Airworthiness Directives; Boeing Model 737-100 and -200 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-72-AD; Amendment 39-10967; AD 98-26-24]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 737-100 and -200 Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive

(AD), applicable to certain Boeing Model 737-100 and -200 series

airplanes, that

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currently requires replacement of certain outboard and inboard wheel

halves with improved wheel halves; cleaning and inspecting certain

outboard and inboard wheel halves for corrosion, missing paint in large

areas, and cracks; and repair or replacement of the wheel halves with

serviceable wheel halves, if necessary. That AD was prompted by a

review of the design of the flight control systems on Model 737 series

airplanes. This amendment requires that the actions be accomplished in

accordance with revised service information. The actions specified by

this AD are intended to prevent failure of the wheel flanges, which

could result in damage to the hydraulics systems, jammed flight

controls, loss of electrical power, or other combinations of failures;

and consequent reduced controllability of the airplane.

DATES: Effective February 8, 1999.

The incorporation by reference of Allied Signal Service Bulletin

737-32-026, dated June 27, 1988, including Attachment 1, dated January

17, 1978, and Attachment 2, dated June 27, 1988, is approved by the

Director of the Federal Register as of February 8, 1999.

The incorporation by reference of certain other publications, as

listed in the regulations, was approved previously by the Director of

the Federal Register as of September 16, 1997 (62 FR 43067, August 12,

1997).

ADDRESSES: The service information referenced in this AD may be

obtained from Allied Signal Aerospace Company, Bendix Wheels and Brakes

Division, South Bend, Indiana 46624; and Bendix, Aircraft Brake and

Strut Division, 3520 Westmoor Street, South Bend, Indiana 46628-1373.

This information may be examined at the Federal Aviation Administration

(FAA), Transport Airplane Directorate, Rules Docket, 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: David Herron, Aerospace Engineer,

Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane

Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue,

SW., Renton, Washington 98055-4056; telephone (425) 227-2672; fax (425)

227-1181.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) by superseding AD 97-17-01,

amendment 39-10102 (62 FR 43067, August 12, 1997), which is applicable

to certain Boeing Model 737-100 and -200 series airplanes, was

published in the Federal Register on July 9, 1998 (63 FR 37072). The

action proposed to continue to require replacement of certain outboard

and inboard wheel halves with improved wheel halves; cleaning and

inspecting certain outboard and inboard wheel halves for corrosion,

missing paint in large areas, and cracks; and repair or replacement of

the wheel halves with serviceable wheel halves, if necessary. The

action also proposed to require that the actions be accomplished in

accordance with revised service information.

Comments

Interested persons have been afforded an opportunity to participate

in the making of this amendment. Due consideration has been given to

the three comments received.

The commenters support the proposed rule.

Explanation of Changes Made to This Final Rule

The notice of proposed rulemaking (NPRM) references Allied Signal

Service Bulletin No. 737-32-026, dated June 27, 1998, including

Attachment 1, dated January 17, 1978, and Attachment 2, dated June 27,

1988, as the appropriate source of service information for

accomplishment of the actions specified in paragraph (a)(1) of the

NPRM. However, the FAA intended to give credit to any operator that may

have accomplished the actions previously in accordance with Allied

Signal Service Bulletin No. 737-32-026, dated April 26, 1988 (which was

referenced as the appropriate source of service information for

accomplishment of certain actions in AD 97-17-01). Reference to Allied

Signal Service Bulletin No. 737-32-026, dated April 26, 1988, was

inadvertently omitted from paragraph (a)(1) of the NPRM. Therefore, the

FAA has revised the final rule to specify that accomplishment of the

actions specified in paragraphs (a)(1)(i), (a)(1)(ii), and (a)(1)(iii)

of this AD in accordance with Allied Signal Service Bulletin No. 737-

32-026, dated April 26, 1988, or Allied Signal Service Bulletin No.

737-32-026, dated June 27, 1988, including Attachment 1, dated January

17, 1978, and Attachment 2, dated June 27, 1988; prior to the effective

date of this AD; is acceptable for compliance with the applicable

requirements of this AD.

Conclusion

After careful review of the available data, including the comments

noted above, the FAA has determined that air safety and the public

interest require the adoption of the rule with the change described

previously. The FAA has determined that this change will neither

increase the economic burden on any operator nor increase the scope of

the AD.

Cost Impact

There are approximately 634 Model 737-100 and -200 series airplanes

of the affected design in the worldwide fleet. The FAA estimates that

241 airplanes of U.S. registry will be affected by this AD.

Because this AD merely requires that the actions currently required

by AD 97-17-01 be accomplished in accordance with revised service

information, the AD adds no additional costs and requires no additional

work to be performed by affected operators. The current costs

associated with this amendment are reiterated in their entirety (as

follows) for the convenience of affected operators.

The FAA estimates that it will take approximately 4 work hours per

airplane to accomplish the required replacement of wheel halves, at an

average labor rate of $60 per work hour. Required parts will cost

approximately $20,212 per airplane. Based on these figures, the cost

impact of the required replacement on U.S. operators is estimated to be

$4,928,932, or $20,452 per airplane.

The FAA also estimates that it will take approximately 2 work hours

per airplane to accomplish the required cleaning and inspection, at an

average labor rate of $60 per work hour. Based on these figures, the

cost impact of the required cleaning and inspection on U.S. operators

is estimated to be $28,920, or $120 per airplane.

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 final evaluation has

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been prepared for this action and it is contained in the Rules Docket.

