[Federal Register Volume 61, Number 203 (Friday, October 18, 1996)]
[Proposed Rules]
[Pages 54362-54364]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-26708]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-51-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Model BAe 146 and 
Avro 146-RJ Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all British Aerospace Model BAe 
146 and Avro 146-RJ series airplanes. This proposal would require 
modification of the left and right elevators, and replacement of the 
elevator spring with a stiffer spring. This proposal is prompted by 
reports indicating that water and ice have accumulated at the trailing 
edge of the left and right elevators; this accumulation can cause the 
elevators to become unbalanced, and oscillate or flutter. The actions 
specified by the proposed AD are intended to prevent this oscillation 
or flutter. Elevator oscillation, if not corrected, could result in 
reduced controllability of the airplane. Elevator flutter, if not 
corrected, could couple with the natural vibrations of the airplane, 
and result in loss of the airplane's structural integrity.

DATES: Comments must be received by November 25, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-51-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 Regional Aircraft Limited, Avro 
International Aerospace Division, Customer Support, Woodford Aerodrome, 
Woodford, Cheshire SK7 1QR, 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 96-NM-51-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. 96-NM-51-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation 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 Model BAe 146 and 
Avro 146-RJ series airplanes. The CAA advises that it has received 
reports indicating that water and ice have accumulated at the trailing 
edge of the left and right elevators; this accumulation can cause the 
elevators to become unbalanced, and to oscillate or flutter. Reduced 
controllability is a consequence of steady elevator oscillation which 
could cause uncommanded pitch (rising and falling movements) of the 
airplane. Reduced structural integrity of the airplane can occur if 
divergent elevator flutter is coupled with natural vibrations of the 
airplane.

Explanation of Relevant Service Information

    British Aerospace has issued Service Bulletin SB.55-014-01510A, 
dated December 15, 1995, which describes procedures for modification of 
the left and right elevators by installing mass balance weights at the 
leading edge of the horn, forward of the hinge line, to counteract the 
effect of accumulated water and ice on the trailing edge of the 
elevator.
    The manufacturer also has issued British Aerospace Service Bulletin 
SB.27-150-01510B, dated December 15, 1995, which describes additional 
procedures for modification of the left and right elevators by 
replacing the elevator spring with a stiffer spring. With the addition 
of mass balance weights to the elevators, a stiffer spring holds down 
the increased weight, and makes it easier for the pilot to conduct full 
movement and free movement checks of the elevators when the airplane is 
on the ground.
    The CAA classified both service bulletins as mandatory and issued 
British airworthiness directive 002-12-95, dated January 31, 1996, in 
order to assure the continued airworthiness of these airplanes in the 
United Kingdom.
    These airplane models are manufactured in the United Kingdom and 
are 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

[[Page 54363]]

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 require modification of the 
left and right elevators by installation of mass balance weights at the 
leading edge of the horn, forward of the hinge line; and replacement of 
the elevator spring with a stiffer spring. The actions would be 
required to be accomplished in accordance with the service bulletins 
described previously.
    On August 15, 1995, the FAA issued AD 95-17-13, amendment 39-9343 
(60 FR 44417, August 28, 1995). [A correction of the rule was published 
in the Federal Register on October 26, 1995 (60 FR 54800).] That AD 
requires operators of British Aerospace Model BAe 146 and Avro 146-RJ 
airplanes to modify the left and right elevators to improve water 
drainage, and thereby help maintain the balance of the elevators. That 
modification involves, among other actions, drilling new drain holes, 
applying sealant, and plugging drain holes on certain airplanes. The 
FAA determined that action to be interim action until further action is 
identified.
    Accomplishment of the actions required by this proposed AD would be 
the next step in eliminating the accumulation of ice and water in the 
left and right elevators. This action also would be interim action 
until final action is identified, at which time the FAA may consider 
further rulemaking.

Difference Between the Proposed Rule and CAA Airworthiness 
Directive

    The proposed AD and the parallel CAA airworthiness directive differ 
on compliance times: the proposed AD would require the actions to be 
completed within 12 months after the effective date of the AD; the CAA 
mandates an 18-month period. In developing a compliance time, the FAA 
considered the safety implications, parts availability, and normal 
maintenance schedules for timely accomplishment of the modification and 
part replacement. After evaluating these factors, the FAA determined 
that a 12-month compliance time is appropriate.

Cost Impact

    The FAA estimates that 52 British Aerospace Model BAe 146 and Avro 
146-RJ series airplanes of U.S. registry would be affected by this 
proposed AD, that it would take approximately 12 work hours per 
airplane to accomplish the proposed actions, and that the average labor 
rate is $60 per work hour. Required parts would cost approximately $700 
per airplane. Based on these figures, the cost impact of the proposed 
AD on U.S. operators is estimated to be $73,840, or $1,420 per 
airplane.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the 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 adding the following new 
airworthiness directive:

British Aerospace Regional Aircraft Limited, Avro International 
Aerospace Division (Formerly British Aerospace, plc; British 
Aerospace Commercial Aircraft Limited): Docket 96-NM-51-AD.

    Applicability: All Model BAe 146 and Avro 146-RJ 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 the left and right elevators from oscillating or 
fluttering, which could result in either reduced controllability of 
the airplane, or loss of the airplane's structural integrity, 
accomplish the following:
    (a) Within 12 months after the effective date of this AD, 
accomplish the requirements of paragraphs (a)(1) and (a)(2) of this 
AD.
    (1) Modify the left and right elevators by installing mass 
balance weights at the leading edge of the horn, forward of the 
elevator hinge line, in accordance with British Aerospace Service 
Bulletin SB.55-014-01510A, dated December 15, 1995. And
    (2) Replace the left and right elevator spring with a stiffer 
spring, in accordance with British Aerospace Service Bulletin SB.27-
150-01510B, dated December 15, 1995.
    (b) As of 12 months after the effective date of this AD, no 
person shall install on any airplane an elevator that has not been 
modified in accordance with paragraph (a) 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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note 2: Information concerning the existence of approved 
alternative methods of

[[Page 54364]]

compliance with this AD, if any, may be obtained from the 
Standardization Branch, ANM-113.

    (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.

    Issued in Renton, Washington, on October 9, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-26708 Filed 10-17-96; 8:45 am]
BILLING CODE 4910-13-U