AD Amdt-39-10643

[Federal Register Volume 63, Number 129 (Tuesday, July 7, 1998)]
[Rules and Regulations]
[Pages 36549-36551]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-17914]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-155-AD; Amendment 39-10643; AD 98-14-10]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400, 757, 767, and 777 
Series Airplanes Equipped with AlliedSignal RIA-35B Instrument Landing 
System Receivers

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 747-400, 757, 767, and 777 series 
airplanes. This action requires a revision to the Airplane Flight 
Manual (AFM) to prohibit certain types of approaches if only one 
instrument landing system (ILS) receiver is operational. This action 
also requires repetitive inspections to detect certain faults of all 
RIA-35B ILS receivers, and replacement of discrepant ILS receivers with 
new, serviceable, or modified units; or, alternatively, an additional 
revision to the AFM and installation of a placard to prohibit certain 
operations. This AD also provides for optional terminating action for 
the AFM revisions and repetitive inspections. This amendment is 
prompted by a report of errors in the glide slope deviation provided by 
an ILS receiver. The actions specified in this AD are intended to 
detect and correct faulty ILS receivers, and to ensure that the 
flightcrew is advised of the potential hazard of performing ILS 
approaches using a localizer deviation from a faulty ILS receiver and 
also advised of the procedures necessary to address that hazard. 
Erroneous localizer deviation could result in a landing outside the 
lateral boundary of the runway.

DATES: Effective July 22, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of July 22, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before September 8, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-155-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this AD may be obtained from 
AlliedSignal Aerospace, Technical Publications, Dept. 65-70, P.O. Box 
52170, Phoenix, Arizona 85072-2170. This information may be examined 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.

FOR FURTHER INFORMATION CONTACT: Jay Yi, Aerospace Engineer, Systems 
and Equipment Branch, ANM-130S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-1013; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received a report indicating 
that, during a test flight of a Boeing airplane, the flightcrew 
detected discrepancies in the glide slope deviation provided by one of 
the onboard Instrument Landing System (ILS) receivers. (The glide slope 
is the flight path that an airplane is to follow when making an ILS 
landing. The display of the glide slope deviation indicates the 
position of the airplane relative to the glide slope and indicates to 
the flightcrew whether the airplane needs to be at a higher or lower 
altitude to be on the normal approach flight path.) The discrepancies 
in the glide slope deviation provided by the discrepant ILS receiver 
resulted in the display showing that the airplane was on the glide 
slope, when the airplane was approximately one dot low on the glide 
slope (as determined from the data provided by the ILS receivers that 
were operating correctly). The flightcrew received no annunciation that 
there were discrepancies between the glide slope deviations being 
provided by the ILS receivers.
    An investigation conducted by AlliedSignal, the manufacturer of the 
RIA-35B ILS receivers installed on the airplane, has revealed that the 
discrepancies in the glide slope deviation were caused by failure of an 
internal component of the ILS receiver due to that component's 
sensitivity to temperature. Due to the nature of the failure, that 
component also could fail on other airplanes.
    The same ILS receiver provides localizer deviation. (The display of 
the localizer deviation indicates the position of the airplane relative 
to the center line of the runway during an ILS landing.) Faults in the 
ILS receiver, if not corrected, could result in a landing outside the 
lateral boundary of the runway. If a faulty ILS receiver provides a 
localizer deviation that contains errors that are not detected by the 
flightcrew, use of a single ILS receiver for ILS or localizer 
approaches could result in the pilot being directed to land the 
airplane outside the lateral boundary of the runway. If the localizer 
deviations generated by two of the ILS receivers onboard the airplane 
contain errors that are not detected by the flightcrew, during category 
II and III operations, the autopilot system may land the airplane 
outside the lateral boundary of the runway.
    The FAA finds that flightcrews are not currently provided with 
adequate information necessary to address the potential hazard of 
performing an ILS or localizer approach using a localizer deviation 
provided by a faulty ILS receiver. Therefore, the FAA has determined 
that flightcrews must be provided with such information and must be 
made aware that certain types

[[Page 36550]]

of operations are prohibited when only one RIA-35B ILS receiver (with 
the affected part number) is operational.
    The RIA-35B ILS receivers installed on certain Boeing Model 747-
400, 757, 767, and 777 series airplanes are the same type as those on 
the affected Boeing airplane. Therefore, those Boeing Model 747-400, 
757, 767, and 777 series airplanes may be subject to the same unsafe 
condition.

