AD 2004-05-13

[Federal Register Volume 69, Number 47 (Wednesday, March 10, 2004)]
[Rules and Regulations]
[Pages 11290-11293]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 04-4682]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2004-NM-11-AD; Amendment 39-13508; AD 2004-05-13]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-8-401 and -402 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Bombardier Model DHC-8-401 and -402 airplanes. 
This action requires a records review to determine the repair/
modification status of the airplane, and follow-on and corrective 
actions as necessary. This action is necessary to prevent cracks in the 
lower fuselage skin due to fatigue damage in the vicinity of the Number 
2 VHF antenna, which could result in rapid decompression of the 
airplane. This action is intended to address the identified unsafe 
condition.

DATES: Effective March 25, 2004.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 25, 2004.
    Comments for inclusion in the Rules Docket must be received on or 
before April 9, 2004.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2004-NM-11-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
<a href="/cdn-cgi/l/email-protection#e6dfcb87888bcb8f879485898b8b838892a6808787c8818990"><span class="__cf_email__" data-cfemail="21180c404f4c0c484053424e4c4c444f55614740400f464e57">[email&#160;protected]</span></a>. Comments sent via the Internet must contain 
``Docket No. 2004-NM-11-AD'' in the subject line and need not be 
submitted in triplicate. Comments sent via fax or the Internet as 
attached electronic files must be formatted in Microsoft Word 97 or 
2000 or ASCII text.
    The service information referenced in this AD may be obtained from 
Bombardier, Inc., Bombardier Regional Aircraft Division, 123 Garratt 
Boulevard, Downsview, Ontario M3K 1Y5, Canada.

[[Page 11291]]

This information may be examined at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, 
New York Aircraft Certification Office, 1600 Stewart Avenue, Westbury, 
New York; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: David Lawson, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft 
Certification Office, 1600 Stewart Avenue, Westbury, New York 11590; 
telephone (516) 228-7327; fax (516) 794-5531.

SUPPLEMENTARY INFORMATION: Transport Canada Civil Aviation (TCCA), 
which is the airworthiness authority for Canada, notified the FAA that 
an unsafe condition may exist on certain Bombardier Model DHC-8-401 and 
-402 airplanes. TCCA advises that, during an A-check on an affected 
airplane, an 8-inch crack was discovered on the fuselage skin in the 
vicinity of the forward Number 2 very high frequency (VHF) antenna. 
Further investigation revealed cracking on four of the eight cleats 
attaching the internal antenna support structure. Since the original 
report, cracked cleats were found on additional airplanes. Cracking of 
the fuselage skin, if not corrected, could result in rapid 
decompression of the airplane.

Explanation of Relevant Service Information

    Bombardier approved Repair Drawing (RD) RD8/4-53-317, Issue 2, on 
December 13, 2002. The RD describes procedures for a temporary repair 
of cracks in the right-hand forward center fuselage skin panel at 
stringer 32S between stations X71.8 and X94.8. The repair involves 
cutting away damaged skin, replacing any other damaged structure with 
new parts, performing a detailed inspection for any remaining cracks, 
installing an external repair doubler with filler, and reprotecting 
bare areas.
    Bombardier approved Modification Summary (ModSum) Package 
IS4Q5300001, Revision B, on March 17, 2003. The modification involves 
installing an external reinforcement doubler and replacing brackets at 
the Number 2 VHF antenna installation.
    Bombardier approved Repair Drawing RD8/4-53-328, Issue 1, approved 
December 13, 2002, which describes procedures for replacing the support 
cleats with new cleats, part number (P/N) 85307891, at stringers 32S 
and 33, between stations X71.8 and X94.8.
    Bombardier also approved ModSum 4-113458, Revision B-1, on 
September 17, 2003, which describes procedures for reinforcing the 
Number 2 VHF antenna support structure.
    Bombardier issued Service Bulletin 84-53-32, Revision ``B,'' dated 
November 24, 2003, which provides instructions for incorporating 
Bombardier ModSum 4-113458.
    Accomplishment of the applicable actions specified in the service 
information is intended to adequately address the identified unsafe 
condition. TCCA issued Canadian airworthiness directive CF-2003-28, 
dated November 28, 2003, to ensure the continued airworthiness of these 
airplanes in Canada.

FAA's Conclusions

    This airplane model is manufactured in Canada 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, TCCA has kept the FAA informed of 
the situation described above. The FAA has examined the findings of 
TCCA, 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 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, this AD is being issued to prevent cracks in the 
lower fuselage skin due to fatigue damage in the vicinity of the Number 
2 antenna, which could result in rapid decompression of the airplane. 
This AD requires a records review to determine repair/modification 
status. For airplanes on which neither Repair Drawing RD8/4-53-317 nor 
ModSum IS4Q5300001 has been incorporated, this AD requires repetitive 
detailed inspections for cracking of the external surface of the 
fuselage skin in the area around the Number 2 antenna and discrepancies 
(cracks, deformation in the area of the bend radius, and broken rivets) 
of the support cleats at stringers 32S and 33 between stations X71.8 
and X94.8; replacement of all eight cleats with newly fabricated 
cleats, if any cleat is discrepant; and reinforcement of cracked 
fuselage skin. This AD also ultimately requires reinforcement of the 
Number 2 antenna support structure (and reinforcement of the fuselage 
skin around the Number 2 antenna, if not already done); the 
reinforcement actions terminate the repetitive inspections.

