Airworthiness Directives; Bell Helicopter Textron, Inc. Model 205A-1 and 205B Helicopters

[Federal Register Volume 64, Number 106 (Thursday, June 3, 1999)]
[Proposed Rules]
[Pages 29814-29817]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-13998]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-72-AD]


Airworthiness Directives; Bell Helicopter Textron, Inc. Model 
205A-1 and 205B Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to Bell Helicopter Textron, Inc. 
(BHTI) Model 205A-1 and 205B helicopters. This proposal would require 
inspecting the vertical fin spar cap (spar cap) for cracking, 
corrosion, or disbonding, and modifying the vertical fin and replacing 
the left-hand spar cap. This proposal is prompted by 5 accidents 
involving helicopters of similar type design. The actions specified by 
the proposed AD are intended to detect fatigue cracking or corrosion on 
the spar cap, which could lead to 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 August 2, 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-72-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., 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, 
FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 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

[[Page 29815]]

Docket No. 98-SW-72-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-72-AD, 2601 Meacham Blvd., Room 663, 
Fort Worth, Texas 76137.

Discussion

    This document proposes the adoption of a new AD that is applicable 
to BHTI Model 205A-1 and 205B helicopters. This proposal would require:

--Visually inspecting the spar cap for any crack or disbonding;
--Inspecting the spar cap for any disbonding using a tap hammer;
--Modifying the vertical fin;
--After modifying the vertical fin, inspecting the spar cap for any 
cracks using a dye-penetrant inspection method; and
--Replacing the left-hand spar cap.

    This proposal is prompted by 5 accidents involving helicopters of 
similar type design. The actions specified by the proposed AD are 
intended to detect fatigue cracking or corrosion on the spar cap, which 
could lead to failure of the vertical fin spar, loss of the tail rotor, 
and subsequent loss of control of the helicopter.

    The FAA has reviewed the following alert service bulletins:

--BHTI Alert Service Bulletin (ASB) 205-98-70, Revision A, dated 
September 21, 1998, which is applicable to Model 205A-1 helicopters; 
and
--BHTI ASB 205B-98-26, Revision A, dated September 21, 1998, which is 
applicable to Model 205B helicopters.

    Both describe procedures for inspecting the vertical fin spar for 
cracks or disbonding, and replacing the vertical fin spar cap if a 
crack or disbonding is found.

    Since an unsafe condition has been identified that is likely to 
exist or develop on other BHTI Model 205A-1 and 205B helicopters of the 
same type design, the proposed AD would require:

--Visually inspecting the spar cap for any crack or disbonding;
--Inspecting the spar cap for any crack or disbonding using a tap 
hammer;
--Modifying the vertical fin;
--After modifying the vertical fin, inspecting the spar cap for any 
cracks using a dye-penetrant inspection method; and
--Replacing the left-hand spar cap.
    The actions would be required to be accomplished in accordance with 
the service bulletins described previously.

    The FAA estimates that 150 helicopters of U.S. registry would be 
affected by this proposed AD, that it would take approximately 4 work 
hours per helicopter to accomplish the initial inspections, 0.5 work 
hour for the repetitive inspections, and 180 hours to replace the 
vertical fin spar assembly, and that the average labor rate is $60 per 
work hour. Required parts would cost approximately $300 per helicopter. 
Based on these figures, the total cost impact of the proposed AD on 
U.S. operators is estimated to be $1,705,500 to conduct the initial 
inspection and one repetitive inspection, and replace the vertical fin 
spar assembly on all the 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 adding a new airworthiness directive 
to read as follows:

Bell Helicopter Textron, Inc.: Docket No. 98-SW-72-AD.

