Federal Register / Vol. 65, No. 79 / Monday, April 24, 2000 / Proposed Rules 21675

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 (d) 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 fatigue failure of a TT strap,

loss of a main rotor blade (blade), and

subsequent loss of control of the helicopter,

accomplish the following:

(a) Before further flight,

(1) Create a component log card or

equivalent record for each TT strap.

(2) Review the history of the helicopter and

each TT strap. Determine the age since initial

installation on any helicopter (age) and the

number of flights on each TT strap. Enter

both the age and the number of flights for

each TT strap on the component log card or

equivalent record. When the number of

flights is unknown, multiply the number of

hours time-in-service (TIS) by 5 to determine

the number of flights. If a TT strap has been

previously used at any time on Model BO–

105LS A–3 ‘‘SUPER LIFTER’’, BO–105 CB–5,

BO–105 CBS–5, BO–105 DBS–5, or any

MBB–BK 117 series helicopter, multiply the

number of flights accumulated on those other

models by a factor of 1.6 and then add that

result to the number of flights accumulated

on the helicopters affected by this AD.

(3) Remove any TT strap from service if the

total hours TIS or number of flights and age

cannot be determined.

(b) On or before January 1, 2001, remove

any TT strap that has been in service 120

months since initial installation on any

helicopter or accumulated 40,000 flights (a

flight is a takeoff and a landing), on any

helicopter. Replace the TT strap with an

airworthy TT strap.

(c) This AD revises the Airworthiness

Limitations Section of the maintenance

manual by establishing a life limit for the TT

strap, P/N 2604067 and J17322–1, of 120

months or 40,000 flights, whichever occurs

first.

(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, Regulations

Group, Rotorcraft Directorate, FAA.

Operators shall submit their requests through

an FAA Principal Maintenance Inspector,

who may concur or comment and then send

it to the Manager, Regulations Group.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Regulations Group.

(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 helicopter

to a location where the requirements of this

AD can be accomplished.

Note 3: The subject of this AD is addressed

in the Luftfahrt Bundesamt (Federal Republic

of Germany) AD 1999–300/3, dated August

31, 1999.

Issued in Fort Worth, Texas, on April 17,

2000.

Mark R. Schilling,

Acting Manager, Rotorcraft Directorate,

Aircraft Certification Service.

[FR Doc. 00–10086 Filed 4–21–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–NM–313–AD]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 747–100, –200, –300, –400, and

747SR Series Airplanes

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 all

Boeing Model 747–100, –200, –300,

–400, and 747SR series airplanes. This

proposal would require repetitive

inspections to detect cracks and

corrosion around the lower bearing of

the actuator attach fittings of the

inboard and outboard flaps. This

proposal also would require repetitive

overhauls for certain attach fittings or

repetitive replacement of the attach

fittings with new attach fittings, as

applicable, which would constitute

terminating action for certain repetitive

actions. This proposal is prompted by

reports of cracks on the lower bearing

journal of the inboard actuator attach

fittings of the outboard trailing edge

flaps due to stress corrosion. The

actions specified by the proposed AD

are intended to detect and correct

cracking on the actuator attach fittings

of the trailing edge flaps, which could

result in abnormal operation or

retraction of a trailing edge flap, and

consequent reduced controllability of

the airplane.

DATES: Comments must be received by

June 8, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 99–NM–

313–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

Boeing Commercial Airplane Group,

P.O. Box 3707, Seattle, Washington

98124–2207. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Tamara L. Anderson, Aerospace

Engineer, Airframe Branch, ANM–120S,

FAA, Transport Airplane Directorate,

Seattle Aircraft Certification Office,

1601 Lind Avenue, SW., Renton,

Washington 98055–4056; telephone

(425) 227–2771; fax (425) 227–1181.

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

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 99–NM–313–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–114, Attention: Rules Docket No.

99–NM–313–AD, 1601 Lind Avenue,

SW., Renton, Washington 98055–4056.

Discussion

The FAA has received reports of

stress corrosion cracks on the lower

21676 Federal Register / Vol. 65, No. 79 / Monday, April 24, 2000 / Proposed Rules

bearing journal of the number 2 and 7

inboard attach fittings of the outboard

trailing edge flaps on Boeing Model

747–200 and –300 series airplanes. Each

flap assembly has two attach fittings,

one on each ballscrew which is attached

to the flap transmission. Such cracking,

if not detected and corrected, could

result in abnormal operation or

retraction of a trailing edge flap, and

consequent reduced controllability of

the airplane.

The subject actuator attach fittings on

the inboard and outboard flaps on

Boeing Model 747–100, –400, and

747SR series airplanes are identical to

that of the affected Boeing Model 747–

200 and –300 series airplanes.

