[Federal Register Volume 71, Number 197 (Thursday, October 12, 2006)]
[Proposed Rules]
[Pages 60080-60083]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-16891]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 71, No. 197 / Thursday, October 12, 2006 / 
Proposed Rules  

[[Page 60080]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26043; Directorate Identifier 2005-NM-010-AD]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model 717-200 
Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all McDonnell Douglas Model 717-200 airplanes. This proposed AD 
would require inspecting the power conversion distribution unit (PCDU) 
to determine its part number, and modifying certain PCDUs. This 
proposed AD is prompted by reports of failed PCDUs, the loss of an 
electrical bus, and the presence of a strong electrical burning odor in 
the flight deck and forward cabin. We are proposing this AD to prevent 
the loss of an electrical bus due to a PCDU failure, which could result 
in an abnormally long time for all flight deck displays to reconfigure, 
and consequent emergency landing.

DATES: We must receive comments on this proposed AD by November 27, 
2006.

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 the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood 
Boulevard, Long Beach, California 90846, Attention: Data and Service 
Management, Dept. C1-L5A (D800-0024).
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street, SW., room PL-
401, on the plaza level of the Nassif Building, Washington, DC. This 
docket number is FAA-2006-26043; the directorate identifier for this 
docket is 2005-NM-010-AD.

FOR FURTHER INFORMATION CONTACT: Thomas Phan, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California 
90712-4137; telephone (562) 627-5342; 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 under ADDRESSES. Include ``Docket No. FAA-2006-26043; 
Directorate Identifier 2005-NM-010-AD'' in the subject line 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 submitted 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 can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.

Examining the Docket

    You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

Discussion

    We have received reports of failed power conversion distribution 
units (PCDUs). Such failures resulted, by design, in the loss of an 
electrical bus (both AC and DC power). Following the loss of the 
electrical bus, the flight deck displays took an abnormally long time 
to reconfigure, and a strong electrical burning odor was noted in the 
flight deck and forward cabin. Investigation revealed a short in the 
power supply of the PCDU's generator control unit. The strong 
electrical burning odor in the cabin has been attributed to a failed 
PCDU on which a short condition can result in overheating of the power 
supply T1 transformer. Further, service history has shown that an 
intermittent loss of engine N2 speed signal to the PCDU can result in a 
bus tie lockout condition and automatic activation of the emergency 
power. The loss of an electrical bus due to a failed PCDU could result 
in an abnormally long time for all flight deck displays to reconfigure, 
and consequent emergency landing.

[[Page 60081]]

Relevant Service Information

    We have reviewed Boeing Alert Service Bulletin 717-24A0028, 
Revision 1, dated December 20, 2005. The service bulletin describes 
procedures for modifying PCDUs having part number 762904E. The 
modification involves modifying the printed wiring board (PWB) assembly 
A4 and installing new PCDU firmware.
    The Boeing service bulletin refers to Hamilton Sundstrand Service 
Bulletin 40EGS22P-24-10, dated August 4, 2004, as an additional source 
of service information for the modification.
    Hamilton Sundstrand Service Bulletin 40EGS22P-24-10 specifies the 
concurrent accomplishment of the actions specified in the Hamilton 
Sundstrand service bulletins listed in the following table:

                                          Concurrent Service Bulletins
----------------------------------------------------------------------------------------------------------------
                                     Hamilton Sundstrand
              Actions                  Service Bulletin        Revision level                   Date
----------------------------------------------------------------------------------------------------------------
Reworking the transformer           40EGS22P-24-3........  Original..............  June 30, 2000.
 rectifier unit assembly (TRU).
Reworking the W3 wiring harness
 assembly to install direct lead
 wires to the TRU.
Adding a ground wire to the TRU
 transformer.
Adding an insulated spacer to the
 PCDU top cover.
Installing new PCDU 186 firmware..  40EGS22P-24-4........  Original..............  April 26, 2001.
                                                           1.....................  January 2, 2002.
Installing new PCDU 186 firmware..  40EGS22P-24-6........  Original..............  July 25, 2002.
Modifying the top cover of the      40EGS22P-24-7........  Original..............  September 3, 2003.
 PCDU.
Modifying PWB assemblies A4 and A5  40EGS22P-24-8........  Original..............  September 4, 2003.
Checking and applying torque seal
 to fasteners on the TRU assembly
 and to PCDU internal fasteners,
 if necessary.
Modifying PWB assembly A4.........  40EGS22P-24-9........  Original..............  November 19, 2003.
----------------------------------------------------------------------------------------------------------------

    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

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 airplanes 
of this same type design. Therefore, we are proposing this AD, which 
would require identifying the part number of the PCDU and accomplishing 
the applicable actions specified in the service information described 
previously.

Costs of Compliance

    There are about 137 airplanes of the affected design in the 
worldwide fleet and 108 U.S.-registered airplanes. The following table 
provides the estimated costs for U.S. operators to comply with this 
proposed AD.

