[Federal Register Volume 64, Number 101 (Wednesday, May 26, 1999)]
[Proposed Rules]
[Pages 28420-28422]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-13319]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-SW-73-AD]
Airworthiness Directives; Bell Helicopter Textron, Inc. Model
204B, 205A, and 205A-1 Helicopters
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to Bell Helicopter Textron,
Inc. (BHTI) Model 204B, 205A, and 205A-1 helicopters, that currently
requires modification and inspections of the vertical fin spar for
cracks. This action would require modification and visual and dye-
penetrant inspections of the vertical fin spar for cracks, and if a
crack is discovered, replacing the vertical fin spar. This action would
also require a tapping test for disbonding and replacing certain fin
spars within 12 calendar months. This proposal is prompted by an
accident involving a Model 205A-1 helicopter and 4 other accidents
involving helicopters of similar type design. The actions specified by
the proposed AD are intended to prevent failure of the vertical fin
spar, loss of the tail rotor, and subsequent loss of control of the
helicopter.
DATES: Comments must be received on or before July 26, 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-73-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137. Comments may be inspected at this location
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal
holidays.
The service information referenced in the proposed rule may be
obtained from Bell Helicopter Textron, Inc., P.O. Box 482, Fort Worth,
Texas 76101, telephone (817) 280-3391, fax (817) 280-6466. This
information may be examined at the FAA, Office of the Regional Counsel,
Southwest Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas.
FOR FURTHER INFORMATION CONTACT: Harry Edmiston, Aerospace Engineer,
Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 2601
Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5158, fax
(817) 222-5783.
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 summarizing 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. 98-SW-73-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, Office of the Regional Counsel, Southwest Region,
Attention: Rules Docket No. 98-SW-73-AD, 2601 Meacham Blvd., Room 663,
Fort Worth, Texas 76137.
Discussion:
On May 4, 1998, the FAA issued AD 97-18-11, Amendment 39-10520 (63
FR 26429, May 13, 1998), to require modifying and inspecting the
vertical fin spar, and replacing it if a crack is found. That action
was prompted by several failures of the vertical fin spar, including
those with steel doublers, caused by fatigue cracks that result from a
large number of high-power events. The requirements of that AD are
intended to prevent failure of the vertical fin spar and subsequent
loss of control of the helicopter.
Since the issuance of that AD, there have been 4 additional
accidents involving models similar in type design to the Model 205A-1
helicopter that were caused by fatigue failure of the vertical fin
spar. The manufacturer has issued BHTI Alert Service Bulletin (ASB)
205-98-71, Revision A, dated September 21, 1998, which specifies
inspections of the vertical fin spar for cracks, and BHTI ASB No. 205-
98-73, dated September 25, 1998, which specifies replacing the vertical
fin spar assembly, part number (P/N) 205-030-899-101, 205-030-846-087
or -089, and P/N 205-032-851-003, -007, and -009, for the Model 205A
and 205A-1 helicopters. Also, the manufacturer has issued BHTI ASB No.
204B-98-50, dated October 22, 1998, which specifies inspections of the
fin spar for cracks, and replacing the fin spar assembly, P/N 205-030-
846-001, -003, -047, -049, and P/N 205-030-899-001, -089, and P/N 204-
030-825-063, -065. The FAA has further determined that the vertical fin
spar must be replaced within 12 calendar months to ensure public
safety.
Since an unsafe condition has been identified that is likely to
exist or develop on other Model 204B, 205A, and 205A-1 helicopters of
the same type design, the proposed AD would supersede AD 97-18-11 to
require initial and repetitive inspections of the vertical fin spar for
cracks. Also, replacing the vertical fin spar would be required within
12 calendar months. Replacing the vertical fin spar with a FAA-approved
vertical fin spar configuration that satisfies the structural fatigue
requirement of repeated high torque events would constitute a
terminating action for the requirements of this AD.
