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

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]

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