DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0659; Product Identifier 2017-CE-014-AD;
Amendment 39-19094; AD 2017-22-14]
RIN 2120-AA64

Airworthiness Directives; Rockwell Collins, Inc. Traffic
Surveillance System Processing Unit

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for certain
Rockwell Collins, Inc. TSS-4100 Traffic Surveillance System Processing
Units that incorporate TSSA-4100 Field Loadable Software (FLS) Rockwell
Collins part numbers 810-0052-002/-003/-010/-011/-012/-100/-101 and are
installed on airplanes. This AD was prompted by five instances of air
traffic control observing coasting (extrapolated stale data) of
automatic dependent surveillance-broadcast data (position/velocity
data). This AD requires installing the TSSA-4100 FLS upgrades on the
TSS-4100 units. We are issuing this AD to address the unsafe condition
on these products.

DATES: This AD is effective December 20, 2017.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of December 20,
2017.

ADDRESSES: For service information identified in this final rule,
contact Rockwell 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 service information at the FAA, Policy and Innovation Division,
901 Locust, Kansas City, Missouri 64106. For information on the
availability of this material at the FAA, call (816) 329-4148. It is
also available on the internet at http://www.regulations.gov by
searching for and locating Docket No. FAA-2017-0659.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.
gov by searching for and locating Docket No. FAA-2017-
0659; 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 final rule, the regulatory evaluation, any comments
received, and other information. The address for the Docket Office
(phone: 800-647-5527) is 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: Paul Rau, Aerospace Engineer, Wichita
Aircraft Certification Office, FAA, 1801 Airport Road, Room 100,
Wichita, Kansas 67209; phone: 316-946-4149; fax: 316-946-4107; email:
paul.rau@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to certain Rockwell Collins,
Inc. TSS-4100 Traffic Surveillance System Processing Units that
incorporate TSSA-4100 Field Loadable Software (FLS) Rockwell Collins
part numbers 810-0052-002/-003/-010/-011/-012/-100/-101 and are
installed on airplanes. The NPRM published in the Federal Register on
July 3, 2017 (82 FR 30802). The NPRM was prompted by five instances of
air traffic control observing coasting (extrapolated stale data)
automatic dependent surveillance-broadcast data (ADS-B position/
velocity data) on a related Rockwell Collins, Inc. platform that shares
a common architecture with the TSS-4100 Traffic Surveillance System
Processing Units. An investigation of the events determined that the
ADS-B position and the Mode S/traffic alert and collision avoidance
system (TCAS) altitude of the TSS-4100 are affected. This condition, if
not corrected, could result in misleading position and/or altitude
being reported by the airplane. Misleading altitude data can adversely
affect TCAS and possibly lead to mid-air collision due to an incorrect
initial resolution advisory (RA) and/or an incorrect RA modification.
The extrapolation of the data occurs with no warning to the crew. The
NPRM proposed to require updating the TSSA-4100 FLS on the TSS-4100
Traffic Surveillance System Processing Unit. We are issuing this AD to
correct the unsafe condition on these products.

Comments

We gave the public the opportunity to participate in developing
this final rule. The following presents the comments received on the
NPRM and the FAA's response to each comment.

Request Reduced Compliance Time

The Air Line Pilots Association (ALPA) requested we reduce the
compliance time for the AD actions. The ALPA requested this change
because of the high number of reports the FAA received and because the
equipment is installed on a variety of airframe types that may operate
in heavily trafficked airspace.
We disagree with this comment. We considered the variety of
airframe types and operations when we determined the compliance time
for the proposed AD. We proposed within 12 months or 750 hours time-in-
service (TIS), whichever occurs first, and we expect that airframes
with the heaviest usage will require compliance in less than 4 months
after the effective date of the AD. Reducing the compliance time would
create an additional burden not supported by the risk assessments.
We have not changed this AD based on this comment.

Request a Delayed Effective Date

Bombardier, Inc. requested we delay the effective date of this AD
until January 1, 2020, when the requirements of 14 CFR 91.225 take
effect. In November 2017, Bombardier, Inc. plans to release service
information for CRJ airplane models that will change the affected TSSA-
4100 FLS part numbers to different part numbers that are not included
the applicability of the AD. Because of the heavy usage of the CRJ
airplanes and the 750 hours TIS of the AD, most CRJ airplanes will
require compliance with the AD by the end of 2017. Also, Bombardier,
Inc. states that air traffic controllers cannot use ADS-B data as a
primary source until 2020; as such, the mid-air collision risk does not
seem clear to them.
We disagree with this comment. Based on the stated usage, a delay
of the effective date until January 1, 2020, could result in airplanes
accumulating an additional 5,000 hours TIS beyond the 750 hours TIS
compliance proposed in the NPRM. The risk assessment does not support
that significant of an increase in the compliance time for this AD. The
stale or coasting Mode S altitude data interferes with proper TCAS
operation, potentially resulting in an incorrect RA or RA modification.
ADS-B operation is not required for that unsafe condition to exist. As
of August 1, 2017, ADS-B is the primary source of data by air traffic
controllers for separation at all FAA enroute air traffic control facilities
and at over 60 percent of U.S. terminal air traffic control facilities. ADS-B
is also widely used by general aviation airplanes for traffic
awareness. You may provide substantiating data to adjust the compliance
time of this AD and request an alternative method of compliance (AMOC)
using the procedures found in 14 CFR 39.19.
We have not changed this AD based on this comment.

