[Federal Register Volume 61, Number 190 (Monday, September 30, 1996)]
[Rules and Regulations]
[Pages 50990-50992]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-24653]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-72-AD; Amendment 39-9769; AD 96-20-03]
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 all de Havilland DHC-8-100 and -300 series
airplanes, that currently requires repetitive inspections to detect
loose bolts at the retract actuator support fitting of the main landing
gear, and various follow-on actions, if necessary. That AD was prompted
by a report of loose actuator supporting bolts and cracks in the relief
radius of the boss at the forward surface of the fittings. This
amendment adds a requirement to install a new modification, which, when
accomplished, terminates the repetitive inspections. The actions
specified by this AD are intended to prevent loss of hydraulic systems
and reduced controllability of the airplane due to loose actuator
support bolts or cracks in the relief radius of the boss at the forward
surface of the fittings.
DATES: Effective November 4, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of Novmeber 4, 1996.
ADDRESSES: The service information referenced in this AD may be
obtained from Bombardier, Inc., Bombardier Regional Aircraft Division,
Garratt Boulevard, Downsview, Ontario, Canada M3K 1Y5. This information
may be examined at the Federal Aviation Administration (FAA), Transport
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton,
[[Page 50991]]
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 and Propulsion Branch, ANE-173, FAA, New York Aircraft
Certification Office, Engine and Propeller Directorate, 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) by superseding AD 91-20-12,
amendment 39-8046 (56 FR 47901, September 23, 1991), which is
applicable to all deHavilland DHC-8-100 and -300 series airplanes, was
published in the Federal Register on July 16, 1996 (61 FR 37019). The
action proposed to supersede AD 91-20-12 to continue to require
repetitive inspections to detect loose bolts at the retract actuator
support fitting of the main landing gear (MLG); and, if necessary, to
require a magnetic particle inspection, replacement of loose bolts, and
replacement of cracked fittings. In addition, the action proposed to
require modification of the frame and the retraction actuator fitting
of the MLG, which would constitute terminating action for the
repetitive inspection requirements. The action also proposed to revise
to 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
There are approximately 125 de Havilland Model DHC-8-100 and -300
series airplanes of U.S. registry that will be affected by this
proposed AD.
The actions that are currently required by AD 91-20-12, and
retained in this AD, take approximately 1 work hour per airplane to
accomplish, at an average labor rate of $60 per work hour. Based on
these figures, the cost impact on U.S. operators of the actions
currently required is estimated to be $7,500, or $60 per airplane.
The installation of modified brackets with new fasteners that is
required by this AD will take approximately 10 work hours per airplane
to accomplish, at an average labor rate of $60 per work hour. Required
parts will cost approximately $3,500 per airplane. Based on these
figures, the cost impact of the installation required on U.S. operators
is estimated to be $512,500, or $4,100 per airplane.
The removal of the enamel application (Modification 8/1830) that is
required by this AD will take approximately 5 work hours per airplane
to accomplish, at an average labor rate of $60 per work hour. Based on
these figures, the cost impact on U.S. operators of the enamel removed
required of this AD is estimated to be $37,500, or $300 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 39-8046 (56 FR
47901, September 23, 1991), and by adding a new airworthiness directive
(AD), amendment 39-9769, to read as follows:
96-20-03 de Havilland, Inc.: Amendment 39-9769. Docket 95-NM-72-AD.
Supersedes AD 91-20-12, Amendment 39-8046.
Applicability: Model DHC-8-100 and -300 series airplanes, serial
numbers 3 through 400 inclusive, except serial number 391;
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 loss of hydraulic systems and reduced controllability
of the airplane due to loose actuator support bolts or cracks in the
relief radius of the boss at the forward surface of the fittings,
accomplish the following:
(a) For Model DHC-8-100 series airplanes: Within 24 hours after
September 9, 1991 (the effective date of AD 91-15-51, amendment 39-
8016), inspect the three actuator attachment fitting bolts on the
right- and left-hand main landing gears (MLG) to detect loose bolts
by applying a torque of not less than 10 foot-pounds to each bolt.
