Document ID: FAA-2006-26110-0019
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes
Posted Date: 2008-07-02T04:00Z

[Federal Register: July 2, 2008 (Volume 73, Number 128)]
[Rules and Regulations]               
[Page 37778-37780]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02jy08-3]                         

[[Page 37778]]

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26110; Directorate Identifier 2006-NM-112-AD; 
Amendment 39-15585; AD 2008-13-22]
RIN 2120-AA64

 
Airworthiness Directives; Boeing Model 747-400, 747-400D, and 
747-400F Series Airplanes

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

ACTION: Final rule.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Boeing Model 747-400, 747-400D, and 747-400F series airplanes. 
This AD requires replacement of an electronic flight instrument system/
engine indicating and crew alerting system (EFIS/EICAS) interface unit 
(EIU) located on the E2-6 shelf of the main equipment center with a new 
or modified EIU. This AD results from two instances where all six 
integrated display units (IDUs) on the flight deck panels went blank in 
flight. We are issuing this AD to prevent loss of the IDUs due to 
failure of all three EIUs, which could result in the inability of the 
flightcrew to maintain safe flight and landing of the airplane.

DATES: This AD becomes effective August 6, 2008.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in the AD as of August 6, 
2008.

ADDRESSES: For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this AD, the regulatory evaluation, 
any comments received, and other information. The address for the 
Docket Office (telephone 800-647-5527) is the Document Management 
Facility, U.S. Department of Transportation, Docket Operations, M-30, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Jay Yi, Aerospace Engineer, Systems 
and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification 
Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone 
(425) 917-6494; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued a supplemental notice of proposed rulemaking (NPRM) 
to amend 14 CFR part 39 to include an AD that would apply to certain 
Boeing Model 747-400, 747-400D, and 747-400F series airplanes. That 
supplemental NPRM was published in the Federal Register on August 23, 
2007 (72 FR 48246). That supplemental NPRM proposed to require 
replacement of an electronic flight instrument system/engine indicating 
and crew alerting system (EFIS/EICAS) interface unit (EIU) located on 
the E2-6 shelf of the main equipment center with a new or modified EIU. 
We issued that supplemental NPRM to propose reducing the compliance 
time for replacing the EIU.

Compliance With AD 2004-10-05, Amendment 39-13635

    We have determined that in order to comply with both this AD and 
the EIU replacements required by paragraph (d)(1) of AD 2004-10-05, at 
least one of the three EIUs must be part number (P/N) 622-8589-105 and 
the other two EIUs may be either P/N 622-8589-104 or P/N 622-8589-105. 
(The installation of P/N 622-8589-105 is required by paragraph (f) of 
this AD, and the installation of P/N 622-8589-104 is required by 
paragraph (d)(1) of AD 2004-10-05.) Boeing has confirmed that P/N 622-
8589-104 and P/N 622-8589-105 are fully interchangeable and may be used 
in any combination. Therefore, we have revised paragraph (h) of this AD 
accordingly. In addition, we have removed the information that appeared 
in paragraph (b) of the supplemental NPRM and included it in paragraph 
(h) of this AD. These changes are necessary to ensure that operators 
are able to comply with both this AD and AD 2004-10-05, in light of the 
parts availability constraint.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Support for the Supplemental NPRM

    The National Transportation Safety Board (NTSB) supports reducing 
the compliance time from 60 months to 24 months. The Association of 
Asia Pacific Airlines (AAPA) supports the intent of the supplemental 
NPRM.

Request To Extend the Compliance Time

    Boeing, Korean Air, Japan Airlines, United Airlines, and the AAPA 
request that we extend the compliance time to 60 months for replacing 
at least one EIU. As justification for extending the compliance time, 
Boeing states that (1) the loss of primary displays has been 
demonstrated and certified as not being a catastrophic condition, (2) 
pilots are able to maintain continued safe flight and landing by using 
backup or standby instruments as certified, and (3) mitigating action 
has been provided with issuance of the Boeing 747-400 Flight Crew 
Operations Maintenance Bulletin (OMB) TB1-20, ``Flight Deck Display 
Unit Blanking Anomaly,'' dated February 25, 2003, to the Boeing 747 
Flight Crew Operations Manual. Boeing further states that the EIU 
manufacturer has advised that it has limited capacity to modify units, 
which needs to be taken into consideration in the fleet modification 
plan. Boeing also asserts that most operators will choose to modify all 
three EIUs simultaneously to ease configuration control and logistics.
    AAPA states that its member airlines operate about 50 percent of 
the affected airplanes worldwide, and that none of its members have 
reported any blanking of all integrated display units (IDUs). AAPA 
further states that many of its members have already planned to replace 
all three EIUs, but that the 24-month compliance time will require them 
to change their existing retrofit programs to meet the new timeline. 
AAPA asserts this schedule change could involve removing airplanes from 
revenue service before scheduled maintenance, thus affecting their 
operational flexibility (capacity, manpower, and revenue generation). 
AAPA also states that the capacity of the EIU manufacturer must be 
considered at the global level, as many operators have already started 
their replacement programs based on replacing all three EIUs within a 
60-month compliance time.
    Korean Air states that the 24-month compliance time will impose an 
excessive burden considering the parts availability constraint. United 
Airlines and Japan Airlines state that replacing one EIU, instead of 
all three EIUs, creates a risk that the requirements of the AD could be 
inadvertently undone at a later time. They further state that replacing 
all three EIUs, which can be done only within a 60-month compliance 
time, will ensure that the