Difference Between FAA and TCCA Airworthiness Directives

    The Canadian airworthiness directive refers to ``detailed visual 
inspections'' for various discrepancies. We have determined that these 
procedures constitute ``detailed inspections.'' Note 1 in this AD 
defines this type of inspection.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Submit comments using the following format:
    <bullet<ls-thn-eq> Organize comments issue-by-issue. For example, 
discuss a request to change the compliance time and a request to change 
the service bulletin reference as two separate issues.
    <bullet<ls-thn-eq> For each issue, state what specific change to 
the AD is being requested.
    <bullet<ls-thn-eq> Include justification (e.g., reasons or data) 
for each request.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact

[[Page 11292]]

concerned with the substance of this AD will be filed in the Rules 
Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2004-NM-11-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will not have a substantial direct 
effect 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, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, 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

0
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

0
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]

0
2. Section 39.13 is amended by adding the following new airworthiness 
directive:

2004-05-13 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-13508. Docket 2004-NM-11-AD.

    Applicability: Model DHC-8-401 and -402 airplanes, certificated 
in any category, serial numbers 4003 through 4076 inclusive, and 
4078 through 4081 inclusive.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent cracks in the lower fuselage skin due to fatigue 
damage in the vicinity of the Number 2 VHF antenna, which could 
result in rapid decompression of the airplane, accomplish the 
following:

Records Review

    (a) Within the applicable compliance time specified in Table 1 
of this AD, review the airplane maintenance records to determine if 
the airplane has been modified or repaired in accordance with 
Bombardier Repair Drawing RD8/4-53-317, Issue 2, approved December 
13, 2002, or earlier issue; or Bombardier Modification Summary 
(ModSum) Package IS4Q5300001, Revision B, approved March 17, 2003, 
or earlier issue.

                                  Table 1.--Compliance Time for Records Review
----------------------------------------------------------------------------------------------------------------
 If the total flight hours accumulated on the airplane,
       as of the effective date of this AD, is--                        Then review the records--
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<=1,450................................................  Before the accumulation of 1,900 total flight hours.
<ls-thn-eq>1,450 and <=2,200...........................  Within 300 flight hours after the effective date of
                                                          this AD.
<ls-thn-eq>2,200 and <=3,000...........................  Within 150 flight hours after the effective date of
                                                          this AD.
<ls-thn-eq>3,000.......................................  Within 50 flight hours after the effective date of this
                                                          AD.
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Follow-on Actions: Drawing/ModSum Incorporated

    (b) If either Bombardier Repair Drawing RD8/4-53-317 or 
Bombardier ModSum IS4Q5300001, as specified in paragraph (a) of this 
AD, has been incorporated before the effective date of this AD: Do 
the terminating action required by, and at the time specified in, 
paragraph (d) of this AD.

Follow-on Actions: Drawing/ModSum Not Incorporated

    (c) If neither Bombardier Repair Drawing RD8/4-53-317 nor 
Bombardier ModSum IS4Q5300001, as specified in paragraph (a) of this 
AD, has been incorporated before the effective date of this AD: 
Before further flight, do the actions specified in paragraphs (c)(1) 
and (c)(2) of this AD.
    (1) Perform a detailed inspection for cracking of the external 
surface of the fuselage skin in the area around the Number 2 VHF 
antenna, in accordance with Bombardier Service Bulletin 84-53-32, 
Revision B, dated November 24, 2003. Use a 10X magnifying glass and 
appropriate lighting to do the inspection.

    Note 1: For the purposes of this AD, a detailed inspection is 
defined as: ``An intensive visual examination of a specific 
structural area, system, installation, or assembly to detect damage, 
failure, or irregularity. Available lighting is normally 
supplemented with a direct source of good lighting at intensity 
deemed appropriate by the inspector. Inspection aids such as mirror, 
magnifying lenses, etc., may be used. Surface cleaning and elaborate 
access procedures may be required.''

