[Federal Register Volume 59, Number 186 (Tuesday, September 27, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-23813]


[[Page Unknown]]

[Federal Register: September 27, 1994]


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DEPARTMENT OF TRANSPORTATION
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: 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 de Havilland Model DHC-8 
series airplanes. This proposal would require 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 
insulation blankets with certain aluminized (silver) insulation. This 
proposal is prompted by reports of corrosion forming on areas of the 
airplane structure where the black film covers the thermal insulation 
blankets. The actions specified by the 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 November 21, 1994.

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, 181 South Franklin Avenue, Room 202, 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, 181 South Franklin Avenue, Room 
202, Valley Stream, New York 11581; telephone (516) 791-6220; fax (516) 
791-9024.

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

    Transport Canada Aviation, which is the airworthiness authority for 
Canada, recently notified the FAA that an unsafe condition may exist on 
certain de Havilland Model DHC-8-100 and -300 series airplanes. 
Transport Canada Aviation advises that there have been reports of 
corrosion forming on areas of the airplane structure where black Orcon 
film covers the thermal insulation blankets. Investigation revealed 
that the black Orcon film used to insulate the forward fuselage, 
passenger compartment, flight compartment, and ventilation ducts 
contains carbon. The cause of this corrosion has been attributed to the 
formation of condensation on any aluminum airplane structure when it is 
in contact with the carbon in the black Orcon film. Such corrosion, if 
not detected and corrected in a timely manner, could result in 
degradation of the strength of the airplane fuselage structure and 
could lead to sudden loss of cabin pressure.
    Bombardier, Inc. (formerly de Havilland) has issued Service 
Bulletins S.B. 8-25-89, Revision D; S.B. 8-25-90, Revision B; S.B. 8-
25-91, Revision C; S.B. 8-25-92, Revision D; and S. B. 8-25-93, 
Revision B; all dated January 19, 1994. These service bulletins 
describe procedures for one-time visual inspection to detect corrosion 
on areas of the airplane structure where black film thermal insulation 
is used, and repaired, if necessary. The service bulletins also 
describe procedures for replacement of black Orcon film insulation 
blankets with AN4C aluminized (silver) film thermal insulation blankets 
in various areas of the airplane structure. Transport Canada Aviation 
classified these service bulletins as mandatory and issued Canadian 
Airworthiness Directive CF-94-08, dated April 26, 1994, in order to 
assure the continued airworthiness of these airplanes in Canada.
    This airplane model is manufactured in Canada 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, Transport Canada Aviation has kept 
the FAA informed of the situation described above. The FAA has 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 require a one-time visual 
inspection to detect corrosion on areas of the airplane structure where 
black film thermal insulation is used, and repaired, if necessary. This 
proposed AD also would require replacement of black Orcon film thermal 
insulation blankets with AN4C aluminized (silver) film insulation 
blankets. The actions would be required to be accomplished in 
accordance with the service bulletins described previously.
    The FAA estimates that 125 airplanes of U.S. registry would be 
affected by this proposed AD, that it would require approximately 650 
work hours to accomplish the required actions, at an average labor 
charge of $55 per work hour. 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 on 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 paragraph (a) 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


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, 
variants and serial numbers specified in paragraph (a) of this AD, 
certificated in any category.
    -Compliance: Required as indicated, unless accomplished 
previously.
    To prevent degradation of the structural capability of the 
fuselage and sudden loss of cabin pressure, accomplish the 
following:
    (a) For airplanes listed in the following table: Within one year 
after the effective date of this AD, accomplish paragraphs (a)(1) 
and (a)(2) of this AD in accordance with the Bombardier Service 
Bulletins, all dated January 19, 1994, as listed in the table below, 
as applicable. 

----------------------------------------------------------------------------------------------------------------
                                                                               Service bulletin       Revision  
            DHC-8 models                     Airplane serial numbers                number             level    
----------------------------------------------------------------------------------------------------------------
101, 102, 103, and 106..............  003 through 353 inclusive...........  S.B. 8-25-89.........  D            
101, 102, 103, and 106..............  003 through 380 inclusive...........  S.B. 8-25-90.........  B            
101, 102, 103, 106, 301, 311, and     003 through 337 inclusive, 339, 341   S.B. 8-25-91.........  C            
 314.                                  through 347 inclusive, 349, 350,                                         
                                       351, 353, and 356.                                                       
301, 311, and 314 -.................  100 through 336 inclusive, 342, 350,  S.B. 8-25-92-........  D            
                                       and 356.                                                                 
301, 311, and 314-..................  100 through 381 inclusive...........  S.B. 8-25-93.........  B            
----------------------------------------------------------------------------------------------------------------

    (1) Perform a visual inspection to detect corrosion of the 
passenger compartment, flight compartment, forward fuselage, and air 
conditioning system. If any corrosion is found; prior to further 
flight, repair damage in accordance with the applicable service 
bulletin.
    (2) Replace the black Orcon film insulation blankets with AN4C 
aluminized (silver) film thermal insulation blankets in accordance 
with the applicable service bulletin.
    (b) As of one year after the effective date of this AD, no 
person shall install black Orcon film insulation, part number AN46B/
AN36B, on any airplane.
    (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), ANE-170, 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: 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.

    Issued in Renton, Washington, on September 21, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-23813 Filed 9-26-94; 8:45 am]
BILLING CODE 4910-13-U