The FAA estimates that 150 helicopters of U.S. registry would be
affected by this proposed AD, that it would take approximately 8 work
hours per helicopter to accomplish the initial inspection and 0.5 work
hour to accomplish each repetitive inspection. Replacing the vertical
fin spar would
[[Page 28421]]
take approximately 150 work hours. The average labor rate is $60 per
work hour. The manufacturer has stated that parts will be provided at
no cost. Based on these figures, the total cost impact of the proposed
AD on U.S. operators is estimated to be $76,500 for the initial
inspection and one repetitive inspection, and $1,350,000 to replace the
vertical fin spars on the entire fleet.
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 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 proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the 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 is contained 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
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 39-10520 (63 FR
26429, May 13, 1998), and by adding a new airworthiness directive (AD),
to read as follows:
Bell Helicopter Textron, Inc.: Docket No. 98-SW-73-AD. Supersedes AD
97-18-11, Amendment 39-10520, Docket No. 97-SW-32-AD.
Applicability: Model 204B helicopters with vertical fin spar
(fin spar), part number (P/N) 205-030-899-001, -089, P/N 205-030-
846-001, -003, -047,- 049, or P/N 204-030-825-063, -065, installed,
and Model 205A and 205A-1 helicopters, with fin spar, P/N 205-030-
899-101, P/N 205-030-846-087, -089, or P/N 205-032-851-003, -007, -
009, installed, certificated in any category.
Note 1: This AD applies to each helicopter 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 helicopters 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 (c) 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 fin spar, loss of the tail rotor, and
subsequent loss of control of the helicopter, accomplish the
following:
(a) For Model 204B helicopters:
(1) Within 8 hours time-in-service (TIS), modify the vertical
fin and visually inspect the fin spar for cracks in accordance with
Part I (A1), paragraphs 1 through 5 of Bell Helicopter Textron
(BHTI) Alert Service Bulletin (ASB) 204B-98-50, dated October 22,
1998.
(i) If a crack is discovered on the spar, replace the fin spar
assembly with an airworthy fin spar assembly before further flight.
Repair any corrosion or disbonding discovered during the inspection
before further flight.
(ii) After inspection, apply MIL-PRF-81352 TYI clear lacquer or
equivalent to the inside of the two lower rivet holes and on the
surface where paint and primer were removed. Spray, brush or wipe on
a protective coat of MIL-C-16173, Grade 2, or equivalent, over the
clear lacquer. To facilitate subsequent inspections do not replace
the two lower rivets. See Figure 2 of BHTI ASB 204B-98-50, dated
October 22, 1998.
Note 2: BHTI-MED-SRM-1, pages 3-36 through 3-38, pertain to the
installation of Hi-Loks.
(iii) Before drilling or reaming, inspect all holes in the spar
cap where rivets were removed for short edge distance. An existing
edge distance less than 1.5 times the diameter of the drill or
reamed hole must have FAA approval of the reworked area before
proceeding.
(iv) Fasten the forward left-hand fin skin to the spar assembly
using Hi-Loks and blind rivets as specified in Figure 2 of BHTI ASB
204B-98-50, dated October 22, 1998.
(v) Refinish the reworked area.
(2) After initial modification and inspection of the fin,
thereafter inspect the fin spar for cracks at intervals not to
exceed 8 hours TIS as follows:
(i) Accomplish Part I (A2), paragraphs 1 through 3 of BHTI ASB
204B-98-50, dated October 22, 1998.
(ii) If a crack is discovered on the spar, replace the fin spar
assembly with an airworthy fin spar assembly before further flight.
Repair any corrosion or disbonding discovered during the inspection
before further flight.
(iii) After inspection, accomplish Part I (A2), paragraphs 5 and
6 of BHTI ASB 204B-98-50, dated October 22, 1998.
(3) Within 25 hours TIS, modify and inspect the vertical fin as
follows:
(i) Accomplish Part I (C1), paragraph 1 of BHTI ASB 204B-98-50,
dated October 22, 1998.
(ii) Remove sufficient rivets from the bottom row of the forward
left-hand fin skin to allow trimming of the forward left-hand fin
skin along the ``skin cutline'', approximately fin station 64.31
(see Figure 2 of BHTI ASB 204B-98-50, dated October 22, 1998).
