Airworthiness Directives; Boeing Model 747-400 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-61-AD; Amendment 39-11245; AD 99-16-10]

RIN 2120-AA64

Airworthiness Directives; Boeing Model 747-400 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),

applicable to certain Boeing Model 747-400 series airplanes. This

action requires repetitive inspections of the E-42 satellite

communications (SATCOM) rack and fuselage (supporting) structure to

detect fatigue cracking of the area surrounding the fastener holes, and

to detect broken or missing fasteners; and corrective actions, if

necessary. This amendment is prompted by reports indicating that

fatigue 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 fatigue 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 August 24, 1999.

The incorporation by reference of certain publications listed in

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

of August 24, 1999.

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

before October 8, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

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

Attention: Rules Docket No. 99-NM-61-AD, 1601 Lind Avenue, SW., Renton,

Washington 98055-4056.

The service information referenced in this AD may be obtained from

Flight Structures Inc., 4407 172nd Street NE, Arlington, Washington

98223. This information may be examined at the FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA,

Transport Airplane Directorate, Los Angeles Aircraft Certification

Office, 3960 Paramount Boulevard, Lakewood, California; or at the

Office of the Federal Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Jon Mowery, Aerospace Engineer,

Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los

Angeles Aircraft Certification Office, 3960 Paramount Boulevard,

Lakewood, California 90712-4137; telephone (562) 627-5322; fax (562)

627-5210.

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

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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.

Related Rulemaking

On June 22, 1999, the FAA issued AD 99-14-04, amendment 39-11212

(64 FR 34707, June 29, 1999), applicable to certain Boeing Model 747-

300 and -400 series airplanes, that requires repetitive 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 and missing fasteners; and corrective actions, if necessary.

Explanation of Relevant Service Information

The FAA has reviewed and approved Flight Structures Alert Service

Bulletins 92FS024-53-A1, 92FS082-53-A1, and 94FS409-53-A2, all dated

March 2, 1999, and 94FS448-53-A1, dated February 12, 1999. These alert

service bulletins describe, among other things, procedures for a one-

time close visual inspection of the E-42 SATCOM rack and fuselage

(supporting) structure to detect fatigue cracking of the area

surrounding the fastener holes, and to detect broken or missing

fasteners.

Explanation of 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 fatigue cracking of the E-42 SATCOM

rack and its supporting structure due to environmental vibration of the

airplane. Such fatigue cracking 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 repetitive inspections of the E-42 SATCOM rack and fuselage

(supporting) structure to detect fatigue cracking of the area

surrounding the fastener holes, and to detect broken or missing

fasteners; and corrective actions, if necessary. The actions are

required to be accomplished in accordance with the applicable alert

service bulletin described previously, except as discussed below. This

AD also would require reporting the findings of the initial inspection

to the FAA.

Differences Between AD and Service Information

While the alert service bulletins do not specify that the

inspection of the E-42 SATCOM rack and fuselage (supporting) structure

be repeated, this AD would require repetitive inspections of the E-42

SATCOM rack and fuselage (supporting) structure, even if fatigue

cracking has been detected and repaired. As stated previously, the

rigid joints of the SATCOM rack coupled with environmental vibration of

the airplane could cause fatigue cracking to initiate in the area

surrounding fastener holes. Furthermore, an isolated repair of an area

and/or replacement of any fastener does not remove the unsafe condition

for the entire E-42 SATCOM rack and fuselage (supporting) structure. In

light of these factors, the FAA has determined that repetitive

inspection at intervals not exceeding 3,000 flight hours, is warranted,

and that it represents an appropriate means of addressing the unsafe

condition while allowing affected airplanes to continue to operate

without comprising safety.

Operators should note that, although the alert service bulletins

specify repair instructions for certain conditions and recommend that

the manufacturer of the SATCOM rack be contacted for disposition of

certain other conditions, this AD will require the repair of those

conditions to be accomplished in accordance with a method approved by

the FAA.

Explanation of Compliance Time

This AD would require compliance in terms of the number of days

after the effective date of this AD, whereas the alert service

bulletins (previously described) recommend compliance based on the

number of flight hours, as specified below:

For airplanes identified in the alert service bulletin as

Group 1: Within 500 flight hours from receipt of alert service

bulletin, or 12,000 flight hours since the E-42 SATCOM rack was

installed and populated with equipment.