    Applicability: Model 205A-1 helicopters with vertical fin spar 
cap, part number (P/N) 212-030-447-001 or -101, installed, and Model 
205B helicopters with vertical fin spar cap, P/N 212-030-447-101, 
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 (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 failure of the vertical fin (fin) spar, loss of the 
tail rotor, and subsequent loss of control of the helicopter, 
accomplish the following:
    (a) For Model 205A-1 helicopters with a fin spar cap (spar cap), 
P/N 212-030-447-001, installed, accomplish the following:
    (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 4 of Bell Helicopter Textron, Inc. 
Alert Service Bulletin No. 205-98-70, Revision A, dated September 
21, 1998 (ASB).
    (i) If a crack is discovered on the fin 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 inspecting, apply MIL-PRF-81352 clear lacquer or an 
equivalent coating to the area where the paint and primer were 
removed. Spray, brush, or wipe on a protective coat of MIL-C-16173, 
Grade 2, or equivalent compound, over the clear lacquer or 
equivalent coating.
    (iii) Install the inspection door, intermediate gearbox cover, 
and tail rotor driveshaft cover.
    (2) After initially modifying and inspecting the fin, 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 the ASB.
    (ii) If a crack is discovered on the fin spar, replace the fin 
spar cap or spar assembly with airworthy parts before further 
flight. Repair any corrosion or disbonding discovered during the 
inspection before further flight.

[[Page 29816]]

