Federal Register / Vol. 65, No. 103 / Friday, May 26, 2000 / Rules and Regulations 34063

Issued in Renton, Washington, on May 18,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–13086 Filed 5–25–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000–NM–111–AD; Amendment

39–11745; AD 2000–10–21]

RIN 2120–AA64

Airworthiness Directives; Boeing

Model 737 Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that is

applicable to certain Boeing Model 737

series airplanes. This action requires a

one-time general visual inspection of

the seat locks and seat tracks of the

flightcrew seats to ensure that the seats

lock in position and to verify that lock

nuts and bolts of adequate length are

installed on the rear tracklock bracket,

and corrective action, if necessary. This

action is necessary to prevent

uncommanded movement of the

flightcrew seats during acceleration and

take-off of the airplane, which could

result in reduced controllability of the

airplane. This action is intended to

address the identified unsafe condition.

DATES: Effective June 12, 2000.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of June 12,

2000.

Comments for inclusion in the Rules

Docket must be received on or before

July 25, 2000.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, ANM–114,

Attention: Rules Docket No. 2000–NM–

111–AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055–4056.

Comments may be inspected at this

location between 9 a.m. and 3 p.m.,

Monday through Friday, except Federal

holidays. Comments may be submitted

via fax to (425) 227–1232. Comments

may also be sent via the Internet using

the following address: 9–anm–

iarcomment@faa.gov. Comments sent

via fax or the Internet must contain

‘‘Docket No. 2000–NM–111–AD’’ in the

subject line and need not be submitted

in triplicate.

The service information referenced in

this AD 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; or at the Office of

the Federal Register, 800 North Capitol

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

FOR FURTHER INFORMATION CONTACT:

Keith Ladderud, Aerospace Engineer,

Airframe Branch, ANM–120S, FAA,

Seattle Aircraft Certification Office,

1601 Lind Avenue, SW., Renton,

Washington; telephone (425) 227–2780;

fax (425) 227–1181.

SUPPLEMENTARY INFORMATION: The FAA

has received reports indicating

instances of the pilot seat sliding to the

aft-most position during acceleration

and take-off on certain Boeing Model

737 series airplanes. Investigation

revealed that the screws attaching the

rear tracklock bracket to the seat track

had broken, allowing excessive lateral

movement and disengagement of the

locking pin from the floor-mounted seat

track. A disengaged locking pin can

cause misalignment of the seat tracks.

Such misalignment of the seat tracks, if

not corrected, could result in

uncommanded movement of the

flightcrew seats during acceleration and

take-off of the airplane, which could

result in reduced controllability of the

airplane.

Explanation of Relevant Service

Information

The FAA has reviewed and approved

Boeing Alert Service Bulletin 737–

25A1363, dated November 5, 1998,

which describes procedures for a onetime general visual inspection of the

seat locks and seat tracks of the

flightcrew seats to ensure that the seats

lock in position and to verify that lock

nuts and bolts of adequate length are

installed on the rear tracklock bracket.

If lock nuts and bolts of adequate length

are not installed on the rear tracklock

bracket, the service bulletin describes

installation of lock nuts and bolts of

adequate length on the tracklock

bracket, and re-alignment of the seat

tracks. Accomplishment of the actions

specified in the alert service bulletin is

intended to adequately address the

identified unsafe condition.

Explanation of the Requirements of the

Rule

Since an unsafe condition has been

identified that is likely to exist or

develop on other Boeing Model 737

series airplanes of the same type design,

this AD is being issued to prevent

uncommanded movement of the

flightcrew seats during acceleration and

take-off of the airplane, and consequent

reduced controllability of the airplane.

This AD requires a one-time general

visual inspection of the seat locks and

seat tracks of the flightcrew seats to

ensure that the seats lock in position

and to verify that lock nuts and bolts of

adequate length are installed on the rear

tracklock bracket, and corrective action,

if necessary. The actions are required to

be accomplished in accordance with the

alert service bulletin described

previously, except as discussed below.

Difference Between Alert Service

Bulletin and This AD

Operators should note that, although

the alert service bulletin recommends

accomplishment of the actions as soon

as manpower and materials are

available, the FAA has determined that

a 90-day compliance time would

address the identified unsafe condition

in a timely manner. In developing an

appropriate compliance time for this

AD, the FAA considered not only the

manufacturer’s recommendation, but

the degree of urgency associated with

addressing the subject unsafe condition,

the average utilization of the affected

fleet, and the time necessary to perform

the actions. In light of all of these

factors, the FAA finds a 90-day

compliance time for completion of the

actions to be warranted, in that it

represents an appropriate interval of

time allowable for affected airplanes to

continue to operate without

compromising safety.

