
[Federal Register Volume 77, Number 7 (Wednesday, January 11, 2012)]
[Notices]
[Pages 1779-1780]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-300]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Emergency Locator Transmitters (ELTs)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of intent to cancel Technical Standard Order (TSO)-C91a, 
Emergency Locator Transmitter (ELT) Equipment.

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SUMMARY: This notice announces the FAA's intent to cancel TSO-C91a, 
Emergency Locator Transmitter (ELT) Equipment. The effect of the 
cancelled TSO will result in no new TSO-C91a 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. This action does not impact 
operation of TSO-C91a ELTs, and these ELTs will continue to satisfy the 
14 Code of

[[Page 1780]]

Federal Regulation (14 CFR) Sec.  91.207 ELT equipage requirement.

DATES: Comments must be received on or before February 10, 2012.

FOR FURTHER INFORMATION CONTACT: Mr. Albert Sayadian, AIR-130, Federal 
Aviation Administration, 470 L'Enfant Plaza, Suite 4102 Washington, DC 
20024. Telephone (202) 385-4652, fax (202) 385-4651, email to: 
Albert.Sayadian@faa.gov.

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. You 
are requested to use the attached comment sheet to make the comment 
review process more efficient. Comments received may be examined, both 
before and after the closing date, in suite 4102 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 December 23, 1992, the FAA published technical standard order 
(TSO-C126), 406 MHz Emergency Locator Transmitters (ELT), for which 
numerous TSO authorizations have been approved. On December 17, 2008, 
the FAA published a revision to the TSO, TSO-C126a. The TSO is a 
minimum performance standard for ELTs that utilize the 406.0 to 406.1 
MHz band. TSO-C126 and TSO-C126a 406 MHz ELTS are monitored by the 
Cospas-Sarsat system, an international satellite-based search and 
rescue (SAR) distress alert detection and information distribution 
system.
    On February 1, 2009 Cospas-Sarsat stopped processing signals from 
121.5 MHz ELTs. It now only processes signals from 406 MHz ELTs. The 
decision to discontinue processing of the 121.5 MHz signal was made by 
the International Cospas-Sarsat program with guidance from the United 
Nations. This was made due to the problems within the 121.5 MHz 
frequency band which inundated SAR authorities with poor accuracy and 
numerous false alerts, thus impacting the effectiveness of lifesaving 
services. The 406 MHz ELT technology is an advance over the older 121.5 
MHz ELT technology.
    TSO-C126a incorporates technology that makes the ELT equipment more 
accurate and reliable than the 121.5 MHz ELT equipment built to the 
minimum performance standards in TSO-C91a. Examples of these 
improvements are: (1) Global satellite coverage; (2) a unique beacon 
identification which is required to be registered so that if an alert 
is launched the rescued coordination center can confirm whether the 
distress is real, who they are looking for, and where the search should 
begin; (3) 406 MHz ELTs can be received by geostationary satellites 
which are always visible and provide instantaneous alerting and, (4) 
increased position accuracy that reduces the search area to less than 
two nautical miles in radius. Additionally, 406 MHz ELTs which have a 
GPS position input can potentially reduce the search area to within 100 
yards of the accident site.
    The performance and benefits of TSO-C126a equipment surpasses TSO-
C91a equipment. The 406 MHz technology is mature and prevalent in the 
ELT market today. The FAA feels new TSO authorizations for ELTs should 
be accomplished to TSO-C126a, or subsequent, and it is appropriate to 
cancel TSO-C91a.

Susan J. M. Cabler,
Assistant Manager, Aircraft Engineering Division, Aircraft 
Certification Service.
[FR Doc. 2012-300 Filed 1-10-12; 8:45 am]
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