[Federal Register Volume 72, Number 150 (Monday, August 6, 2007)]
[Proposed Rules]
[Pages 43578-43580]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-15237]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-28881; Directorate Identifier 2006-NM-263-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-10, DC-9-
20, DC-9-30, DC-9-40, and DC-9-50 Series Airplanes, Equipped with a 
Tail Cone Evacuation Slide Container Installed in Accordance With 
Supplemental Type Certificate (STC) ST735SO

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for McDonnell Douglas Model DC-9-10, DC-9-20, DC-9-30, DC-9-40, and DC-
9-50 series airplanes, equipped with tail cone evacuation slide 
containers as specified above. This proposed AD would require modifying 
the tail cone slide. This proposed AD also would require additional 
tail cone drops and slide deployments, and repair if necessary. This 
proposed AD results from several reports of inadvertent tail cone 
deployments in which the tail cone slide failed to deploy. We are 
proposing this AD to ensure that the tail cone evacuation slide deploys 
correctly; failure of the slide to deploy during an emergency 
evacuation could result in injury to flightcrew and passengers.

DATES: We must receive comments on this proposed AD by September 20, 
2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide Rulemaking Web site: Go to http://www.regulations.gov and follow

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the instructions for sending your comments electronically.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room W12-140 on the ground floor of the 
West Building, 1200 New Jersey Avenue, SE., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Northwest Airlines, Inc., 7500 Airline Drive, Minneapolis, 
Minnesota, 55450-1101, Mail Stop: 8953, for the service information 
identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT: Cheyenne Del Carmen, Aerospace 
Engineer, Cabin Safety/Mechanical and Environmental Systems Branch, 
ANM-150L, FAA, Los Angeles Aircraft Certification Office, 3960 
Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 
627-5338; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2007-
28881; Directorate Identifier 2006-NM-263-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
may visit http://dms.dot.gov.

Examining the Docket

    You may examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Operations office between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The 
Docket Operations office (telephone (800) 647-5527) is located on the 
ground floor of the West Building at the street address stated in the 
ADDRESSES section. Comments will be available in the AD docket shortly 
after the Docket Management System receives them.

Discussion

    We have received several reports that the tail cone emergency slide 
failed to deploy on McDonnell Douglas Model DC-9-10, DC-9-20, DC-9-30, 
DC-9-40, and DC-9-50 series airplanes, equipped with tail cone 
evacuation slide containers installed in accordance with supplemental 
type certificate (STC) ST735SO. Although we are doing further 
investigation and analysis, it appears that the failures resulted from 
either the slide container not clearing the immediate area around the 
slide when the slide deployment handle is pulled, or contaminated 
Velcro attachments that allow the slide container lanyard to separate 
without pulling the container off and activating the inflation bottle.
    STC ST735SO for the tail cone emergency slide containers was 
surrendered to the Los Angeles Aircraft Certification Office (ACO), 
FAA, on January 21, 2003. Therefore, there is no manufacturer's service 
information related to this proposed AD. The affected operator must 
submit a method of compliance to the FAA for approval.
    Failure of the slide to deploy during an emergency evacuation could 
result in injury to flightcrew and passengers.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other products 
of this same type design. For this reason, we are proposing this AD, 
which would require operators to modify the tail cone slide in 
accordance with a method approved by the FAA. One approved method is 
Northwest Airlines STC ST01967CH, issued March 19, 2007. STC ST01967CH 
describes the modification of the DC-9 tail cone slide. (STC ST01967CH 
refers to Northwest Airlines, Drawing 9B25-41477, Revision B, dated 
September 14, 2006; and Northwest Airlines, Drawing 9B25-90399, 
Revision D, dated December 21, 2006; as additional sources of service 
information for modifying the tail cone slide.) This proposed AD also 
would require additional tail cone drops and slide deployments to be 
done no earlier than 150 flight cycles and no later than 24 months 
after modifying the tail cone slide, for a minimum of 10 percent of an 
operator's fleet of affected airplanes (if fewer than 10 airplanes in 
the fleet: at least 1 airplane). If the tailcone and slide deployment 
is unsuccessful, this proposed AD would require repair in accordance 
with a method approved by the FAA.

Costs of Compliance

    There are about 400 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 300 airplanes of 
U.S. registry. The tail cone drops/slide deployments would take about 
16 work hours per airplane, at an average labor rate of $80 per work 
hour. Required parts would cost about $1,300 per airplane. Based on 
these figures, the estimated cost of the proposed AD for U.S. operators 
is about $774,000, or $2,580 per airplane.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect 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.
    For the reasons discussed above, I certify that the 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

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    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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD and placed it in the AD docket. See the 
ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

McDonnell Douglas: Docket No. FAA-2007-28881; Directorate Identifier 
2006-NM-263-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by September 
20, 2007.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to McDonnell Douglas Model DC-9-11, DC-9-12, 
DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-
9-32 (VC-9C), DC-9-32F, DC-9-33F, DC-9-34, DC-9-34F, DC-9-32F (C-9A, 
C-9B), DC-9-41, and DC-9-51 airplanes, certificated in any category, 
equipped with a tail cone evacuation slide container installed in 
accordance with supplemental type certificate (STC) ST735SO.

Unsafe Condition

    (d) This AD results from several reports of inadvertent tail 
cone deployments in which the tail cone slide failed to deploy. We 
are issuing this AD to ensure that the tail cone evacuation slide 
deploys correctly; failure of the slide to deploy during an 
emergency evacuation could result in injury to flightcrew and 
passengers.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Initial Actions To Address Slide Deployment Failures

    (f) Within 24 months after the effective date of this AD: Modify 
the tail cone slide in accordance with a method approved by the 
Manager, Los Angeles Aircraft Certification Office (ACO), FAA. 
Northwest Airlines STC ST01967CH, issued March 19, 2007, is one 
approved method.

    Note 1: STC ST01967CH refers to Northwest Airlines, Drawing 
9B25-41477, Revision B, dated September 14, 2006; and Northwest 
Airlines, Drawing 9B25-90399, Revision D, dated December 21, 2006; 
as additional sources of service information for modifying the tail 
cone slide.

Repeat Deployment and Terminating Action

    (g) Within 150 flight cycles after doing the modification 
required by paragraph (f) of this AD, or within 150 days after the 
effective date of this AD, whichever occurs later: Do additional 
tail cone drops and slide deployments on a minimum of 10 percent of 
an operator's fleet of affected airplanes (if fewer than 10 
airplanes in the fleet: At least one airplane).
    (1) If the tailcone and slide deployments are successful 
according to the applicable McDonnell Douglas DC-9 maintenance 
manual, no further action is required by this AD.
    (2) If any tailcone and slide deployment is unsuccessful 
according to the applicable McDonnell Douglas DC-9 maintenance 
manual, before further flight, repair in accordance with a method 
approved by the Manager, Los Angeles ACO, FAA.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Los Angeles ACO, FAA, has the authority to 
approve AMOCs for this AD, if requested in accordance with the 
procedures found in 14 CFR 39.19.
    (2) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Before using any approved AMOC on any airplane to which the AMOC 
applies, notify your appropriate principal inspector (PI) in the FAA 
Flight Standards District Office (FSDO), or lacking a PI, your local 
FSDO.

    Issued in Renton, Washington, on July 30, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-15237 Filed 8-3-07; 8:45 am]
BILLING CODE 4910-13-P