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PROPOSED AD ROCKWELL COLLINS, INC.: Docket No. FAA-2020-0915; Project Identifier AD-2020-00661-Q.
(a) COMMENTS DUE DATE

    The FAA must receive comments by December 14, 2020.

(b) AFFECTED ADS

    None.

(c) APPLICABILITY

    This airworthiness  directive (AD)  applies to  Rockwell Collins, Inc.
    GPS-4000S Global Positioning System  (GPS) part number (P/N)  822-2189
    -100 installed on airplanes, certificated in any category.

(d) SUBJECT

    Joint Aircraft System Component (JASC)/Air Transport Association (ATA)
    of America Code 3400, NAVIGATION SYSTEM.

(e) UNSAFE CONDITION

    This AD  was prompted  by an  un-annunciated GPS  vertical error  that
    could  result  in  a  hazardously  misleading  localizer   performance
    vertical (LPV)  glidepath. The  FAA is  issuing this  AD to  prevent a
    misleading GPS position on an  LPV approach. The unsafe condition,  if
    not addressed, result in a misleading GPS position on an LPV  approach
    resulting in controlled flight into terrain.

(f) COMPLIANCE

    Comply with this AD within the compliance times specified,  unless al-
    ready done.

(g) ACTIONS

(1) Within 24 months  after  the  effective date of this AD,  replace GPS-
    4000S GPS P/N 822-2189-100 with P/N 822-2189-101.

(2) As of the effective date of this AD,  do not install GPS-4000S GPS P/N
    822-2189-100 on any airplane.

(h) ALTERNATIVE METHODS OF COMPLIANCE (AMOCS)

(1) The  Manager,  Wichita ACO Branch,  FAA,  has the authority to approve
    AMOCs for this AD, if requested  using the procedures found in 14  CFR
    39.19. In  accordance with  14 CFR  39.19, send  your request  to your
    principal  inspector  or  local Flight  Standards District  Office, as
    appropriate. If  sending information  directly to  the manager  of the
    certification  office,  send  it  to  the  attention  of  the   person
    identified in paragraph (i)(1) of this AD.

(2) Before using any approved AMOC,  notify your appropriate principal in-
    spector, or lacking  a principal inspector,  the manager of  the local
    flight standards district office/certificate holding district office.

(i) RELATED INFORMATION

(1) For more information about this AD,  contact Paul Rau, Aerospace Engi-
    neer,  Wichita ACO Branch,  FAA,  1801 Airport Road,  Wichita,  Kansas
    67209; phone: 316-946-4149; fax: 316-946-4107; email: paul.rau@faa.gov
    or Wichita-COS@faa.gov.

(2) For service information identified in this proposed AD,  contact Rock-
    well Collins, Inc, Collins Aviation Services, 400 Collins Road NE, M/S
    164-100, Cedar Rapids, IA 52498-0001;  telephone:  888-265-5467 (U.S.)
    or 319-265-5467; fax: 319-295-4941 (outside U.S.); email: techmanuals@
    rockwellcollins.com; internet: https://portal.rockwellcollins.com/web/
    publications-and-training. You may view this referenced service infor-
    mation at the FAA, Airworthiness Products Section,  Operational Safety
    Branch,  901 Locust,  Kansas City, MO 64106.  For information  on  the
    availability of this material at the FAA, call 816-329-4148.

Issued on October 21, 2020. Lance T Gant, Director, Compliance & Airworth-
iness Division, Aircraft Certification Service.

DATES: The FAA must receive comments  on this proposed AD  by December 14,
2020.
PREAMBLE 

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0915; Project Identifier AD-2020-00661-Q]
RIN 2120-AA64

Airworthiness Directives; Rockwell Collins, Inc., Global
Positioning Systems

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Rockwell Collins, Inc. (Rockwell Collins), GPS-4000S Global
Positioning Systems (GPS) installed on airplanes. This proposed AD was
prompted by an un-annunciated GPS position error, which could cause a
misleading localizer performance with vertical guidance (LPV)
glidepath, resulting in controlled flight into terrain (CFIT). This
proposed AD would require upgrading the GPS-4000S. The FAA is proposing
this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by December
14, 2020.

ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:

Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the
instructions for submitting comments.

Fax: 202-493-2251.

Mail: U.S. Department of Transportation, Docket Operations, M-30, West
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE,
Washington, DC 20590.

Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact Rockwell
Collins, Inc., 400 Collins Road NE, Cedar Rapids, IA 52498; phone: 319-
295-5000; email: customersupport@rockwellcollins.com; internet: https://
www.rockwellcollins.com/. You may view this service information at the
FAA, Airworthiness Products Section, Operational Safety Branch, 901
Locust, Kansas City, MO 64106. For information on the availability of
this material at the FAA, call 816-329-4148. It is also available on
the internet at https://www.regulations.gov by searching for and
locating Docket No. FAA-2020-0915.

Examining the AD Docket


You may examine the AD docket on the internet at https://www.regulations.
gov by searching for and locating Docket No. FAA-2020-0915;
or in person at Docket Operations between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays. The AD docket contains
this NPRM, any comments received, and other information. The street
address for Docket Operations is listed in the ADDRESSES section.
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Paul Rau, Aerospace Engineer, Wichita
ACO Branch, FAA, 1801 Airport Road, Wichita, Kansas 67209; phone: 316-
946-4149; fax: 316-946-4107; email: paul.rau@faa.gov or Wichita-COS@faa.
gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2020-0915;
Project Identifier AD-2020-00661-Q" at the beginning of your comments.
The most helpful comments reference a specific portion of the proposal,
explain the reason for any recommended change, and include supporting
data. The FAA will consider all comments received by the closing date
and may amend this proposal because of those comments.

Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
https://www.regulations.gov, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact we receive about this NPRM.

Confidential Business Information

CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as "PROPIN." The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to Paul
Rau, Aerospace Engineer, Wichita ACO Branch, FAA, 1801 Airport Road,
Wichita, Kansas 67209; phone: 316-946-4149; fax: 316-946-4107; email:
paul.rau@faa.gov or Wichita-COS@faa.gov. Any commentary that the FAA
receives which is not specifically designated as CBI will be placed in
the public docket for this rulemaking.

Discussion

The FAA was notified of a software error in the Rockwell Collins
GPS-4000S GPS, part number (P/N) 822-2189-100, installed on airplanes.
The software error can result in an un-annunciated inaccurate GPS
position in the region within approximately 1,000 miles (+/- 20
degrees) of 180 degrees west longitude. The software improperly applies
the wide area augmentation system ionospheric delay corrections to the
GPS signal from satellites located across the 180th meridian. Due to
this anomaly, the position accuracy may be diminished such that the
GPS-4000S P/N 822-2189-100 will not support LPV approaches in the
affected region. This condition, if not addressed, could result in a
misleading glidepath on an affected LPV approach resulting in CFIT.

Related Service Information

The FAA reviewed Rockwell Collins Service Information Letter (SIL)
GPS-4X00( )-19-3, Revision No. 2, dated March 25, 2020. The service
letter describes the unsafe condition and provides operating
limitations for approaches to airports in the affected region until the
software is upgraded.

The FAA also reviewed Rockwell Collins Service Bulletin GPS-4X00( )-34-
510, Revision No. 1, dated March 6, 2020. The service bulletin
specifies procedures for upgrading the GPS-4000S software, which
removes P/N 822-2189-100 and installs P/N 822-2189-101.

FAA's Determination


The FAA is issuing this AD because it evaluated all the relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the same type design.

AD Requirements

This proposed AD would require removing P/N 822-2189-100 GPS-4000S
Global Positioning System(s) from the airplane and installing P/N 822-
2189-101 GPS-4000S Global Positioning System(s).

Costs of Compliance

The FAA estimates that this proposed AD would affect 3,500
airplanes of U.S. registry. The FAA estimates that 2,000 airplanes have
two GPS-4000S units installed and 1,500 airplanes have one GPS-4000S
unit installed.

The FAA estimates the following costs to comply with this proposed
AD:

Estimated Costs

Action Labor cost Parts cost Cost per product Cost on U.S. operators
Replace GPS-4000S (airplanes with 2 units installed). 7 work-hours x $85 per hour = $595 $4,540.00 $5,135 $10,270,000
Replace GPS-4000S (airplanes with single unit installed). 3.50 work-hours x $85 per hour = $297.50 2,270 2,567.50 3,851,250

According to the manufacturer, some of the costs of this proposed
AD may be covered under warranty, thereby reducing the cost impact on
affected individuals. The FAA does not control warranty coverage for
affected individuals. As a result, the FAA has included all costs in
this cost estimate.

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.

The FAA is 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

The FAA 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 this proposed
regulation:

(1) Is not a "significant regulatory action" under Executive
Order 12866,

(2) Will not affect intrastate aviation in Alaska, 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, 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: