[Federal Register Volume 76, Number 158 (Tuesday, August 16, 2011)]
[Notices]
[Pages 50808-50809]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-20812]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Airborne Supplemental Navigation Equipment Using the Global 
Positioning System (GPS)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of intent to cancel Technical Standard Order (TSO)-
C129a, Airborne Supplemental Navigation Equipment Using the Global 
Positioning System (GPS), and request for public comment.

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

SUMMARY: This notice announces the FAA's intent to cancel TSO-C129a, 
Airborne Supplemental Navigation Equipment Using the Global Positioning 
System (GPS). The effect of the cancelled TSO will result in no new 
TSO-C129a design or production approvals. However, cancellation will 
not affect production according to an existing TSO authorization 
(TSOA). Articles produced under an existing TSOA can still be installed 
according to existing airworthiness approvals and applications for new 
airworthiness approvals will still be processed.

DATES: Comments must be received on or before September 15, 2011.

FOR FURTHER INFORMATION CONTACT: Mr. Kevin Bridges, AIR-130, Federal 
Aviation Administration, 470 L'Enfant Plaza, Suite 4102, Washington, DC 
20024. Telephone (202) 385-4627, fax (202) 385-4651, e-mail to: 
[email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    You are invited to comment on the cancellation of the TSO by 
submitting written data, views, or arguments to the above address. 
Comments received may be examined, both before and after the closing 
date at the above address, weekdays except Federal holidays, between 
8:30 a.m. and 4:30 p.m. The Director, Aircraft Certification Service, 
will consider all comments received on or before the closing date.

Background

    On September 21, 2009, the FAA published TSO-C196, Airborne 
Supplemental Navigation Sensors for Global Positioning System Equipment 
Using Aircraft-Based Augmentation; an updated minimum performance 
standard for GPS sensors not augmented by satellite-based or ground-
based systems (i.e., TSO-C129a Class B and Class C). The FAA has also 
published two GPS TSOs augmented by the satellite-based augmentation 
system (TSO-C145c, Airborne Navigation Sensors Using the Global 
Positioning System Augmented by the Satellite-Based Augmentation 
System; and, TSO-C146c, Stand-Alone Navigation Equipment Using the 
Global Positioning System Augmented by the Satellite-Based Augmentation 
System).
    TSO-C145c, TSO-C146c, and TSO-C196 incorporate more stringent 
standards that make the GPS equipment more accurate and robust than 
sensors

[[Page 50809]]

built to the minimum requirements in TSO-C129a. Two examples of these 
improvements are: (1) A requirement for the receiver to properly 
account for satellite range error if it is reflected in the User Range 
Accuracy index (commonly referred to as being ``Selective Availability 
aware''); and, (2) requirements to ensure performance is not degraded 
due to an increasing radio frequency noise environment as other 
satellite systems become available.
    Since 1995, there has been one application for TSOA for TSO-C129a. 
Therefore, we believe that it is appropriate to cancel TSO-C129a, given 
the eventual obsolescence of TSO-C129a equipment, and the lack of 
industry interest in new TSO-C129a product designs.

    Issued in Washington, DC, on August 1, 2011.
Susan J.M. Cabler,
Assistant Manager, Aircraft Engineering Division, Aircraft 
Certification Service.
[FR Doc. 2011-20812 Filed 8-15-11; 8:45 am]
BILLING CODE 4910-13-P