Federal Register / Vol. 62, No. 203 / Tuesday, October 21, 1997 / Rules and Regulations 54577

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96–CE–25–AD; Amendment 39–

10170; AD 97–22–01]

RIN 2120–AA64

Airworthiness Directives; Pilatus

Britten-Norman Ltd. (Formerly BrittenNorman) BN–2A, BN–2B, and BN–2T

Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive that applies

to Pilatus Britten-Norman Ltd. (Pilatus

Britten-Norman) BN–2A, BN–2B, and

BN–2T series airplanes. This AD

requires repetitively inspecting the

junction of the torque link lug and

upper case of the main landing gear

(MLG) torque link assemblies for cracks,

and replacing any MLG torque link

assembly with a Modification A39 MLG

torque link assembly, either

immediately when cracks are found or

after a certain period of time if cracks

are not found. Replacing all MLG torque

link assemblies with Modification A39

MLG torque link assemblies eliminates

the need for the repetitive inspections.

These repetitive inspections are

currently required by AD 86–07–02 for

the BN–2A, BN–2B, and BN–2T series

airplanes, as well as the BN2A MK. 111

series airplanes. There are no improved

design parts for the BN2A MK. 111

series airplanes. The Federal Aviation

Administration (FAA) is issuing in a

separate action a revision to AD 86–07–

02 to retain the repetitive inspection

and replacement (if necessary)

requirements for the BN2A MK. 111

series airplanes. The actions specified in

this AD are intended to prevent failure

of the main landing gear caused by

cracks in the torque link area, which

could lead to loss of control of the

airplane during landing operations.

DATES: Effective November 28, 1997.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of November

28, 1997.

ADDRESSES: Service information that

applies to this AD may be obtained from

Fairey Hydraulics Limited, Claverham,

Bristol, England; or Pilatus BrittenNorman Limited, Bembridge, Isle of

Wight, United Kingdom PO35 5PR;

telephone 44–1983 872511; facsimile

44–1983 873246. This information may

also be examined at the FAA, Central

Region, Office of the Regional Counsel,

Attention: Rules Docket 96–CE–25–AD,

Room 1558, 601 E. 12th Street, Kansas

City, Missouri 64106; or at the Office of

the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Mr.

S.M. Nagarajan, Aerospace Engineer,

Small Airplane Directorate, Airplane

Certification Service, FAA, 1201

Walnut, suite 900, Kansas City, Missouri

64106; telephone (816) 426–6932;

facsimile (816) 426–2169.

SUPPLEMENTARY INFORMATION:

Events Leading to the Issuance of This

AD

A proposal to amend part 39 of the

Federal Aviation Regulations (14 CFR

part 39) to include an AD that would

apply to Pilatus Britten-Norman BN–2A,

BN–2B, and BN–2T series airplanes was

published in the Federal Register as a

notice of proposed rulemaking (NPRM)

on May 27, 1997 (62 FR 28646). The

NPRM proposed to require repetitively

inspecting the junction of the torque

link lug and upper case of the MLG

torque link assemblies for cracks, and

replacing any MLG torque link assembly

with a Modification A39 MLG torque

link assembly, either immediately when

cracks are found or at a certain period

of time if cracks are not found.

Installation of the improved part would

eliminate the need for the repetitive

inspections. Accomplishment of the

proposed inspections and installation as

specified in the NPRM would be in

accordance with Fairey Hydraulics

Limited SB 32–4, Issue 4, dated January

30, 1990.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. No

comments were received on the

proposed rule or the FAA’s

determination of the cost to the public.

The FAA’s Determination

After careful review of all available

information related to the subject

presented above, the FAA has

determined that air safety and the

public interest require the adoption of

the rule as proposed except for minor

editorial corrections. The FAA has

determined that these minor corrections

will not change the meaning of the AD

and will not add any additional burden

upon the public than was already

proposed.

The FAA’s Aging Commuter-Class

Airplane Policy

This AD applies to the FAA’s aging

commuter-class airplane policy. This

policy simply states that reliance on

repetitive inspections of critical areas on

commuter-class airplanes carries an

unnecessary safety risk when a design

change exists that could eliminate or, in

certain instances, reduce the number of

those critical inspections. The

alternative to issuing this AD would be

to rely on repetitive inspections to

detect failure of the MLG torque link

assemblies on the affected airplanes.