A copy of it 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing amendment 39-10102 (62 FR

43067, August 12, 1997), and by adding a new airworthiness directive

(AD), amendment 39-10967, to read as follows:

98-26-24 Boeing: Amendment 39-10967. Docket 98-NM-72-AD. Supersedes

AD 97-17-01, Amendment 39-10102.

Applicability: Model 737-100 and -200 series airplanes equipped

with Bendix main wheel assemblies having part number (P/N) 2601571-

1, 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 (c)(1)

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 failure of the wheel flanges, which could result in

damage to the hydraulics systems, jammed flight controls, loss of

electrical power, or other combinations of failures; and consequent

reduced controllability of the airplane; accomplish the following:

Note 2: Allied Signal, Aircraft Landing Systems, Service

Information Letter (SIL) # 619, dated February 26, 1997, is an

additional source of service information for appropriate wheel half

serial numbers.

(a) For airplanes equipped with a Bendix main wheel assembly

having P/N 2601571-1 with an inboard wheel half with serial number

(S/N) B-5898 or lower, or S/N H-1721 or lower; or with an outboard

wheel half with S/N B-5898 or lower, or S/N H-0863 or lower;

accomplish the following:

(1) Within 180 days after September 16, 1997 (the effective date

of AD 97-17-01, amendment 39-10102, 62 FR 43067), and thereafter at

each tire change until the replacement required by paragraph (b) of

this AD is accomplished: Accomplish the actions specified in

paragraphs (a)(1)(i), (a)(1)(ii), and (a)(1)(iii) of this AD, in

accordance with the Accomplishment Instructions of Allied Signal

Service Bulletin No. 737-32-026, dated April 26, 1988, or Allied

Signal Service Bulletin No. 737-32-026, dated June 27, 1988,

including Attachment 1, dated January 17, 1978, and Attachment 2,

dated June 27, 1988. After the effective date of this AD, only

Allied Signal Service Bulletin No. 737-32-026, dated June 27, 1998,

including Attachment 1, dated January 17, 1978, and Attachment 2,

dated June 27, 1988, shall be used.

(i) Clean any inboard and outboard wheel half specified in

paragraph (a) of this AD. And

(ii) Inspect the wheel halves for corrosion or missing paint. If

any corrosion is found, or if any paint is missing in large areas,

prior to further flight, strip or remove paint, and remove any

corrosion. And

(iii) Perform an eddy current inspection to detect cracks of the

bead seat area.

(2) If any cracking is found during the inspections required by

this paragraph, prior to further flight, repair or replace the wheel

halves with serviceable wheel halves in accordance with procedures

specified in the Component Maintenance Manual.

(b) For airplanes equipped with a Bendix main wheel assembly

having P/N 2601571-1 with an inboard wheel half with S/N B-5898 or

lower, or S/N H-1721 or lower; or with an outboard wheel half with

S/N B-5898 or lower, or S/N H-0863 or lower; accomplish the

following: Within 2 years after September 16, 1997, accomplish the

actions specified in paragraphs (b)(1) and (b)(2) of this AD, in

accordance with Bendix Service Information Letter 392, Revision 1,

dated November 15, 1979. Accomplishment of the replacement

constitutes terminating action for the repetitive inspections

required by paragraph (a) of this AD.

(1) Remove any inboard wheel half specified in paragraph (b) of

this AD, and replace it with an inboard wheel half having P/N

2607046, S/N 5899 or greater, or S/N H-1722 or greater. And

(2) Remove any outboard wheel half specified in paragraph (b) of

this AD, and replace it with an outboard wheel half having P/N

2607047, S/N B-5899 or greater, or S/N H-0864 or greater.

(c)(1) 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.

(2) Alternative methods of compliance, approved previously in

accordance with AD 97-17-01, amendment 39-10102, are approved as

alternative methods of compliance with this AD.

Note 3: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the Seattle ACO.

(d) 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.

(e) Except as provided by paragraph (a)(2) of this AD, the

actions shall be done in accordance with Bendix Service Information

Letter 392, Revision 1, dated November 15, 1979; Allied Signal

Service Bulletin No. 737-32-026, dated April 26, 1988; or Allied

Signal Service Bulletin No. 737-32-026, dated June 27, 1998;

including Attachment 1, dated January 17, 1978, and Attachment 2,

dated June 27, 1988; which contains the following list of effective

pages:

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Revision level

Page No. shown on page Date shown on page

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1-6......................... Original....... June 27, 1988.

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Attachment 1

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7-14........................ Original....... January 17, 1978.

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Attachment 2

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15.......................... Original....... June 27, 1988.

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(1) The incorporation by reference of Allied Signal Service

Bulletin 737-32-026, dated June 27, 1988, including Attachment 1,

dated January 17, 1978, and Attachment 2, dated June 27, 1988, is

approved by the Director of the Federal Register in accordance with

5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of Bendix Service Information

Letter 392, Revision 1, dated November 15, 1979; and Allied Signal

Service Bulletin No. 737-32-026, dated April 26, 1988; was approved

previously by the Director of the Federal Register as of September

16, 1997 (62 FR 43067, August 12, 1997).

(3) Copies may be obtained from Allied Signal Aerospace Company,

Bendix Wheels and Brakes Division, South Bend, Indiana 46624; and

Bendix Aircraft Brake and Strut Division, 3520 Westmoor Street,

South Bend, Indiana 46628-1373. 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.

(f) This amendment becomes effective on February 8, 1999.

Issued in Renton, Washington, on December 17, 1998.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 98-34097 Filed 12-31-98; 8:45 am]

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