[Federal Register Volume 64, Number 243 (Monday, December 20, 1999)]
[Rules and Regulations]
[Pages 71003-71004]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-32582]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-165-AD; Amendment 39-11470; AD 99-26-11]
RIN 2120-AA64


Airworthiness Directives; Bombardier Model DHC-7 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-7 series airplanes, that 
requires a one-time visual inspection to detect corrosion on the upper 
half of the lower longerons on the inboard nacelles; and corrective 
actions, if necessary. This AD also requires modification of the upper 
and lower longeron halves. This amendment is prompted by issuance of 
mandatory continuing airworthiness information by a foreign civil 
airworthiness authority. The actions specified by this AD are intended 
to detect and correct corrosion in the upper halves of the left and 
right hand lower longerons on the inboard nacelles, which could result 
in a landing gear failure.

DATES: Effective January 24, 2000.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of January 24, 2000.

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 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: Franco Pieri, Aerospace Engineer, 
Airframe and Propulsion Branch, ANE-171, FAA, Engine and Propeller 
Directorate, New York Aircraft Certification Office, 10 Fifth Street, 
Third Floor, Valley Stream, New York 11581; telephone (516) 256-7526; 
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-7 
series airplanes was published in the Federal Register on October 14, 
1999 (64 FR 55640). That action proposed to require a one-time visual 
inspection to detect corrosion on the upper half of the lower longerons 
on the inboard nacelles; and corrective actions, if necessary. That 
action also proposed to require modification of the upper and lower 
longeron halves.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Conclusion

    The FAA has determined that air safety and the public interest 
require the adoption of the rule as proposed.

Cost Impact

    The FAA estimates that 32 airplanes of U.S. registry will be 
affected by this AD.
    It will take approximately 8 work hours per airplane to accomplish 
the required inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the inspection required by 
this AD on U.S. operators is estimated to be $15,360, or $480 per 
airplane.
    It will take approximately 12 work hours per airplane to accomplish 
the required modification, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of the modification 
required by this AD on U.S. operators is estimated to be $23,040, or 
$720 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the 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 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.
    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:

99-26-11 Bombardier, Inc. (Formerly de Havilland, Inc.): Amendment 
39-11470. Docket 99-NM-165-AD.

    Applicability: Model DHC-7 series airplanes, serial numbers 004 
through 113 inclusive, except serial numbers 037 and 061, 
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 (d) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or

[[Page 71004]]

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 detect and correct corrosion in the upper halves of the left 
and right hand lower longerons on the inboard nacelles, which could 
result in a landing gear failure, accomplish the following:

Inspection

    (a) Within 6 months after the effective date of this AD, perform 
a visual inspection to detect corrosion on the upper half of the 
lower longerons on the inboard nacelles in accordance with 
Bombardier Service Bulletin S.B. 7-54-19, Revision `C,' dated April 
16, 1999.

Modification

    (b) If no corrosion is detected, prior to further flight, modify 
the upper and lower longeron halves in accordance with Bombardier 
Service Bulletin S.B. 7-54-19, Revision `C,' dated April 16, 1999.

Corrective Action

    (c) If any corrosion is detected, prior to further flight, 
accomplish the actions specified in paragraph (c)(1) or (c)(2) of 
this AD, as applicable, in accordance with Bombardier Service 
Bulletin S.B. 7-54-19, Revision `C,' dated April 16, 1999.
    (1) For corrosion that is within the limits specified in the 
service bulletin: Accomplish the corrective actions specified in the 
service bulletin, and perform a fluorescent penetrant inspection or 
high frequency eddy current inspection to detect cracks in areas 
where corrosion was blended out. The corrective actions and 
inspections shall be done in accordance with the service bulletin.
    (i) If no crack is detected, prior to further flight, modify the 
upper and lower longeron halves in accordance with the service 
bulletin.
    (ii) If any crack is detected, prior to further flight, 
accomplish the actions required by paragraphs (c)(1)(ii)(A) and 
(c)(1)(ii)(B) of this AD.
    (A) Either replace the longeron with a new longeron in 
accordance with the service bulletin, or repair in accordance with a 
method approved by either the Manager, New York Aircraft 
Certification Office (ACO), FAA, Engine and Propeller Directorate; 
or Transport Canada Civil Aviation (or it's delegated agent). For a 
repair method to be approved by the Manager, New York ACO, as 
required by this paragraph, the Manager's approval letter must 
specifically reference this AD.
    (B) Modify the upper and lower longeron halves in accordance 
with the service bulletin.
    (2) For corrosion that exceeds the limits specified in the 
service bulletin: Accomplish the actions required in paragraphs 
(c)(1)(ii)(A) and (c)(1)(ii)(B) of this AD.

Alternative Methods of Compliance

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

Special Flight Permits

    (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.

Incorporation by Reference

    (f) Except at provided by paragraph (c)(1)(ii)(A) of this AD, 
the actions shall be done in accordance with Bombardier Service 
Bulletin S.B. 7-54-19, Revision `C,' dated April 16, 1999. 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, 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 directive CF-99-07, dated March 15, 1999.

    (g) This amendment becomes effective on January 24, 2000.

    Issued in Renton, Washington, on December 10, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-32582 Filed 12-17-99; 8:45 am]
BILLING CODE 4910-13-P