Explanation of Relevant Service Information

    The FAA has reviewed and approved AlliedSignal Electronic and 
Avionics Systems Service Bulletin M-4426 (RIA-35B-34-6), Revision 3, 
dated May 1998, which describes procedures for modifying RIA-35B ILS 
receivers, part number (P/N) 066-50006-0101. The modification includes 
removing the radio frequency (RF) assembly; modifying the RF module by 
cutting two solder-side tracks, installing two 221-ohm resistors, and 
replacing components U8009 and U8206; and reinstalling the modified RF 
assembly. Once modified, the P/N of the ILS receiver is converted to 
066-50006-1101. Accomplishment of the actions specified in the service 
bulletin is intended to adequately address the identified unsafe 
condition.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to detect and correct faulty ILS receivers, and to ensure 
that the flightcrew is advised of the potential hazard of performing 
ILS approaches using a localizer deviation from a faulty ILS receiver 
and also advised of the procedures necessary to address that hazard. 
This AD requires a revision to the Limitations Section of the FAA-
approved Airplane Flight Manual (AFM) to prohibit ILS or localizer 
approaches if only one ILS receiver is operational. This AD also 
requires repetitive visual inspections for faults stored in the 
internal fault memory of all RIA-35B ILS receivers, P/N 066-50006-0101; 
or, alternatively, an additional revision to the Limitations Section of 
the AFM and installation of a placard in the cockpit to prohibit 
category II and III operations. For cases where certain faults are 
detected in the internal fault memory, this AD also requires 
replacement of the faulty ILS receiver with a new, serviceable, or 
modified part. If accomplished, replacement of all ILS receivers, P/N 
066-50006-0101, with modified ILS receivers terminates the repetitive 
inspections and AFM revisions described previously.

Explanation of the Applicability of the Rule

    The FAA may consider separate rulemaking to address the identified 
unsafe condition on other transport category airplanes equipped with 
the affected ILS receiver. The FAA notes that its general policy is 
that, when an unsafe condition results from the installation of an 
appliance or other item that is installed in a limited number of 
airplane models, an AD is issued so that it is applicable to those 
airplanes, rather than the item. The reason for this is simple: making 
the AD applicable to the airplane models on which the item is installed 
ensures that operators of those airplanes will be notified directly of 
the unsafe condition and the action required to correct it. While it is 
assumed that an operator will know the models of airplanes that it 
operates, there is a potential that the operator will not know or be 
aware of specific items that are installed on its airplanes. Therefore, 
calling out the airplane model as the subject of the AD prevents 
``unknowing non-compliance'' on the part of the operator.

Interim Action

    This is considered to be interim action. The FAA is considering 
further rulemaking action to supersede this AD to require replacement 
of all existing RIA-35B ILS receivers with modified parts. However, the 
planned compliance time for such replacement is sufficiently long so 
that notice and opportunity for prior public comment will be 
practicable.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-155-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the Rules Docket. 
A copy of it, if filed, may be obtained from the Rules Docket at the 
location provided under the caption ADDRESSES.

[[Page 36551]]

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:

98-14-10  Boeing: Amendment 39-10643. Docket 98-NM-155-AD.

    Applicability: Model 747-400, 757, 767, and 777 series 
airplanes; equipped with AlliedSignal RIA-35B Instrument Landing 
System (ILS) receivers, part number (P/N) 066-50006-0101; 
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 (e) 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 detect and correct faulty ILS receivers, and to ensure that 
the flightcrew is advised of the potential hazard of performing ILS 
approaches using a localizer deviation from a faulty ILS receiver 
and also advised of the procedures necessary to address that hazard, 
accomplish the following:
    (a) Within 10 days after the effective date of this AD, revise 
the Limitations Section of the FAA-approved Airplane Flight Manual 
(AFM) to include the following statement. This may be accomplished 
by inserting a copy of this AD into the AFM.
    Any Instrument Landing System (ILS) or Localizer approach with 
only one operative AlliedSignal ILS receiver, P/N 066-50006-0101, 
installed is prohibited.