(iii) Before drilling or reaming, inspect all holes in the spar
cap where rivets were removed for short edge distance. An existing
edge distance less than 1.5 times the diameter of the drill or
reamed hole must have FAA approval of the reworked area before
proceeding.
(iv) Accomplish Part I (C1), paragraphs 3, 4, and 6 of BHTI ASB
204B-98-50, dated October 22, 1998.
(v) If a crack is discovered on the spar, replace the fin spar
assembly with an airworthy fin spar assembly before further flight.
Repair any corrosion or disbonding discovered during the inspection
before further flight.
(vi) Accomplish Part I (C1), paragraphs 10 through 14 of BHTI
ASB 204B-98-50, dated October 22, 1998.
(4) After the initial modification and dye-penetrant inspection
of the fin spar, thereafter at intervals not to exceed 300 hours
TIS, inspect the fin spar as follows:
(i) Accomplish Part I (C2), paragraphs 1, 2, 3, 4, 5, and 7 of
BHTI ASB 204B-98-50, dated October 22, 1998.
(ii) If a crack is discovered on the spar, replace the fin spar
assembly with an airworthy fin spar assembly before further flight.
Repair any corrosion or disbonding discovered during the inspection
before further flight.
(iii) Accomplish Part I (C2), paragraphs 11 through 14 of BHTI
ASB 204B-98-50, dated October 22, 1998.
(5) Within 25 hours TIS, and thereafter at intervals not to
exceed 300 hours TIS, inspect the fin spar as follows:
(i) Accomplish Part I (B), paragraphs 1 through 13 of BHTI ASB
204B-98-50, dated October 22, 1998.
(ii) Repair any disbonding discovered during the inspection
before further flight.
[[Page 28422]]
(6) Within 12 calendar months, remove fin spar P/N 205-030-899-
001, or -089, or P/N 205-030-846-001, -003, -047, or -049, or P/N
204-030-825-063, or -065. Replace it with an airworthy fin spar
configuration that has been demonstrated to the FAA to satisfy the
structural fatigue requirements of repeated high torque events and
is approved by the Manager, Rotorcraft Standards Staff.
(7) Installation of a replacement fin spar approved by the
Manager, Rotorcraft Standards Staff, constitutes a terminating
action for the requirements of this AD.
(b) For Model 205A and 205A-1 helicopters:
(1) Within 8 hours TIS, modify the vertical fin and visually
inspect the fin spar for cracks in accordance with Part I (A1),
paragraphs 1 through 5 of BHTI ASB 205-98-71, Revision A, dated
September 21, 1998.
(i) If a crack is discovered on the spar, replace the fin spar
assembly with an airworthy fin spar assembly before further flight.
Repair any corrosion or disbonding discovered during the inspection
before further flight.
(ii) After inspection, apply MIL-PRF-81352 TYI clear lacquer or
equivalent to the inside of the two lower rivet holes and on the
surface where paint and primer were removed. Spray, brush, or wipe
on a protective coat of MIL-C-16173, Grade 2, or equivalent, over
the clear lacquer. To facilitate subsequent inspections do not
replace the two lower rivets. See figure 2 of BHTI ASB 205-98-71,
Revision A, dated September 21, 1998.
(iii) Before drilling or reaming, inspect all holes in the spar
cap where rivets were removed for short edge distance. An existing
edge distance less than 1.5 times the diameter of the drill or
reamed hole must have FAA approval of the reworked area before
proceeding.
(iv) Fasten the forward left-hand fin skin and the retainer, P/N
205-032-851-045, to the fin spar assembly using Hi-Loks and blind
rivets as specified in Figure 2 of BHTI ASB 205-98-71, Revision A,
dated September 21, 1998. Reinstall clip and radius block (if
existing) removed in paragraph 2 of Part 1 (A1) of BHTI ASB 205-98-
71, Revision A, dated September 21, 1998.
(v) Refinish the reworked area.
