Airworthiness Directives; Boeing Model 747-300 and -400 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-45-AD; Amendment 39-11212; AD 99-14-04]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 747-300 and -400 Series

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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

is applicable to certain Boeing Model 747-300 and -400 series

airplanes. This action requires repetitive inspections of the E-42

satellite communications (SATCOM) rack and fuselage (supporting)

structure to detect cracking in the area surrounding the fastener

holes, and to detect broken and missing fasteners; and corrective

actions, if necessary. This amendment is prompted by reports indicating

that cracking and broken and/or missing fasteners were found on the E-

42 SATCOM equipment rack structure that attaches to the fuselage

structure. The actions specified in this AD are intended to detect and

repair cracking of the E-42 SATCOM rack and its supporting structure,

which could result in the SATCOM equipment falling from the rack, loss

of SATCOM capabilities, injury to passengers, and reduced

controllability of the airplane.

DATES: Effective July 14, 1999.

The incorporation by reference of certain publications listed in

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

of July 14, 1999.

Comments for inclusion in the Rules Docket must be received on or

before August 30, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 99-NM-45-AD, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056.

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.

[[Page 34708]]

FOR FURTHER INFORMATION CONTACT: Elizabeth A. Gnehm, Aerospace

Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane

Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue,

SW., Renton, Washington 98055-4056; telephone (425) 227-1426; fax (425)

227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received reports indicating that

cracking and broken and/or missing fasteners were found on the E-42

SATCOM equipment rack structure that attaches to the fuselage structure

on several Boeing Model 747-300 and -400 series airplanes.

Investigation revealed that one of the four stanchions (i.e., a

supporting prop or brace) was found completely broken on two airplanes

(one that had accumulated 23,693 total flight hours and the other with

24,752 total flight hours). Further investigation revealed that the

rigid joints of the supporting structure of the E-42 SATCOM rack,

coupled with environmental vibration of the airplane, may have caused

the cracking to initiate in the area surrounding the fastener holes

(located at the rigid joints) of the supporting structure of the E-42

SATCOM rack. The FAA also has received a report indicating that

cracking has been detected on four freighter airplanes; one of the

airplanes had accumulated less than 1,500 total flight hours.

On all airplanes, the E-42 SATCOM rack hangs above the main deck

ceiling. On freighter airplanes and ``combi'' airplanes (i.e.,

configurations with provisions for passenger seating and cargo on the

main deck), the E-42 SATCOM rack is located near rudder and elevator

control cables, and the SATCOM wires run above the rudder and elevator

control cables.

On all airplanes, failure of the rack and its supporting structure

could result in loss of support for the E-42 SATCOM equipment, which

could lead to chafing and arcing of the electrical wires and loss of

SATCOM capabilities. Such failure also could result in the following

unsafe conditions:

On passenger-only airplanes, the E-42 SATCOM equipment

could break through the ceiling, which could result in injury to

passengers.

On freighter and ``combi'' airplanes, the E-42 SATCOM

equipment could fall and cause the SATCOM wires to pull and possibly

break the rudder and/or elevator control cables, which could result in

reduced controllability of the airplane. Failure of the SATCOM rack on

``combi'' airplanes carrying passengers also could result in injury to

the passengers.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin

747-53A2428, dated December 17, 1998, which describes procedures for

repetitive close visual inspections of the E-42 SATCOM rack and

fuselage (supporting) structure to detect cracking in the area

surrounding the fastener holes, and to detect broken or missing

fasteners.

Explanation of the Requirements of the Rule

Since an unsafe condition has been identified that is likely to

exist or develop on other airplanes of the same type design, this AD is

being issued to detect and repair cracking of the E-42 SATCOM rack and

its supporting structure, which could result in the SATCOM equipment

falling from the rack, loss of SATCOM capabilities, injury to

passengers, and reduced controllability of the airplane. This AD

requires accomplishment of the actions specified in the alert service

bulletin described previously, except as discussed below. This AD also

requires that operators report results of initial inspection findings

to the manufacturer.

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.

Differences Between AD and Alert Service Bulletin

Operators should note that, although the Boeing alert service

bulletin specifies that the manufacturer may be contacted for

disposition of certain conditions, this proposal would require the

repair of those conditions to be accomplished in accordance with a

method approved by the FAA.

Operators also should note that the Boeing alert service bulletin

specifies that the manufacturer determine the repetitive inspection

intervals in the event a repair and/or replacement of the fasteners is

necessary. This AD would require repetitive inspections of the E-42

SATCOM rack and its supporting structure at intervals not exceeding

3,000 flight cycles, whether a repair and/or replacement of fasteners

is required or not. While a manufacturer Designated Engineering

Representative (DER) is authorized to determine whether a design or

repair method complies with a specific requirement, at this time the

FAA has not delegated the authority to a manufacturer DER to make the

discretionary determination for repetitive inspection requirements.

