Federal Register / Vol. 60, No. 89 / Tuesday, May 9, 1995 / Proposed Rules 24587

challenge virus provided or approved by

APHIS.

(3) All chickens shall be observed

until 7 weeks of age, necropsied, and

examined for grossly observable lesions

consistent with Marek’s disease. All

chickens dying before the end of the 7

week observation period shall be

necropsied and evaluated for gross

lesions of Marek’s disease. Any

chickens not so examined shall be

scored as positive for Marek’s disease.

(4) For a valid test, at least 80% of the

chickens in group 2 must develop

grossly observable lesions, none of the

chickens in group 3 shall develop

grossly observable lesions, and (when

included) at least 20% of the chickens

in group 4 must develop grossly

observable lesions.

(5) For a valid test to be considered

satisfactory, at least 80% of the chickens

in group 1 must remain free of grossly

observable lesions. the appropriate

product claim resulting from a

satisfactory test would be to aid in the

prevention of Marek’s disease, for

vaccines containing only a Serotype 3

virus as the Marek’s disease fraction, or

to aid in the prevention of very virulent

Marek’s disease, for all other vaccines.

(d) Test requirements for release. Each

serial and subserial shall meet the

applicable requirements prescribed in

§ 113.300. The identity test required in

§ 113.300(c) shall be conducted in a

serotype-specific manner by a method

acceptable to APHIS. Final container

samples of completed product shall also

meet the requirements in paragraphs

(d)(1), (2), and (3) of this section. Any

serial or subserial found unsatisfactory

by a prescribed test shall not be

released.

(1) Purity test. The chicken embryo

inoculation test prescribed in § 113.37

shall be conducted, except that, if the

test is inconclusive because of a vaccine

virus override, the chicken inoculation

test prescribed in § 113.36 may be

conducted and the virus judged

accordingly.

(2) Safety test. At least 25 one-dayold, specific pathogen free chickens

shall be injected, by the subcutaneous

route, with the equivalent of 10 chicken

doses of virus (vaccine concentrated

10X). The chickens shall be observed

each day for 21 days. Chickens dying

during the period shall be examined,

cause of death determined, and the

results recorded.

(i) If at least 20 chickens do not

survive the observation period, the test

is inconclusive.

(ii) If lesions of any disease or cause

of death are directly attributable to the

vaccine, the serial is unsatisfactory.

(iii) If less than 20 chicks survive the

observation period and there are no

deaths or lesions attributable to the

vaccine, the test may be repeated one

time, Provided, that if the test is not

repeated, the serial shall be declared

unsatisfactory.

(3) Potency test. The samples shall be

titrated using a cell culture system or

other titration method acceptable to

APHIS. For vaccines composed of more

than one Marek’s disease virus serotype,

each fraction shall be titrated in a

serotype-specific manner.

(i) Samples of desiccated vaccine

shall be incubated at 37°C for 3 days

before preparation for use in the

potency test. Samples of desiccated or

frozen vaccine shall be reconstituted in

diluent according to the label

recommendations, and held in an ice

bath at 0°C to 4°C for 2 hours prior to

use in the potency test.

(ii) For a serial or subserial to be

eligible for release, each serotype

contained in the vaccine shall have a

virus titer per dose which is at least 3

times greater than the number of plaque

forming units (pfu) used in the

immunogenicity test prescribed in

paragraph (c) of this section, but not less

than 1000 pfu per dose.

(iii) When tested (without the pretest

incubation of desiccated products) at

any time within the expiration period,

each serotype contained in the vaccine

shall have a virus titer per dose which

is at least 2 times the number of pfu

used in the immunogenicity test, but not

less than 750 pfu per dose.

Done in Washington, DC, this 28th day of

April 1995.

Lonnie J. King,

Acting Administrator, Animal and Plant

Health Inspection Service.

