[Federal Register Volume 63, Number 223 (Thursday, November 19, 1998)]
[Rules and Regulations]
[Pages 64175-64179]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-30788]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-SW-29-AD; Amendment 39-10899; AD 98-24-13]
RIN 2120-AA64
Airworthiness Directives; Eurocopter Deutschland GmbH (ECD)
(Eurocopter) Model MBB-BK117 A-1, A-3, A-4, B-1, B-2, and C-1
Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to Eurocopter Model MBB-BK117 A-1, A-3, A-4, B-1, B-2,
and C-1 helicopters, that currently requires initial and repetitive
inspections of both surfaces of the tail boom vertical fin (vertical
fin) spar, the skin, and the left-hand and right-hand frame sheets for
cracks or loose rivets. That AD also requires repairing certain cracks,
if found, and repairing and reporting those loose rivets and certain
other cracks, if found. This amendment requires the same inspections,
repairs, and reporting as the existing AD, but changes the reference to
the service bulletin and
[[Page 64176]]
prohibits the use of blind rivets for the vertical fin spar repair.
This amendment is prompted by an accident that occurred on April 15,
1997, resulting in one fatality. The actions specified by this AD are
intended to prevent failure of the vertical fin and subsequent loss of
control of the helicopter.
DATES: Effective December 4, 1998.
The incorporation by reference of Eurocopter Alert Service Bulletin
MBB-BK 117-30-106, Revision 4, dated December 19, 1997, as listed in
the regulations, is approved by the Director of the Federal Register as
of December 4, 1998.
The incorporation by reference of Eurocopter Alert Service Bulletin
No. MBB-BK 117-30-106, Revision 3, dated May 5, 1997, as listed in the
regulations, was approved previously by the Director of the Federal
Register as of October 24, 1997 (62 FR 52655, October 9, 1997).
Comments for inclusion in the Rules Docket must be received on or
before January 19, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 98-SW-29-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
The service information referenced in this AD may be obtained from
American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas
75053-4005, telephone (972) 641-3460, fax (972) 641-3527. This
information may be examined at the FAA, Office of the Regional Counsel,
Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas
76137; or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Mr. Richard Monschke, Aerospace
Engineer, Rotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth,
Texas 76137, telephone (817) 222-5116, fax (817) 222-5961.
SUPPLEMENTARY INFORMATION: On April 25, 1997, the FAA issued priority
letter AD 97-09-16, to require inspecting both surfaces of the vertical
fin spar, part number (P/N) 105-304061.03, P/N 1120-30406.03, or P/N
117-30423-03, paying particular attention to the area extending from
the top edge of the second lightening hole from the top of the vertical
fin spar to the bottom edge of the fourth lightening hole, the outer
skin (skin), and the left-hand and right-hand frame plates for cracks,
loose rivets, or other anomalies. That priority letter AD required that
the inspection be performed before further flight, then repeated at
intervals not to exceed 100 hours time-in-service (TIS). That action
was prompted by an accident involving a Eurocopter Model MBB-BK117
series helicopter that occurred on April 15, 1997, resulting in one
fatality. A subsequent investigation revealed that the vertical fin had
failed as a result of a fatigue crack that initiated on the left side
of the vertical fin. The crack propagated across the spar cap and spar.
A crack in the skin propagated horizontally toward the vertical fin
leading edge until catastrophic overstress occurred. Inspections of
other helicopters of the same type design revealed cracks in the
vertical fin spars of three additional helicopters. That condition, if
not corrected, could result in failure of the vertical fin and
subsequent loss of control of the helicopter.
On September 26, 1997 the FAA issued AD 97-20-16, Amendment 39-
10153 (62 FR 52655, October 9, 1997), superseding priority letter AD
97-09-16 to require the same initial and repetitive inspections of the
vertical fin spar, and additionally, requiring the repair of certain
cracks, if found, and reporting and repairing loose rivets and certain
other cracks. That action was prompted by the issuance of Eurocopter
Alert Service Bulletin (ASB) No. MBB-BK 117-30-106, Revision 3, dated
May 5, 1997, which contains repair procedures for the cracks that were
unavailable at the time of the release of priority letter AD 97-09-16.
The requirements of both those ADs are intended to prevent failure of
the vertical fin spar and subsequent loss of control of the helicopter.
Since the issuance of AD 97-20-16, Eurocopter has issued Eurocopter
ASB MBB-BK117 No. ASB-MBB-BK 117-30-106, Revision 4, dated December 19,
1997, which replaces all previous revisions and specifies repair
procedures for the spar cap as well as inspection requirements. It also
deletes a reference that allows the use of blind rivets for the
vertical fin spar repair.
