Federal Register / Vol. 63, No. 117 /Thursday, June 18, 1998 / Proposed Rules 33293

than 2 years, assuming an immediate

and sustained parallel shift in the yield

curve of plus 300 basis points, nor

shorten for more than 3 years, assuming

an immediate and sustained parallel

shift in the yield curve of minus 300

basis points.

(3) Price Sensitivity Test. The

estimated change in price is not more

than thirteen (13) percent due to an

immediate and sustained parallel shift

in the yield curve of plus or minus 300

basis points.

(4) Exemption. A floating-rate

mortgage security shall not be subject to

paragraphs (a)(1) and (2) of this section

if at the time of purchase, and each

subsequent quarter, it bears a rate of

interest that is below the contractual cap

on the instrument.

(b) A Farm Credit bank may use

alternative stress tests to evaluate the

price sensitivity of its investments in

mortgage securities. Alternative stress

tests must be able to measure the price

sensitivity of mortgage instruments over

different interest rate/yield curve

scenarios prior to purchase and each

quarter thereafter. The methodology

used to analyze mortgage securities

shall be commensurate with the

complexity of the instrument’s structure

and cashflows. Prior to purchase and

quarterly thereafter, the stress test

should determine that the mortgage

security’s risk is compatible with the

bank’s investment policies and the

investment does not expose the bank’s

capital and earnings to excessive risks.

(c) In applying the stress tests in

either paragraphs (a) or (b) of this

section, each Farm Credit bank shall

rely on verifiable information to support

all of its assumptions, including

prepayment and interest-rate volatility

assumptions. All assumptions that form

the basis of the bank’s evaluation of the

security and its underlying collateral

shall be available for review by the

Office of Examination of the Farm

Credit Administration. Subsequent

changes in the bank’s assumptions shall

be documented. If at any time after

purchase, a mortgage security no longer

complies with requirements in this

section, the bank shall divest the

security in accordance with § 615.5143

of this part.

§ 615.5143 [Amended]

8. Newly designated § 615.5143 is

amended by removing paragraph (a) and

the paragraph designation from

paragraph (b).

Subpart F—Property and Other

Investments

§ 615.5174 [Amended]

9. Section 615.5174 is amended by

removing the words ‘‘mortgage-backed

securities (MBSs), as defined by

§ 615.5131(l), collateralized mortgage

obligations (CMOs), as defined by

§ 615.5131(e), and Real Estate Mortgage

Investment Conduits (REMICs), as

defined by § 615.5131(p)’’ in paragraph

(a), and adding in their place, the words

‘‘mortgage securities as defined by

§ 615.5131(l);’’ by removing the words,

‘‘as defined by § 615.5131(b),’’ from

paragraph (b)(1); by removing paragraph

(c); and redesignating paragraphs (d)

and (e) as paragraphs (c) and (d),

respectively.

Dated: June 15, 1998.

Floyd Fithian,

Secretary, Farm Credit Administration Board.

[FR Doc. 98–16208 Filed 6–17–98; 8:45 am]

BILLING CODE 6705–01–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98–CE–51–AD]

RIN 2120–AA64

Airworthiness Directives; SchemppHirth K.G. Model Cirrus Sailplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes to

adopt a new airworthiness directive

(AD) that would apply to certain

Schempp-Hirth K.G. (Schemmp-Hirth)

Model Cirrus sailplanes. The proposed

AD would require modifying or

replacing the connecting rod between

the airbrake bellcranks, and replacing

the existing 6 millimeter (mm) bolt with

an 8 mm bolt. The proposed AD is the

result of mandatory continuing

airworthiness information (MCAI)

issued by the airworthiness authority for

Germany. The actions specified by the

proposed AD are intended to prevent

the threaded bolt that is welded to the

connecting rod between the airbrake

bellcranks from breaking, which could

result in loss of airbrake control with a

possible reduction/loss of sailplane

control.

DATES: Comments must be received on

or before July 21, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Central Region,

Office of the Regional Counsel,

Attention: Rules Docket No. 98–CE–51–

AD, Room 1558, 601 E. 12th Street,

Kansas City, Missouri 64106. Comments

may be inspected at this location

between 8 a.m. and 4 p.m., Monday

through Friday, holidays excepted.

Service information that applies to the

proposed AD may be obtained from

Schempp-Hirth Flugzeugbau GmbH,

Krebenstrasse 25, Postfach 1443, D–

73230 Kircheim/Teck, Germany. This

information also may be examined at

the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr.

Mike Kiesov, Aerospace Engineer, FAA,

Small Airplane Directorate, 1201

Walnut, suite 900, Kansas City, Missouri

64106; telephone: (816) 426–6934;

facsimile: (816) 426–2169.

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 that

summarizes 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 No. 98–CE–51–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, Central Region, Office of the

Regional Counsel, Attention: Rules

Docket No. 98–CE–51–AD, Room 1558,

601 E. 12th Street, Kansas City, Missouri

64106.
33294 Federal Register / Vol. 63, No. 117 /Thursday, June 18, 1998 / Proposed Rules

Discussion

The Luftfahrt-Bundesamt (LBA),

which is the airworthiness authority for

Germany, notified the FAA that an

unsafe condition may exist on certain

Schempp-Hirth Model Cirrus sailplanes.

The LBA reports that the threaded bolt

welded to the connecting rod of the

airbrake bellcranks broke off on two of

the above-referenced sailplanes. The

threaded bolt is a 6 millimeter (mm)

bolt. Beginning with serial number 51,

Schempp-Hirth manufactured Model

Cirrus sailplanes with an 8 mm bolt that

is welded to the connecting rod of the

airbrake bellcranks. The FAA has not

received reports of broken 8 mm bolts

on Schempp-Hirth Model Cirrus

sailplanes.

These conditions, if not corrected,

could result in loss of airbrake control

with a possible reduction/loss of

sailplane control.

Relevant Service Information

Schempp-Hirth has issued Technical

Note No. 265–8, dated February 11,

1985, which specifies procedures for

modifying or replacing the connecting

rod between the airbrake bellcranks, and

replacing the existing 6 mm bolt with an

8 mm bolt.

The LBA classified this technical note

as mandatory and issued German AD

85–56, dated March 4, 1985, in order to

assure the continued airworthiness of

these sailplanes in Germany.

The FAA’s Determination

This sailplane model is manufactured

in Germany 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 LBA has kept the FAA informed of

the situation described above.

The FAA has examined the findings

of the LBA; reviewed all available

information, including the technical

note referenced above; 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 Provisions of the

Proposed AD

Since an unsafe condition has been

identified that is likely to exist or

develop in other Schempp-Hirth Model

Cirrus sailplanes of the same type

design registered in the United States,

the FAA is proposing AD action. The

proposed AD would require modifying

or replacing the connecting rod between

the airbrake bellcranks, and replacing

the existing 6 mm bolt with an 8 mm

bolt. Accomplishment of the proposed

action would be in accordance with

Schempp-Hirth Technical Note 265–8,

dated February 11, 1985.

Compliance Time of the Proposed AD

Although the unsafe condition

identified in this proposed AD occurs

during flight and is a direct result of

sailplane operation, the FAA has no

way of determining how long the 6 mm

bolt may go without breaking. For

example, the condition could exist on a

sailplane with 200 hours time-in-service

(TIS), but could be developing and not

actually exist on another sailplane until

300 hours TIS. For this reason, the FAA

has determined that a compliance based

on calendar time should be utilized in

the proposed AD in order to assure that

the unsafe condition is addressed on all

gliders in a reasonable time period.

Cost Impact

The FAA estimates that 21 sailplanes

in the U.S. registry would be affected by

the proposed AD, that it would take

approximately 12 workhours per

sailplane to accomplish the proposed

action, and that the average labor rate is

approximately $60 an hour. Parts cost

approximately $60 per sailplane. Based

on these figures, the total cost impact of

the proposed AD on U.S. operators is

estimated to be $16,380, or $780 per

sailplane.

Regulatory Impact

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 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) 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 has been placed 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.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding a new airworthiness directive

(AD) to read as follows:

Schempp-Hirth K.G.: Docket No. 98–CE–51–

AD.

Applicability: Model Cirrus sailplanes,

serial numbers 1 through 50, certificated in

any category.

Note 1: This AD applies to each sailplane

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

sailplanes 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: Within the next 4 calendar

months after the effective date of this AD,

unless already accomplished.

To prevent the threaded bolt that is welded

to the connecting rod between the airbrake

bellcranks from breaking, which could result

in loss of airbrake control with a possible

reduction/loss of sailplane control,

accomplish the following:

(a) Modify or replace the connecting rod

between the airbrake bellcranks, and replace

the existing 6 millimeter (mm) bolt with an

8 mm bolt. Accomplish these actions in

accordance with Schempp-Hirth Technical

Note 265–8, dated February 11, 1985.

(b) 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 sailplane

to a location where the requirements of this

AD can be accomplished.

(c) An alternative method of compliance or

adjustment of the compliance time that

provides an equivalent level of safety may be

approved by the Manager, Small Airplane

Directorate, FAA, 1201 Walnut, suite 900,

Kansas City, Missouri 64106. The request

shall be forwarded through an appropriate
Federal Register / Vol. 63, No. 117 /Thursday, June 18, 1998 / Proposed Rules 33295

FAA Maintenance Inspector, who may add

comments and then send it to the Manager,

Small Airplane Directorate.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Small Airplane

Directorate.