[FR Doc. 95–11375 Filed 5–8–95; 8:45 am]

BILLING CODE 3410–34–M

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94–NM–135–AD]

Airworthiness Directives; British

Aerospace Model Viscount 744, 745D,

and 810 Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

supersedure of an existing airworthiness

directive (AD), applicable to certain

British Aerospace Model Viscount 744,

745D, and 810 airplanes, that currently

establishes time-in-service limits for

components of the fuselage pressure

vessel, and requires modifications and

inspections of various fuselage

components to assure the continued

structural integrity of these airplanes

through the manufacturer’s design life

goal. This action would require

additional modifications and

inspections of the fuselage pressure

vessel to extend the fuselage pressure

vessel life from 30 to 45 years since

new. This proposal is prompted by

results of a review of fatigue test

findings, stress analysis, and in-service

history associated with pressure vessel

components. The actions specified by

the proposed AD are intended to

prevent reduced structural capability of

the fuselage pressure vessel.

DATES: Comments must be received by

June 20, 1995.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 94–NM–

135–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

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

British Aerospace Regional Aircraft Ltd.,

Engineering Support Manager, Military

Business Unit, Chadderton Works,

Greengate, Middleton, Manchester M24

1SA, England. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

William Schroeder, Aerospace Engineer,

Standardization Branch, ANM–113,

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(206) 227–2148; fax (206) 227–1320.

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 shall

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
24588 Federal Register / Vol. 60, No. 89 / Tuesday, May 9, 1995 / Proposed Rules

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 Number 94–NM–135–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, Transport Airplane Directorate,

ANM–103, Attention: Rules Docket No.

94–NM–135–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

On January 30, 1978, the FAA issued

AD 65–20–04, amendment 39–3138 (23

FR 5506, February 9, 1978), applicable

to certain British Aerospace Model

Viscount 744, 745D, and 810 airplanes.

That AD establishes time-in-service

limits of 30 years since new or 75,000

landings (whichever occurs first) for

components of the fuselage pressure

vessel. That AD also requires

modifications and repetitive inspections

of various fuselage components to

assure the continued structural integrity

of these airplanes to 30 years since new

or 75,000 landings (whichever occurs

first). That action was prompted by

results of the manufacturer’s fatigue

tests, stress analysis, and in-service

history associated with life-limited

fuselage parts. The requirements of that

AD are intended to prevent reduced

structural capability of the fuselage

pressure vessel.

Since the issuance of that AD, the

airplane manufacturer has conducted an

additional review of fatigue test results,

stress analysis, and in-service

experience. Results of that review have

revealed that additional new

modifications and repetitive inspections

are necessary to ensure that the fuselage

pressure vessel can maintain the

continued structural integrity necessary

to attain the initial time-in-service limit

of 30 years since new or 75,000 landings

(whichever occurs first) specified in the

existing AD.

In addition, the manufacturer has

developed a program for Model

Viscount 744, 745D, and 810 airplanes,

which involves performing new

inspections and modifications, and

revising the implementation times for

existing requirements. Once

accomplished, these actions will allow

an extension of the initial time-inservice limit of 30 years or 75,000

landings (whichever occurs first) of the

fuselage pressure vessel to 45 years or

75,000 landings (whichever occurs

first).

British Aerospace has issued

Preliminary Technical Leaflet (PTL) No.

221, Issue 10, dated May 1, 1994 (for

Model Viscount 744 and 745D

airplanes), and PTL No. 94, Issue 10,

dated September 1, 1993 (for Model

Viscount 810 airplanes). These PTL’s

describe procedures for additional

visual inspections, non-destructive

testing (NDT) inspections, and

modifications of the fuselage necessary

to assure the continued structural

integrity of the pressure vessel to the

initial time-in-service limit of 30 years

or 75,000 landings (whichever occurs

first). These PTL’s also specify

compliance with two other PTL’s,

described below, for operation of

affected airplanes beyond 30 years, but

not to exceed 75,000 landings. The Civil

Aviation Authority (CAA), which is the

airworthiness authority for the United

Kingdom, classified PTL No. 221 and

PTL No. 94 as mandatory in order to

assure the continued airworthiness of

these airplanes in the United Kingdom.

British Aerospace also has issued PTL

No. 320, Issue 3, dated October 1, 1993

(for Model Viscount 744 and 745D

airplanes), and PTL No. 189, Issue 5,

dated May 1, 1994 (for Model Viscount

810 airplanes). These PTL’s specify

inspections and modifications of the

fuselage pressure vessel assembly, and

revise the implementation times for

certain existing requirements for

continued operation of specific

airplanes (listed in the PTL’s) beyond 30

years since new. Accomplishment of the

actions specified in these PTL’s will

allow extension of the initial time-inservice limit of the fuselage pressure

vessel to 45 years or 75,000 landings

(whichever occurs first).

This airplane model is manufactured

in the United Kingdom and is type

certificated for operation in the United

States under the provisions of section

21.29 of the Federal Aviation

Regulations (14 CFR 21.29) and the

applicable bilateral airworthiness

agreement. Pursuant to this bilateral

airworthiness agreement, the CAA has

kept the FAA informed of the situation

described above. The FAA has

examined the findings of the CAA,

reviewed all available information, and

determined that AD action is necessary

for products of this type design that are

certificated for operation in the United

States.

Since an unsafe condition has been

identified that is likely to exist or

develop on other airplanes of the same

type design registered in the United

States, the proposed AD would

supersede AD 65–20–04 to require

additional modifications and

inspections of the fuselage pressure

vessel. The actions would be required to

be accomplished in accordance with the

PTL’s described previously.

As a result of recent communications

with the Air Transport Association

(ATA) of America, the FAA has learned

that, in general, some operators may

misunderstand the legal effect of AD’s

on airplanes that are identified in the

applicability provision of the AD, but

that have been altered or repaired in the

area addressed by the AD. The FAA

points out that all airplanes identified in

the applicability provision of an AD are

legally subject to the AD. If an airplane

has been altered or repaired in the

affected area in such a way as to affect

compliance with the AD, the owner or

operator is required to obtain FAA

approval for an alternative method of

compliance with the AD, in accordance

with the paragraph of each AD that

provides for such approvals. A note has

been included in this notice to clarify

this requirement.

The FAA estimates that 29 airplanes

of U.S. registry would be affected by this

proposed AD, that it would take

approximately 400 work hours per

airplane to accomplish the proposed

actions, and that the average labor rate

is $60 per work hour. Required parts

would cost approximately $37,400 per

airplane. Based on these figures, the

total cost impact of the proposed AD on

U.S. operators is estimated to be

$1,780,600, or $61,400 per airplane.

The total cost impact figure discussed

above is based on assumptions that no

operator has yet accomplished any of

the proposed requirements of this AD

action, and that no operator would

accomplish those actions in the future if

this AD were not adopted.

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
Federal Register / Vol. 60, No. 89 / Tuesday, May 9, 1995 / Proposed Rules 24589

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. App. 1354(a), 1421

and 1423; 49 U.S.C. 106(g); and 14 CFR

11.89.

§ 39.13 [Amended]

2. Section 39.13 is amended by

removing amendment 39–3138 (23 FR

5506, February 9, 1978), and by adding

a new airworthiness directive (AD), to

read as follows:

British Aerospace Regional Aircraft Limited

(Formerly British Aerospace

Commercial Aircraft Limited, VickersArmstrongs Aircraft Limited): Docket

94–NM–135–AD. Supersedes AD 65–20–

04, Amendment 39–3138.

Applicability: All Model Viscount 744,

745D, and 810 airplanes, certificated in any

category.

Note 1: This AD applies to each airplane

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

airplanes 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 airplane from

the applicability of this AD.

Compliance: Required as indicated, unless

accomplished previously.

To prevent reduced structural capability of

the fuselage pressure vessel, accomplish the

following:

(a) To operate the airplane for a maximum

of 30 years since the date of manufacture or

75,000 total landings, whichever occurs first,

accomplish the following:

(1) Perform visual, eddy current, dye

penetrant, and x-ray inspections in

accordance with Sections 2 through 10 of

British Aerospace Preliminary Technical

Leaflet (PTL) No. 221, Issue 10, dated May 1,

1994 (for Model Viscount 744 and 745D

airplanes); or PTL No. 94, Issue 10, dated

September 1, 1993 (for Model Viscount 810

airplanes); as applicable. Perform the initial

inspection at the later of the times specified

in paragraphs (a)(1)(i) and (a)(2)(ii) of this

AD. Thereafter, repeat these inspections at

the repetitive intervals specified in the

applicable PTL.