The intent of the FAA’s aging

commuter airplane program is to ensure

safe operation of commuter-class

airplanes that are in commercial service

without adversely impacting private

operators. Of the approximately 112

airplanes in the U.S. registry that would

be affected by this AD, the FAA has

determined that approximately 25

percent are operated in scheduled

passenger service by 11 different

operators. A significant number of the

remaining 75 percent are operated in

other forms of air transportation such as

air cargo and air taxi.

This AD allows at least 1,000 hours

TIS after the effective date of the AD

before mandatory accomplishment of

the design modification (upon the

accumulation of 5,000 hours TIS or

within the next 1,000 hours TIS after the

effective date of the AD, whichever is

later). The average utilization of the fleet

for those airplanes in commercial

commuter service is approximately 25

to 50 hours TIS per week. Based on

these figures, operators of commuter

airplanes involved in commercial

operation will have to accomplish the

replacement within 5 to 10 calendar

months (at the least) after this AD

becomes effective. For private owners,

who typically operate between 100 to

200 hours TIS per year, this will allow

5 to 10 years (at the least) before the

replacement becomes mandatory. The

time it would take those in air cargo/air

taxi operations before the replacement

becomes mandatory is unknown

because of the wide variation between

each airplane used in this service. The

exact numbers would fall somewhere

between the average for commuter

operators and private operators.

Cost Impact

The FAA estimates that 112 airplanes

in the U.S. registry will be affected by

this AD, that it will take approximately

13 workhours per airplane to

accomplish this AD (1 workhour per

inspection and 12 workhours for the

installation), and that the average labor

rate is approximately $60 an hour. Parts

cost approximately $6,200 per airplane.

Based on these figures, the total cost

impact of this AD on U.S. operators is
54578 Federal Register / Vol. 62, No. 203 / Tuesday, October 21, 1997 / Rules and Regulations

estimated to be $781,760 or $6,980 per

airplane.

The inspections are currently required

on the 112 affected airplanes by AD 86–

07–02. This AD would not require any

additional inspection requirements over

that already required by AD 86–07–02.

In addition, the cost figures referenced

above are based on the presumption that

no affected airplane operator has

incorporated the inspection-terminating

installation. Pilatus Britten-Norman

does not know the number of parts

distributed to the affected airplane

owners/operators. Numerous sets of

parts were sent out to the owners/

operators of the affected airplanes, but

over the years Pilatus Britten-Norman

has not retained these records.

Regulatory Flexibility Determination

and Analysis

The Regulatory Flexibility Act of 1980

(RFA) was enacted by Congress to

ensure that small entities are not

unnecessarily or disproportionally

burdened by government regulations.

The RFA requires government agencies

to determine whether rules would have

a ‘‘significant economic impact on a

substantial number of small entities,’’

and, in cases where they would,

conduct a Regulatory Flexibility

Analysis in which alternatives to the

rule are considered. FAA Order

2100.14A, Regulatory Flexibility Criteria

and Guidance, outlines FAA procedures

and criteria for complying with the

RFA. Small entities are defined as small

businesses and small not-for-profit

organizations that are independently

owned and operated or airports

operated by small governmental

jurisdictions. A ‘‘substantial number’’ is

defined as a number that is not less than

11 and that is more than one-third of the

small entities subject to a rule, or any

number of small entities judged to be

substantial by the rulemaking official. A

‘‘significant economic impact’’ is

defined by an annualized net

compliance cost, adjusted for inflation,

which is greater than a threshold cost

level for defined entity types.

The entities that would be affected by

this AD are mostly in the portion of

Standard Industrial Classification (SIC)

4512, Operators of Aircraft for Hire,

classified as ‘‘unscheduled.’’ FAA Order

2100.14A sets the size threshold for

small entities operating aircraft in this

category at nine or fewer aircraft owned

and the annualized cost thresholds of at

least $4,975 (1996 dollars) for

unscheduled operators. A four-year life

for the torque link assembly and capital

cost of 15-percent would establish an

annualized cost of $2,445 (1996 dollars).

This is less than 50-percent of the

threshold cost of $4,975 per year. In

order to incur costs of at least $4,975,

an entity would have to operate three or

more of the airplanes referenced in this

AD. FAA data shows that only five

small entities operate three or more of

these airplanes. In addition, this data

shows that approximately 60 entities

operate the airplanes referenced in this

AD, but that only 15 of these entities

(one-fourth) operate two or more of

these airplanes.

