[Federal Register Volume 60, Number 219 (Tuesday, November 14, 1995)]
[Proposed Rules]
[Pages 57201-57203]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-27984]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-CE-47-AD]
Airworthiness Directives; de Havilland Model DHC-3 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes to supersede Airworthiness Directive
(AD) 90-12-08, which currently requires the following on de Havilland
Model DHC-3 airplanes: repetitively inspecting (using dye penetrant
methods) the tailplane main rib forward flanges and the main rib
forward lower flanges at the tailplane front attachment fitting for
cracks and repairing any cracked flange. The proposed action would
retain the repetitive inspections currently required by AD 90-12-08,
and would allow the provision of incorporating a certain modification
as terminating action for these repetitive inspections. The proposed
action is prompted by the Federal Aviation Administration's
determination that installing new angles and plates on the tailplane
root ribs on de Havilland Model DHC-3 airplanes provides an equivalent
level of safety to the repetitive inspections required by AD 90-12-08.
The actions specified by the proposed AD are intended to prevent
failure of the tailplane structure caused by cracked tailplane main rib
forward flanges or main rib forward lower flanges at the tailplane
front attachment fitting, which, if not detected and corrected, could
result in loss of control of the airplane.
DATES: Comments must be received on or before January 12, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 95-CE-47-AD, Room 1558, 601 E.
12th Street, Kansas City, Missouri 64106. Comments may be inspected at
this location between 8 a.m. and 4 p.m., Monday through Friday,
holidays excepted.
Service information that applies to the proposed AD may be obtained
from Bombardier Inc., (the parent company of de Havilland) Bombardier
Regional Aircraft Division, Garrett Boulevard, Downsview, Ontario,
Canada M3K 1Y5; telephone (416) 633-7310. This information also may be
examined at the Rules Docket at the address above.
[[Page 57202]]
FOR FURTHER INFORMATION CONTACT: Mr. Jeff Casale, Aerospace Engineer,
FAA, New York Aircraft Certification Office, 10 5th St., 3rd Floor,
Valley Stream, New York 11581; telephone (516) 256-7521; facsimile
(516) 568-2716.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed 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 concerned
with the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket No. 95-CE-47-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Central Region, Office of the Assistant Chief Counsel,
Attention: Rules Docket No. 95-CE-47-AD, Room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106.
Discussion
AD 90-12-08, Amendment 39-6622 (55 FR 1450, January 16, 1990),
currently requires the following on de Havilland Model DHC-3 airplanes:
repetitively inspecting (using dye penetrant methods) the tailplane
main rib forward flanges and the main rib forward lower flanges at the
tailplane front attachment fitting for cracks and repairing any cracked
flange. Accomplishment of the actions required by AD 90-12-08 is in
accordance with de Havilland Service Bulletin (SB) No. 3/46, Revision
B, dated December 1, 1989.
Since issuance of AD 90-12-08, de Havilland has developed tailplane
root rib angles and plates of improved design (Modification 3/935).
When incorporated, Modification 3/935 eliminates the need for the
repetitive inspections required by AD 90-12-08.
Bombardier, Inc. (the parent company of de Havilland) has issued de
Havilland SB No. 3/50, Revision A, dated February 17, 1995, which
specifies procedures for incorporating Modification 3/935 on de
Havilland Model DHC-3 airplanes.
Transport Canada, which is the airworthiness authority for Canada,
classified this service bulletin as mandatory and revised Transport
Canada AD CF-89-20 to the R1 level, dated February 22, 1995, in order
to assure the continued airworthiness of these airplanes in Canada.
This airplane model is manufactured in Canada and is type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement between Canada and the
United States. Pursuant to this bilateral airworthiness agreement,
Transport Canada has kept the FAA informed of the situation described
above.
After examining the findings of Transport Canada and reviewing all
available information related to the incidents described above
including the referenced service information, the FAA has determined
that (1) incorporating Modification 3/935 provides an equivalent level
of safety to the repetitive inspections required by AD 90-12-08; and
(2) AD action should be taken to prevent failure of the tailplane
structure caused by cracked tailplane main rib forward flanges or main
rib forward lower flanges at the tailplane front attachment fitting,
which, if not detected and corrected, could result in loss of control
of the airplane.
Since an unsafe condition has been identified that is likely to
exist or develop in other de Havilland Model DHC-3 airplanes of the
same type design that do not have Modification 3/935 incorporated, the
proposed AD would supersede AD 90-12-08 with a new AD that would (1)
retain the requirement of repetitively inspecting the tailplane main
rib forward flanges and the main rib forward lower flanges at the
tailplane front attachment fitting for cracks and repairing any cracked
flange; and (2) allowing for the provision of incorporating
Modification 3/935 as terminating action for the repetitive
inspections. Accomplishment of the proposed inspections would be in
accordance with de Havilland SB No. 3/46, Revision B, dated December 1,
1989. Accomplishment of the proposed modification would be in
accordance with de Havilland SB No. 3/50, Revision A, dated February
17, 1995.
