[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