(1) If no loose bolt is found as a result of the inspection
required by paragraph (a) of this AD, repeat this inspection
thereafter at intervals not to exceed 500 landings.
(2) If any loose bolt is found as a result of the inspection
required by paragraph (a) of this AD, accomplish paragraphs
(a)(2)(i), (a)(2)(ii), and (a)(2)(iii) of this AD.
(i) Prior to further flight, replace the loose bolt with a new
bolt of the same part number.
(ii) Within 250 landings after October 7, 1991 (the effective
date of 91-20-12, amendment 39-8046) accomplish paragraphs
(a)(2)(ii)(A) and (a)(2)(ii)(B) of this AD.
(A) Remove the associated support fitting having part number (P/
N) 85410084.
[[Page 50992]]
(B) Perform a magnetic particle inspection to detect cracks
throughout the fitting, paying particular attention to the relief
radius at the forward surface boss. If any crack is detected as a
result of this inspection, prior to further flight, replace the
fitting with a serviceable part.
(iii) Repeat the inspection required by paragraph (a) of this AD
thereafter at intervals not to exceed 500 landings.
(b) For Model DHC-8-300 series airplanes: Within 250 landings
after October 7, 1991 (the effective date of AD 91-20-12, amendment
39-8046), inspect the three actuator attachment fitting bolts on the
right- and left-hand ML's to detect loose bolts by applying a torque
of not less than 10 foot-pounds to each bolt.
(1) If no loose bolt is found as a result of the inspection
required by paragraph (b) of this AD, repeat this inspection
thereafter at intervals not to exceed 500 landings.
(2) If any loose bolt is found as a result of the inspection
required by paragraph (a) of this AD, accomplish paragraphs
(b)(2)(i), (b)(2)(ii), and (b)(2)(iii) of this AD.
(i) Prior to further flight, replace the loose bolt with a new
bolt of the same part number.
(ii) Within 250 landings after October 7, 1991 (the effective
date of AD 91-20-12, amendment 39-8046), accomplish (b)(2)(ii)(A)
and (b)(2)(ii)(B) of this AD.
(A) Remove the associated support fitting (P/N 85410084 for
Model DHC-8-301 airplanes, and P/N 85411701 for Model DHC-8-311
airplanes).
(B) Perform a magnetic particle inspection to detect cracks
throughout the fitting, pay particular attention to the relief
radius at the forward surface boss. If any crack is detected as a
result of this inspection, prior to further flight, replace the
fitting with a serviceable part.
(iii) Repeat the inspection required by paragraph (b) of this AD
thereafter at intervals not to exceed 500 landings.
(c) Within 90 days after the effective date of this AD,
accomplish paragraphs (c)(1) and (c)(2), as applicable, of this AD.
Accomplishment of this paragraph constitutes terminating action for
the inspections required by paragraphs (a) and (b) of this AD.
(1) For Model DHC-8-100 and -300 series airplanes, having serial
numbers 3 through 400 inclusive, except serial number 391: Modify
the frame and the retraction actuator fitting of the MLG, in
accordance with de Havilland Service Bulletin S.B. 8-54-34, Revision
`A', dated July 21, 1995.
(2) For Model DHC-8-100 and -300 series airplanes, having serial
number 3 through 332 inclusive: Modify the retraction actuator
fitting of the MLG, in accordance with de Havilland Service Bulletin
S.B. 8-54-27, Revision AD, dated August 22, 1994.
(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 modifications shall be done in accordance with de
Havilland Service Bulletin S.B. 8-54-34, Revision `A', dated July
21, 1995; and de Havilland Service Bulletin S.B. 8-54-27, Revision
`B', dated August 22, 1994, as applicable. 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, Canada M3K 1Y5.
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 November 4, 1996.
Issued in Renton, Washington, on September 19, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-24653 Filed 9-27-96; 8:45 am]
BILLING CODE 4910-13-U