Explanation of Applicability

Operators should note that the Boeing alert service bulletin

(previously described), does not specify the line number for the

effectivity of Boeing Model 747-400 series airplanes, but states that

``a line number will be specified at a later date,'' when a design

improvement can be incorporated into the production line. To account

for this interpretative effectivity, this AD is applicable to Boeing

Model 747-300 series airplanes as listed in the alert service bulletin

and Boeing Model 747-400 series airplanes equipped with a Boeing-

installed E-42 SATCOM rack. As discussed previously, because this AD is

considered interim action, applicability may be revised accordingly in

subsequent AD action.

Explanation of Compliance Time

Operators should note that the Boeing alert service bulletin

(previously described) recommends that the initial inspection be

performed at the applicable time, as specified below:

For airplanes identified in the alert service as Group 1:

Within 500 flight hours or within 14,000 flight hours since the E-42

SATCOM rack was installed and populated with equipment.

For airplanes identified in the alert service as Groups 2,

3, and 4: Within 500 flight hours or 20,000 flight hours since the E-42

SATCOM rack was installed and populated with equipment.

This AD would require that the initial inspection be performed at

the applicable time, as specified below:

For airplanes identified in the alert service bulletin as

Group 1: Within 30 days after the effective date of this AD.

For airplanes identified in the alert service bulletin as

Groups 2, 3, and 4: Within 90 days after the effective date of this AD.

The FAA finds that, in view of a recent report indicating that

cracking has been detected on an airplane that had accumulated less

than 1,500 total flight hours, and because of the safety implications

and consequences associated with such cracking, the initial compliance

time specified in this AD is appropriate.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of

this regulation, it is found that notice and

[[Page 34709]]

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 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.

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 99-NM-45-AD.'' The postcard will be date stamped and

returned to the commenter.

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.

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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

99-14-04 Boeing: Amendment 39-11212. Docket 99-NM-45-AD.

Applicability: Model 747-300 series airplanes, as listed in

Boeing Alert Service Bulletin 747-53A2428, dated December 17, 1998;

and Model 747-400 series airplanes equipped with a Boeing installed

E-42 satellite communications (SATCOM) rack; 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 (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 detect and repair cracking of the E-42 SATCOM rack and its

supporting structure, which could result in the SATCOM equipment

falling from the rack, loss of SATCOM capabilities, injury to

passengers, and reduced controllability of the airplane, accomplish

the following:

Initial and Repetitive Detailed Visual Inspections

(a) Perform a detailed visual inspection of the E-42 SATCOM rack

and fuselage (supporting) structure to detect cracking in the area

surrounding the fastener holes, and to detect broken or missing

fasteners, in accordance with Boeing Alert Service Bulletin 747-

53A2428, dated December 17, 1998, at the time specified in paragraph

(a)(1) or (a)(2) of this AD, as applicable. Thereafter, repeat the

inspection at intervals not to exceed 3,000 flight hours.

(1) For airplanes identified as Group 1: Within 30 days after

the effective date of this AD.

(2) For airplanes identified as Groups 2, 3, and 4: Within 90

days after the effective date of this AD.

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 mirror,

magnifying lenses, etc. may be used. Surface cleaning and elaborate

access procedures may be required.''

Corrective Actions

(b) If any cracking is found, or if any fastener is broken or

missing, during any inspection required by paragraph (a) of this AD,

prior to further flight: Repair in accordance with a method approved

by the Manager, Seattle Aircraft Certification Office (ACO), FAA,

Transport Airplane Directorate; or in accordance with data meeting

the type certification basis of the airplane approved by a Boeing

Company Designated Engineering Representative who has been

authorized by the Manager, Seattle ACO, to make such findings.

Repeat the detailed visual inspection of the SATCOM rack and

fuselage (supporting) structure thereafter at the intervals

specified by paragraph (a) of this AD.

Reporting Requirements

(c) Submit a report of the initial inspection findings (positive

and negative) to Boeing Commercial Airplane Group, Attention:

Manager, Airline Support, P.O. Box 3707, Seattle, Washington 98124-

2207; at the time specified in paragraph (c)(1) or (c)(2) of this

AD, as applicable. The report must include a description of any

discrepancy found, the airplane serial number, the number of

landings and flight hours on the airplane, and, when possible,

sketches and photographs of the inspected area. Information

collection requirements contained in this regulation have been

approved by the Office of Management and Budget (OMB) under the

provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et

seq.) and have been assigned OMB Control Number 2120-0056.

[[Page 34710]]

(1) For airplanes on which the initial inspection is

accomplished after the effective date of this AD: Submit the report

within 10 days after performing the initial inspection required by

paragraph (a) of this AD.

(2) For airplanes on which the initial inspection has been

accomplished prior to the effective date of this AD: Submit the

report within 30 days after the effective date of this AD.

Alternative Methods of Compliance

(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, Seattle ACO. 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

(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 airplane to a location where

the requirements of this AD can be accomplished, provided that all

the equipment is removed from the E-42 SATCOM rack.

Incorporation by Reference

(f) The inspections shall be done in accordance with Boeing

Alert Service Bulletin 747-53A2428, dated December 17, 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 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.

(g) This amendment becomes effective on July 14, 1999.

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

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-16326 Filed 6-28-99; 8:45 am]

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