Federal Register / Vol. 63, No. 92 /Wednesday, May 13, 1998 /Rules and Regulations 26439

(e) This amendment becomes effective

on May 28, 1998, to all persons except

those persons to whom it was made

immediately effective by Priority Letter

AD 97–18–11, issued August 29, 1997,

which contained the requirements of

this amendment.

Issued in Fort Worth, Texas, on May 4,

1998.

Eric Bries.

Acting Manager, Rotorcraft Directorate,

Aircraft Certification Service.

[FR Doc. 98–12508 Filed 5–12–98; 8:45 am]

BILLING CODE 4910–13–C

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–SW–35–AD; Amendment

39–10521; AD 97–20–09]

RIN 2120–AA64

Airworthiness Directives; Bell

Helicopter Textron (Bell)-manufactured

Model HH–1K, TH–1F, TH–1L, UH–1A,

UH–1B, UH–1E, UH–1F, UH–1H, UH–1L,

and UH–1P Helicopters; and

Southwest Florida Aviation SW204,

SW204HP, SW205, and SW205A–1

Helicopters

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment supersedes

an existing priority letter airworthiness

directive (AD), applicable to Bellmanufactured Model HH–1K, TH–1F,

TH–1L, UH–1A, UH–1B, UH–1E, UH–

1F, UH–1H, UH–1L, and UH–1P

helicopters; and Southwest Florida

Aviation SW204, SW204HP, and SW205

helicopters, that currently requires

modification and inspections of the

vertical fin spar. This amendment

requires the same modification and

inspections required by the existing

priority letter AD, but adds the

Southwest Florida Aviation Model

SW205A–1 and Utah State University

UH–1H helicopters to the applicability

of this AD. This amendment is

prompted by accidents involving inflight failure of the tailboom vertical fin

spar. The actions specified by this AD

are intended to prevent in-flight failure

of the vertical fin spar and subsequent

loss of control of the helicopter.

DATES: Effective May 28, 1998.

Comments for inclusion in the Rules

Docket must be received on or before

July 13, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Office of the

Regional Counsel, Southwest Region,

Attention: Rules Docket No. 97–SW–35–

AD, 2601 Meacham Blvd., Room 663,

Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Mr.

Charles Harrison, Aerospace Engineer,

FAA, Rotorcraft Directorate, Rotorcraft

Certification Office, 2601 Meacham

Blvd., Fort Worth, Texas 76137,

telephone (817) 222–5447, fax (817)

222–5960.
26440 Federal Register / Vol. 63, No. 92 /Wednesday, May 13, 1998 /Rules and Regulations

SUPPLEMENTARY INFORMATION: On

September 17, 1997, the FAA issued

priority letter AD 97–20–09, applicable

to Bell-manufactured Model HH–1K,

TH–1F, TH–1L, UH–1A, UH–1B, UH–

1E, UH–1F, UH–1H, UH–1L, and UH–1P

helicopters; and Southwest Florida

Aviation SW204, SW204HP and SW205

helicopters, which requires

modification and inspections of the

vertical fin spar. That priority letter AD

was prompted by two accidents

involving in-flight failures of the

tailboom vertical fin spars (vertical fin

spars) on Model TH–lL and UH–1B

helicopters. One other accident

occurred on a Model 205A–1 helicopter

which is of similar type design. One of

the accidents resulted in a fatality. As a

result of those accident investigations,

the FAA determined that a large number

of high-power events can cause fatigue

cracks which will cause the vertical fin

spar to fail. This condition, if not

corrected, could result in in-flight

failure of the vertical fin spar and

subsequent loss of control of the

helicopter.

Since the issuance of that priority

letter AD, the FAA has determined that

additional helicopter models are

affected by the same unsafe condition.

Since an unsafe condition has been

identified that is likely to exist or

develop on other Bell-manufactured

Model HH–1K, TH–1F, TH–1L, UH–1A,

UH–1B, UH–1E, UH–1F, UH–1H, UH–

1L, and UH–1P helicopters; and

Southwest Florida Aviation SW204,

SW204HP, SW205, and SW205A–1

helicopters of a similar type design, this

AD supersedes priority letter AD 97–20–

09 to add the Model SW205A–1

helicopters and the Utah State

University UH–1H helicopters to the

applicability of this AD. The short

compliance time involved is required

because the previously described

critical unsafe condition can adversely

affect the structural integrity of the

helicopter. Therefore the inspections

and modification are required within 8

hours time-in-service and this AD must

be issued immediately.