(d) Questions or technical information

related to Schempp-Hirth Technical Note

265–8, dated February 11, 1985, should be

directed to Schempp-Hirth Flugzeugbau

GmbH, Krebenstrasse 25, Postfach 1443, D–

73230 Kircheim/Teck, Germany. This service

information may be examined at the FAA,

Central Region, Office of the Regional

Counsel, Room 1558, 601 E. 12th Street,

Kansas City, Missouri 64106.

Note 3: The subject of this AD is addressed

in German AD 85–56, dated March 4, 1985.

Issued in Kansas City, Missouri, on June 9,

1998.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft

Certification Service.

[FR Doc. 98–16165 Filed 6–17–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–ANE–53–AD]

RIN 2120–AA64

Airworthiness Directives; Pratt &

Whitney PW4000 Series Turbofan

Engines

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes the

adoption of a new airworthiness

directive (AD) that is applicable to

certain Pratt & Whitney (PW) PW4000

series turbofan engines not

incorporating modifications described

in certain PW service bulletins listed in

the applicability section. This proposal

would require high pressure compressor

(HPC) blade tip grinding of the rotor

assembly, installation of aluminum

oxide coated HPC blade tips in stages 9

through 12, modification of HPC 8th

through 14th stage stators, incorporation

of 1st stage high pressure turbine (HPT)

vanes with increased airflow area which

also requires additional HPT hardware

modifications, and incorporation of HPC

13th–15th stage zirconium oxide blade

tips. This proposal is prompted by

reports of HPC surge caused by

excessive HPC rear stage rotor-to-case

clearance. The actions specified by the

proposed AD are intended to prevent

HPC surge, which can result in engine

power loss at a critical phase of flight

such as takeoff or climb.

DATES: Comments must be received by

August 17, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), New England

Region, Office of the Regional Counsel,

Attention: Rules Docket No. 97–ANE–

53–AD, 12 New England Executive Park,

Burlington, MA 01803–5299. Comments

may also be sent via the Internet using

the following address: ‘‘9-adengineprop@faa.dot.gov’’. Comments

sent via the Internet must contain the

docket number in the subject line.

Comments may be inspected at this

location between 8:00 a.m. and 4:30

p.m., Monday through Friday, except

Federal holidays.

The service information referenced in

the proposed rule may be obtained from

Pratt & Whitney, 400 Main St., East

Hartford, CT 06108; telephone (860)

565–6600, fax (860) 565–4503. This

information may be examined at the

FAA, New England Region, Office of the

Regional Counsel, 12 New England

Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Chris Gavriel, Aerospace Engineer,

Engine Certification Office, FAA, Engine

and Propeller Directorate, 12 New

England Executive Park, Burlington, MA

01803–5299; telephone (781) 238–7147,

fax (781) 238–7199.

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

Docket Number 97–ANE–53–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, New England Region, Office of the

Regional Counsel, Attention: Rules

Docket No. 97–ANE–53–AD, 12 New

England Executive Park, Burlington, MA

01803–5299.

Discussion

The Federal Aviation Administration

(FAA) has received reports of certain

Pratt & Whitney (PW) PW4000 series

turbofan engine power loss events

occurring frequently during a critical

phase of flight such as takeoff or climb.

The events have led to the flight crew

conducting rejected takeoffs and to

engine power loss or shutdown events

in flight. A rejected takeoff could result

in the airplane overrunning the runway,

incurring airplane damage, and injuring

airplane occupants. Engine power loss

or shutdown during takeoff also

significantly increases crew workload

during a critical phase of flight. The

investigations into these events revealed

that they were caused by high pressure

compressor (HPC) surge that could

require crew action to recover. Further

investigation revealed that the surge

results from excessive HPC rear stage

rotor-to-case clearance. This condition,

if not corrected, could result in HPC

surge, which can result in engine power

loss at a critical phase of flight such as

takeoff.

The FAA has reviewed and approved

the technical contents of the following

PW Service Bulletins (SB): PW4ENG–

72–484, Revision 3, dated July 1, 1997,

that describes procedures for HPC blade

tip grinding at the rotor assembly and

introduces HPC aluminum oxide blade

tip coating in stages 9 through 15

compatible with tip grinding; PW4ENG–

72–486, Revision 1, dated November 23,

1994, that describes procedures for

modifying HPC 8th through 14th stage

stators; PW4ENG–72–514, Revision 1,

dated August 2, 1996, that describe

procedures for high pressure turbine

(HPT) hardware modifications to

accommodate the incorporation of 1st

stage HPT vanes with increased airflow

area; and PW4ENG–72–575, Revision 1,

dated June 30, 1997, that describes

procedures for incorporating HPC 13th–

15th stage zirconium oxide tips.