[Federal Register Volume 63, Number 150 (Wednesday, August 5, 1998)]
[Proposed Rules]
[Pages 41741-41743]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20833]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-04-AD]
RIN 2120-AA64


Airworthiness Directives; de Havilland Model DHC-8-100, -200, and 
-300 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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SUMMARY: This document revises an earlier proposed airworthiness 
directive (AD), applicable to certain de Havilland Model DHC-8-100, -
200, and -300 series airplanes, that would have required modification 
of the flight compartment door. That proposal was prompted by a report 
that the door lock mechanism of the flight compartment door jammed and 
could not be opened using the alternate release mechanism. This new 
action would add repetitive inspections for wear of the flight 
compartment door hinges following modification, and repair or 
replacement of the hinges with new hinges, if necessary. This new 
action also revises the applicability of the existing AD. The actions 
specified by this new proposed AD are intended to prevent failure of 
the alternate release mechanism of the flight compartment door, which 
could delay or impede the evacuation of the flightcrew during an 
emergency. Such failure also could result in the flightcrew not being 
able to assist passengers in the event of an emergency.

DATES: Comments must be received by August 31, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 97-NM-04-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 Bombardier, Inc., Bombardier Regional Aircraft Division, 
Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information 
may be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the FAA Engine and Propeller 
Directorate, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York.

FOR FURTHER INFORMATION CONTACT: Ezra Sasson, Aerospace Engineer, 
Systems and Equipment Branch, ANE-172, FAA, New York Aircraft 
Certification Office, Engine and Propeller Directorate, 10 Fifth 
Street, Third Floor, Valley Stream, New York 11581; telephone (516) 
256-7520; fax (516) 568-2716.

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

[[Page 41742]]

statement is made: ``Comments to Docket Number 97-NM-04-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-04-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    A proposal to amend part 39 of the Federal Aviation Regulations (14 
CFR part 39) to add an airworthiness directive (AD), applicable to 
certain de Havilland Model DHC-8-100, -200, and -300 series airplanes, 
was published as a notice of proposed rulemaking (NPRM) in the Federal 
Register on July 11, 1997 (62 FR 37170). That NPRM would have required 
modification of the flight compartment door. That NPRM was prompted by 
a report that the door lock mechanism of the flight compartment door 
jammed and it could not be opened using the alternate release 
mechanism. That condition, if not corrected, could result in failure of 
the alternate release mechanism of the flight compartment door, which 
could delay or impede the evacuation of the flightcrew during an 
emergency. Such failure also could result in the flightcrew not being 
able to assist passengers in the event of an emergency.

Actions Since Issuance of Previous Proposal

    Since the issuance of that NPRM, the manufacturer has issued de 
Havilland Service Bulletin S.B. 8-52-39, Revision `C,' dated September 
1, 1997, and Revision `D,' dated February 27, 1998.
    Among other things, Revision `C' revises the effectivity of the 
earlier releases of the service bulletin. In addition, the 
Accomplishment Instructions of the service bulletin have been revised 
to include a section titled ``Special Inspection/Repair,'' which 
describes procedures for repetitive inspections of the door hinges for 
wear. For airplanes on which any wear is found that is greater than 
0.050 inch in depth, the service bulletin describes procedures for 
removal and replacement of the hinges with new hinges. For airplanes on 
which any wear is found that is less than 0.050 inch, but greater than 
0.020 inch in depth, the service bulletin describes procedures for 
repair of the hinge.
    Revision `D' is essentially identical to Revision `C;' however, it 
provides information for an additional modification kit for certain 
Model DHC-8-300 series airplanes with a forward galley where a -100 
series lavatory has been installed.
    Transport Canada Aviation, which is the airworthiness authority for 
Canada, classified these service bulletin revisions as mandatory and 
issued Canadian airworthiness directive CF-96-20R2, dated July 16, 
1997, in order to assure the continued airworthiness of these airplanes 
in Canada.