Since a situation exists that requires

the immediate adoption of this

regulation, it is found that notice and

opportunity for prior public comment

hereon are impracticable, and that good

cause exists for making this amendment

effective in less than 30 days.

The FAA estimates that 68 helicopters

of U.S. registry would be affected by this

proposed AD, that it would take

approximately 2.5 work hours per

helicopter for the initial modification

and inspection, 200 work hours to

replace the vertical fin spar, and that the

average labor rate is $60 per work hour.

Required parts would cost

approximately $8,000 per helicopter to

replace the vertical fin spar. Based on

these figures, the total cost impact of the

proposed AD on U.S. operators is

estimated to be $1,370,200 to modify the

vertical fin, conduct an initial

inspection, and replace the vertical fin

spars on all helicopters in the U.S. fleet.

Comments Invited

Although this action is in the form of

a final rule that involves requirements

affecting flight safety and, thus, was not

preceded by notice and an opportunity

for public comment, comments are

invited on this rule. Interested persons

are invited to comment on this 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

under the caption ADDRESSES. All

communications received on or before

the closing date for comments will be

considered, and this rule may be

amended in light of the comments

received. Factual information that

supports the commenter’s ideas and

suggestions is extremely helpful in

evaluating the effectiveness of the AD

action and determining whether

additional rulemaking action would be

needed.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the rule that might suggest a need to

modify the 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 that

summarizes each FAA-public contact

concerned with the substance of this AD

will be filed in the Rules Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this rule must

submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket No. 97–SW–35–AD.’’ The

postcard will be date stamped and

returned to the commenter.

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.

The FAA has determined that this

regulation is an emergency regulation

that must be issued immediately to

correct an unsafe condition in aircraft,
Federal Register / Vol. 63, No. 92 /Wednesday, May 13, 1998 /Rules and Regulations 26441

and that it is not a ‘‘significant

regulatory action’’ under Executive

Order 12866. It has been determined

further that this action involves an

emergency regulation under DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979). If it is

determined that this emergency

regulation otherwise would be

significant under DOT Regulatory

Policies and Procedures, a final

regulatory evaluation will be prepared

and placed in the Rules Docket. A copy

of it, if filed, 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, 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.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding a new airworthiness directive

(AD), Amendment 39–10521, to read as

follows:

AD 97–20–09 California Department of

Forestry; Firefly Aviation Helicopter

Services (Previously Erickson Air Crane

Co.); Garlick Helicopters, Inc.; Hawkins

and Powers Aviation, Inc.; International

Helicopters, Inc.; Ranger Helicopter

Services; Robinson Aircrane; Scott

Paper Co.; Smith Helicopters; Southern

Helicopter; Southwest Florida Aviation;

Utah State University; Western

International Aviation, Inc.; UNC

Helicopters; and U.S. Helicopter, Inc.:

Amendment 39–10521. Docket No. 97–

SW–35–AD. Supersedes priority letter

AD 97–20–09.

Applicability: Model HH–1K (Type

Certificate Data Sheet (TCDS) H5NM), TH–lF

(TCDS H12NM, and R0008AT), TH–1L

(TCDS H5NM, H7SO, and H4NM), UH–1A

(TCDS H3SO), UH–1B (TCDS H1RM, H3NM,

H13WE, H3SO, H5SO, and R00012AT), UH–

1E (TCDS H5NM, H7SO, H8NM, and H4NM),

UH–1F (TCDS H2NM, H7NE, H11SW,

H12NM, and R0008AT), UH–1H (TCDS

H13WE, H3SO, and H15NM), UH–lL (TCDS

H5NM, H7SO, and H4NM), UH–1P (TCDS

H12NM, and R0008AT), and SW204 (TCDS

H6SO), SW204HP (TCDS H6SO), SW205

(TCDS H6SO), and SW205A–1 (TCDS H6SO)

helicopters, with tailboom vertical fin spar,

part number (P/N) 205–032–899, 205–030–

846, or 205–032–851, all dash numbers,

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

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 use the authority

provided in paragraph (d) to request approval

from the FAA. This approval may address

either no action, if the current configuration

eliminates the unsafe condition, or different

actions necessary to address the unsafe

condition described in this AD. Such a

request should include an assessment of the

effect of the changed configuration on the

unsafe condition addressed by this AD. In no

case does the presence of any modification,

alteration, or repair remove any helicopter

from the applicability of this AD.

Compliance: Required as indicated, unless

accomplished previously.