The FAA estimates that 49 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 35
workhours per airplane to accomplish the proposed inspection and that
the average labor rate is approximately $60 an hour. Based on these
figures, the total cost impact of the proposed AD on U.S. operators is
estimated to be $102,900 or $2,100 per airplane. This figure represents
the cost of the initial inspection, and does not reflect the costs for
repetitive inspections or possible repairs. The FAA has no way of
determining how many tailplane main rib forward or main rib forward
lower flanges may need repaired or how many repetitive inspections each
owner/operator of the affected airplanes would incur over the life of
the airplane.
The FAA has issued alternative methods of compliance (AMOC) to the
repetitive inspection requirement of AD 90-12-08 for owners/operators
of three de Havilland Model DHC-3 airplanes. These AMOC's consist of
the incorporation of a certain design modification in the tailplane
root rib area of the affected airplanes. These AMOC's would remain in
effect for the proposed AD, which would eliminate the inspection costs
for these three airplanes. With this in mind, the cost of the proposed
AD would be reduced by $6,300 from $102,900 to $96,600.
The compliance time of the proposed AD is in calendar time instead
of hours time-in-service (TIS). In developing the compliance time of AD
90-12-08, the FAA utilized calendar time because it was unknown whether
the rib flange cracking was a result of in-flight loads (flight hours)
or loads associated with ground gusts. With this in mind, airplanes
with lower usage may experience a cracked rib flange before an airplane
with higher usage. For this reason, calendar time rather than flight
hours was judged to be an appropriate inspection basis. This situation
still exists and in order to maintain the repetitive inspection
continuity between AD 90-12-08 and the proposed AD, a compliance based
on calendar time is proposed.
The regulations proposed herein would not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of
[[Page 57203]]
power and responsibilities among the various levels of government.
Therefore, in accordance with Executive Order 12612, it is determined
that this proposal would 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) if promulgated,
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 copy of the draft regulatory evaluation
prepared for this action has been placed in the Rules Docket. A copy of
it may be obtained by contacting the Rules Docket at the location
provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend 14
CFR part 39 of the Federal Aviation Regulations 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); 40101, 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Airworthiness Directive
(AD) 90-12-08, Amendment 39-6622 (55 FR 1450, January 16, 1990), and by
adding the following new AD:
De Havilland: Docket No. 95-CE-47-AD; Supersedes AD 90-12-08,
Amendment 39-6622.
Applicability: Model DHC-3 Airplanes (all serial numbers),
certificated in any category, that do not have Modification 3/935
incorporated in accordance with de Havilland Service Bulletin (SB)
number (No.) 3/50, Revision A, dated February 17, 1995.
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: Within the next 3 calendar months after the
effective date of this AD, unless already accomplished (compliance
with AD 90-12-08), and thereafter at intervals not to exceed 24
calendar months.
To prevent failure of the tailplane structure caused by cracked
tailplane main rib forward flanges or main rib forward lower flanges
at the tailplane front attachment fitting, which, if not detected
and corrected, could result in loss of control of the airplane,
accomplish the following:
(a) Inspect, using dye penetrant methods, the tailplane main rib
forward flanges and the main rib forward lower flanges at the
tailplane front attachment fitting in accordance with the
ACCOMPLISHMENT INSTRUCTIONS section of de Havilland SB No. 3/46,
Revision B, dated December 1, 1989.
(b) Prior to further flight, repair any tailplane main rib
forward flange or main rib forward lower flange found cracked during
any inspection required by this AD. Accomplish this repair in
accordance with the ACCOMPLISHMENT INSTRUCTIONS section of de
Havilland SB No. 3/46, Revision B, dated December 1, 1989.
(c) Installing tailplane root rib angles and plates of improved
design (Modification 3/935) in accordance with de Havilland SB 3/50,
Revision A, dated February 17, 1995, terminates the repetitive
inspection requirement of this AD. Modification 3/935 may be
incorporated at any time provided that any tailplane main rib
forward flange or main rib forward lower flange found cracked during
any inspection required by this AD is repaired.
(d) 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.
(e) An alternative method of compliance or adjustment of the
initial or repetitive compliance times that provides an equivalent
level of safety may be approved by the Manager, New York Aircraft
Certification Office (ACO), 10 5th St., 3rd Floor, Valley Stream,
New York 11581. The request shall be forwarded through an
appropriate FAA 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) Alternative methods of compliance approved in accordance
with AD 90-12-08 (superseded by this action) are considered approved
as alternative methods of compliance with this AD.
(g) All persons affected by this directive may obtain copies of
the document referred to herein upon request to Bombardier Inc.,
Bombardier Regional Aircraft Division, Garrett Boulevard, Downsview,
Ontario, Canada M3K 1Y5; telephone (416) 633-7310; or may examine
this document at the FAA, Central Region, Office of the Assistant
Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri
64106.
(h) This amendment supersedes AD 90-12-08, Amendment 39-6622.
Issued in Kansas City, Missouri, on November 6, 1996.
Henry A. Armstrong,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-27984 Filed 11-13-95; 8:45 am]
BILLING CODE 4910-13-U