These helicopter models are manufactured in The Federal Republic of
Germany and are 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. Pursuant to this bilateral airworthiness agreement, the
Luftahrt-Bundesamt (LBA), the airworthiness authority for The Federal
Republic of Germany, has kept the FAA informed of the situation
described above. The LBA superseded AD No. 97-144/2, dated June 5,
1997, with AD 1997-144/3, effective May 11, 1998. The FAA has examined
the findings of the LBA, 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.
Since an unsafe condition has been identified that is likely to
exist or develop on other Eurocopter Model MBB-BK117 A-1, A-3, A-4, B-
1, B-2, and C-1 helicopters of the same type design, this AD supersedes
AD 97-20-16, Amendment 39-10153 (62 FR 52655, October 9, 1997) to
require inspecting both surfaces of the vertical fin spar, P/N 105-
304061.03, P/N 1120-30406.03, or P/N 117-30423-03, paying particular
attention to the area extending from the top edge of the third
lightening hole from the top of the vertical fin spar to halfway
between the fourth and fifth lightening hole (see Figure 1 for
description of area to be inspected), the skin, and the left-hand and
right-hand frame sheets for cracks or loose rivets. This inspection
must be repeated at intervals not to exceed 100 hours TIS until the
repair is accomplished. If a crack is found in the area of the fourth
lightening hole of the vertical fin spar, including a crack in the cap
or ``c'' channel area of the spar, or in the left-hand frame sheet, P/N
105-304161 or P/N 1120-30416, or in the right-hand frame sheet, P/N
105-304211 or P/N 1120-30421, before further flight, the crack must be
repaired in accordance with the repair instructions that are an
Appendix titled ``Repair of BK117 Vertical Fin'' to Eurocopter ASB MBB-
BK 117 No. ASB-MBB-BK 117-30-106, Revision 4, dated December 19, 1997,
or in accordance with Eurocopter ASB No. MBB-BK 117-30-106, Revision 3,
dated May 5, 1997, except use of blind rivets is not permitted.
Thereafter, this AD requires that a visual inspection for cracks be
performed at intervals not to exceed 300 hours TIS. If a crack or loose
rivet is found in the area other than that described in paragraph (a)
of this AD, including any crack that is found to extend into the skin,
P/N 105-304011.18 or P/N 1120-30402.0, contact the Rotorcraft Standards
Staff before further flight for further evaluation. If no crack is
found, the repetitive visual inspection for cracks is required at
intervals not to exceed 100 hours TIS until the repair specified in the
repair instruction is accomplished. The repair must be accomplished
within 600 hours TIS after October 24, 1997. Thereafter, the repetitive
visual inspections for cracks are required at intervals not to exceed
300 hours TIS. The actions are required to be accomplished in
accordance with the service bulletins described. The
[[Page 64177]]
short compliance time involved is required because the previously
described critical unsafe condition can adversely affect the structural
integrity of the helicopter. Therefore, inspections, reporting, and
repairs, if necessary, are required prior to further flight, and this
AD must be issued immediately.
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.
The FAA estimates that 132 helicopters will be affected by this AD,
that it will take approximately 4 work hours for each inspection and 35
hours for each repair, if necessary, per helicopter, and that the
average labor rate is $60 per work hour. Required parts will cost
approximately $302 per helicopter. Based on these figures, the total
cost impact of the AD on U.S. operators is estimated to be $348,744,
assuming one inspection and one repair per helicopter.
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 should 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.
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 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 No. 98-SW-29-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
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
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 39-10153 (62 FR
52655, October 9, 1997), and by adding a new airworthiness directive
(AD), Amendment 39-10899, to read as follows:
AD 98-24-13 Eurocopter Deutschland GmbH (ECD): Amendment 39-10899.
Docket No. 98-SW-29-AD. Supersedes AD 97-20-16, Amendment 39-10153,
Docket No. 97-SW-15-AD.
Applicability: Model MBB-BK117 A-1, A-3, A-4, B-1, B-2, and C-1
helicopters, certificated in any category.
Note 1: This AD applies to each helicopter 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 helicopters that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must use the authority
provided in paragraph (f) to request approval from the FAA. This
approval may address either no action, if the current configuration
eliminates the unsafe condition, or different actions necessary to
address the unsafe condition described in this AD. Such a request
should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any helicopter from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent failure of the tail boom vertical fin (vertical fin)
and subsequent loss of control of the helicopter, accomplish the
following:
(a) Before further flight, remove the tail rotor drive shaft
between the intermediate and tail rotor gearboxes and the yaw servo
(if installed). Thoroughly clean the vertical fin spar and adjacent
areas and visually inspect the following for cracks or loose rivets:
(1) Both surfaces of the vertical fin spar, part number (P/N)
105-304061.03, P/N 1120-30406.03, or P/N 117-30423-03, paying
particular attention to the area extending from the top edge of the
third lightening hole from the top of the vertical fin spar to
halfway between the fourth and fifth lightening hole (see Figure 1).
