AD Amdt-39-10785

[Federal Register Volume 63, Number 184 (Wednesday, September 23, 1998)]
[Rules and Regulations]
[Pages 50755-50757]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-25120]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-89-AD; Amendment 39-10785; AD 98-20-19]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-100 and -300 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Bombardier Model DHC-8-100 and -300 series 
airplanes, that requires 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. This amendment 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 this 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: Effective October 28, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 28, 1998.

ADDRESSES: The service information referenced in this AD may be 
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division, 
Garratt Boulevard, Downsview, Ontario M3K 1Y5, Canada. This information 
may be examined at the Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 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; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Bombardier Model DHC-8-100 
and -300 series airplanes was published as a supplemental notice of 
proposed rulemaking (NPRM) in the Federal Register on March 28, 1996 
(61 FR 13785). That supplemental NPRM proposed to require 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.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the proposed AD.
    As proposed, paragraph (a) of the supplemental NPRM would require a 
determination from airplane modification records as to whether any of 
the retrofit kits listed in the applicable service bulletin have been 
installed. If any have been installed, that paragraph also would 
require removal of the black film insulation blanket and inspection of 
the affected areas ``prior to further flight.'' One commenter believes 
that this compliance time of ``prior to further flight'' is too 
restrictive, since the airplane could be in operation at the time the 
modification records are consulted. The commenter requests that the 
supplemental NPRM be reworded to allow a records search to determine 
which aircraft have had the retrofit kits installed, and that the 
inspection for black insulation be completed within a compliance time 
of one year. The commenter adds that subsequent repairs could be 
accomplished prior to further flight. The commenter states that this 
would allow the required inspections to be carried out coincidentally 
with scheduled major airplane inspection and maintenance activities, 
thereby minimizing costs associated with special airplane scheduling.
    The FAA concurs that paragraph (a), as proposed, would be more 
restrictive than intended. The FAA has revised paragraph (a)(1)(ii) of 
this final rule to require removal of the insulation and inspection of 
the affected areas within one year after the effective date of the AD, 
rather than immediately after the records are searched. Depending on 
how early the records are searched, an operator will have as much as 
one year following the search in which to accomplish the required 
insulation removal and inspections. Any corrosion found will be 
required to be repaired prior to further flight in accordance with 
paragraph (a)(1)(ii)(A) or (a)(1)(ii)(B), regardless of when the 
inspection is accomplished.
    Another commenter notes that compliance with the proposed 
requirements of paragraph (b) would make paragraph (a) redundant, and 
asks that paragraph (a) be revised (1) to state that it does not apply 
to airplanes on which the service bulletins specified in paragraph (b) 
have been accomplished, and (2) to specify the serial numbers of 
affected airplanes as Series 100 serial numbers 003-179, and Series 300 
serial numbers 100-138. The commenter states that all areas of the 
airplane are inspected, and all black insulation is removed during 
accomplishment of the applicable service bulletins referenced in 
paragraph (b) of the supplemental NPRM.
    The FAA concurs partially with the commenter's remarks. The FAA has 
revised paragraph (a) of this final rule and has added a new paragraph 
(c) to specify that compliance with paragraph (a) is only necessary if 
compliance with paragraph (b) has not been accomplished. However, the 
FAA does not agree that specifying the serial numbers of affected 
airplanes in paragraph (a) of the AD, as suggested by the commenter, is 
necessary. Paragraph (a) of the supplemental NPRM specifies that the 
affected airplanes are those listed in Bombardier Service Bulletin S.B. 
8-21-68, dated July 20, 1994. The FAA has verified with the 
manufacturer that the serial numbers listed in that service bulletin 
are the appropriate serial numbers of affected airplanes. (The service 
bulletin specifies the affected airplanes as those having serial 
numbers 003 through 381 inclusive.) Therefore, no change to paragraph 
(a) of the final rule is necessary in this regard.
    As proposed, paragraph (a)(1)(ii)(B) would require repair of 
corrosion beyond the limits specified in the service bulletin in 
accordance with a method approved by the FAA. One

[[Page 50756]]

commenter requests that the supplemental NPRM allow repairs approved by 
the manufacturer, since this would allow the use of the manufacturer's 
repair drawings without any further approval. The FAA does not concur, 
since to do so would be delegating its rulemaking authority to the 
manufacturer.
    Another commenter also requests that paragraph (b) be revised to 
permit compliance with any previous revision of the referenced service 
bulletins to eliminate unnecessary filing for approval of alternative 
methods of compliance by operators. The FAA does not concur, since 
previous revisions of the service bulletin are not immediately 
available for review by the FAA. The FAA does not consider that further 
delay of this action until such time as the service bulletin revisions 
could be received and reviewed is warranted in light of the amount of 
time that has already passed since the issuance of the original NPRM. 
No change has been made to the final rule in this regard.
    The final rule has been revised to change the manufacturer's name 
from de Havilland, Inc., to Bombardier, Inc.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 125 Model DHC-8-100 and -300 series 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 650 work hours per airplane to accomplish the 
required actions, and that the average labor rate is $60 per work hour. 
(Work hours associated with the 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 will provide required parts and 
accomplish the required modification at no expense to operators. 
Therefore, there is no cost impact to U.S. operators that is associated 
with this 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 rule, the one-
year compliance time specified in paragraphs (a) and (b) of this 
proposed AD should allow ample time for the requirements to be 
accomplished coincidentally with scheduled major airplane inspection 
and maintenance activities, thereby minimizing the costs associated 
with special airplane scheduling.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

98-20-19  Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-10785. 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:

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           DHC-8 Models               Service Bulletin No.         Revision level                 Date
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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                         Mar. 24, 1995.
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    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 (e) 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: Except as provided by paragraph (c) of 
this AD, within one year after the effective

[[Page 50757]]

date of this AD, accomplish the requirements of paragraphs (a)(1) 
and (a)(2) of this AD.
    (1) Determine from the airplane modification records whether 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, within one year after the 
effective date of this AD, 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 one 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 
bulletins, 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; or
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) Airplanes on which the actions required by paragraph (b) of 
this AD are performed prior to accomplishment of the actions 
required by paragraph (a) of this AD are not required to accomplish 
the actions required by paragraph (a).
    (d) As of the effective date of this AD, no person shall install 
black Orcon film insulation, part number AN46B/AN36B, on any 
airplane.
    (e) 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.

    (f) 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.
    (g) The actions shall be done in accordance with the following 
Bombardier service bulletins:

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      Service bulletin No.        Revision level           Date
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S.B. 8-21-68....................  Original        July 20, 1994.
S.B. 8-25-89....................  E               July 6, 1994.
S.B. 8-25-90....................  C               July 5, 1994.
S.B. 8-25-91....................  D               July 20, 1994.
S.B. 8-25-92....................  E               July 20, 1994.
S.B. 8-25-93....................  C               July 20, 1994.
S.B. 8-21-66....................  C               Mar. 25, 1995.
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This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 
51. Copies may be obtained from Bombardier, Inc., Garratt Boulevard, 
Downsview, Ontario M3K 1Y5, Canada. Copies may be inspected 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; or at the Office of the Federal Register, 
800 North Capitol Street, NW., suite 700, Washington, DC.

    Note 3: The subject of this AD is addressed in Canadian 
airworthiness directives CF-94-25R1 and CF-94-26R1, both dated June 
30, 1995.

    (h) This amendment becomes effective on October 28, 1998.

    Issued in Renton, Washington, on September 14, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-25120 Filed 9-22-98; 8:45 am]
BILLING CODE 4910-13-U