Airworthiness Directives; McDonnell Douglas Model DC-9 and DC-9- 80 Series Airplanes, Model MD-88 Airplanes, and Model C-9 (Military) Airplanes

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 94-NM-100-AD]

Airworthiness Directives; McDonnell Douglas Model DC-9 and DC-9-

80 Series Airplanes, Model MD-88 Airplanes, and Model C-9 (Military)

Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness

directive (AD) that is applicable to McDonnell Douglas Model DC-9 and

DC-9-80 series airplanes, Model MD-88 airplanes, and Model C-9

(military) airplanes. This proposal would require inspection of the

tailcone release locking cable fitting assembly, and replacement or

modification of the assembly, if necessary. This proposal is prompted

by reports of the inability of the tailcone to deploy because the

swaged ball on the cable had jammed after passing into the release

handle hole. The actions specified by the proposed AD are intended to

prevent the inability of the tailcone to deploy, which could impede the

egress of passengers from the airplane during an emergency evacuation.

DATES: Comments must be received by December 13, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 94-NM-100-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056. Comments may be inspected at this

location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except

Federal holidays.

The service information referenced in the proposed rule may be

obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach,

California 90801-1771, Attention: Business Unit Manager, Technical

Administrative Support, Dept. L51, M.C. 2-98. This information may be

examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,

SW., Renton, Washington; or at FAA, Los Angeles Aircraft Certification

Office, Transport Airplane Directorate, 3229 East Spring Street, Long

Beach, California.

FOR FURTHER INFORMATION CONTACT: Walter Eierman, Aerospace Engineer,

Systems & Equipment Branch, ANM-130L, Los Angeles Aircraft

Certification Office, FAA, Transport Airplane Directorate, 3229 East

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

5336; fax (310) 988-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the

proposed 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 above. All

communications received on or before the closing date for comments,

specified above, will be considered before taking action on the

proposed rule. The proposals contained in this notice may be changed in

light of the comments received.

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with

the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this notice must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket Number 94-NM-100-AD.'' The postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request

to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules

Docket No. 94-NM-100-AD, 1601 Lind Avenue, SW., Renton, Washington

98055-4056.

Discussion

One operator of McDonnell Douglas Model DC-9 series airplanes has

reported that, while performing a functional drop test of the tailcone,

the locking cable connected to the internal handle jammed inside the

handle fitting assembly. This prevented the tailcone from deploying.

Investigation revealed that the swaged ball on the cable had jammed

after passing into the handle hole. This condition, if not corrected,

could prevent the tailcone from deploying, which could impede the

egress of passengers from the airplane during an emergency evacuation.

The FAA has reviewed and approved McDonnell Douglas DC-9 Service

Bulletin 53-269, dated August 11, 1994, which describes procedures for

inspecting the tailcone release locking cable fitting assembly to

determine if the swaged ball can enter the handle hole from the locking

cable. It also describes procedures for replacing or modifying the

fitting to ensure the proper operation of the assembly.

Since an unsafe condition has been identified that is likely to

exist or develop on other products of this same type design, the

proposed AD would require inspecting the tailcone release locking cable

fitting assembly, and replacing or modifying fittings that do not

operate properly. This proposed AD would also require the eventual

replacement or modification of the fitting on all airplanes. The

actions would be required to be accomplished in accordance with the

service bulletin described previously.

There are approximately 1,986 Model DC-9 and DC-9-80 series

airplanes, Model MD-88 airplanes, and Model C-9 airplanes of the

affected design in the worldwide fleet. The FAA estimates that 1,170

airplanes of U.S. registry would be affected by this proposed AD.

The proposed inspection would take approximately 2 work hours per

airplane to accomplish, at an average labor rate of $55 per work hour.

Based on these figures, the total cost impact of this proposed action

on U.S. operators is estimated to be $128,700, or $110 per airplane.

The proposed replacement or modification would take approximately 5

work hours per airplane to accomplish, at an average labor rate of $55

per work hour. Required parts would cost approximately $2,388 per

airplane. Based on these figures, the total cost impact of this

proposed action on U.S. operators is estimated to be $3,115,710, or

$2,663 per airplane.

The total cost impact figures discussed above are based on

assumptions that no operator has yet accomplished any of the proposed

requirements of this AD action, and that no operator would accomplish

those actions in the future if this AD were not adopted.

The FAA recognizes that the obligation to maintain aircraft in an

airworthy condition is vital, but sometimes expensive. Because AD's

require specific actions to address specific unsafe conditions, they

appear to impose costs that would not otherwise be borne by operators.

However, because of the general obligation of operators to maintain

aircraft in an airworthy condition, this appearance is deceptive.

Attributing those costs solely to the issuance of this AD is

unrealistic because, in the interest of maintaining safe aircraft, most

prudent operators would accomplish the required actions even if they

were not required to do so by the AD.

A full cost-benefit analysis has not been accomplished for this

proposed AD. As a matter of law, in order to be airworthy, an aircraft

must conform to its type design and be in a condition for safe

operation. The type design is approved only after the FAA makes a

determination that it complies with all applicable airworthiness

requirements. In adopting and maintaining those requirements, the FAA

has already made the determination that they establish a level of

safety that is cost-beneficial. When the FAA, as in this proposed AD,

makes a finding of an unsafe condition, this means that the original

cost-beneficial level of safety is no longer being achieved and that

the proposed actions are necessary to restore that level of safety.

Because this level of safety has already been determined to be cost-

beneficial, a full cost-benefit analysis for this proposed AD would be

redundant and unnecessary.

The regulations proposed herein would 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

proposal would not have sufficient federalism implications to warrant

the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this proposed

regulation (1) -Is not a ``significant regulatory action'' under

Executive Order 12866; (2) is not a ``significant rule'' under the DOT

Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);

and (3) if promulgated, 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 copy of the draft

regulatory evaluation prepared for this action is contained in the

Rules Docket. A copy of it may be obtained by contacting the Rules

Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration proposes to amend

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:

McDonnell Douglas: Docket 94-NM-100-AD.

Applicability: Model DC-9 series airplanes, Model DC-9-80 (MD-

80) series airplanes, Model MD-88 airplanes, and Model C-9

(military) airplanes; as listed in McDonnell Douglas DC-9 Service

Bulletin 53-269, dated August 11, 1994; certificated in any

category.

Compliance: Required as indicated, unless accomplished

previously.

To prevent the inability of the tailcone to deploy, which could

impede the egress of passengers from the airplane during an

emergency evacuation, accomplish the following:

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

inspect the tailcone release locking cable fitting assembly for

proper operation in accordance with the procedures specified in

McDonnell Douglas DC-9 Service Bulletin 53-269, dated August 11,

1994. If the swaged ball on the cable can pass into the handle hole,

prior to further flight, replace or modify the fitting assembly in

accordance with the service bulletin.

(b) Within 36 months after the effective date of this AD,

replace or modify the fitting assembly in accordance with McDonnell

Douglas DC-9 Service Bulletin 53-269, dated August 11, 1994. Such

replacement or modification constitutes terminating action for the

requirements of this AD.

(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, 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: Information concerning the existence of approved

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

obtained from the Los Angeles ACO.

(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. Issued in Renton,

Washington, on October 12, 1994.

Darrell M. Pederson,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 94-25695 Filed 10-17-94; 8:45 am]

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