[Federal Register Volume 63, Number 156 (Thursday, August 13, 1998)]
[Rules and Regulations]
[Pages 43294-43297]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-21656]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-154-AD; Amendment 39-10707; AD 98-17-05]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A319, A320, A321, A330, 
and A340 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 Airbus Model A319, A320, A321, A330, and A340 
series airplanes. This action requires revising the Airplane Flight 
Manual (AFM) to require the flightcrew to discontinue use of any 
Instrument Landing System (ILS) receiver for which a certain caution 
message is displayed. This action also requires, for certain airplanes, 
replacing any faulty ILS receiver with a new, serviceable, or modified 
unit. This AD also provides for an optional terminating action for the 
AFM revisions. This amendment is prompted by a pilot's 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 advised of the procedures necessary to address 
that hazard. An erroneous localizer deviation could result in a landing 
outside the lateral boundary of the runway.

DATES: Effective August 28, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before October 13, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-154-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.

FOR FURTHER INFORMATION CONTACT: Tim Backman, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2797; fax (425) 227-1149.

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 vertical 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 on a higher or lower 
glidepath 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.
    The same ILS receiver also 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.) An erroneous localizer deviation 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

[[Page 43295]]

outside the lateral boundary of the runway.
    Additionally, certain ground proximity warning systems (GPWS) and 
enhanced GPWS's use the glide slope deviation provided by ILS 
receivers. For these systems, if the ILS receiver used by the GPWS has 
experienced an unannunciated failure, there may be late or false GPWS 
alerts/callouts. Affected GPWS features may include sink rate alerts, 
glide slope deviation alerts, and altitude callouts.
    The RIA-35B ILS receivers installed on certain Airbus Model A319, 
A320, A321, 330, and A340 series airplanes are the same type as those 
on the affected Boeing airplane. Therefore, those Airbus Model A319, 
A320, A321, A330, and A340 series airplanes may be subject to the same 
unsafe condition. Unlike the affected Boeing airplane, during most of 
the flight profile, the flightcrew on Airbus Model A319, A320, A321, 
A330, and A340 series airplanes would receive an annunciation of 
discrepancies between the glide slope or localizer deviations being 
provided by the ILS receivers. However, such annunciation is not 
available to the flightcrew during the approach and landing portions of 
the flight when the ILS is active (ILS tuned and receiving).

Explanation of Relevant Service Information

    The FAA has reviewed and approved AlliedSignal Electronic and 
Avionics Systems Service Bulletin M-4431 (RIA-35B-34-7), Revision 1, 
dated May 1998, which describes procedures for modifying RIA-35B ILS 
receivers, part number (P/N) 066-50006-0202. 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 P/
N 066-50006-1202. Accomplishment of the actions specified in the 
service bulletin is intended to adequately address the identified 
unsafe condition.
    Airbus has issued A319/320/321 Flight Manual Temporary Revision 
4.02.00/03, A330 Flight Manual Temporary Revision 4.02.00/11, and A340 
Flight Manual Temporary Revision 4.02.00/22; all dated March 30, 1998. 
These temporary revisions (TR's) specify that the pilot should 
discontinue use of an ILS receiver for which a certain caution message 
(``ILS 1 FAULT,'' ``ILS 2 FAULT,'' or ``ILS 1+2 FAULT'') is displayed 
intermittently or continuously on the electronic centralized aircraft 
monitor (ECAM) during any portion of the flight, until the affected 
unit is replaced with a new, serviceable, or modified unit.

U.S. Type Certification of the Airplanes

    These airplane models are manufactured in France and are type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement.

Explanation of Requirements of 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 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 provide the flightcrew with explicit 
restrictions on operation in the event that a certain caution message 
is displayed intermittently or continuously on the ECAM during any 
portion of the flight. For cases where certain caution messages are 
displayed, this AD also requires replacement of the faulty ILS receiver 
with a new, serviceable, or modified unit. This AD also provides for an 
optional terminating action for the AFM revision described previously.

Explanation of the Applicability of the Rule

    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 require replacement of all existing RIA-
35B ILS receivers with modified parts, which would constitute 
terminating action for the AFM revision required by this AD action. 
However, the planned compliance time for such replacement is 
sufficiently long so that notice and opportunity for prior public 
comment will be practicable.

Differences Between the Rule and the Airbus Temporary AFM Revisions

    The FAA is not referencing the Airbus TR's described previously as 
the appropriate source of service information.
    Operators should note that, unlike the procedures described in the 
TR's, this AD would not permit use of a single ILS receiver for ILS or 
localizer approaches. The TR's allow use of a single source ILS 
receiver for ILS or localizer approaches even though the ILS receiver 
does not display caution messages on the ECAM during the approach and 
landing portions of the flight when the ILS is active. If there is a 
failure of a single ILS, or if the aircraft is dispatched with a single 
operative ILS, there is no way for the crew to identify a failure of 
the second ILS during these phases of flight. In such a case, the 
remaining ILS receiver may be providing erroneous localizer or glide 
slope deviation, and, therefore, a single ILS receiver should not be 
used for ILS or localizer approaches.
    Operators also should note that, unlike the procedures described in 
the TR's, this AD would not permit an ILS approach to be continued if a 
discrepancy between the glide slope and/or localizer deviation provided 
by ILS receivers 1 and 2 is detected. The TR's allow the crew to 
continue the ILS or localizer approach, if the crew can immediately 
identify the faulty ILS. This determination is to be made by the crew, 
based on continuous monitoring and comparison of the glide slope and 
localizer deviations displayed from both ILS receivers. However, should 
a discrepancy be detected during this continuous monitoring and 
comparison procedure, it may not be apparent to the crew which ILS 
receiver is providing correct glide slope and/or localizer deviation. 
For this reason, during an ILS or localizer approach, if the crew 
detects a discrepancy between the glide slope and/or localizer 
deviation provided by the two ILS receivers, the ILS approach should be 
immediately interrupted.

