Airworthiness Directives; Boeing Model 747-100, -200, -300, and - 400 Series Airplanes Equipped with BFGoodrich Evacuation Ramp/Slides

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 93-NM-106-AD; Amendment 39-9004; AD 94-17-09]

Airworthiness Directives; Boeing Model 747-100, -200, -300, and -

400 Series Airplanes Equipped with BFGoodrich Evacuation Ramp/Slides

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 747-100, -200, -300, and -400 series

airplanes, that requires various modifications of certain evacuation

ramp/slides. This amendment is prompted by reports of several

evacuation ramp/slide malfunctions. The actions specified by this AD

are intended to prevent delayed inflation of evacuation ramp/slides,

which could delay or impede the evacuation of passengers during an

emergency.

DATES: Effective September 21, 1994.

The incorporation by reference of certain publications listed in

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

of September 21, 1994.

ADDRESSES: The service information referenced in this AD may be

obtained from the BFGoodrich Company, Aircraft Evacuation Systems,

Sustaining Engineering, D/7916, Phoenix, Arizona 85040. 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 FAA, Transport Airplane Directorate,

Los Angeles Aircraft Certification Office, 3229 East Spring Street,

Long Beach, California; or at the Office of the Federal Register, 800

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

FOR FURTHER INFORMATION CONTACT: Andrew Gfrerer, Aerospace Engineer,

Systems and Equipment Branch, ANM-131L, FAA, Transport Airplane

Directorate, Los Angeles Aircraft Certification Office, 3229 East

Spring Street, Long Beach, California 90806-2425; telephone (310) 988-

5338; fax (310) 988-5210.

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 747-100, -

200, -300, and -400 series airplanes was published as a supplemental

notice of proposed rulemaking (NPRM) in the Federal Register on March

15, 1994 (59 FR 11940). That action proposed to require various

modifications of certain evacuation ramp/slides. -

Interested persons have been afforded an opportunity to participate

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

the comments received. -

One commenter supports the proposed rule. -

Another commenter requests that the proposed 24-month compliance

time for modification of the ramp/slides be extended to 36 months so

that it will coincide with affected operators' scheduled overhauls. The

commenter points out that the manufacturer of the subject ramp/slides

recommends a compliance time of 36 months. The commenter believes that

safety will not be compromised if an extension is allowed. The FAA does

not concur with the commenter's request. In developing an appropriate

compliance time for this action, the FAA considered not only the degree

of urgency associated with addressing the subject unsafe condition, but

the availability of required parts, the average utilization of the

affected fleet, and normal maintenance schedules for timely

accomplishment of the modification. The FAA finds that the proposed 24-

month compliance time represents the maximum interval of time allowable

wherein the modifications can reasonably be accomplished and an

acceptable level of safety can be maintained. Further, the FAA took

into account the 36-month compliance time recommended by the

manufacturer, as well as the number of days required for the rulemaking

process; in consideration of these factors, the FAA finds that 24

months after the effective date of this final rule will fall

approximately at the same time for compliance as recommended by the

manufacturer. -

Another commenter requests that the proposed 24-month compliance

time for modification be shortened to 6 months. This commenter believes

that a shorter compliance time is necessary for continued safe

operation of airplanes equipped with the affected ramp/slides. The FAA

does not concur with the commenter's request. As explained above, the

FAA considered many factors, including the safety implications, when

developing an appropriate compliance time for this AD. After

consideration of all the available information, the FAA cannot conclude

that a reduction of the proposed compliance time, without prior notice

and opportunity for public comment, is warranted. To reduce the

compliance time of the AD would necessitate (under the provisions of

the Administrative Procedure Act) reissuing the notice, reopening the

period for public comment, considering additional comments received,

and eventually issuing a final rule; the time required for that process

may be as long as four additional months. In comparing the actual

compliance date of the final rule after completing such a process to

the compliance date of this final rule as issued, the increment in time

is minimal. In light of this, and in consideration of the amount of

time that has already elapsed since issuance of the original proposal,

the FAA has determined that further delay of this final rule action is

not appropriate. -

Two commenters request that paragraph (a) of the proposed rule be

revised to require accomplishment of the modifications specified only

in paragraphs 2.C., 2.D.(2), 2.E., and 2.F. of the BFGoodrich service

bulletin cited in the AD. The commenters believe that accomplishment of

paragraph 2.G. of the service bulletin should be optional, since the

modifications included in that paragraph are considered to be product

improvements that are not associated with the addressed unsafe

condition. One of these commenters, BFGoodrich, states that

approximately 40 percent of the slide modification kits were shipped to

operators prior to the issuance of the supplemental NPRM, and some

operators may not have accomplished the modifications specified in

paragraph 2.G. of the service bulletin. The commenter expresses a

concern that a requirement to accomplish that paragraph would result in

additional costs and unscheduled removal and maintenance actions for

operators. -

The FAA concurs with the commenters' request, and has revised

paragraph (a) of the final rule to specify that accomplishment of the

product improvement modifications specified in paragraph 2.G. of the

Accomplishment Instructions of the service bulletin is not required by

this AD. -

Two commenters request that the proposal be revised to cite the

latest revision to the BFGoodrich service bulletin specified in the AD

and to reference Boeing Service Bulletin 747-25-3028. The FAA concurs.