Changes to the Original NPRM

    The FAA has determined that, in order to adequately address the 
unsafe condition presented by problems associated with the flight 
compartment door, the originally proposed rule must be revised to 
require repetitive inspections for wear of the modified flight 
compartment door hinges, and repair, if necessary. These additional 
actions would be required to be accomplished in accordance with the 
revised service bulletins described previously.
    Additionally, the applicability of this supplemental NPRM has been 
revised to correspond with the revised service bulletin effectivity 
discussed previously.

Conclusion

    Since these changes expand the scope of the originally proposed 
rule, the FAA has determined that it is necessary to reopen the comment 
period to provide additional opportunity for public comment.

Interim Action

    This is considered to be interim action. The manufacturer has 
advised the FAA that it currently is developing a modification that 
will eliminate the need for the repetitive inspections for wear of the 
flight compartment door hinges. Once this modification is developed, 
approved, and available, the FAA may consider additional rulemaking.

Cost Impact

    The FAA estimates that 133 de Havilland Model DHC-8-100, -200, and 
-300 series airplanes of U.S. registry would be affected by this 
proposed AD.
    It would take approximately 4 work hours per airplane to accomplish 
the proposed modification, at an average labor rate of $60 per work 
hour. Required parts would be provided by the manufacturer at no cost 
to operators. Based on these figures, the cost impact of the 
modification proposed by this AD on U.S. operators is estimated to be 
$31,920, or $240 per airplane.
    It would take approximately 2 work hours per airplane to accomplish 
the proposed inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the inspection proposed by 
this AD on U.S. operators is estimated to be $15,960, or $120 per 
airplane, per inspection cycle.
    The cost impact figures discussed above are 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.

[[Page 41743]]

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

De Havilland, Inc.: Docket 97-NM-04-AD.

    Applicability: Model DHC-8-100, -200, and -300 series airplanes 
having serial numbers 3 and subsequent; 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 (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 failure of the alternate release mechanism of the 
flight compartment door, which could delay or impede the evacuation 
of the flightcrew and passengers during an emergency, accomplish the 
following:
    (a) Within 90 days after the effective date of this AD, modify 
the lower hinge assembly and main door latch (Modification 8/2337) 
of the flight compartment door, in accordance with de Havilland 
Service Bulletin S.B. 8-52-39, Revision `D,' dated February 27, 
1998.

    Note 2: Modification of the flight compartment door accomplished 
prior to the effective date of this AD in accordance with de 
Havilland Service Bulletin S.B. 8-52-39, dated August 30, 1996; 
Revision `A,' dated October 31, 1996; Revision `B,' dated July 4, 
1997; or Revision `C,' dated September 1, 1997; is considered 
acceptable for compliance with the modification required by 
paragraph (a) of this AD.

    (b) Within 800 flight hours after accomplishment of the 
modification required by paragraph (a) of this AD, inspect the hinge 
areas around the hinge pin holes of the flight compartment door for 
wear, in accordance with de Havilland Service Bulletin S.B. 8-52-39, 
Revision `C,' dated September 1, 1997, or Revision `D,' dated 
February 27, 1998.
    (1) If no wear is detected, or if the wear is less than or equal 
to 0.020 inch in depth, repeat the inspection thereafter at 
intervals not to exceed 800 flight hours.
    (2) If any wear is detected and its dimension around the hinge 
pin holes is less than 0.050 inch and greater than 0.020 inch in 
depth, prior to further flight, perform the applicable corrective 
actions specified in the service bulletin. Repeat the inspection 
thereafter at intervals not to exceed 800 flight hours.
    (3) If any wear is detected and its dimension around the hinge 
pin holes is greater than or equal to 0.050 inch in depth, prior to 
further flight, replace the worn hinges with new hinges in 
accordance with the service bulletin. Repeat the inspection 
thereafter at intervals not to exceed 800 flight hours.
    (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, New York Aircraft Certification 
Office (ACO), FAA, Engine and Propeller Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, New York ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

    (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.

    Note 4: The subject of this AD is addressed in Canadian 
airworthiness directive CF-96-20R2, dated July 16, 1997.

    Issued in Renton, Washington, on July 29, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-20833 Filed 8-4-98; 8:45 am]
BILLING CODE 4910-13-U