Request To Allow Subsequent FLS Part Numbers for Compliance

Delta Air Lines, Inc. requested we change the language in this AD
to allow the use of subsequent FLS part numbers for compliance with
this AD. They request, for example, we add the words, ``or subsequent''
or ``any subsequent FLS part number that complies with the intent of
this AD'' to allow the use of future part numbers that may comply with
the AD actions.
We disagree with this comment. RCPN 810-0052-013 or 810-0052-102
are the only part numbers currently available that comply with this AD.
We cannot use language ``or subsequent'' or similar language because we
cannot approve documents or materials that do not currently exist. The
AD only applies to the FLS part numbers listed in the Applicability,
paragraph (c) of this AD, so future software upgrades not listed in
paragraph (c) of this AD are not affected by this AD. Operators may
request an alternative method of compliance (AMOC) to use future FLS
part numbers if they become available using the procedures found in 14
CFR 39.19.
We have not changed this AD based on this comment.

Request To Allow Credit for Work Done With Other Instructions

Bombardier, Inc. requested that we allow AD credit for operators
who have already completed the replacement of the affected part numbers
using parts found in aircraft illustrated parts catalogs (AIPCs) not
identified in the Applicability, paragraph (c) of this AD. Certain
AIPCs already allow operators to replace some of the affected TSSA-4100
FLS part numbers with part numbers not identified in the Applicability,
paragraph (c) of this AD.
We disagree with this comment. We recognize that other instructions
for upgrade of the TSSA-4100 exist. However, the actions of this AD
must be completed using the service information cited in the AD and
incorporated by reference into the AD. Operators may request an AMOC,
using the procedures found in 14 CFR 39.19, to use service information
other than those referenced in this AD. If, as of the effective date of
this AD, the affected TSSA-4100 FLS part numbers identified in the
Applicability, paragraph (c) of this AD, are not installed on the
airplane, the AD does not apply to that airplane. Therefore, if before
the effective date of this AD, operators replaced the affected TSSA-
4100 FLS part numbers with part numbers not identified in the
Applicability, paragraph (c) of this AD, using the AIPC, they do not
require credit for compliance with this AD because this AD does not
apply to those airplanes.
We have not changed this AD based on this comment.

Request Changes to the List of Possible Affected Airplanes

Delta Air Lines, Inc. and Bombardier, Inc. requested we add
Bombardier, Inc. Models CS 100 (BD-500-1A10) and CS300 (BD-500-1A11)
airplanes and remove Bombardier, Inc. Models Global 5000 (BD-700-1A11)
and Challenger 605 (CL-600-2B16) from the Applicability, paragraph (c)
of this AD. The C series include the TSSA-4100 system; however, the
Global 5000 and the Challenger 605 do not have the affected part
numbers installed.
We agree with this comment. The list of possible affected airplanes
is intended to include airplanes known to have the TSS-4100 installed.
The Bombardier C series airplanes were inadvertently omitted, and we
added them to the Applicability, paragraph (c) of this AD. The Global
5000 without the Global Vision Flight Deck and the Challenger 605 did
not include the installation of the TSS-4100, and we removed them from
the Applicability, paragraph (c) of this AD. However, this AD applies
specifically to TSS-4100 units, RCPN 822-2132-001, that incorporate
TSSA-4100 FLS RCPN 810-0052-002/-003/-010/-011/-012/-100/-101 installed
on airplanes. If the TSS-4100 unit with the affected part numbers is
installed, for example, through an avionics upgrade, on an airplane not
listed in paragraph (c) of this AD, the AD would apply to that
airplane.

Request Clarification of the Unsafe Condition

Bombardier, Inc. requested we change the language in the Unsafe
Condition, paragraph (e) of this AD, to more accurately describe the
instances of coasting errors. The five observed coasting errors were
not observed on the TSS-4100 units but on different units with similar
software.
We agree with this comment. We did include more descriptive
language in the preamble of the NPRM and this final rule. We added
similar language to the Unsafe Condition in paragraph (e) of this AD to
clarify the specific units where coasting error were observed.

Conclusion

We reviewed the relevant data, considered the comments received,
and determined that air safety and the public interest require adopting
this final rule with the changes described previously and minor
editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for correcting the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
We also determined that these changes will not increase the
economic burden on any operator or increase the scope of this final
rule.

Related Service Information Under 1 CFR Part 51

We reviewed Rockwell Collins Service Information Letter, TSSA-4100-
SIL-10-1, Revision No. 9, dated March 31, 2017; and Rockwell Collins
Service Information Letter, TSSA-4100-SIL-10-1, Revision No. 10, dated
July 10, 2017. The service letters both describe procedures for
determining the part number of the affected FLS and the installation
procedure for updating the FLS; however, Revision No. 10 contains minor
editorial changes not included Revision No. 9. This service information
is reasonably available because the interested parties have access to
it through their normal course of business or by the means identified
in the ADDRESSES section.

Costs of Compliance

We estimate that this AD affects 1,000 products installed on
airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

According to the manufacturer, some of the costs of this proposed
AD may be covered by the manufacturer, thereby reducing the cost impact
on affected individuals. We do not control manufacturer coverage for
affected individuals. As a result, we have included all costs in our
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.
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.
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to small airplanes and domestic
business jet transport airplanes to the Director of the Policy and
Innovation Division.

Regulatory Findings

This AD will not have federalism implications under Executive Order
13132. This AD 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.
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),
(3) Will not affect intrastate aviation in Alaska, and
(4) 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.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 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 (AD):