Since the issuance of the supplemental NPRM, the FAA has reviewed and

approved Revision 2 of BFGoodrich Service Bulletin 7A1418-25-253, dated

April 15, 1994, which corrects certain typographical errors that

appeared in Revision 1 of that service bulletin and references the

Boeing service bulletin. The Boeing service bulletin describes

procedures for an alternative method of modifying of the packboard and

girt. Paragraph (a) of the final rule has been revised to cite the

latest revision of the service bulletin as an additional source of

service information. Further, ``NOTE 2'' has been added to paragraph

(a) of the final rule to reference Boeing Service Bulletin 747-25-3028

as an additional source of service information for modifying the

packboard and girt. -

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 changes previously

described. The FAA has determined that these changes will neither

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

the AD.

There are approximately 1,100 BFGoodrich ramp/slides of the

affected design installed on Boeing Model 747-100, -200, -300, and -400

series airplanes in the worldwide fleet. The FAA estimates that 300 of

these subject ramp/slides are installed on Boeing Model 747-100, -200,

-300, and -400 series airplanes of U.S. registry that will be affected

by this AD. It will take approximately 22 work hours per ramp/slide to

accomplish the required actions, at an average labor rate of $55 per

work hour. Required parts will be provided by the ramp/slide

manufacturer at no cost to operators. Based on these figures, the total

cost impact of the AD on U.S. operators is estimated to be $363,000, or

$1,210 per airplane.

The total 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.

However, the FAA has been advised that 40 percent of the required

modification kits have been delivered to airlines having airplanes

affected by this AD. From this information, the FAA can assume that 40

percent of the affected fleet already have been modified in accordance

with the requirements of this AD. Therefore, the future economic cost

impact of this rule on U.S. operators is expected to be 40 percent less

than the ``total cost impact'' figure indicated above.

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. App. 1354(a), 1421 and 1423; 49 U.S.C.

106(g); and 14 CFR 11.89.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new

airworthiness directive:

94-17-09 Boeing: Amendment 39-9004. Docket 93-NM-106-AD.

Applicability: Model 747-100, -200, -300, and -400 series

airplanes equipped with BFGoodrich evacuation ramp/slides; as listed

in BFGoodrich Service Bulletin 7A1418-25-253, dated April 28, 1993,

or Revision 2, dated April 15, 1994; certificated in any category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent delayed inflation of evacuation ramp/slides, which

could delay or impede the evacuation of passengers during an

emergency, accomplish the following:

(a) Within 24 months after the effective date of this AD, modify

the door 3 offwing evacuation ramp/slide, part number 7A1418-( ),

in accordance with the Accomplishment Instructions of BFGoodrich

Service Bulletin 7A1418-25-253, dated April 28, 1993; or Revision 2,

dated April 15, 1994; as applicable. Accomplishment of the product

improvement modifications specified in paragraph 2.G. of the

Accomplishment Instructions of the service bulletin is not required

by this AD.

Note 1: Modification of the reservoir assembly (part number

4A3416-1) to the part number 4A3416-3 configuration, as specified in

paragraph 2.D.(1) of the service bulletin, is required currently by

AD 91-25-02, Amendment 39-8103 (56 FR 63629, December 5, 1991).

Note 2: BFGoodrich Service Bulletin 7A1418-25-253, Revision 2,

dated April 15, 1994, references Boeing Service Bulletin 747-25-

3028, dated August 26, 1993, as an additional source of service

information for modification of the packboard and girt.

(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, Los Angeles 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, 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.

(c) 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.

(d) The modification shall be done in accordance with BFGoodrich

Service Bulletin 7A1418-25-253, dated April 28, 1993; or BFGoodrich

Service Bulletin 7A1418-25-253, Revision 2, dated April 15, 1994.

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 the BFGoodrich Company, Aircraft

Evacuation Systems, Sustaining Engineering, D/7916, Phoenix, Arizona

85040. Copies may be inspected at the FAA, Transport Airplane

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

FAA, Transport Airplane Directorate, Los Angeles Aircraft

Certification Office, 3229 East Spring Street, Long Beach,

California; or at the Office of the Federal Register, 800 North

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

(e) This amendment becomes effective on September 21, 1994.

Issued in Renton, Washington, on August 11, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-20157 Filed 8-19-94; 8:45 am]

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