    Note 2: On Model 747-400 and 777 series airplanes, the existence 
of only one operative ILS receiver is indicated by the Engine 
Indication and Crew Alerting System advisory message, ``SNGL SOURCE 
ILS.'' On Model 757 and 767 series airplanes, failure of an ILS 
receiver is indicated by an ILS flag on the display of the 
Electronic Flight Instrument System when approach mode is selected.

    (b) Within 30 days after the effective date of this AD, 
accomplish the requirements of either paragraph (b)(1) or (b)(2) of 
this AD.
    (1) Perform a visual inspection of the 64 flight legs of the 
internal fault memory of all AlliedSignal RIA-35B ILS receivers, P/N 
066-50006-0101, for fault codes ``Nl'' (glide slope antialias fault) 
or ``Nm'' (localizer antialias fault). Repeat the inspection 
thereafter at intervals not to exceed 64 flight cycles. If any fault 
code ``Nl'' or ``Nm'' is found, prior to further flight, replace the 
existing ILS receiver with a new or serviceable ILS receiver having 
the same P/N; or with an ILS receiver that has been modified to P/N 
066-50006-1101 in accordance with AlliedSignal Electronic and 
Avionics Systems Service Bulletin M-4426 (RIA-35B-34-6), Revision 3, 
dated May 1998. Installation of an ILS receiver that has been 
modified (and the P/N converted) in accordance with the service 
bulletin constitutes terminating action for the inspection 
requirement of paragraph (b)(1) of this AD for that part.
    (2) Accomplish the actions required by paragraphs (b)(2)(i) and 
(b)(2)(ii) of this AD.
    (i) Revise the Limitations Section of the FAA-approved AFM to 
include the following statement. This may be accomplished by 
inserting a copy of this AD into the AFM.
    Category II and III operations are prohibited with AlliedSignal 
ILS receiver P/N 066-50006-0101 installed.
    (ii) Install a placard on the forward instrument panel of the 
cockpit in clear view of the pilots, which states:
    ``Category II and III operations are prohibited.''
    (c) Replacement of all existing RIA-35B ILS receivers, P/N 066-
50006-0101, with RIA-35B ILS receivers that have been modified in 
accordance with AlliedSignal Electronic and Avionics Systems Service 
Bulletin M-4426 (RIA-35B-34-6), Revision 3, dated May 1998; and that 
have had their P/N's converted to 066-50006-1101; constitutes 
terminating action for the requirements of this AD. After the 
replacement has been accomplished, the AFM limitations required by 
paragraphs (a) and (b)(2)(i) of this AD may be removed from the AFM, 
and the placard required by (b)(2)(ii) may be removed from the 
cockpit.

    Note 3: Modification of all AlliedSignal RIA-35B ILS receivers, 
P/N 066-50006-0101, prior to the effective date of this AD in 
accordance with AlliedSignal Electronic and Avionics Systems Service 
Bulletin M-4426 (RIA-35B-34-6), dated December 1997; Revision 1, 
dated January 1998; or Revision 2, dated April 1998; is considered 
acceptable for compliance with the applicable action specified in 
this amendment.

    (d) As of the effective date of this AD, no person shall install 
on any airplane an RIA-35B ILS receiver, P/N 066-50006-0101, that 
has been found to be discrepant (that is, on which fault codes 
``Nl'' or ``Nm'' were found during an inspection of the internal 
fault memory) unless the discrepancy has been corrected by modifying 
the ILS receiver in accordance with AlliedSignal Electronic and 
Avionics Systems Service Bulletin M-4426 (RIA-35B-34-6), Revision 3, 
dated May 1998.
    (e) 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, 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, 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.

    (f) 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.
    (g) The modification, if accomplished, shall be done in 
accordance with AlliedSignal Electronic and Avionics Systems Service 
Bulletin M-4426 (RIA-35B-34-6), Revision 3, dated May 1998. 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 AlliedSignal Aerospace, Technical 
Publications, Dept. 65-70, P.O. Box 52170, Phoenix, Arizona 85072-
2170. 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.
    (h) This amendment becomes effective on July 22, 1998.

    Issued in Renton, Washington, on June 29, 1998.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-17914 Filed 7-6-98; 8:45 am]
BILLING CODE 4910-13-U