Based on this information, less than

one-third of the entities will incur

significant operating costs under FAA

Order 2100.14A. Therefore, this AD will

not significantly affect a number of

small entities.

A copy of the full Cost Analysis and

Regulatory Flexibility Determination for

this AD may be examined at the FAA,

Central Region, Office of the Regional

Counsel, Attention: Rules Docket No.

96–CE–25–AD, Room 1558, 601 E. 12th

Street, Kansas City, Missouri.

Regulatory Impact

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 copy of the final

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, 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.

§39.13 [Amended]

2. Section 39.13 is amended by

adding a new airworthiness directive

(AD) to read as follows:

97–22–01 Pilatus Britten-Norman:

Amendment 39–10170; Docket No. 96–

CE–25–AD.

Applicability: Models BN–2, BN–2A, BN–

2A–2, BN–2A–3, BN–2A–6, BN–2A–8, BN–

2A–9, BN–2A–20, BN–2A–21, BN–2A–26,

BN–2A–27, BN–2B–20, BN–2B–21, BN–2B–

26, BN–2B–27, and BN–2T airplanes (all

serial numbers), 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 request approval for an

alternative method of compliance in

accordance with paragraph (f) of this AD. The

request should include an assessment of the

effect of the replacement, 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 after

the effective date of this AD, unless already

accomplished.

To prevent failure of the main landing gear

caused by cracks in the torque link assembly

area, which could lead to loss of control of

the airplane during landing operations,

accomplish the following:

(a) Prior to further flight after the effective

date of this AD or within the next 100 hours

time-in-service (TIS) after the last inspection

required by AD 86–07–02, whichever occurs

later, and thereafter at intervals not to exceed

100 hours TIS until the installations required

by paragraph (c) of this AD are accomplished,

inspect the junction of the torque link lug

and upper case of all main landing gear

(MLG) torque link assemblies for cracks

(using a 10-power magnifying glass or by dye

penetrant methods). Accomplish these

inspections in accordance with the

ACCOMPLISHMENT INSTRUCTIONS

section of Fairey Hydraulics Limited Service

Bulletin (SB) 32–4, Issue 4, dated January 30,

1990. Pilatus Britten-Norman SB BN–2/

SB.170, Issue 4, November 16, 1990,

references this service bulletin.

Note 2: The inspections required by

paragraph (a) of this AD were initially a part

of AD 86–07–02, which applied to the BN2A

MK. 111 series airplanes as well as the

airplanes affected by this AD. The ‘‘prior to

further flight after the effective date of this

AD’’ compliance time was the original initial

compliance time of AD 86–07–02, and is

being retained to provide credit and

continuity for already-accomplished and

future inspections.
Federal Register / Vol. 62, No. 203 / Tuesday, October 21, 1997 / Rules and Regulations 54579

(b) If any cracks are found during any of

the inspections required by this AD, prior to

further flight, replace the MLG torque link

assembly with a Modification A39 MLG

torque link assembly in accordance with the

ACCOMPLISHMENT INSTRUCTIONS

section of Fairey Hydraulics Limited SB No.

32–4, Issue 4, dated January 30, 1990.

(1) Repetitive inspections are no longer

required when all MLG torque assemblies are

replaced with Modification A39 MLG torque

link assemblies.

(2) Repetitive inspections may no longer be

required on one MLG torque assembly, but

still be required on another if all haven’t been

replaced with a Modification A39 MLG

torque link assembly.

(c) Upon the accumulation of 5,000 hours

TIS or within the next 1,000 hours TIS after

the effective date of this AD, whichever

occurs later, unless already accomplished as

specified in paragraph (b) of this AD, replace

each MLG torque link assembly with a

Modification A39 MLG torque link assembly

in accordance with the ACCOMPLISHMENT

INSTRUCTIONS section of Fairey Hydraulics

Limited SB No. 32–4, Issue 4, dated January

30, 1990.

(d) The intervals between the repetitive

inspections required by this AD may be

adjusted up to 10 percent of the specified

interval to allow accomplishing these actions

along with other scheduled maintenance on

the airplane.

(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 inspection requirements

of this AD can be accomplished.

(f) An alternative method of compliance or

adjustment of the initial or repetitive

compliance times that provides an equivalent

level of safety may be approved by the

Manager, Small Airplane Directorate, 1201

Walnut, suite 900, Kansas City, Missouri

64106. The request should be forwarded

through an appropriate FAA Maintenance

Inspector, who may add comments and then

send it to the Manager, Small Airplane

Directorate.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Small Airplane

Directorate.

(g) The inspections and replacement

required by this AD shall be done in

accordance with Fairey Hydraulics Limited

Service Bulletin (SB) 32–4, Issue 4, dated

January 30, 1990. This incorporation by

reference was 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 Fairey Hydraulics Limited,

Claverham, Bristol, England; or Pilatus

Britten-Norman Limited, Bembridge, Isle of

Wight, United Kingdom PO35 5PR. Copies

may be inspected at the FAA, Central Region,

Office of the Regional Counsel, Room 1558,

601 E. 12th Street, Kansas City, Missouri, or

at the Office of the Federal Register, 800

North Capitol Street, NW., suite 700,

Washington, DC.

(h) This amendment (39–10170) becomes

effective on November 28, 1997.

Issued in Kansas City, Missouri, on

October 14, 1997.

Mary Ellen Schutt,

Acting Manager, Small Airplane Directorate,

Aircraft Certification Service.

[FR Doc. 97–27795 Filed 10–20–97; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–246–AD; Amendment

39–10169; AD 97–19–16]

RIN 2120–AA64

Airworthiness Directives; Fokker

Model F28 Mark 0100 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This document publishes in

the Federal Register an amendment

adopting airworthiness directive (AD)

97–19–16, that was sent previously to

all known U.S. owners and operators of

Fokker Model F28 Mark 0100 series

airplanes equipped with Rolls-Royce

Tay 650–15 engines, by individual

notices. This AD requires a revision to

the FAA-approved Airplane Flight

Manual (AFM) to include procedures to

prohibit use of reverse engine thrust

power settings between idle and

emergency maximum; and submission

of a report to the airplane manufacturer.

This action is prompted by a report that,

during preparation for takeoff, an engine

fan blade failure occurred, followed by

an engine fire. The actions specified by

this AD are intended to prevent

uncontained engine fan blade failure

due to high cycle fatigue cracking,

which could result in loss of thrust from

the affected engine and secondary

damage to aircraft and/or fire.

DATES: Effective October 27, 1997, to all

persons except those persons to whom

it was made immediately effective by

emergency AD 97–19–16, issued on

September 12, 1997, which contained

the requirements of this amendment.

Comments for inclusion in the Rules

Docket must be received on or before

November 20, 1997.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–103,

Attention: Rules Docket No. 97–NM–

246–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

FOR FURTHER INFORMATION CONTACT: Tim

Dulin, Aerospace Engineer,

Standardization Branch, ANM–113,

FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(425) 227–2141; fax (425) 227–1320.

SUPPLEMENTARY INFORMATION: On

September 12, 1997, the FAA issued

emergency AD 97–19–16, which is

applicable to Fokker Model F28 Mark

0100 series airplanes equipped with

Rolls-Royce (RR) Tay 650–15 engines.

That action was prompted by a report

that during preparation for takeoff, a

Fokker Model F28 Mark 0100 series

airplane equipped with Rolls-Royce Tay

650–15 engines sustained an engine fan

blade failure, followed by an engine fire.

Investigation revealed that five fan

blades failed at the root area, three fan

blades failed at mid-height, and the

remainder were severely damaged.

Further investigation revealed that all

five fan blades failed due to rapid high

cycle fatigue cracking with low cycle

fatigue cracking origin. Evidence of

rapid high cycle fatigue cracking

indicates that an operational effect is

causing high vibratory stresses. Rolls

Royce considers that the high cycle

fatigue cracking was caused by vibration

during previous thrust reverser

applications. This condition, if not

corrected, could result in uncontained

engine fan blade failure due to high

cycle fatigue cracking, which could

result in loss of thrust from the affected

engine and secondary damage to aircraft

and/or fire.

FAA’s Conclusions

This airplane model is manufactured

in the Netherlands 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

Rijksluchtvaartdienst (RLD), which is

the airworthiness authority for the

Netherlands, has kept the FAA informed

of the situation described above. The

FAA has examined the findings of the

RLD, 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.

Explanation of the Requirements of the

Rule

Since the unsafe condition described

is likely to exist or develop on other

airplanes of the same type design

registered in the United States, the FAA

issued emergency AD 97–19–16 to

require a revision to the FAA-approved

Airplane Flight Manual (AFM). The