(2) The skin and left-hand and right-hand frame sheets.
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(b) If a crack or loose rivet is found in the area described in
paragraph (a) of this AD (see Figure 1), before further flight,
repair in accordance with the Appendix, ``Repair of BK117 Vertical
Fin'', to Eurocopter Alert Service Bulletin (ASB) MBB-BK 117 No.
ASB-MBB-BK 117-30-106, Revision 4, dated December 19, 1997, or in
accordance with Eurocopter ASB No. MBB-BK 117-30-106, Revision 3,
dated May 5, 1997, except use of blind rivets is not permitted.
Thereafter, perform the inspection described in paragraph (a) of
this AD at intervals not to exceed 300 hours TIS.
(c) If a crack or loose rivet is found in the area other than
that described in paragraph (a) of this AD, including any crack that
is found to extend into the skin, P/N 105-304011.18 or P/N 1120-
30402.08, before further flight, contact the Rotorcraft Standards
Staff. Reporting requirements have been approved by the Office of
Management and Budget and assigned OMB control number 2120-0056.
(d) If no crack or loose rivet is found as a result of the
inspection required by paragraph (a) of this AD, until the repair is
made in accordance with the Appendix, ``Repair of BK117 Vertical
Fin,'' to Eurocopter ASB MBB-BK 117 No. ASB-MBB-BK 117-30-106,
Revision 4, dated December 19, 1997, or in accordance with the
Appendix, ``Repair of BK117 Vertical Fin,'' to Eurocopter ASB No.
MBB-BK 117-30-106, Revision 3, dated May 5, 1997, except use of
blind rivets is not permitted, perform the visual inspection
required by paragraph (a) of
[[Page 64179]]
this AD at intervals not to exceed 100 hours TIS.
(e) Within 600 hours TIS after October 24, 1997, accomplish the
repair to the vertical fin in accordance with the Appendix, ``Repair
of BK117 Vertical Fin,'' to Eurocopter ASB MBB-BK-117 No. ASB-MBB-BK
117-30-106, Revision 4, dated December 19, 1997, or in accordance
with the Appendix, ``Repair of BK117 Vertical Fin,'' to Eurocopter
ASB No. MBB-BK 117-30-106, Revision 3, dated May 5, 1997, except use
of blind rivets is not permitted. If blind rivets were previously
used to accomplish the vertical fin repair, they must be removed and
replaced with solid rivets to comply with the requirements of this
AD. Thereafter, perform the visual inspection required by paragraph
(a) of this AD at intervals not to exceed 300 hours TIS.
(f) 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, FAA, Rotorcraft Directorate,
Rotorcraft Standards Staff. Operators shall submit their requests
through an FAA Principal Maintenance Inspector, who may concur or
comment and then send it to the Manager, Rotorcraft Standards Staff.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Rotorcraft Standards Staff.
(g) Special flight permits will not be issued.
(h) The inspections and repairs shall be done in accordance with
the Appendix, ``Repair of BK117 Vertical Fin,'' to Eurocopter Alert
Service Bulletin MBB-BK 117-30-106, Revision 4, dated December 19,
1997, or in accordance with the Appendix, ``Repair of BK117 Vertical
Fin,'' to Eurocopter Alert Service Bulletin No. MBB-BK 117-30-106,
Revision 3, dated May 5, 1997, except use of blind rivets is not
permitted. The incorporation by reference of Eurocopter Alert
Service Bulletin No. MBB-BK 117-30-106, Revision 3, dated May 5,
1997, 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 October 24, 1997 (62 FR 52655, October 9, 1997). The
incorporation by reference of Eurocopter Alert Service Bulletin MBB-
BK 117-30-106, Revision 4, dated December 19, 1997, 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 American
Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas
75053-4005, telephone (972) 641-3460, fax (972) 641-3527. Copies may
be inspected at the FAA, Office of the Regional Counsel, Southwest
Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC.
Note 3: Accomplishment of the requirements of Revision 3 of the
referenced service bulletin, except for using solid rivets instead
of blind rivets, or Revision 4 of the referenced service bulletin
constitutes compliance with the requirements of this AD.
(i) This amendment becomes effective on December 4, 1998.
Note 4: The subject of this AD is addressed in Luftahrt-
Bundesamt (Germany) AD 1997-144/3, effective May 11, 1998.
Issued in Fort Worth, Texas, on November 12, 1998.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 98-30788 Filed 11-18-98; 8:45 am]
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