AD 2001-12-14

final rule

Airworthiness Directives; Boeing Model 747-400 Series Airplanes

AD Number
2001-12-14
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. 2000-NM-320-AD
FR Citation
66 FR 33016

Applicability

TypeManufacturerModelDetails
aircraft The Boeing Company 747-400 Series Airworthiness Directives; Boeing Model 747-400 Series Airplanes
aircraft The Boeing Company 747-400D Series Airworthiness Directives; Boeing Model 747-400 Series Airplanes
aircraft The Boeing Company 747-400F Series Airworthiness Directives; Boeing Model 747-400 Series Airplanes

Unsafe Condition

Miswiring of diodes in the heating system of the pitot static probes can lead to reduced power, causing ice accumulation on the probes, which may result in erroneous airspeed or altitude indications to the flight crew.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Inspect the pitot static probe heating system using a multimeter to verify continuity, absence of diodes, and diode orientation between relay sockets. If miswiring is detected, rewire the system prior to further flight.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within 15 months after the effective date of the AD.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

Boeing Model 747-400 series airplanes, as listed in Boeing Alert Service Bulletin 747-30A2078, Revision 1, dated November 16, 2000, certificated in any category.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-400 series airplanes, that requires an inspection to detect miswiring of diodes in the heating system of the pitot static probes, and corrective action, if necessary. The actions specified by this AD are intended to prevent reduced power to the heating system of the pitot static probes, leading to ice accumulation on the pitot static probes, which could result in erroneous airspeed or altitude indications to the flight crew, and consequent reduced operational safety in all phases of flight. This action is intended to address the identified unsafe condition.

Document Text

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[Federal Register Volume 66, Number 119 (Wednesday, June 20, 2001)]
[Rules and Regulations]
[Pages 33016-33017]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-15209]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-320-AD; Amendment 39-12269; AD 2001-12-14]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400 Series Airplanes

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 747-400 series airplanes, that 
requires an inspection to detect miswiring of diodes in the heating 
system of the pitot static probes, and corrective action, if necessary. 
The actions specified by this AD are intended to prevent reduced power 
to the heating system of the pitot static probes, leading to ice 
accumulation on the pitot static probes, which could result in 
erroneous airspeed or altitude indications to the flight crew, and 
consequent reduced operational safety in all phases of flight. This 
action is intended to address the identified unsafe condition.

DATES: Effective July 25, 2001.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 25, 2001.

ADDRESSES: The service information referenced in this AD may be 
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, 
Washington 98124-2207. 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 Office of 
the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC.

FOR FURTHER INFORMATION CONTACT: Don Eiford, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2788; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: A Notice of Proposed Rulemaking (NPRM) to 
amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to 
include an airworthiness directive (AD) applicable to certain Boeing 
Model 747-400 series airplanes was published in the Federal Register on 
February 21, 2001 (66 FR 10972). That action proposed to require an 
inspection to detect miswiring of diodes in the heating system of the 
pitot static probes, and corrective action, if necessary.

Editorial Change

    The compliance time for rewiring of any miswiring, detected during 
the special detailed inspection required by paragraph (a) of this AD, 
was inadvertently omitted. Paragraph (a) of this AD has been changed to 
require rewiring of any miswiring prior to further flight.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received.
    The commenter supports the proposed rule.

Conclusion

    After careful review of the available data, including the comment 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the change described 
previously. The FAA has determined that this change will neither 
increase the economic burden on any operator nor increase the scope of 
this AD.

Cost Impact

    There are approximately 497 Model 747-400 series airplanes of the 
affected design in the worldwide fleet. The FAA estimates that 69 
airplanes of U.S. registry will be affected by this AD, that it will 
take approximately 2 work hours per airplane to accomplish the required 
actions, and that the average labor rate is $60 per work hour. Based on 
these figures, the cost impact of the AD on U.S. operators is estimated 
to be $8,280, or $120 per airplane.
    The 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. The cost impact figures discussed 
in AD rulemaking actions represent only the time necessary to perform 
the specific actions actually required by the AD. These figures 
typically do not include incidental costs, such as the time required to 
gain access and close up, planning time, or time necessitated by other 
administrative actions.

Regulatory Impact

    The regulations adopted herein will 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. Therefore, it 
is determined that this final rule does not have federalism 
implications under Executive Order 13132.
    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)

[[Page 33017]]

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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]


    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

2001-12-14  Boeing: Amendment 39-12269. Docket 2000-NM-320-AD.

    Applicability: Model 747-400 series airplanes, as listed in 
Boeing Alert Service Bulletin 747-30A2078, Revision 1, dated 
November 16, 2000; certificated in any category.

    Note 1:
    This AD applies to each airplane identified in the preceding 
applicability provision, regardless of whether it has been modified, 
altered, or repaired in the area subject to the requirements of this 
AD. For airplanes that have been modified, altered, or repaired so 
that the performance of the requirements of this AD is affected, the 
owner/operator must request approval for an alternative method of 
compliance in accordance with paragraph (b) of this AD. The request 
should include an assessment of the effect of the modification, 
alteration, or repair on the unsafe condition addressed by this AD; 
and, if the unsafe condition has not been eliminated, the request 
should include specific proposed actions to address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent reduced power to the heating system of the pitot 
static probes, leading to ice accumulation on the pitot static 
probes, which could result in erroneous airspeed or altitude 
indications to the flight crew, and consequent reduced operational 
safety in all phases of flight, accomplish the following:

Inspection

    (a) Within 15 months after the effective date of this AD, 
perform a special detailed inspection to detect miswiring of diodes 
in the heating system of the pitot static probes by using a 
multimeter to verify continuity between certain relay sockets, 
absence of a diode between certain relay sockets, and diode 
orientation between certain relay sockets, per Boeing Alert Service 
Bulletin 747-30A2078, Revision 1, dated November 16, 2000. If any 
miswiring is found, prior to further flight, rewire per Boeing 747-
400 Wiring Diagrams 30-31-11 and 30-31-21, as referenced in the 
service bulletin.

    Note 2:
    Inspections accomplished prior to the effective date of this AD 
per Boeing Alert Service Bulletin 747-30A2078, dated August 24, 
2000, are considered acceptable for compliance with the applicable 
action specified in this amendment.


    Note 3:
    For the purposes of this AD, a special detailed inspection is 
defined as: ``An intensive examination of a specific item(s), 
installation, or assembly to detect damage, failure, or 
irregularity. The examination is likely to make extensive use of 
specialized inspection techniques and/or equipment. Intricate 
cleaning and substantial access or disassembly procedures may be 
required.''

Alternative Methods of Compliance

    (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, Seattle Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (c) Special flight permits may be issued in accordance with 
sections 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.

Incorporation by Reference

    (d) Except as provided by paragraph (a) of this AD, The actions 
shall be done in accordance with Boeing Alert Service Bulletin 747-
30A2078, Revision 1, dated November 16, 2000. 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 Boeing Commercial Airplane Group, P.O. Box 3707, 
Seattle, Washington 98124-2207. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.

Effective Date

    (e) This amendment becomes effective on July 25, 2001.

    Issued in Renton, Washington, on June 11, 2001.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-15209 Filed 6-19-01; 8:45 am]
BILLING CODE 4910-13-P

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