[[Page 37779]]

requirements of the AD cannot be undone.
    We do not agree to extend the compliance time for any of the stated 
reasons. We also disagree with AAPA's assertion that none of its 
members have experienced blanking of the IDUs; we have received a 
report that one of its members experienced losing all IDUs on two Model 
747-400 series airplanes. We have determined that a 24-month compliance 
time is the longest acceptable compliance time for ensuring that an 
acceptable level of safety is maintained, even with the mitigating 
action mentioned by Boeing.
    While the loss of the primary displays, by itself, is not 
catastrophic in the same sense as other types of failures such as a 
major structural failure, it is still considered to be unsafe. When all 
primary displays are lost, flightcrew access to critical flight 
management information is denied and flightcrew workload could be 
significantly increased. In addition to the primary displays of 
airplane flight and navigation data, such information includes engine 
monitoring, depiction of hazardous weather and terrain, flightcrew 
warnings, fuel management, and other vital systems information. Access 
to this information is critical to the flightcrew's ability to maintain 
airplane control, positional awareness, and awareness of the airplane's 
condition. Conversely, a simultaneous loss of all of this information 
unacceptably degrades the flightcrew's ability to continue safe flight 
and landing. We have taken AD action on other airplane models that also 
experienced loss of the primary displays.
    We recognize that operators would prefer to replace all three EIUs 
simultaneously for fleet management reasons, and that replacing only 
one EIU involves more complicated maintenance planning. However, 
operators' approved maintenance programs should provide sufficient 
controls to minimize the risk of releasing airplanes for service in a 
noncompliant condition. Further, the parts availability constraint will 
prevent operators from replacing all three EIUs on all affected 
airplanes within 24 months. The only course of action that likely can 
be supported with adequate parts availability for a 24-month compliance 
time is a requirement to replace one EIU. Although under the provisions 
of paragraph (i) of this AD, we will consider requests for adjustments 
to the compliance time if data are submitted to substantiate that such 
an adjustment would provide an acceptable level of safety. We have 
revised paragraph (i) of this AD to specify the information that must 
be submitted with the request.

Request To Require Replacement of All Three EIUs

    The NTSB reiterates its concern about requiring replacement of only 
one EIU. The NTSB states that, despite the intended redundancy of three 
EIUs, if only one EIU is replaced and that modified EIU suffers an 
unrelated fault removing it from operation, an airplane is still 
exposed to the potential for the IDUs to go blank since the other two 
EIUs would not have the auto-restart capability. The NTSB urges that we 
continue to work with the EIU manufacturer and operators to ensure that 
all three EIUs are replaced with new or modified parts in a timely 
manner.
    We infer the NTSB requests that we revise this AD to require 
replacement of all three EIUs. Although we understand the NTSB's 
concern, we do not agree to revise this AD. We have performed a risk 
assessment of a modified EIU failing and have determined that the risk 
of failure of the modified EIU is remote enough that an acceptable 
level of safety is maintained by replacing only one EIU. Further, since 
we have reduced the compliance time, there are only enough modification 
kits available for all operators to replace one EIU per airplane within 
the 24-month compliance time. Further, operators have already indicated 
that, for fleet management reasons, they are likely to replace all 
three EIUs as more parts become available. Also, the unsafe condition 
has been further mitigated by the Boeing 747-400 Flight Crew OMB TB1-
20, ``Flight Deck Display Unit Blanking Anomaly.'' That document 
advises flightcrews of the problem and provides instructions for 
restarting the EIUs should there be a display blanking problem during 
operation. We have not revised this AD in this regard.

Request To Revise Work-Hour Estimate

    AAPA states that the work-hour estimate in the supplemental NPRM is 
without basis, and that time to remove, install, and test the EIU must 
be included to accurately determine the time for performing the task. 
Based on operator experience, AAPA asserts that the EIU modification, 
replacement, and testing range between 6 to 40 hours per airplane.
    We disagree with revising the work hour estimate. The cost 
information in an AD describes only the direct costs of the specific 
actions required by this AD. Based on the best data available, the 
manufacturer provided the number of work hours necessary to do the 
required actions. This number represents the time necessary to perform 
only the actions actually required by this AD. We recognize that, in 
doing the actions required by an AD, operators might incur incidental 
costs in addition to the direct costs. The cost analysis in AD 
rulemaking actions, however, typically does not include incidental 
costs such as the time required to gain access and close up, time 
necessary for planning, or time necessitated by other administrative 
actions. Those incidental costs, which might vary significantly among 
operators, are almost impossible to calculate. Therefore, we have not 
revised this AD in this regard.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD as proposed in the supplemental NPRM.

