[Federal Register Volume 63, Number 65 (Monday, April 6, 1998)]
[Proposed Rules]
[Pages 16713-16715]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8901]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-312-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace BAe Model ATP 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 certain British Aerospace BAe 
Model ATP airplanes. This proposal would require a one-time inspection 
to detect corrosion, wear, or damage of the operating mechanism of the 
forward door of the main landing gear (MLG); operational inspections to 
ensure smooth operation of the MLG operating mechanism; and follow-on 
actions. This proposal is prompted by issuance of mandatory continuing 
airworthiness information by a foreign civil airworthiness authority. 
The actions specified by the proposed AD are intended to prevent 
partial seizure of the forward door of the MLG operating mechanism, 
which could result in the inability to lower or retract the MLG.

DATES: Comments must be received by May 6, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-312-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 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.

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 97-NM-312-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. 97-NM-312-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, notified the FAA that an unsafe 
condition may exist on

[[Page 16714]]

certain British Aerospace BAe Model ATP airplanes. The CAA advises that 
an operator made an emergency landing with the left main landing gear 
(MLG) jammed in the ``up'' position. Investigation of the incident 
revealed that the probable cause was entrapped grit in the operating 
mechanism of the MLG, which caused partial seizure of the spring strut 
that drives part of the forward door of the MLG operating mechanism. 
Grit and other runway debris also could enter the MLG operating 
mechanism of other airplanes with this type design. Resistance in the 
MLG operating mechanism caused by entrapped grit can cause the door `A' 
frame to function out of sequence with the movement of the oleo (a 
cylindrical strut with a built-in telescopic shock absorber that damps 
or absorbs rectilinear shock). Such partial seizure of the forward door 
of the MLG operating mechanism, if not corrected, could result in the 
inability to lower or retract the MLG.

Explanation of Relevant Service Information

    The manufacturer has issued British Aerospace Service Bulletin ATP-
32-84, Revision 1, dated September 26, 1997, which describes procedures 
for a one-time visual inspection to detect corrosion, wear, or damage 
of the operating mechanism of the forward door of the MLG; cleaning, 
degreasing, and relubricating the door operating mechanism; and 
replacement of worn components with new or serviceable parts.
    The service bulletin also describes procedures for repetitive 
operational inspections to ensure smooth operation of the spring strut 
of the forward door of the MLG, and relubrication of the operating 
spring and sliding tube of the forward door `A' frame.

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 Sec. 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 require accomplishment of 
the actions specified in the service bulletin described previously, 
except as discussed below.

Differences Between This AD and Service Bulletin

    Operators should note that, unlike the procedures described in 
British Aerospace Service Bulletin ATP-32-84, Revision 1, dated 
September 26, 1997, which do not specify actions to be taken if 
corroded or damaged parts are detected during inspection, this proposed 
AD requires repair of corroded or damaged parts, in accordance with a 
method approved by the FAA. Additionally, unlike the service bulletin, 
which does not specify action to be taken if smooth operation of the 
spring strut cannot be achieved, this proposed AD would require 
replacement of discrepant parts with new or serviceable parts, prior to 
further flight, in accordance with a method approved by the FAA. The 
FAA has determined that, in light of the safety implications and 
consequences associated with the discrepancies described previously, 
these discrepancies must be corrected prior to further flight.

Cost Impact

    The FAA estimates that 10 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 8 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$4,800, or $480 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 [Formerly Jetstream Aircraft 
Limited; British Aerospace (Commercial Aircraft) Limited]: Docket 
97-NM-312-AD.

    Applicability: BAe Model ATP airplanes, constructor's number 
2001 through 2063 inclusive; 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 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, unless accomplished 
previously.

[[Page 16715]]

    To prevent partial seizure of the forward door of the main 
landing gear (MLG) operating mechanism, which could result in the 
inability to lower or retract the MLG, accomplish the following:
    (a) Within 300 flight hours or within 90 days after the 
effective date of this AD, whichever occurs first, perform a one-
time visual inspection to detect corrosion, wear, or damage of the 
operating mechanism of the forward door of the MLG; and clean, 
degrease, and relubricate the door operating mechanism; in 
accordance with British Aerospace Service Bulletin ATP-32-84, 
Revision 1, dated September 26, 1997.
    (1) If no corrosion, wear, or damage is detected during the 
inspection required by paragraph (a) of this AD, no further action 
is required by this AD.
    (2) If any corrosion, damage, or worn component is detected 
during the inspection required by paragraph (a) of this AD, 
accomplish the requirements of paragraphs (a)(2)(i) and (a)(2)(ii) 
of this AD, as applicable.
    (i) If any corrosion or damage is detected, prior to further 
flight, repair in accordance with a method approved by the Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate.
    (ii) If any worn component is detected, within 600 flight hours 
after performing the inspection required by paragraph (a) of this 
AD, replace the component with a new or serviceable part in 
accordance with the service bulletin.
    (b) Within 300 flight hours after accomplishing the inspection 
required by paragraph (a) of this AD, perform an operational 
inspection to ensure smooth operation of the spring strut of the 
forward door of the MLG, and relubricate the operating spring and 
sliding tube of the forward door `A' frame, in accordance with 
British Aerospace Service Bulletin ATP-32-84, Revision 1, dated 
September 26, 1997.
    (1) Repeat the operational inspections thereafter at intervals 
not to exceed 300 flight hours, until the accumulation of 1,500 
flight hours after the accomplishment of the inspection required by 
paragraph (a) of this AD.
    (2) Following the accomplishment of all inspections required by 
paragraph (b)(1) of this AD, repeat the operational inspections and 
relubrication required by paragraph (b) of this AD at intervals not 
to exceed 1,500 flight hours.
    (c) If any discrepancy is detected during any operational 
inspection and relubrication required by paragraph (b) of this AD, 
prior to further flight, replace any discrepant part with a new or 
serviceable part in accordance with a method approved by the 
Manager, International Branch, ANM-116.
    (d) 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (e) Special flight permits may be issued in accordance with 
Secs. 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 March 31, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8901 Filed 4-3-98; 8:45 am]
BILLING CODE 4910-13-U