[Federal Register Volume 61, Number 61 (Thursday, March 28, 1996)]
[Proposed Rules]
[Pages 13785-13787]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-7550]



 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 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.
 
 ========================================================================
 

  Federal Register / Vol. 61, No. 61 / Thursday, March 28, 1996 / 
Proposed Rules  

[[Page 13785]]


DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-89-AD]


Airworthiness Directives; de Havilland Model DHC-8-100 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 and 
-300 series airplanes, that would have required inspections to detect 
corrosion on areas of the airplane structure where black film thermal 
insulation is used; repair, if necessary; and replacement of black 
insulation blankets with certain aluminized (silver) insulation. That 
proposal was prompted by reports of corrosion forming on areas of the 
airplane structure where the black film covers the thermal insulation 
blankets. This action would expand the inspection area, and would 
require replacement of the black film insulation in that area. This 
action also would expand the applicability of the proposed AD to 
include additional airplanes. The actions specified by this proposed AD 
are intended to prevent degradation of the structural capability of the 
airplane fuselage and sudden loss of cabin pressure due to corrosion of 
the airplane fuselage structure.

DATES: Comments must be received by April 24, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-89-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., 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: Jon Hjelm, Aerospace Engineer, 
Airframe Branch, ANE-172, FAA, Engine and Propeller Directorate, New 
York Aircraft Certification Office, 10 Fifth Street, Third Floor, 
Valley Stream, New York 11581; telephone (516) 256-7523; 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 statement is made: ``Comments 
to Docket Number 94-NM-89-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-89-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 and -300 series airplanes, was 
published as a notice of proposed rulemaking (NPRM) in the Federal 
Register on September 27, 1994 (59 FR 49219). That NPRM would have 
required a one-time visual inspection to detect corrosion on areas of 
the airplane structure where black film thermal insulation is used, and 
repair, if necessary; and replacement of black Orcan film insulation 
blankets with AN4C aluminized (silver) film insulation. That NPRM was 
prompted by reports of corrosion forming on areas of the airplane 
structure where the black film covers the thermal insulation blankets. 
That condition, if not corrected, could result in degradation of the 
structural capability of the airplane fuselage and sudden loss of cabin 
pressure due to corrosion of the airplane fuselage structure.
    Since the issuance of that NPRM, Bombardier has issued revisions to 
each of the service bulletins cited in the NPRM. These service bulletin 
revisions are essentially the same as those referenced in the proposed 
AD. However, in each of these revisions, the service bulletin 
effectivity has been updated to remove those airplanes on which silver 
insulation was installed during production. Further, references to 
existing part numbers, part descriptions, and new part numbers have 
been revised. Two of the service bulletin revisions address the black 
thermal insulation in the passenger compartment area:
     S.B. 8-25-89, Revision E, dated July 6, 1994; and
     S.B. 8-25-92, Revision E, dated July 20, 1994.
    Two of the service bulletins address the insulation in the air 
conditioning ducts:
     S.B. 8-25-90, Revision C, dated July 5, 1994; and
    
[[Page 13786]]

     S.B. 8-25-93, Revision C, dated July 20, 1994.
    One service bulletin revision addresses the insulation in the 
flight compartment and the forward fuselage areas: S.B. 8-25-91, 
Revision D, dated July 20, 1994.
    Bombardier also issued Service Bulletin S.B. 8-21-68, dated July 
20, 1994, which descries procedures to determine from the airplane 
modification records if any of the retrofit kits listed in the service 
bulletin have been installed on the airplane. The service bulletin also 
describes procedures for removal of the black Orcon film insulation 
that may have been installed in a retrofit kit; inspections for 
corrosion of the airplane structure that has been in contact with the 
black film insulation, and repair, if necessary; and replacement of the 
black Orcon film insulation with AN4C aluminized (silver) film 
insulation blankets. The effectivity of this service bulletin addresses 
airplanes on which the black insulation was installed through retrofit 
kits.
    Additionally, Bombardier issued Service Bulletin S.B. 8-21-66, 
Revision C, dated March 24, 1995, which describes procedures for 
removal of the black Orcon film from delivery and recirculation ducts 
of the air conditioning system in the rear fuselage, inspections for 
corrosion of the airplane structure that has been in contact with the 
black film insulation, and repair, if necessary. The service bulletin 
also describes procedures for replacement of the black Orcon film 
insulation with AN4C aluminized (silver) film insulation.
    Transport Canada Aviation, which is the airworthiness authority for 
Canada, classified these service bulletins as mandatory and issued 
Canadian airworthiness directives CF-94-25R1 and CF-94-26R1, both dated 
June 30, 1995, in order to assure the continued airworthiness of these 
airplanes in Canada.
    The FAA has examined the findings of Transport Canada Aviation and 
has reviewed the service bulletin revisions and new service 
information. The FAA has determined that the proposed rule must be 
revised to cite the latest revisions of the service bulletins 
referenced in the NPRM as the appropriate sources of service 
information.
    The FAA also has determined that the addressed unsafe condition is 
also likely to exist or develop on the airplanes addressed in 
Bombardier Service Bulletin S.B. 8-21-68. Therefore, the FAA has added 
a new paragraph (a) to this supplemental NPRM to require the procedures 
specified in that service bulletin.
    Additionally, the FAA finds that the proposed rule must be revised 
to address inspection for corrosion and replacement of black Orcon film 
insulation with AN4C aluminized (silver) film insulation blankets in 
the delivery and recirculation ducts of the air condition system, as 
specified in Bombardier Service Bulletin S.B. 8-21-66. The FAA has 
revised paragraph (b) of this supplemental NPRM to include those 
requirements.
    In addition, the applicability of this supplemental NPRM has been 
revised to specify that the AD applies to those airplanes on which 
black Orcon film insulation is installed to include airplanes listed in 
Bombardier Service Bulletins S.B. 8-21-66 and S.B. 8-21-68.
    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.
    There are approximately 378 Model DHC-8-100 and -300 series 
airplanes of the affected design in the worldwide fleet. The FAA 
estimates that 125 airplanes of U.S. registry would be affected by this 
proposed AD, that it would take approximately 650 work hours per 
airplane to accomplish the proposed actions, and that the average labor 
rate is $60 per work hour. (Work hours associated with the proposed 
actions described in Service Bulletin S.B. 8-21-68 cannot be estimated 
at this time since exact numbers of the retrofit kits installed are 
unknown.) However, the FAA has been advised that the manufacturer plans 
to provide required parts and to accomplish the required modification 
at no expense to operators. Therefore, there is no cost impact to U.S. 
operators that is associated with this proposed rule with regard to 
labor charges or parts costs.
    The FAA does recognize, however, that while operators may incur 
administrative costs associated with compliance to this proposed rule, 
the one-year compliance time specified in paragraphs (a) and (b) of 
this proposed AD should allow ample time for the proposed requirements 
to be accomplished coincidentally with scheduled major airplane 
inspection and maintenance activities, thereby minimizing the costs 
associated with special airplane scheduling.
    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:

De Havilland, Inc.: Docket 94-NM-89-AD.

    Applicability: Model DHC-8-100 and -300 series airplanes, 
equipped with black Orcon film insulation; certificated in any 
category; and listed in the following Bombardier Service Bulletins:

[[Page 13787]]


----------------------------------------------------------------------------------------------------------------
           DHC-8 models                  Service bulletin No.         Revision level              Date          
----------------------------------------------------------------------------------------------------------------
102, 103, and 106................  S.B. 8-25-89...................  E                   July 6, 1994.           
102, 103, and 106................  S.B. 8-25-90...................  C                   July 5, 1994.           
102, 103, 106, 301, 311, and 314.  S.B. 8-25-91...................  D                   July 20, 1994.          
301, 311, and 314................  S.B. 8-25-92...................  E                   July 20, 1994.          
301, 311, and 314................  S.B. 8-25-93...................  C                   July 20, 1994.          
102, 103, 106, 301, 311, and 314.  S.B. 8-21-68...................  ..................  July 20, 1994.          
102, 103, 301, 311, and 314......  S.B. 8-21-66...................  C                   March 24, 1995.         
----------------------------------------------------------------------------------------------------------------

    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 (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.
    To prevent degradation of the structural capability of the 
airplane fuselage and sudden loss of cabin pressure due to corrosion 
of the airplane fuselage structure, accomplish the following:
    (a) For airplanes listed in Bombardier Service Bulletin S.B. 8-
21-68, dated July 20, 1994: Within one year after the effective date 
of this AD, accomplish the requirements of paragraphs (a)(1), and 
(a)(2) of this AD.
    (1) Determine from the airplane modification records if any of 
the retrofit kits listed in the service bulletin have been installed 
in the airplane, in accordance with the service bulletin.
    (i) If no kit has been installed, no further action is required 
by this paragraph.
    (ii) If any kit has been installed, prior to further flight, 
remove any black film insulation blanket, and perform a visual 
inspection to detect corrosion of all airplane structure in contact 
with the black insulation, in accordance with the service bulletin.
    (A) If any corrosion is found that is within the limits 
specified in the service bulletin, prior to further flight, repair 
in accordance with the service bulletin.
    (B) If any corrosion is found that is beyond the limits 
specified in the service bulletin, prior to further flight, repair 
in accordance with a method approved by the New York Aircraft 
Certification Office (ACO), ANE-170, FAA Engine and Propeller 
Directorate.
    (2) Install the AN4C aluminized (silver) film insulation in 
accordance with the service bulletin.
    (b) Within 1 year after the effective date of this AD, 
accomplish the requirements of paragraph (b)(1), (b)(2), and (b)(3) 
of this AD, in accordance with the following Bombardier service 
bulletin, as applicable:

S.B. 8-25-89, Revision E, dated July 6, 1994;
S.B. 8-25-90, Revision C, dated July 5, 1994;
S.B. 8-25-91, Revision D, dated July 20, 1994;
S.B. 8-25-92, Revision E, dated July 20, 1994;
S.B. 8-25-93, Revision C, dated July 20, 1994; and
S.B. 8-21-66, Revision C, dated March 24, 1995.

    (1) Remove any black Orcon film insulation from the flight 
compartment and forward fuselage of the airplane, the passenger 
compartment, the air conditioning ducts, and the delivery and 
recirculation ducts of the air conditioning system in the rear 
fuselage, in accordance with the applicable service bulletin.
    (2) Perform a visual inspection to detect corrosion of all 
airplane structure in contact with the black insulation, in 
accordance with the applicable service bulletin.
    (i) If any corrosion is found that is within the limits 
specified in the service bulletin, prior to further flight, repair 
in accordance with the applicable service bulletin.
    (ii) If any corrosion is found that is beyond the limits 
specified in the service bulletin, prior to further flight, repair 
in accordance with a method approved by the Manager, New York ACO.
    (3) Install the AN4C aluminized (silver) film insulation in 
accordance with the applicable service bulletin.
    (c) As of the effective date of this AD, no person shall install 
black Orcon film insulation, part number AN46B/AN36B, on any 
airplane.
    (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, New York ACO. 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the New York ACO.

    (e) 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 March 22, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-7550 Filed 3-27-96; 8:45 am]
BILLING CODE 4910-13-U