For airplanes identified in the alert service bulletin as

Group 2: Within 1,000 flight hours from receipt of alert service

bulletin, 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

Group 2: 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.

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

None of the Model 747-400 series airplanes affected by this action

are on the U.S. Register. All airplanes included in the applicability

of this rule currently are operated by non-U.S. operators under foreign

registry; therefore, they

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are not directly affected by this AD action. However, the FAA considers

that this rule is necessary to ensure that the unsafe condition is

addressed in the event that any of these subject airplanes are imported

and placed on the U.S. Register in the future.

Should an affected airplane be imported and placed on the U.S.

Register in the future, it would require approximately 3 work hours to

accomplish the required inspection, at an average labor rate of $60 per

work hour. Based on these figures, the cost impact of this AD would be

$180 per airplane, per inspection cycle.

Determination of Rule's Effective Date

Since this AD action does not affect any airplane that is currently

on the U.S. register, it has no adverse economic impact and imposes no

additional burden on any person. Therefore, prior notice and public

procedures hereon are unnecessary and the amendment may be made

effective in less than 30 days after publication in the Federal

Register.

Comments Invited

Although this action is in the form of a final rule and was not

preceded by notice and 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-61-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.

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:

99-16-10 Boeing: Amendment 39-11245. Docket 99-NM-61-AD.

Applicability: Model 747-400 series airplanes as listed in

Flight Structures Alert Service Bulletins 92FS082-53-A1, 92FS024-53-

A1, and 94FS409-53-A2, all dated March 2, 1999, and 94FS448-53-A1,

dated February 12, 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 (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 fatigue cracking of the E-42 satellite

communications (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 Inspections

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

and fuselage (supporting) structure to detect fatigue cracking of

the area surrounding the fastener holes, and to detect broken or

missing fasteners, at the time specified in paragraph (a)(1) or

(a)(2) of this AD, as applicable; in accordance with Flight

Structures Alert Service Bulletin 92FS082-53-A1, 92FS024-53-A1, or

94FS409-53-A2, all dated March 2, 1999; or 94FS448-53-A1, dated

February 12, 1999, as applicable. Thereafter, repeat the inspection

at intervals not to exceed 3,000 flight hours.

(1) For all airplanes identified as Group 1 in the applicable

alert service bulletin: Inspect within 30 days after the effective

date of this AD.

(2) For all airplanes identified as Group 2 in the applicable

alert service bulletin: Inspect 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 fatigue 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, Los Angeles Aircraft Certification Office

(ACO), FAA, Transport Airplane Directorate. Thereafter, repeat the

inspection required by paragraph (a) of this AD, at intervals not to

exceed 3,000 flight hours.

Reporting Requirements

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

and negative) to the

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Manager, Los Angeles ACO, 3960 Paramount Boulevard, Lakewood,

California 90712-4137; telephone (562) 627-5322; fax (562) 627-5210;

at the applicable time specified in paragraph (c)(1) or (c)(2) of

the AD, as applicable. The report must include the initial

inspection results, a description of any discrepancy found, the

airplane serial number, 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.

(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 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, Los Angeles ACO. Operators shall

submit their requests through an appropriate FAA Principal

Maintenance Inspector, who may add comments and then send it to the

Manager, Los Angeles ACO.

Note 3: Information concerning the existence of approved

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

obtained from the Los Angeles ACO.

Special Flight Permits

(e) 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, 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 Flight

Structures Alert Service Bulletin 92FS082-53-A1, dated March 2,

1999; Flight Structures Alert Service Bulletin 92FS024-53-A1, dated

March 2, 1999; Flight Structures Alert Service Bulletin 94FS409-53-

A2, dated March 2, 1999; or Flight Structures Alert Service Bulletin

94FS448-53-A1, dated February 12, 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 Flight Structures Inc., 4407 172nd

Street NE, Arlington, Washington 98223. Copies may be inspected at

the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW.,

Renton, Washington; or at Los Angeles ACO, 3960 Paramount Boulevard,

Lakewood, California 90712-4137; or at the Office of the Federal

Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on August 24, 1999.

Issued in Renton, Washington, on July 29, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-20059 Filed 8-6-99; 8:45 am]

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