(i) Prior to the threshold specified in

Sections 2 through 10 of the applicable PTL;

or within the next repetitive inspection

specified in Sections 2 through 10 of the

applicable PTL following the immediately

preceding inspection accomplished in

accordance with PTL No. 221, Issue 4 (for

Model Viscount 744 and 745D airplanes), or

PTL No. 94, Issue 4 (for Model Viscount 810

airplanes); whichever occurs first. Or

(ii) Within 60 days after the effective date

of this AD.

(2) Install the modifications specified in

Sections 2 through 10 of British Aerospace

PTL No. 221, Issue 10, dated May 1, 1994 (for

Model Viscount 744 and 745D airplanes); or

PTL No. 94, Issue 10, dated September 1,

1993 (for Model Viscount 810 airplanes); as

applicable. Accomplish this installation at

the later of the times specified in paragraphs

(a)(2)(i) and (a)(2)(ii) of this AD.

(i) Prior to the accumulation of the number

of equivalent flights at 6.5 pounds per square

inch (psi) specified in the initial compliance

columns of Sections 2 through 10 of the

applicable PTL. Or

(ii) Within 60 days after the effective date

of this AD.

Note 2: The number of equivalent flights at

6.5 psi is determined by using the procedure

specified in Section 1, Part 6, Paragraph 6.6,

of PTL No. 221 or PTL No. 94, as applicable.

(3) Modify the components of the

pressurization system to reduce the cabin

pressure maximum pressure setting to 3.5

psi, in accordance with Section 1, Part 7,

Paragraph 7.5.2 of British Aerospace PTL No.

221, Issue 10, dated May 1, 1994 (for Model

Viscount 744 and 745D airplanes); or PTL

No. 94, Issue 10, dated September 1, 1993

(for Model Viscount 810 airplanes); as

applicable. Accomplish this modification at

the later of the times specified in paragraphs

(a)(3)(i) and (a)(3)(ii) of this AD.

(i) Prior to the accumulation of 25 years

since date of manufacture, or prior to the

accumulation of the number of flights

equivalent to 17,000 flights at 6.5 psi;

whichever occurs first. Or

(ii) Within 30 days after the effective date

of this AD.

(b) This paragraph is applicable only to

airplanes listed in British Aerospace PTL No.

320, Issue 3, dated October 1, 1993 (for

Model Viscount 744 and 745D airplanes);

and PTL No. 189, Issue 5, dated May 1, 1994

(for Model Viscount 810 airplanes). To

operate the airplane for a maximum of 45

years since date of manufacture or 75,000

total landings, whichever occurs first: Prior

to the accumulation of 30 years since date of

manufacture, or within 2 months after the

effective date of this AD, whichever occurs

later, perform the inspections, change the

inspection times, install the modifications,

and perform all other actions specified in the

applicable PTL.

(c) If any crack(s) or corrosion is found

during any inspection required by this AD,

prior to further flight, repair in accordance

with British Aerospace PTL No. 221, Issue

10, dated May 1, 1994 (for Model 744 and

745D airplanes), or PTL No. 94, Issue 10,

dated September 1, 1993 (for Model 810

airplanes).

(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,

Standardization Branch, ANM–113, FAA,

Transport Airplane Directorate. Operators

shall submit their requests through an

appropriate FAA Principal Maintenance

Inspector, who may add comments and then

send it to the Manager, Standardization

Branch, ANM–113.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Standardization Branch,

ANM–113.

(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 airplane to

a location where the requirements of this AD

can be accomplished.

Issued in Renton, Washington, on May 3,

1995.

James V. Devany,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 95–11357 Filed 5–8–95; 8:45 am]

BILLING CODE 4910–13–U

14 CFR Part 39

[Docket No. 94–NM–107–AD]

Airworthiness Directives; British

Aerospace Model ATP Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Supplemental notice of

proposed rulemaking; reopening of

comment period.