To prevent in-flight failure of the tailboom

vertical fin spar (vertical fin spar) and

subsequent loss of control of the helicopter,

accomplish the following:

(a) Within 8 hours time-in-service (TIS)

after the effective date of this AD, modify the

vertical fin spar as follows:

(1) Remove the 42° gearbox cover and open

the drive shaft cover on the vertical fin spar

assembly (see Figure 1).
26442 Federal Register / Vol. 63, No. 92 /Wednesday, May 13, 1998 /Rules and Regulations

(2) Remove the first four rivets from the

vertical fin spar located at the bottom of the

vertical fin spar left-hand side at the tailboom

and vertical fin spar junction, and the first

four rivets aft of the junction along the lower

edge of the vertical fin spar side-skin as

shown (see Figure 2).

Caution: Extreme care must be taken when

drilling and removing rivets from the side of

the vertical fin spar to ensure the vertical fin

spar assembly is not damaged.

BILLING CODE 4910–13–P
Federal Register / Vol. 63, No. 92 /Wednesday, May 13, 1998 /Rules and Regulations 26443

(3) Trim the vertical fin spar left-hand skin using extreme care to not damage the vertical fin spar assembly (see

Figure 3).
26444 Federal Register / Vol. 63, No. 92 /Wednesday, May 13, 1998 /Rules and Regulations

BILLING CODE 4910–13–C
Federal Register / Vol. 63, No. 92 /Wednesday, May 13, 1998 /Rules and Regulations 26445

(4) Deburr the rivet holes and trimmed skin

edges. Remove all debris. In a ventilated

work area, remove any surface contaminants

with a cloth that has been dampened with

aliphatic naphtha or an equivalent cleaning

solvent.

(5) Reattach the side-skin to the vertical fin

spar using MS 20470AD rivets. DO NOT

install the bottom two rivets into the vertical

fin spar where the skin was trimmed.

(6) Reinstall the vertical fin spar skin lower

edge rivets using M 7885/6–5 rivets (see

Figure 2).

(7) Refinish all reworked areas.

(8) After modifying the vertical fin spar,

immediately inspect the vertical fin spar in

accordance with paragraphs (b)(3) and (b)(4)

of this AD.

(b) After the initial modification and

inspection of the vertical fin spar have been

accomplished in accordance with paragraph

(a) of this AD, thereafter, at intervals not to

exceed 8 hours TIS, inspect the vertical fin

spar for cracks as follows:

(1) Remove the lower aft tailboom

inspection door, located at tailboom station

180 (see Figure 4).

(2) Remove the 42° gearbox cover and open

the drive shaft cover on the vertical fin (see

Figure 1).

(3) Through the lower aft tailboom

inspection door, using a bright light and an

inspection mirror, inspect the vertical fin

spar assembly adjacent to the tailboom top

skin on the forward side, paying special

attention to the left-hand edge and the

adjacent surfaces (see Figure 2).

(4) In a ventilated work area, clean all

surfaces to be inspected with a cloth

dampened with aliphatic naphtha or an

equivalent cleaning solvent. Using a bright

light and a 10x magnifying glass, inspect the

vertical fin spar assembly adjacent to the

tailboom top-skin on the in-board and outboard sides, the vertical edge, and the two

open rivet holes. Using a bright light and a

mirror, inspect the aft side of the vertical fin

spar in the same area. Special attention must

be given to the left-hand edge of the vertical

fin spar and any adjacent surfaces between

fin stations 66.31 and 71.31 (see Figure 2).

(c) If any crack is discovered on the vertical

fin spar as a result of the inspection specified

in paragraphs (b)(3) or (b)(4) of this AD,

replace the vertical fin spar assembly with an

airworthy vertical fin spar assembly before

further flight.

(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

Certification Office, FAA. Operators shall

submit their requests through an FAA

Principal Maintenance Inspector, who may

concur or comment and then send it to the

Manager, Rotorcraft Certification Office.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Rotorcraft Certification

Office.

(e) Special flight permits may be issued in

accordance with §§ 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.

(f) This amendment becomes effective on

May 28, 1998.

Issued in Fort Worth, Texas, on May 4,

1998.

Eric Bries,

Acting Manager, Rotorcraft Directorate,

Aircraft Certification Service.

[FR Doc. 98–12509 Filed 5–12–98; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 71

[Airspace Docket No. 98–ASW–18]

Revocation of Class D Airspace,

Lubbock Reese AFB, TX, and Revision

of Class E Airspace, Lubbock, TX

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Direct final rule; confirmation of

effective date.