Determination of Rule’s Effective Date

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.

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 shall identify the

Rules Docket number and be submitted

in triplicate to the address specified

under the caption ADDRESSES. All

communications received on or before

34064 Federal Register / Vol. 65, No. 103 / Friday, May 26, 2000 / Rules and Regulations

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.

Submit comments using the following

format: • Organize comments issue-by-issue.

For example, discuss a request to

change the compliance time and a

request to change the service bulletin

reference as two separate issues. • For each issue, state what specific

change to the AD is being requested. • Include justification (e.g., reasons or

data) for each request. 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 Number 2000–NM–111–AD.’’

The postcard will be date stamped and

returned to the commenter.

Regulatory Impact

The regulations adopted herein will

not have a substantial direct effect 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, it is

determined that this final rule does not

have federalism implications under

Executive Order 13132.

The FAA has determined that this

regulation is an emergency regulation

that must be issued immediately to

correct an unsafe condition in aircraft,

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, 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 the following new airworthiness

directive:

2000–10–21 BOEING: Amendment 39–

11745. Docket 2000–NM–111—AD.

Applicability: Model 737–300, –400,

and –500 series airplanes equipped with IPECO flightcrew seats; as listed in

Boeing Alert Service Bulletin 737–

25A1363, dated November 5, 1998;

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 (b) 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 uncommanded movement

of the flightcrew seats during

acceleration and take-off of the airplane,

accomplish the following:

One-Time Inspection

(a) Within 90 days after the effective

date of this AD, perform a one-time

general visual inspection of the seat

locks and seat tracks of the flightcrew

seats to ensure that the seats lock in

position and to verify that lock nuts and

bolts of adequate length are installed on

the rear tracklock bracket, in accordance

with Boeing Alert Service Bulletin 737–

25A1363, dated November 5, 1998.

(1) If the seat lock pin fully engages

in all lock positions of the seat track,

and the rear tracklock bracket is

correctly installed, no further action is

required by this AD.

General Visual Inspection

Note 2: For the purposes of this AD, a

general visual inspection is defined as: ‘‘A

visual examination of an interior or exterior

area, installation, or assembly to detect

obvious damage, failure, or irregularity. This

level of inspection is made under normally

available lighting conditions such as

daylight, hangar lighting, flashlight, or droplight and may require removal or opening of

access panels or doors. Stands, ladders, or

platforms may be required to gain proximity

to the area being checked.’’

Corrective Action

(2) If the seat lock pin does not fully

engage in all positions of the seat track,

and lock nuts and bolts of adequate

length are not installed on the rear

tracklock bracket, prior to further flight,

install lock nuts and bolts of adequate

length on the tracklock bracket and realign the seat tracks, in accordance with

the alert service bulletin.

Alternative Methods of Compliance

(b) 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 3: 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

(c) 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.

Incorporation by Reference

(d) The actions shall be done in

accordance with Boeing Alert Service

Bulletin 737–25A1363, dated November

5, 1998. 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 Boeing

Commercial Airplane Group, P.O. Box

Federal Register / Vol. 65, No. 103 / Friday, May 26, 2000 / Rules and Regulations 34065

3707, Seattle, Washington 98124–2207.

Copies may be inspected at the FAA,

Transport Airplane Directorate, 1601

Lind Avenue, SW., Renton, Washington;

or at the Office of the Federal Register,

800 North Capitol Street, NW., suite

700, Washington, DC.

(e) This amendment becomes effective

on June 12, 2000.

Issued in Renton, Washington, on May 18,

2000.

Donald L. Riggin,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 00–13085 Filed 5–25–00; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99–CE–27–AD; Amendment 39–

11746; AD 2000–10–22]

RIN 2120–AA64

Airworthiness Directives; REVO,

Incorporated Models Lake LA–4, Lake

LA–4A, Lake LA–4P, Lake LA–4–200,

and Lake Model 250 Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule; request for

comments.

SUMMARY: This amendment adopts a

new airworthiness directive (AD) that

applies to certain REVO, Incorporated

(REVO) Models Lake LA–4, Lake LA–

4A, Lake LA–4P, Lake LA–4–200, and

Lake Model 250 airplanes. This AD

requires you to: inspect the left and

right wing upper and lower spar

doublers for cracks; replace any cracked

parts; and incorporate a modification

kit. This AD is the result of a report of

a fatigue crack found at the second most

inboard wing attachment bolt hole on

one of the affected airplanes. Similar

fatigue cracking has since been reported

on seven more of the affected airplanes,

including incidents where the fatigue

cracking occurred on airplanes with less

than 500 hours time-in-service (TIS).