    (iii) After inspecting, accomplish Part I (A2), paragraphs 5 and 
6 of the ASB.
    (3) Within 25 hours TIS, inspect and modify the fin assembly as 
follows:
    (i) Accomplish Part II (C1), paragraph 1 of the ASB.
    (ii) Remove the clip, part number (P/N) 212-030-099-091, and 
radius block, P/N 212-030-099-095, if existing. Remove the retainer, 
P/N 212-030-121-037, and sufficient rivets from the bottom row of 
the forward left-hand fin skin to allow trimming of the forward 
left-hand skin along the skin ``cutline'', approximately fin station 
66.31 (see Figure 2 of the ASB).
    (iii) Before drilling or reaming, inspect all holes in the spar 
cap where rivets were removed for short edge distance. If an 
existing edge distance will be less than 1.5 times the diameter of 
the drill or reamed hole, repairs must be performed and must be FAA 
approved before proceeding.
    (iv) Accomplish Part II (C1), paragraphs 3, 4, and 6 in the ASB.
    (v) If a crack is discovered on the fin spar, replace the fin 
spar cap or spar assembly with airworthy parts before further 
flight. Repair any corrosion or disbonding discovered during the 
inspection before further flight.
    (vi) Accomplish Part II (C1), paragraphs 10 through 14 of the 
ASB.
    (4) After initially modifying and dye-penetrant inspecting the 
fin spar, inspect the fin spar at intervals not to exceed 300 hours 
TIS as follows:
    (i) Accomplish Part II (C2), paragraphs 1, 2, 3, 4, 5, and 7 of 
the ASB.
    (ii) If a crack is discovered on the fin spar, replace the fin 
spar cap or spar assembly with airworthy parts before further 
flight. Repair any corrosion or disbonding discovered during the 
inspection before further flight.
    (iii) Accomplish Part II (C2), paragraphs 11 through 14 of the 
ASB.
    (5) Within 12 calendar months, remove the left-hand fin spar 
cap, P/N 212-030-447-001. Replace it with an airworthy fin spar cap 
or spar assembly 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.
    (6) Installation of a fin spar cap or assembly that has been 
approved by the Manager, Rotorcraft Standards Staff, constitutes 
terminating action for the requirements of this AD.
    (b) For Model 205A-1, helicopters with a fin spar cap, P/N 212-
030-447-101, installed, accomplish the following:
    (1) Within 8 hours TIS, modify the vertical fin and visually 
inspect the fin spar for cracks in accordance with Part II (A1), 
paragraphs 1 through 5 of the ASB.
    (i) If a crack is discovered on the fin spar, replace the fin 
spar cap or assembly with an airworthy parts before further flight. 
Repair any corrosion or disbonding discovered during the inspection 
before further flight.
    (ii) After inspecting, apply MIL-PRF-81352 clear lacquer or an 
equivalent coating to 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 compound, over 
the clear lacquer or equivalent coating. To facilitate subsequent 
inspections, do not replace the two lower rivets (see Figure 2 of 
the ASB).
    (iii) Before drilling or reaming, inspect all holes in the spar 
cap where rivets were removed for short edge distance. If an 
existing edge distance will be less than 1.5 times the diameter of 
the drill or reamed hole, repairs must be performed and must be FAA 
approved before proceeding.
    (iv) Fasten the forward left-hand fin skin and the retainer, P/N 
212-030-121-037, to the spar assembly using Hi-Loks and blind rivets 
as specified in Figure 2 of the ASB. Reinstall the clip and radius 
block, if existing, that were removed in accordance with paragraph 2 
of Part II (A1) of the ASB.
    (v) Refinish the reworked area.
    (vi) Install the inspection door, intermediate gearbox cover, 
and tail rotor driveshaft cover.
    (2) After initially modifying and inspecting the fin, inspect 
the fin spar for cracks at intervals not to exceed 8 hours TIS as 
follows:
    (i) Accomplish Part II (A2), paragraphs 1 through 3 of the ASB.
    (ii) If a crack is discovered on the fin spar, replace the fin 
spar cap or assembly with airworthy parts before further flight. 
Repair any corrosion or disbonding discovered during the inspection 
before further flight.
    (iii) After inspecting, accomplish Part II (A2), paragraphs 5 
and 6, of the ASB.
    (3) Within 25 hours TIS, modify and inspect the vertical fin as 
follows:
    (i) Accomplish Part II (C1), paragraph 1 of the ASB.
    (ii) Remove the clip, P/N 212-030-099-091, and radius block, P/N 
212-030-099-095, if existing. Remove the retainer, P/N 212-030-121-
037, 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'', approximately fin station 66.31 (see 
Figure 2 of the ASB).
    (iii) Before drilling or reaming, inspect all holes in the spar 
cap where rivets were removed for short edge distance. If an 
existing edge distance will be less than 1.5 times the diameter of 
the drill or reamed hole, repairs must be performed and must be FAA 
approved before proceeding.
    (iv) Accomplish Part II (C1), paragraphs 3, 4, and 6 of the ASB.
    (v) If a crack is discovered on the fin spar, replace the fin 
spar cap or assembly with airworthy parts before further flight. 
Repair any corrosion or disbonding discovered during the inspection 
before further flight.
    (vi) Accomplish Part II (C1), paragraphs 10 through 14 of the 
ASB.
    (4) After initially modifying and dye-penetrant inspecting the 
fin spar, inspect the fin spar at intervals not to exceed 300 hours 
TIS as follows:
    (i) Accomplish Part II (C2), paragraphs 1 through 7 of the ASB.
    (ii) If a crack is discovered on the fin spar, replace the fin 
spar cap or assembly with airworthy parts before further flight. 
Repair any corrosion or disbonding discovered during the inspection 
before further flight.
    (iii) Accomplish Part II (C2), paragraphs 11 through 14 of the 
ASB.
    (5) Within 25 hours TIS, and thereafter at intervals not to 
exceed 300 hours TIS, inspect the fin spar as follows:
    (i) Accomplish Part II (B), paragraphs 1 through 13 of the ASB.
    (ii) Repair any disbonding discovered during the inspection 
before further flight.
    (6) Within 12 calendar months, remove the left-hand fin spar 
cap, P/N 212-030-447-101. Replace it with an airworthy fin spar cap 
or spar assembly 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 fin spar that has been approved by the 
Manager, Rotorcraft Standards Staff, that satisfies the requirements 
of paragraph (b)(6) of this AD constitutes terminating action for 
the requirements of this AD.
    (c) For Model 205B helicopters with a fin spar cap, P/N 212-030-
447-101, installed, accomplish the following:
    (1) Within 8 hours TIS, modify the fin and visually inspect the 
fin spar for cracks in accordance with Part I (A1), paragraphs 1 
through 5 of Bell Helicopter Textron, Inc. Alert Service Bulletin 
No. 205B-98-26, Revision A, dated September 21, 1998 (205B ASB).
    (i) If a crack is discovered on the fin spar, replace the fin 
spar cap or assembly with airworthy parts before further flight. 
Repair any corrosion or disbonding discovered during the inspection 
before further flight.
    (ii) After inspecting, apply MIL-PRF-81352 clear lacquer or an 
equivalent coating to 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 compound, 
over the clear lacquer. To facilitate subsequent inspections, do not 
replace the two lower rivets (see Figure 2 of the 205B ASB).
    (iii) Before drilling or reaming, inspect all holes in the spar 
cap where rivets were removed for short edge distance. If an 
existing edge distance will be less than 1.5 times the diameter of 
the drill or reamed hole, repairs must be performed and must be FAA 
approved before proceeding.
    (iv) Fasten the forward left-hand fin skin and the retainer, P/N 
212-030-121-037, to the spar assembly using Hi-Loks and blind rivets 
as specified in Figure 2 of the 205B ASB. Reinstall the clip and 
radius block, if existing, removed in paragraph 2 of Part I (A1) of 
the 205B ASB.
    (v) Install the inspection door, intermediate gearbox cover, and 
tail rotor driveshaft cover.
    (2) After initially modifying and inspecting the fin, 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 the 205B 
ASB.
    (ii) If a crack is discovered on the spar, replace the fin spar 
cap or assembly with airworthy parts before further flight. Any 
corrosion or disbonding discovered during the inspection must be 
repaired before further flight.