[[Page 43296]]

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-154-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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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:

98-17-05  Airbus Industrie: Amendment 39-10707. Docket 98-NM-154-AD.

    Applicability: Model A319, A320, A321, A330, and A340 series 
airplanes; equipped with AlliedSignal RIA-35B Instrument Landing 
System (ILS) receivers, part number (P/N) 066-50006-0202; 
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 (d) 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 advised of the procedures necessary to address that hazard, 
accomplish the following:
    (a) Within 10 days after the effective date of this AD, 
accomplish the requirements of paragraphs (a)(1) and (a)(2) of this 
AD.
    (1) 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.
    ``Instrument Landing (ILS) 1(2) Fault
    If `ILS 1(2) FAULT,' electronic centralized aircraft monitor 
(ECAM) caution, is triggered at any time during the flight, the 
affected ILS receiver must be considered as no longer available 
until it is replaced, and the flight crew must make the appropriate 
entry in the aircraft maintenance log prior to the next flight.
    During an ILS or LOC approach, the glide slope deviation and 
localizer deviation from ILS receivers 1 and 2 must be monitored and 
compared. If a discrepancy between the glide slope deviation and/or 
localizer deviation provided by ILS receivers 1 and 2 is 
experienced, interrupt the ILS approach.
    Do not conduct ILS or LOC approaches using a single ILS 
receiver.
    If ILS 1 has experienced an unannunciated failure there may be 
late or false ground proximity warning system (GPWS) alerts/
callouts. Affected GPWS features may include sink rate alerts, glide 
slope deviation alerts, and altitude callouts.''
    (2) Following accomplishment of the AFM revision required by 
paragraph (a)(1) of this AD, if a caution message reading ``ILS 1 
FAULT,'' ``ILS 2 FAULT,'' or ``ILS 1+2 FAULT'' is displayed 
intermittently or continuously on ECAM during any portion of any 
flight: Within 10 days after the message is first displayed, remove 
the faulty ILS receiver and install either a new or serviceable part 
that has the same P/N as the ILS receiver that was removed from the 
airplane or a part that has been modified in accordance with 
AlliedSignal Electronic and Avionics Systems Service Bulletin M-4431 
(RIA-35B-34-7), Revision 1, dated May 1998.

    Note 2: The ECAM messages described in paragraph (a)(2) of this 
AD, when displayed to the pilot, are normally preceded by ``NAV'' 
indicating a fault in the navigation system.

    (b) Replacement of all RIA-35B ILS receivers, P/N 066-50006-
0202, with
    RIA-35B ILS receivers that have been modified in accordance with 
AlliedSignal Electronic and Avionics Systems Service Bulletin M-4431 
(RIA-35B-34-7), Revision 1, dated May 1998; on which the P/N's have 
been converted to 066-50006-1202; constitutes terminating action for 
the requirements of this AD. After the replacement has been 
accomplished, the limitations required by paragraph (a)(1) may be 
removed from the AFM.

    Note 3: Modification of all AlliedSignal RIA-35B ILS receivers, 
P/N 066-50006-0202, accomplished prior to the effective date of this 
AD in accordance with AlliedSignal

[[Page 43297]]

Electronic and Avionics Systems Service Bulletin M-4431 (RIA-35B-34-
7), dated April 1998; is considered acceptable for compliance with 
the modification specified in this amendment.

    (c) As of the effective date of this AD, no person shall install 
on any airplane an AlliedSignal RIA-35B ILS receiver, P/N 066-50006-
0202, that has been found to be discrepant [that is, an ILS receiver 
for which one of the caution messages specified in paragraph (a)(2) 
of this AD was displayed on the ECAM] unless the discrepancy has 
been corrected by modifying the ILS receiver in accordance with 
AlliedSignal Electronic and Avionics Systems Service Bulletin M-4431 
(RIA-35B-34-7), Revision 1, dated May 1998.
    (d) 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, International Branch, ANM-116, FAA, 
Transport Airplane Directorate. Operators shall submit their 
requests through an appropriate FAA Principal Operations Inspector 
or Principal Avionics Inspector, who may add comments and then send 
it to the Manager, International Branch, ANM-116.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (e) 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.
    (f) This amendment becomes effective on August 28, 1998.

    Issued in Renton, Washington, on August 6, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-21656 Filed 8-12-98; 8:45 am]
BILLING CODE 4910-13-P