Costs of Compliance

    There are about 639 airplanes of the affected design in the 
worldwide fleet. This AD affects about 79 airplanes of U.S. registry. 
The required actions take about 1 work hour per airplane, at an average 
labor rate of $80 per work hour. Required parts cost about $2,840 per 
airplane (for one EIU). Based on these figures, the estimated cost of 
this AD for U.S. operators is $230,680, or $2,920 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 AD will not have federalism 
implications under Executive Order 13132. This AD will not have a 
substantial direct effect on

[[Page 37780]]

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 this AD:
    (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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

2008-13-22 Boeing: Amendment 39-15585. Docket No. FAA-2006-26110; 
Directorate Identifier 2006-NM-112-AD.

Effective Date

    (a) This AD becomes effective August 6, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 747-400, 747-400D, and 747-
400F series airplanes, certificated in any category; as identified 
in Boeing Service Bulletin 747-31-2368, Revision 1, dated July 24, 
2006.

Unsafe Condition

    (d) This AD results from two instances where all six integrated 
display units (IDUs) on the flight deck panels went blank in flight. 
We are issuing this AD to prevent loss of the IDUs due to failure of 
all three electronic flight instrument system/engine indicating and 
crew alerting system (EFIS/EICAS) interface units (EIUs), which 
could result in the inability of the flightcrew to maintain safe 
flight and landing of the airplane.

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.

Replacement

    (f) Within 24 months after the effective date of this AD, 
replace at least one of the three EIUs, part number (P/N) 622-8589-
104, located on the E2-6 shelf of the main equipment center with a 
new or modified EIU, P/N 622-8589-105, in accordance with the 
Accomplishment Instructions of Boeing Service Bulletin 747-31-2368, 
Revision 1, dated July 24, 2006.

    Note 1: Boeing Service Bulletin 747-31-2368, Revision 1, dated 
July 24, 2006, refers to Rockwell Collins Service Bulletin EIU-7000-
31-502, dated March 21, 2006, as an additional source of service 
information for modifying an EIU by adding auto restart circuitry, 
which converts EIU P/N 622-8589-104 to P/N 622-8589-105.

Credit for Actions Done According to Previous Service Bulletin

    (g) Actions done before the effective date of this AD in 
accordance with Boeing Service Bulletin 747-31-2368, dated November 
22, 2005 (Revision 1 of the service bulletin specifies that the 
original issue is dated December 1, 2005), are acceptable for 
compliance with the corresponding requirements of paragraph (f) of 
this AD.

Terminating Action for AD 2004-10-05, Amendment 39-13635

    (h) Replacing an EIU with a new or modified EIU in accordance 
with paragraph (f) of this AD constitutes terminating action for the 
EIU replacement of paragraph (d)(1) of AD 2004-10-05, provided that 
the other two EIUs are replaced with EIUs having P/N 622-8589-104 or 
P/N 622-8589-105. All other actions required by paragraph (d)(1) of 
AD 2004-10-05 must be complied with.

Alternative Methods of Compliance (AMOCs)

    (i)(1) The Manager, Seattle Aircraft Certification Office, 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. 
We will only grant a compliance time extension for this AD if the 
requestor can show that it is unable to accomplish the minimum 
requirements of the AD (i.e., one modified EIU for each airplane) by 
the compliance time for reasons beyond its control, such as the 
inability to obtain enough parts to comply with the minimum 
requirements of the AD by the compliance time. Therefore, requests 
to extend the compliance time for this AD must include the following 
information:
    (i) How many airplanes are included in the request,
    (ii) An inventory of how many modified EIUs the requestor 
currently has on hand,
    (iii) A forecast inventory showing that the requestor will not 
have enough modified EIUs available to accomplish the minimum AD 
requirements (i.e., one modified EIU for each airplane) by the AD 
compliance time, based upon the current inventory on hand and 
delivery rates from the parts supplier,
    (iv) Documentation of supplier delivery commitments for modified 
EIUs or conversion kits, as applicable, including firm delivery 
commitment dates, that will provide the requestor with an adequate 
number of parts to be able to accomplish the minimum AD requirements 
on its affected airplanes, and
    (v) Documentation of maintenance facility schedule availability 
for accomplishing the AD requirements on all airplanes included in 
the request. We will not approve AMOC requests that propose 
replacing or modifying all three EIUs in a time frame longer than 24 
months instead of replacing or modifying one EIU within 24 months. 
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.

Material Incorporated by Reference

    (j) You must use Boeing Service Bulletin 747-31-2368, Revision 
1, dated July 24, 2006, to do the actions required by this AD, 
unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 
98124-2207.
    (3) You may review copies of the service information 
incorporated by reference at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call 202-741-6030, or 
go to: http://www.archives.gov/federal_register/code_of_federal_
regulations/ibr_locations.html.

    Issued in Renton, Washington, on June 8, 2008.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E8-14188 Filed 7-1-08; 8:45 am]

BILLING CODE 4910-13-P