The actions specified by this AD are

intended to detect and correct cracks in

the wing spars, which could result in

the wing separating from the airplane

with consequent loss of control.

DATES: This AD becomes effective on

June 20, 2000.

The Director of the Federal Register

approved the incorporation by reference

of certain publications listed in the

regulation as of June 20, 2000.

The Federal Aviation Administration

(FAA) must receive any comments on

this rule on or before July 28, 2000.

ADDRESSES: Submit comments in

triplicate to the FAA, Central Region,

Office of the Regional Counsel,

Attention: Rules Docket No. 99–CE–27–

AD, 901 Locust, Room 506, Kansas City,

Missouri 64106.

You may get the service information

referenced in this AD from REVO,

Incorporated, P.O. Box 312, One High

Street, Sanford, Maine 04073. You may

examine this information at FAA,

Central Region, Office of the Regional

Counsel, Attention: Rules Docket No.

99–CE–27–AD, 901 Locust, Room 506,

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.

Richard B. Noll, Aerospace Engineer,

FAA, Boston Aircraft Certification

Office, 12 New England Executive Park,

Burlington, Massachusetts 01803;

telephone: (781) 238–7160; facsimile:

(781) 238–7199.

SUPPLEMENTARY INFORMATION:

Discussion

What Caused This AD?

This AD is the result of a report of

fatigue cracks that were found at the

second-most inboard wing attachment

bolt hole on a REVO Lake Model 250

airplane. The cracks were detected

during wing repair where the wing spar

and wing skin were disassembled.

Further analysis indicated that the

cracks initiated at a machined notch at

the flange termination point of the spar

cap.

The REVO Models Lake LA–4, Lake

LA–4A, Lake LA–4P, and Lake LA–4–

200 airplanes are of the same type

design as the Lake Model 250 airplanes.

Fatigue cracking similar to that of the

above-referenced report has been found

on seven more of these airplanes.

What Is the Potential Impact If FAA

Took No Action?

Cracks in the wing spars, if not

detected and corrected in a timely

manner, could result in the wing

separating from the airplane with

consequent loss of control.

Has FAA Taken Any Action to This

Point?

We issued a notice of proposed

rulemaking (NPRM) to amend part 39 of

the Federal Aviation Regulations (14

CFR part 39) to include an AD that

would apply to certain REVO Models

Lake LA–4, Lake LA–4A, Lake LA–4P,

Lake LA–4–200, and Lake Model 250

airplanes. We published this NPRM in

the Federal Register on October 6, 1999

(64 FR 54234). The NPRM proposed to

require you to accomplish the following:

—Inspect the left and right wing upper

and lower spar caps and doublers for

cracks;

—Replace any cracked parts;

—Incorporate a modification kit if

damaged past a certain level; and

—Report the results of the inspection to

FAA.

REVO Service Bulletin B–79, dated

June 12, 1999, includes the procedures

necessary for you to accomplish the

proposed inspection and modification.

Was the Public Invited To Comment?

The FAA offered interested persons

the opportunity to participate in the

making of this amendment. The

following paragraphs present the

comments received on the NPRM. Also

included is FAA’s response to each

comment, including any changes

incorporated into the final rule based on

the comments.

Comment Issue No. 1: Wing Spar

Cracking Does Not Warrant AD Action

What are the Commenters’ Concerns?

Numerous commenters question FAA’s

justification for issuing an AD. Several

commenters do not believe our service

difficulty database provides accurate

information. A few commenters

recommend that we conduct additional

research on the cause of the wing spar

cracks and determine if the cracks are

unique to a particular configuration of

the affected airplanes. Other

commenters propose various causes of

the cracks, including:

—Installation of auxiliary fuel tanks in

the wing floats;

—Increased braking power in the Model

Lake LA–4–200 and Lake Model 250

airplanes; and

—The presence of corrosion.

What is FAA’s Response to the

Concerns? We do not concur that the

AD is not justified. We began our

investigation of the wing spar cracks on

the affected airplanes when the

Australian Civil Aviation Safety

Authority reported cracks in both the

spar cap and doubler in the lower spar

of a Lake Model 250 airplane. We then

received several reports of similar

cracking from personnel of maintenance

and repair facilities that were working

on the affected airplanes. Reports

indicated that both the upper and lower

spars were cracked. These subsequent

reports did not specify corrosion

damage. All of the wing spar cracks

initiated at a machined notch at the

flange termination point of the spar cap