Therefore, all of these airplanes may be

subject to the same unsafe condition.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Service Bulletin 747–57A2310,

Revision 1, dated November 23, 1999.

This service bulletin describes

procedures for repetitive ultrasonic and

detailed visual inspections (as

applicable) to detect cracks and

corrosion around the lower bearing of

the actuator attach fittings of the

inboard and outboard flaps. This service

bulletin also describes procedures for

repetitive overhauls for the attach

fittings on the outboard flaps or

repetitive replacement of the attach

fittings with new attach fittings, as

applicable, which would eliminate the

need for certain repetitive actions. In

addition, the service bulletin describes

procedures for accomplishing a

terminating action for the inboard flap

attach fittings.

Explanation of Requirements of

Proposed Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other products of this same

type design, the proposed AD would

require accomplishment of the actions

specified in the service bulletin

described previously.

Interim Action

This is considered to be interim

action. The manufacturer has advised

that it currently is developing a

modification that will positively address

the unsafe condition addressed by this

AD. Once this modification is

developed, approved, and available, the

FAA may consider additional

rulemaking.

Cost Impact

There are approximately 1,008

airplanes of the affected design in the

worldwide fleet. The FAA estimates that

206 airplanes of U.S. registry would be

affected by this proposed AD.

It would take approximately 2 work

hours per airplane to accomplish the

proposed inspection(s), at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact of the

inspection(s) proposed by this AD on

U.S. operators is estimated to be

$24,720, or $120 per airplane, per

inspection cycle.

Should an operator be required to

accomplish the proposed overhaul, it

would take approximately 5 work hours

per airplane to accomplish at an average

labor rate of $60 per work hour. Based

on these figures, the cost impact of the

overhaul proposed by this AD on U.S.

operators is estimated to be $61,800, or

$300 per airplane, per overhaul cycle.

Should an operator be required to

accomplish the proposed replacement,

it would take approximately 2 work

hours per airplane to accomplish at an

average labor rate of $60 per work hour.

Required parts would cost

approximately $6,623 (for each of the 4

attach fittings on the outboard flaps) and

$7,566 (for each 4 attach fittings on the

inboard flaps) per airplane. Based on

these figures, the cost impact of the

replacement proposed by this AD on

U.S. operators is estimated to be $26,972

(outboard flaps) and $30,744 (inboard

flaps) per airplane.

The cost impact figures discussed

above are 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.

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 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. 106(g), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

Boeing: Docket 99–NM–313–AD.

Applicability: All Model 747–100, –200,

–300, –400, and 747SR series 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 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 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 detect and correct cracking on the

actuator attach fittings of the trailing edge

flaps, which could result in abnormal

operation or retraction of a trailing edge flap,

and consequent reduced controllability of the

airplane, accomplish the following:

Attach Fittings That Have Not Been

Overhauled or Replaced

(a) For attach fittings on the outboard flaps

that have not been overhauled in accordance

with Boeing 747 OHM 57–52–55, dated June

1, 1997, or replaced with a new fitting; and

for attach fittings on the inboard actuators

that have not been replaced with a new

fitting: Accomplish the actions of paragraph

(c) of this AD at the later of the times

specified in paragraphs (a)(1) and (a)(2) of

this AD.

Federal Register / Vol. 65, No. 79 / Monday, April 24, 2000 / Proposed Rules 21677

(1) Prior to the accumulation of 8 years

since date of manufacture or 8,000 total flight

cycles, whichever occurs first.

(2) Within 6 months after the effective date

of this AD.

Attach Fittings That Have Been Overhauled

or Replaced

(b) For attach fittings on the outboard flaps

that have been overhauled in accordance

with Boeing 747 OHM 57–52–55, dated June

1, 1997, prior to the effective date of this AD,

or replaced with a new fitting; and for attach

fittings on the inboard actuators that have

been replaced with a new fitting: Accomplish

the actions of paragraph (c) of this AD at the

later of the times specified in paragraphs

(b)(1) and (b)(2) of this AD.

(1) Within 8 years or 8,000 total flight

cycles after the attach fitting was overhauled

or replaced, whichever occurs first.

(2) Within 6 months after the effective date

of this AD.

Inspections and Corrective Action

(c) Perform a detailed visual inspection to

detect corrosion around the lower bearing

journal on the actuator attach fittings on the

inboard and outboard flaps, and perform an

ultrasonic inspection to detect cracks around

the lower bearing journal of the attach fittings

of the outboard flaps, in accordance with

Boeing Service Bulletin 747–57A2310,

Revision 1, dated November 23, 1999.

