[Federal Register Volume 61, Number 227 (Friday, November 22, 1996)]
[Rules and Regulations]
[Pages 59315-59317]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-28869]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-NM-194-AD; Amendment 39-9814; AD 96-23-09]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain de Havilland Model DHC-8-100 and -300 
series airplanes, that currently requires repetitive inspections to 
detect cracks of the upper drag strut trunnion fittings of the nose 
landing gear (NLG) and to verify tightness of the fitting attachment 
bolts, and replacement of fittings or fasteners, if necessary. This 
amendment requires the installation of a modification to terminate the 
repetitive inspections. This amendment is prompted by the development 
of a modification that positively addresses the identified unsafe 
condition. The actions specified by this AD are intended to prevent 
failure of the upper drag strut trunnion fittings of the NLG, which 
could lead to collapse of the NLG.

DATES: Effective December 27, 1996.
    The incorporation by reference of de Havilland DHC-8 Alert Service 
Bulletin S.B. A8-53-40, Revision `D', dated June 30, 1995; and de 
Havilland DHC-8 Service Bulletin S.B. 8-53-49, dated June 30, 1995, as 
listed in the regulations, is approved by the Director of the Federal 
Register as of December 27, 1996.
    The incorporation by reference of certain other publications, as 
listed in the regulations was approved previously by the Director of 
the Federal Register

[[Page 59316]]

as of May 27, 1993 (58 FR 25549, April 27, 1993).

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, New York Aircraft Certification Office, 
Engine and Propeller Directorate, 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, 181 South Franklin Avenue, Room 
202, 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) by superseding AD 93-08-03, 
amendment 39-8550 (58 FR 25549, April 27, 1993), which is applicable to 
certain de Havilland Model DHC-8-100 and -300 series airplanes, was 
published as a supplemental notice of proposed rulemaking (NPRM) in the 
Federal Register on September 9, 1996 (61 FR 47459). The action 
proposed to supersede AD 93-08-03 to continue to require repetitive 
inspections to detect cracks of the upper drag strut trunnion fittings 
of the nose landing gear (NLG) and to verify tightness of the fitting 
attachment bolts, and replacement of the fittings or fasteners, if 
necessary. That action also proposed to require the installation of a 
modification to terminate the repetitive inspections. Additionally, the 
action also proposed revise the applicability of the existing AD.
    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 146 de Havilland Model DHC-8-100 and -300 
series airplanes of U.S. registry will be affected by this AD.
    Accomplishment of the currently required inspections takes 
approximately 1 work hour per airplane, at an average labor rate of $60 
per hour. Based on these figures, the cost impact of the currently 
required inspection actions on U.S. operators is estimated to be 
$8,760, or $60 per airplane, per inspection.
    The modification will take approximately 18 work hours per airplane 
to accomplish, at an average labor rate of $60 per work hour. Required 
parts will cost approximately $3,325 per airplane. Based on these 
figures, the cost impact of the AD on U.S. operators is estimated to be 
$638,725, or $4,405 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 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 removing amendment 39-8550 (58 FR 
25549, April 27, 1993), and by adding a new airworthiness directive 
(AD), amendment 39-9814, to read as follows:

96-23-09  De Havilland, Inc.: Amendment 39-9814. Docket 93-NM-194-
AD. Supersedes AD 93-08-03, Amendment 39-8550.

    Applicability: Model DHC-8-102, -103, -301, -311, and -314 
series airplanes; having serial numbers 003 through 395 inclusive, 
but excluding serial numbers 011, 362, and 391; on which 
Modification 8/2139 (as described in de Havilland Service Bulletin 
S.B. 8-53-49, dated June 30, 1995) has not been accomplished; 
certificated in any category.

    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 failure of the upper drag strut trunnion fittings of 
the nose landing gear (NLG), which could lead to collapse of the 
NLG, accomplish the following:
    (a) Within 500 landings after May 27, 1993 (the effective date 
of AD 93-08-03, Amendment 39-8550), unless accomplished within the 
last 500 landings, conduct a visual inspection of both upper drag 
strut trunnion fittings of the NLG to detect cracks; and conduct an 
inspection of the fitting attachment bolts to verify tightness; in 
accordance with de Havilland DHC-8 Alert Service Bulletin S.B. A8-
53-40, Revision `A', dated June 12, 1992; or Revision `B', dated 
February 24, 1993; or Revision `D', dated June 30, 1995.
    (1) If no crack is detected in the upper drag strut trunnion 
fittings of the NLG, and no looseness is detected in the fitting 
attachment bolts, repeat the inspections at intervals not to exceed 
1,000 landings until the modification required by paragraph (b) of 
this AD is accomplished.
    (2) If any crack is detected on either fitting, prior to further 
flight, replace both fittings

[[Page 59317]]

with confirmed crack-free fittings in accordance with the service 
bulletin. After such replacement, the inspections required by this 
paragraph must continue at intervals not to exceed 1,000 landings 
until the modification required by paragraph (b) of this AD is 
accomplished.
    (3) If any fitting attachment bolt is found to be loose during 
the initial inspection, prior to further flight, replace the 
fasteners (nut, washer, and bolt) that secure the fitting, in 
accordance with the service bulletin. After such replacement, the 
inspections required by this paragraph must continue at intervals 
not to exceed 1,000 landings until the modification required by 
paragraph (b) of this AD is accomplished.
    (4) If any fastener is found to be loose during any repetitive 
inspection required by this AD, prior to further flight, tighten the 
bolt to the value specified in the service bulletin.
    (b) Within 6 months after the effective date of this AD, install 
Modification 8/2139 in accordance with de Havilland Service Bulletin 
S.B. 8-53-49, dated June 30, 1995. Installation of this modification 
constitutes terminating action for the inspection requirements of 
this AD.
    (c) Installation of Modification 8/2139, in accordance with de 
Havilland Service Bulletin S.B. 8-53-49, dated June 30, 1995, 
constitutes terminating action for the inspections required by this 
AD.
    (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 Aircraft Certification 
Office (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.

    (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.
    (f) The actions shall be done in accordance with de Havilland 
DHC-8 Alert Service Bulletin S.B. A8-53-40, Revision `A', dated June 
12, 1992 Revision `B', dated February 24, 1993, Revision `D', dated 
June 30, 1995; and de Havilland Service Bulletin S.B. 8-53-49, dated 
June 30, 1995. The incorporation by reference of de Havilland DHC-8 
Alert Service Bulletin S.B. A8-53-40, Revison `A', dated June 12, 
1992; and Revision `B', dated February 24, 1993, was approved 
previously by the Director of the Federal Register in accordance 
with 5 U.S.C. 552(a) and 1 CFR part 51 as of May 27, 1993 (58 FR 
25549, April 27, 1993). The incorporation by reference of de 
Havilland DHC-8 Alert Service Bulletin S.B. A8-53-40, Revision `D', 
dated June 30, 1995; and de Havilland Service Bulletin S.B. 8-53-49, 
dated June 30, 1995, is 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, New York Aircraft Certification Office, Engine and Propeller 
Directorate, 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.
    (g) This amendment becomes effective on December 27, 1996.

    Issued in Renton, Washington, on November 5, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-28869 Filed 11-21-96; 8:45 am]
BILLING CODE 4910-13-U