[[Page 29817]]

    (iii) After inspecting, accomplish Part I (A2), paragraphs 5 and 
6 of the 205B ASB.
    (3) Within 25 hours TIS, modify and inspect the fin as follows:
    (i) Accomplish Part I (C1), paragraph 1 of the 205B ASB.
    (ii) Remove the clip, P/N 212-030-099-091, and radius block, P/N 
212-030-099-095, if existing. Remove the retainer, P/N 212-030-121-
037, 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'', approximately fin station 66.31 (see 
Figure 2 of the 205B ASB).
    (iii) Before drilling or reaming, inspect all holes in the spar 
cap where rivets were removed for short edge distance. If an 
existing edge distance will be less than 1.5 times the diameter of 
the drill or reamed hole, repairs must be performed and must be FAA 
approved before proceeding.
    (iv) Accomplish Part I (C1), paragraphs 3, 4, and 6 in the 205B 
ASB.
    (v) If a crack is discovered on the spar, replace the fin spar 
cap or assembly with airworthy parts before further flight. Any 
corrosion or disbonding discovered during the inspection must be 
repaired before further flight.
    (vi) Accomplish Part I (C1), paragraphs 10 through 14 of the 
205B ASB.
    (4) After initially modifying and dye-penetrant inspecting the 
fin spar, inspect the fin spar at intervals not to exceed 300 hours 
TIS as follows:
    (i) Accomplish Part I (C2), paragraphs 1, 2, 3, 4, 5, and 7 of 
the 205B ASB.
    (ii) If a crack is discovered on the spar, replace the fin spar 
cap or assembly with airworthy parts before further flight. Any 
corrosion or disbonding discovered during the inspection must be 
repaired before further flight.
    (iii) Accomplish Part I (C2), paragraphs 11 through 14 of the 
205B ASB.
    (5) Within 25 hours TIS, inspect the fin spar at intervals not 
to exceed 300 hours TIS as follows:
    (i) Accomplish Part I (B), paragraphs 1 through 13 of the 205B 
ASB.
    (ii) Any disbonding discovered during the inspection must be 
repaired before further flight.
    (6) Within 12 calendar months, remove the left-hand fin spar 
cap, P/N 212-030-447-101. Replace it with an airworthy fin spar cap 
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 fin spar that satisfies the above 
requirements and has been approved by the Manager, Rotorcraft 
Standards Staff, constitutes a terminating action for the 
requirements of this AD.
    (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, Rotorcraft Standards Staff, 
Rotorcraft Directorate, FAA. Operators shall submit their requests 
through a 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.

    (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 helicopter to a location where 
the requirements of this AD can be accomplished.

    Issued in Fort Worth, Texas, on May 25, 1999.
Henry A. Armstrong,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. 99-13998 Filed 6-2-99; 8:45 am]
BILLING CODE 4910-13-P