                                       Estimated Costs for Primary Actions
----------------------------------------------------------------------------------------------------------------
                                                                  Labor rate per                     Cost per
             Boeing Service Bulletin                Work hours         hour         Parts cost       airplane
----------------------------------------------------------------------------------------------------------------
Part number identification......................               1             $80              $0             $80
Modification (717-24A0028)......................              12              80               0             960
----------------------------------------------------------------------------------------------------------------


                                     Estimated Costs for Concurrent Actions
----------------------------------------------------------------------------------------------------------------
    Hamilton Sundstrand Service                              Labor rate per                            Cost per
              Bulletin                     Work hours             hour             Parts cost          airplane
----------------------------------------------------------------------------------------------------------------
40EGS22P-24-3......................  6.....................             $80  $154, per airplane....         $634
40EGS22P-24-4......................  3.....................              80  0.....................          240
40EGS22P-24-6......................  3.....................              80  0.....................          240
40EGS22P-24-7......................  1 per PCDU............              80  10 per PCDU, maximum 3      \1\ 110
                                                                              PCDUs per airplane.
40EGS22P-24-8......................  10....................              80  0.....................          800
40EGS22P-24-9......................  10....................              80  0.....................         800
----------------------------------------------------------------------------------------------------------------
\1\ Maximum.

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

[[Page 60082]]

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
    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. 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 FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

McDonnell Douglas: Docket No. FAA-2006-26043; Directorate Identifier 
2005-NM-010-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by November 27, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all McDonnell Douglas Model 717-200 
airplanes, certificated in any category.

Unsafe Condition

    (d) This AD was prompted by reports of failed power conversion 
distribution units (PCDUs), the loss of an electrical bus, and the 
presence of a strong electrical burning odor in the flight deck and 
forward cabin. We are issuing this AD to prevent the loss of an 
electrical bus due to a PCDU failure, which could result in an 
abnormally long time for all flight deck displays to reconfigure, 
and consequent emergency landing.

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.

Identification of PCDU Part Number

    (f) Within 20 months after the effective date of this AD, 
inspect the PCDU to determine its part number. A review of airplane 
maintenance records is acceptable in lieu of this inspection if the 
part number can be conclusively determined from that review.
    (1) If the part number is 762904E, do the actions specified in 
paragraphs (g) and (h) of this AD.
    (2) If the part number is not 762904E, no further work is 
required by this AD.

Modification

    (g) Within 20 months after the effective date of this AD, modify 
the PCDU in accordance with Boeing Alert Service Bulletin 717-
24A0028, Revision 1, dated December 20, 2005. A modification done 
before the effective date of this AD in accordance with Boeing Alert 
Service Bulletin 717-24A0028, dated November 24, 2004, is acceptable 
for compliance with the requirements of this paragraph.

    Note 1: Boeing Alert Service Bulletin 717-24A0028 refers to 
Hamilton Sundstrand Service Bulletin 40EGS22P-24-10, Revision 1, 
dated May 11, 2005, as an additional source of service information 
for the modification.

Concurrent Requirements

    (h) Before or concurrently with the modification required by 
paragraph (g) of this AD, do the applicable actions specified in 
Table 1 of this AD.

                 Table 1.--Concurrent Service Bulletins
------------------------------------------------------------------------
                                             In accordance with Hamilton
             Do the following--                   Sundstrand Service
                                                      Bulletin--
------------------------------------------------------------------------
Rework the transformer rectifier unit        40EGS22P-24-3, dated June
 assembly (TRU).                              30, 2000.
Rework the W3 wiring harness assembly to
 install direct lead wires to the TRU.
Add a ground wire to the TRU transformer.
Add an insulated spacer to the PCDU top
 cover.
Install new PCDU 186 firmware..............  40EGS22P-24-4, Revision 1,
                                              dated January 2, 2002.
Install new PCDU 186 firmware..............  40EGS22P-24-6, dated July
                                              25, 2002.
Modify the top cover of the PCDU...........  40EGS22P-24-7, dated
                                              September 3, 2003.
Modify printed wiring board (PWB)            40EGS22P-24-8, dated
 assemblies A4 and A5.                        September 4, 2003.
Check and apply torque seal to fasteners on
 the TRU assembly and to PCDU internal
 fasteners, as applicable.
Modify the PWB assembly A4.................  40EGS22P-24-9, dated
                                              November 19, 2003.
------------------------------------------------------------------------

Credit for Accomplishment of Earlier Service Bulletin

    (i) Installation of new PCDU 186 firmware before the effective 
date of this AD in accordance with Hamilton Sundstrand Service 
Bulletin 40EGS22P-24-4, dated April 26, 2001, is acceptable for 
compliance with the corresponding requirements of paragraph (h) of 
this AD.

Alternative Methods of Compliance (AMOCs)

    (j) The Manager, Los Angeles Aircraft Certification Office 
(ACO), FAA, has the authority to approve AMOCs for this AD, if 
requested in accordance with the procedures found in 14 CFR 39.19.

[[Page 60083]]


    Issued in Renton, Washington, on October 3, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-16891 Filed 10-11-06; 8:45 am]
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