Airworthiness Directives; Boeing Model 737 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-02-AD; Amendment 39-11394; AD 99-22-16]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 737 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD),

applicable to certain Boeing Model 737 series airplanes, that requires

a one-time detailed visual inspection of the upper decompression panel

on the flight deck door to verify that a minimum overlap dimension

exists, and corrective action, if necessary. This amendment is prompted

by reports indicating that, during production, some upper decompression

panels were installed incorrectly on the flight deck door. The actions

specified by this AD are intended to detect an incorrectly installed

upper decompression panel, which could cause the emergency exit panel

on the flight deck door to become inoperable, thereby preventing

crewmembers from performing essential duties during an emergency

evacuation.

DATES: Effective December 7, 1999.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of December 7, 1999.

ADDRESSES: 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 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: Mike Thompson, Aerospace Engineer,

Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle

Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056; telephone (425) 227-1157; fax (425) 227-1181.

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

Aviation Regulations (14 CFR part 39) to include an airworthiness

directive (AD) that is applicable to certain Boeing Model 737 series

airplanes was published in the Federal Register on August 20, 1999 (64

FR 45470). That action proposed to require a one-time detailed visual

inspection of the upper decompression panel on the flight deck door to

verify that a minimum overlap dimension exists, and corrective action,

if necessary.

Comments

Interested persons have been afforded an opportunity to participate

in the making of this amendment. No comments were submitted in response

to the proposal or the FAA's determination of the cost to the public.

Conclusion

The FAA has determined that air safety and the public interest

require the adoption of the rule as proposed.

Cost Impact

There are approximately 1,299 airplanes of the affected design in

the worldwide fleet. The FAA estimates that 901 airplanes of U.S.

registry will be affected by this AD, that it will take approximately 1

work hour per airplane to accomplish the required inspection, and that

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

the cost impact of the inspection required

[[Page 59117]]

by this AD on U.S. operators is estimated to be $54,060, or $60 per

airplane.

The cost impact figure discussed above is based on assumptions that

no operator has yet accomplished any of the 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 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 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 adding the following new

airworthiness directive:

99-22-16 BOEING: Amendment 39-11394. Docket 99-NM-02-AD.

Applicability: Model 737 series airplanes, as listed in Boeing

Service Bulletin 737-52-1128, dated April 22, 1999, or in Boeing

Service Bulletin 737-52-1137, dated May 13, 1999; 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) 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 an incorrectly installed upper decompression panel,

which could cause the emergency exit panel on the flight deck door

to become inoperable, thereby preventing crewmembers from performing

essential duties during an emergency evacuation, accomplish the

following:

One-Time Inspection

(a) Within 18 months after the effective date of this AD,

perform a one-time detailed visual inspection of the upper

decompression panel on the flight deck door to verify that a minimum

overlap dimension of 0.05 inch exists, as specified in Boeing

Service Bulletin 737-52-1128, dated April 22, 1999 (for Model 737-

300/-400/-500 series airplanes); or Boeing Service Bulletin 737-52-

1137, dated May 13, 1999 (for Model 737-600/-700/-800 series

airplanes); as applicable.

Note 2: For the purposes of this AD, a detailed visual

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 mirror, magnifying lenses, etc., may be used. Surface cleaning

and elaborate access procedures may be required.''

Corrective Action

(b) If a minimum overlap dimension of 0.05 inch is not found

during the inspection required by paragraph (a) of this AD, prior to

further flight, adjust the decompression panel and, as applicable,

the adjacent decorative channel, in accordance with Boeing Service

Bulletin 737-52-1128, dated April 22, 1999 (for Model 737-300/-400/-

500 series airplanes); or Boeing Service Bulletin 737-52-1137, dated

May 13, 1999 (for Model 737-600/-700/-800 series airplanes); as

applicable.

Alternative Methods of Compliance

(c) 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

(d) Special flight permits may be issued in accordance with

Secs. 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

(e) The actions shall be done in accordance with Boeing Service

Bulletin 737-52-1128, dated April 22, 1999, or Boeing Service

Bulletin 737-52-1137, dated May 13, 1999, as applicable. 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 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.

(f) This amendment becomes effective on December 7, 1999.

Issued in Renton, Washington, on October 22, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-28246 Filed 11-1-99; 8:45 am]

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