Airworthiness Directives; Bell Helicopter Textron, Inc. Model 204B, 205A, and 205A-1 Helicopters

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-SW-73-AD; Amendment 39-11252; AD 99-17-03]

RIN 2120-AA64

Airworthiness Directives; Bell Helicopter Textron, Inc. Model

204B, 205A, and 205A-1 Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive

(AD), applicable to Bell Helicopter Textron, Inc. (BHTI) Model 204B,

205A, and 205A-1 helicopters, that currently requires modifying and

inspecting the vertical fin spar (fin spar) for cracks. This amendment

requires modification and visual and dye-penetrant inspections of the

fin spar for cracks, and if a crack is discovered, replacing the fin

spar. A tapping test for disbonding and replacing certain fin spars

within 12 calendar months is also required. This amendment is prompted

by an accident involving a Model 205A-1 helicopter and four other

accidents involving helicopters of similar type design. The actions

specified by this AD are intended to prevent failure of the fin spar,

loss of the tail rotor, and subsequent loss of control of the

helicopter.

DATES: Effective September 16, 1999.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of September 16, 1999.

ADDRESSES: The service information referenced in this AD 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; or

at the Office of the Federal Register, 800 North Capitol Street, NW.,

suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) by superseding AD 97-18-11,

Amendment 39-10520 (63 FR 26429), applicable to BHTI Model 204B, 205A,

and 205A-1 helicopters, was published in the Federal Register on May

26, 1999 (64 FR 28420). That action proposed to require initial and

repetitive inspections of the fin spar for cracks. Also proposed was a

requirement to replace the fin spar within 12 calendar months.

Replacing the fin spar with a FAA-approved fin spar configuration that

satisfies the structural fatigue requirement of repeated high torque

events would constitute a terminating action for the requirements of

the AD. That action was prompted by an accident involving a Model 205A-

1 helicopter and four other accidents involving helicopters of similar

type design.

Interested persons have been afforded an opportunity to participate

in the making of this amendment. No comments were received on the

proposal or the FAA's determination of the cost to the public. The FAA

has determined that air safety and the public interest require the

adoption of the rule as proposed.

The FAA estimates that 150 helicopters of U.S. registry will be

affected by this AD, that it will take approximately 8 work hours per

helicopter to accomplish the initial inspection and 0.5 work hour to

accomplish each repetitive inspection. Replacing the fin spar will 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 fin spars

on the entire fleet.

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.

For the reasons discussed above, I certify that this action (1) is

not a ``significant regulatory action'' under Executive Order 12866;

(2) is not a ``significant rule'' under DOT Regulatory Policies and

Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action

and it is contained in the Rules Docket. A copy of it 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 39-10520 (63 FR

26429, May 13, 1998), and by adding a new airworthiness directive (AD),

Amendment 39-11252, to read as follows:

AD 99-17-03 Bell Helicopter Textron, Inc.: Amendment 39-11252.

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:

[[Page 43906]]

(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.

(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

Manger, 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

[[Page 43907]]

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.

(e) The inspections and modifications shall be done in

accordance with Bell Helicopter Textron, Inc. Alert Service Bulletin

204B-98-50, dated October 22, 1998; 205-98-71, Revision A, dated

September 21, 1998; or 205-98-73, dated September 25, 1998, as

applicable. These incorporations by reference were 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 Bell Helicopter

Textron, Inc., P.O. Box 482, Fort Worth, Texas 76101, telephone

(817) 280-3391, fax (817) 280-6466. 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.

(f) This amendment becomes effective on September 16, 1999.

Issued in Fort Worth, Texas, on August 4, 1999.

Henry A. Armstrong,

Manager, Rotorcraft Directorate, Aircraft Certification Service.

[FR Doc. 99-20754 Filed 8-11-99; 8:45 am]

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