Note 2: For the purposes of this AD, a

detailed inspection is defined as: ‘‘An

intensive visual examination of a specific

structural area, system, installation, or

assembly to detect damage, failure, or

irregularity. Available lighting is normally

supplemented with a direct source of good

lighting at intensity deemed appropriate by

the inspector. Inspection aids such as

mirrors, magnifying lenses, etc., may be used.

Surface cleaning and elaborate access

procedures may be required.’’

Note 3: Inspections and replacements

accomplished in accordance with Boeing

Alert Service Bulletin 747–57A2310, dated

June 17, 1999, are acceptable for compliance

with the requirements of paragraph (c) of this

AD.

(1) If no corrosion or cracks are detected,

repeat the inspections required by paragraph

(c) of this AD at intervals not to exceed 18

months. Within 5 years after the initial

inspections required by paragraph (c) of this

AD, accomplish the actions specified in

paragraph (d) or (e) of this AD.

(2) If any corrosion is detected, prior to

further flight, remove the corrosion by

accomplishing the actions of either paragraph

(c)(2)(i) or (c)(2)(ii) of this AD.

(i) If corrosion is within the limits of the

Boeing 747 Overhaul Manual, prior to further

flight, accomplish the actions specified in

paragraph (d) or (e) of this AD.

(ii) If corrosion is not within the limits of

the Boeing 747 Overhaul Manual, prior to

further flight, accomplish the actions

specified in paragraph (e) of this AD.

(3) If any crack is detected, prior to further

flight, accomplish the actions specified in

paragraph (e) of this AD.

Overhaul

(d) Overhaul the actuator attach fittings on

the outboard flaps in accordance with Boeing

OHM 57–52–55, Temporary Revision 57–7,

dated June 1, 1999. Repeat the overhaul of

actuators on the outboard flaps as specified

in Part 2 of the Work Instructions of the

service bulletin thereafter at intervals not to

exceed 8 years or 8,000 flight cycles,

whichever occurs first. Accomplishment of

the overhaul of the attach fittings on the

outboard flaps constitutes terminating action

for the repetitive inspection requirements of

paragraph (c)(1) of this AD. Overhaul the

attach fittings on the inboard flaps in

accordance with Boeing OHM 57–52–35,

Temporary Revision 57–8, dated June 10,

1999. Accomplishment of the overhaul of the

actuators on the inboard flaps constitutes

terminating action for the requirements of

this AD for the inboard flap attach fittings.

Replacement

(e) Replace the attach fittings on the

inboard and outboard flap actuators with

new attach fittings in accordance with Boeing

Service Bulletin 747–57A2310, Revision 1,

dated November 23, 1999. Accomplishment

of the replacement constitutes terminating

action for the repetitive inspection and

overhaul requirements of paragraphs (c)(1),

(c)(2), and (c)(3) of this AD. Within 8 years

or 8,000 flight cycles following

accomplishment of the replacement,

whichever occurs first, repeat the

replacement or accomplish the overhaul

specified in paragraph (d) of this AD.

Note 4: Replacement of the attach fitting on

the inboard flaps with fittings that have been

overhauled in accordance with Boeing OHM

57–52–35, Temporary Revision 57–8, dated

June 10, 1999, constitutes terminating action

for the requirements of this AD for the

inboard flap attach fittings.

Alternative Methods of Compliance

(f) 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, Seattle

Aircraft Certification Office (ACO), 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, Seattle ACO.

Note 5: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Seattle ACO.

Special Flight Permits

(g) 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 April 18,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–10162 Filed 4–21–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–25–AD]

RIN 2120–AA64

Airworthiness Directives; Saab Model

SAAB SF340A and SAAB 340B Series

Airplanes

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 Saab Model SAAB SF340A and

SAAB 340B series airplanes. This

proposal would require a one-time

inspection to detect chafing of the wires

and harnesses in the cabin compartment

ceiling; repair, if necessary; and

installation of protective sleeving. This

proposal is prompted by issuance of

mandatory continuing airworthiness

information by a foreign civil

airworthiness authority. The actions

specified by the proposed AD are

intended to prevent false warnings of a

hot engine exhaust tailpipe and

intermittent signal failure, which could

result in the consequent execution of

unnecessary procedures by the

flightcrew.

DATES: Comments must be received by

May 24, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 2000–NM–

25–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

Saab Aircraft AB, SAAB Aircraft

Product Support, S–581.88, Linko ̈

ping,

Sweden. This information may be

examined at the FAA, Transport

Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Norman B. Martenson, Manager,

International Branch, ANM–116, FAA,

Transport Airplane Directorate, 1601

Lind Avenue, SW., Renton, Washington

98055–4056; telephone (425) 227–2110;

fax (425) 227–1149.

SUPPLEMENTARY INFORMATION: