to all British 
Aerospace Model BAC 1-11 200 and 400 series airplanes. That AD requires 
repetitive visual inspections to detect cracks in the flight deck 
canopy area, and repair, if necessary. That action was prompted by 
several reports of cracks in various structural members in the flight 
deck canopy area. The requirements of that AD are intended to prevent 
reduced structural integrity of the fuselage.
    Since the issuance of that AD, additional reports have been 
received indicating that cracking was found in the structural members 
in the flight deck canopy area on Model BAC 1-11 series airplanes. In a 
number of these cases, complete failure of the top sill joint strap, 
doubler, and angle has occurred. Cracking also has been found in the 
fuselage frame at station 160.5 (left-hand only). This cracking was 
found on airplanes that had accumulated between 28,000 and 78,000 total 
landings. The cause of the cracking has been attributed primarily to 
fatigue. Such cracking, if not detected and corrected in a timely 
manner, could result in reduced structural integrity of the cockpit 
frame and the adjacent fuselage structure.
    British Aerospace has issued Alert Service Bulletin 53-A-PM5994, 
Issue 3, dated April 8, 1993, which describes procedures for the 
following:
    1. Repetitive detailed visual inspections to detect cracks of the 
top sill joint strap at station 82.5;
    2. Repetitive detailed visual inspections to detect cracks of the 
frame at station 113 in the flight deck canopy area;
    3. Repetitive non-destructive testing (NDT) inspections using eddy 
current techniques to detect cracks of the top sill joint strap, angle, 
and doubler at station 82.5;
    4. Repetitive detailed visual inspections to detect cracks of the 
frame at station 160.5 (left-hand only) between stringers 13 and 15; 
and
    5. Replacement of any cracked part with a new part, or repair in 
accordance with the Structural Repair Manual. 

[[Page 132]]

    This alert service bulletin recommends a reduced inspection 
threshold from that specified in earlier issues of the alert service 
bulletin, since inspection results have indicated that cracks can occur 
before the previous threshold had been reached. In addition, the alert 
service bulletin recommends reduced intervals (specified in numbers of 
landings) for accomplishment of the repetitive inspections, and also 
includes flight hour limits for those intervals since resonance in the 
canopy area may have contributed to the cracking.
    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, classified this alert service 
bulletin as mandatory in order to assure the continued airworthiness of 
these airplanes in the United Kingdom.
    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.
    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 91-02-12 to 
continue to require repetitive visual inspections to detect cracks in 
the flight deck canopy area, and repair, if necessary. However, it 
would reduce the inspection threshold and repetitive inspection 
interval, and would identify specific structural members to be 
inspected. This proposed AD also would require repetitive eddy current 
inspections to detect cracks of the top sill members at station 82.5, 
and replacement of cracked parts with new parts, or repair of the top 
sill members. Certain repairs would be required to be accomplished in 
accordance with the Structural Repair Manual or in accordance with a 
method approved by the FAA. Other actions would be required to be 
accomplished in accordance with the alert service bulletin described 
previously.
    There are approximately 31 Model BAC 1-11-200 and -400 series 
airplanes of U.S. registry that would be affected by this proposed AD.
    The actions that are currently required by AD 91-02-12 take 
approximately 18 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact on U.S. operators of the actions currently required is estimated 
to be $33,480, or $1,080 per airplane.
    The new actions that are proposed in this AD action would take 
approximately 19 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact on U.S. operators of the proposed requirements of this AD is 
estimated to be $35,340, or $1,140 per airplane.
    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.
    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 USC 106(g), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-6861 (56 FR 
1569, January 16, 1991), 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 94-NM-164-AD.
    Supersedes AD 91-02-12, Amendment 39-6861.
    Applicability: All Model BAC 1-11 200 and 400 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 use the authority 
provided in paragraph (e) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition, or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent reduced structural integrity of the cockpit frame and 
the adjacent fuselage structure, accomplish the following:
    (a) Prior to the accumulation of 30,000 total landings, or 
within 6 months after February 25, 1991 (the effective date of AD 
91-02-12, amendment 39-6861), whichever occurs later; and thereafter 
at intervals not to exceed 5,000 landings: Perform a visual 
inspection to detect cracks of the flight deck canopy area, in 
accordance with British Aerospace Alert Service Bulletin 53-A-
PM5994, Issue 2, dated June 5, 1990; or Issue 3, dated April 8, 
1993. Pay particular attention to the top sill joint strap, the top 
sill intercostal, the frame at Station 113, and the top sill boom 
and web. Repeat this inspection until the inspections required by 
paragraph (c) of this AD are accomplished. After the effective date 
of this AD, the inspection shall be accomplished only in accordance 
with Issue 3 of the alert service bulletin.
    (b) If any crack is found during the inspection required by 
paragraph (a) of this AD, prior to further flight, repair in 
accordance with a method approved by the Manager, Standardization 
Branch, ANM-113, FAA, Transport Airplane Directorate. 

[[Page 133]]
Following accomplishment of the repair, repeat the inspection required 
by paragraph (a) of this AD thereafter at intervals not to exceed 
5,000 landings until the inspections required by paragraph (c) of 
this AD are accomplished.
    (c) Perform a detailed visual inspection to detect cracks of the 
top sill joint strap at station 82.5, of the frame at station 113, 
and of the frame at station 160.5 (left-hand side only) between 
stringers 13 and 15; and an eddy current inspection to detect cracks 
of the top sill members at station 82.5. Perform these inspections 
in accordance with British Aerospace Airbus Limited Alert Service 
Bulletin 53-A-PM5994, Issue 3, dated April 8, 1993, at the time 
specified in paragraph (c)(1) or (c)(2) of this AD, as applicable. 
Accomplishment of these inspections terminates the repetitive 
inspection requirement of paragraph (a) of this AD.
    (1) For airplanes operating at a maximum cabin differential 
pressure not exceeding 7.5 pounds per square inch (psi): Perform the 
inspections at the later of the times specified in paragraphs 
(c)(1)(i) and (c)(1)(ii) of this AD. Thereafter, repeat these 
inspections at intervals not to exceed 5,000 landings or 7,500 hours 
time-in-service, whichever occurs first.
    (i) Prior to the accumulation of 20,000 total landings since 
date of entry into service; or
    (ii) Within 1,200 landings or 12 months after the effective date 
of this AD, whichever occurs later.
    (2) For airplanes operating at a maximum cabin differential 
pressure greater than 7.5 psi, but not exceeding 8.2 psi, including 
those airplanes having incorporated British Aerospace Airbus Limited 
Modification PM3187: Perform the inspections at the later of the 
times specified in paragraphs (c)(2)(i) and (c)(2)(ii) of this AD. 
Thereafter, repeat these inspections at intervals not to exceed 
3,500 landings or 5,250 hours time-in-service, whichever occurs 
first.
    (i) Prior to the accumulation of 14,000 total landings since 
date of entry into service; or
    (ii) Within 800 landings or 12 months after the effective date 
of this AD, whichever occurs later.
    Note 2: British Aerospace Airbus Limited Modification PM3187 
increases the cabin differential pressure from the normal 7.5 psi to 
8.2 psi. If Modification PM3187 has been incorporated on the 
airplane, that airplane is considered to be subject to the 
requirements of paragraph (c)(2) of this AD.
    (d) If any crack is found during any inspection required by 
paragraph (c) of this AD, prior to further flight, accomplish the 
requirements of paragraph (d)(1), (d)(2), or (d)(3), as applicable.
    (1) For cracking of the joint strap, doubler, or angle at the 
sill joint at station 82.5: Replace the cracked part with a new part 
in accordance with British Aerospace Airbus Limited Alert Service 
Bulletin 53-A-PM5994, Issue 3, dated April 8, 1993.
    (2) For cracking of the frame at station 113: Repair in 
accordance with a method approved by the Manager, Standardization 
Branch, ANM-113.
    (3) For cracking of the frame at station 160.5: Repair in 
accordance with the Structural Repair Manual, as specified in 
British Aerospace Airbus Limited Alert Service Bulletin 53-A-PM5994, 
Issue 3, dated April 8, 1993.
    (e) 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, Standardization Branch, ANM-113. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, Standardization Branch, ANM-113.
    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.
    (f) 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. Issued in Renton, 
Washington, on December 27, 1995.

Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-45 Filed 1-2-96; 8:45 am]
BILLING CODE 4910-13-U