    (i) If any crack is found: Before further flight, do the actions 
specified in paragraphs (c)(1)(i)(A) and (c)(1)(i)(B) of this AD.
    (A) Repair in accordance with Bombardier Repair Drawing RD8/4-
53-317, Issue 2, approved December 13, 2002.
    (B) Replace all 8 support cleats, part number (P/N) 85307891, at 
stringers 32S and 33, between stations X71.8 and X94.8, in 
accordance with Repair Drawing RD8/4-53-328, Issue 1, approved 
December 13, 2002.
    (ii) If no crack is found: Before further flight, do the 
requirements of paragraph (c)(2) of this AD.
    (2) Do a detailed inspection to detect discrepancies (cracks, 
deformation in the area of the bend radius, and broken rivets) of 
the support cleats, P/N 85307891, at stringers 32S and 33, between 
stations X71.8 and X94.8; in accordance with Bombardier Service 
Bulletin 84-53-32, Revision B, dated November 24, 2003.
    (i) If any discrepancy is found: Before further flight, remove 
the antenna and do a detailed inspection for cracks of the external 
surface of the fuselage skin underneath the antenna, in accordance 
with Bombardier Service Bulletin 84-53-32, Revision B, dated 
November 24, 2003. Use a 10X magnifying glass and appropriate 
lighting to do the inspection.
    (A) If no crack is found: Before further flight, reinforce the 
fuselage skin around the Number 2 VHF antenna and replace all 8 
support cleats with new cleats, P/N 85307891, at stringers 32S and 
33, between stations X71.8 and X94.8. Do the actions in accordance 
with Bombardier ModSum IS4Q5300001, Revision B, approved March 17, 
2003.
    (B) If any crack is found: Before further flight, repair in 
accordance with Bombardier Repair Drawing RD8/4-53-317, Issue 2, 
approved December 13, 2002; and replace all 8 support cleats with 
new cleats, P/N 85307891, at stringers 32S and 33, between stations 
X71.8 and X94.8, in accordance with Bombardier Repair Drawing RD8/4-
53-328, Issue 1, approved December 13, 2002.

[[Page 11293]]

    (ii) If no discrepancy is found: Repeat the inspections required 
by paragraph (c)(1) of this AD at the following times, as 
applicable:
    (A) If all 8 cleats have not been replaced: Repeat the 
inspections at intervals not to exceed 200 flight hours until 
accomplishment of the terminating action required by paragraph (d) 
of this AD.
    (B) If all 8 cleats have been replaced: Repeat the inspections 
at intervals not to exceed 500 flight hours until accomplishment of 
the terminating action required by paragraph (d) of this AD.

Terminating Action

    (d) Within 4,000 flight hours after the effective date of this 
AD, do the actions specified in paragraphs (d)(1) and (d)(2), as 
applicable, of this AD. Accomplishment of the applicable 
requirements of this paragraph terminates the repetitive inspections 
required by paragraph (c) of this AD.
    (1) For all airplanes: Reinforce the Number 2 VHF antenna 
support structure in accordance with Bombardier ModSum 4-113458, 
Revision B-1, approved September 17, 2003. Bombardier Service 
Bulletin 84-53-32, Revision B, dated November 24, 2003, provides 
instructions for incorporating ModSum 4-113458.
    (2) For airplanes on which neither Bombardier Repair Drawing 
RD8/4-53-317 nor Bombardier ModSum IS4Q5300001 has been 
incorporated: Reinforce the fuselage skin around the Number 2 VHF 
antenna in accordance with Bombardier ModSum IS4Q5300001, Revision 
B, approved March 17, 2003.

Alternative Methods of Compliance

    (e) In accordance with 14 CFR 39.19, the Manager, New York 
Aircraft Certification Office (ACO), FAA, is authorized to approve 
alternative methods of compliance for this AD.

Incorporation by Reference

    (f) Unless otherwise specified in this AD, the actions must be 
done in accordance with the Bombardier modification summary packages 
and repair drawings listed in Table 2 of this AD, as applicable. 
(The approval date of the repair drawings and modification summary 
packages appears only on the first page of these documents.)

                                     Table 2.--Applicable Service Documents
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                                                           Revision level shown
             Document                    Page number            on the page           Date shown on the page
----------------------------------------------------------------------------------------------------------------
Bombardier Modification Summary     1-3, 6...............  Revision B..........  March 17, 2003.
 Package IS4Q5300001.
                                    4, 5.................  Revision A..........  December 22, 2002.
Bombardier Repair Drawing RD8/4-53- 1, 2.................  Issue 2.............  December 13, 2002.
 317.
                                    3-5..................  Issue 1.............  December 11, 2002.
Bombardier Repair Drawing RD8/4-53- All..................  Issue 1.............  December 13, 2002.
 328.
Bombardier Modification Summary     All..................  Revision B-1........  September 17, 2003.
 Package 4-113458.
Bombardier Service Bulletin 84-53-  All..................  Revision `B'........  November 24, 2003.
 32.
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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., Bombardier 
Regional Aircraft Division, 123 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, New York Aircraft Certification Office, 
1600 Stewart Avenue, Westbury, New York; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

    Note 2: The subject of this AD is addressed in Canadian 
airworthiness directive CF-2003-28, dated November 28, 2003.

Effective Date

    (g) This amendment becomes effective on March 25, 2004.

    Issued in Renton, Washington, on February 25, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-4682 Filed 3-9-04; 8:45 am]
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