(2) After initial modification and inspection of the vertical
fin, thereafter, inspect the fin spar for cracks at intervals not to
exceed 8 hours TIS as follows:
(i) Accomplish Part I (A2), paragraphs 1 through 3 of BHTI ASB
205-98-71, Revision A, dated September 21, 1998.
(ii) If a crack is discovered on the spar, replace the fin spar
assembly with an airworthy fin spar assembly before further flight.
Repair any corrosion or disbonding discovered during the inspection
before further flight.
(iii) After inspection, accomplish Part I (A2), paragraphs 5 and
6, of BHTI ASB 205-98-71, Revision A, dated September 21, 1998.
(3) Within 25 hours TIS, modify and inspect the vertical fin as
follows:
(i) Accomplish Part I (C1), paragraph 1 of BHTI ASB 205-98-71,
Revision A, dated September 21, 1998.
(ii) Remove the clip, P/N 212-030-099-091, and radius block, P/N
212-030-099-095, if present. Remove the retainer, P/N 205-032-851-
045, and sufficient rivets from the bottom row of the forward left-
hand fin skin to allow trimming of the forward left-hand fin skin
along the ``skin cutline'', at approximately Fin Station 66.31 (see
Figure 2 of BHTI ASB 205-98-71, Revision A, dated September 21,
1998).
(iii) Before drilling or reaming, inspect all holes in the spar
cap where rivets were removed for short edge distance. An existing
edge distance less than 1.5 times the diameter of the drill or
reamed hole must have FAA approval of the reworked area before
proceeding.
(iv) Accomplish Part I (C1), paragraphs 3, 4, and 6 in BHTI ASB
205-98-71, Revision A, dated September 21, 1998.
(v) If a crack is discovered on the spar, replace the fin spar
assembly with an airworthy fin spar assembly before further flight.
Repair any corrosion or disbonding discovered during the inspection
before further flight.
(vi) Accomplish Part I (C1) paragraphs 10 through 14 of BHTI ASB
205-98-71, Revision A, dated September 21, 1998.
(4) After the initial modification and dye-penetrant inspection
of the fin spar, thereafter, at intervals not to exceed 300 hours
TIS, inspect the fin spar as follows:
(i) Accomplish Part I (C2), paragraphs 1, 2, 3, 4, 5, and 7 of
BHTI ASB 205-98-71, Revision A, dated September 21, 1998.
(ii) If a crack is discovered on the spar, replace the fin spar
assembly with an airworthy fin spar assembly before further flight.
Repair any corrosion or disbonding discovered during the inspection
before further flight.
(iii) Accomplish Part I (C2), paragraphs 11 through 14 of ASB
205-98-71, Revision A, dated September 21, 1998.
(5) Within 25 hours TIS, and thereafter at intervals not to
exceed 300 hours TIS inspect the fin spar as follows:
(i) Accomplish Part I (B), paragraphs 1 through 13 of BHTI ASB
205-98-71, Revision A, dated September 21, 1998.
(ii) Repair any disbonding discovered during the inspection
before further flight.
(6) Within 12 calendar months, remove fin spar, P/N 205-030-899-
001, or -089, or P/N 205-030-846-087, or -089, or P/N 205-032-851-
003, -007, or -009. Replace it with an airworthy fin spar
configuration that has been demonstrated to the FAA to satisfy the
structural fatigue requirements of repeated high torque events and
is approved by the Manager, Rotorcraft Standards Staff, or replace
it with fin spar assembly, P/N 205-530-514-103, as specified in BHTI
ASB 205-98-73, dated September 25, 1998.
(7) Installing fin spar, P/N 205-530-514-103, or a fin spar that
has been approved by the Manager, Rotorcraft Standards Staff,
constitutes terminating action for the requirements of this AD.
(c) 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 Certification Office. Operators shall submit their
requests through a FAA Principal Maintenance Inspector, who may
concur or comment and then send it to the Manager, Rotorcraft
Certification Office.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Rotorcraft Certification Office.
(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 helicopter to a location where
the requirements of this AD can be accomplished.
Issued in Fort Worth, Texas, on May 18, 1999.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-13319 Filed 5-25-99; 8:45 am]
BILLING CODE 4910-13-P
