
[Federal Register Volume 80, Number 129 (Tuesday, July 7, 2015)]
[Notices]
[Page 38798]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-16557]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration


Emergency Locator Transmitters (ELTs)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final notice recommending voluntary change to securing existing 
ELTs as specified in Technical Standard Order (TSO)-C126b, 406MHz 
Emergency Locator Transmitter.

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SUMMARY: This notice summarizes the inadequacies of hook and loop 
fasteners as a means for securing automatic fixed (AF) and automatic 
potable (AP) ELTs, and avoids placing an undue burden on aircraft 
owners while acknowledging the voluntary efforts of ELT manufacturers 
to improve designs.

FOR FURTHER INFORMATION CONTACT: Ms. Charisse R. Green, AIR-131, 
Federal Aviation Administration, 470 L'Enfant Plaza, Suite 4102, 
Washington, DC 20024. Telephone (202) 267-8551, fax (202) 267-8589, 
email to: Charisse.Green@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

    On March 10, 2015, the Federal Aviation Administration (FAA) 
published in the Federal Register, (80 FR 12697 (2015)), a Notice 
announcing the recommendation of voluntary change to a metal strap type 
restraint method for securing ELTs. The FAA recommends voluntary 
changes to existing ELTs installed with hook and loop fasteners because 
of their tendency to become dislodged from their mounting trays on 
impact. The separation of those ELTs from their mounting trays caused 
their antenna connection to sever, thus rendering the ELTs to be 
ineffective and unable to perform their intended function. The FAA also 
evaluated the retention tests specified by TSO-C91a, TSO-C126, and TSO-
C126a and determined these standards did not adequately address the use 
of hook and loop fasteners. Hook and loop fasteners were not an 
acceptable means of compliance to meet the mounting and retention 
requirements of the ELT TSOs. While the evaluation of installation 
approval using hook and loop fasteners may meet the TSO requirements 
for retention forces in laboratory conditions, accident investigations 
found these fasteners did not perform their intended function. 
Technical Standard Order TSO-C126b, 406 MHz Emergency Locator 
Transmitters, already excludes hook and loop fasteners as the primary 
method of ELT attachment.

FAA Concerns

    The agency identified the following concerns after completing its 
evaluation of the use of hook and loop fasteners:
    (1) Hook and loop fasteners fail to retain the ELT when 
insufficient tension is applied to close the fastener. There is no 
repeatable method for installation and no method to evaluate the 
tension of the hook and loop fastener. The allowance for pilots to 
secure ELTs to the aircraft when changing ELT batteries further 
increases the potential for inconsistent and unsatisfactory 
installations.
    (2) Hook and loop fasteners closed with proper tension may stretch 
or loosen over time due to wear, fluids, vibration, and repeated use, 
leading to insufficient tension to retain the ELT.
    (3) Hook and loop fasteners closed with proper tension do not 
provide stated retention capability due to debris which can contaminate 
the hooks and loops of the fastener.
    (4) Hook and loop fasteners closed with proper tension degrade due 
to environmental factors such as repeated heating and cooling cycles, 
temperature extremes, and contamination resulting from location in 
equipment areas.

Comments

    The FAA received one comment in response to the March 10, 2015, 
Federal Register Notice. The comment, by ELTA, stated that there is 
some potential confusion as to which ELTs were applicable under the 
FAA's proposed voluntary change from the use of hook and loop fasteners 
to metallic straps. Some customers could assume the Federal Register 
notice is applicable to all types of ELTs, including the survival type 
ELT.
    The FAA acknowledges this comment. This final Federal Register 
notice clarifies the FAA recommends voluntary changes to the securing 
mechanisms for automatic fixed and automatic portable ELTs. 
Additionally, the requirements section of TSO-C126b specifies the use 
of hook and loop fasteners is not an acceptable means of attachment 
when showing compliance with the Crash Safety requirements of RTCA/DO-
204A, section 2.2.5. Section 2.2.5 of this RTCA document applies only 
to AF and AP ELTs.

Conclusion

    The FAA evaluated the mounting requirements and retention test and 
determined the standards do not adequately address the use of hook and 
loop fasteners. Upon completion of the evaluation, the FAA identified 
numerous concerns with the use of hook and loop fasteners and continues 
to recommend voluntary changes of securing mechanisms for existing ELTs 
which utilize hook and loop fasteners. The FAA also asks aircraft 
owners/operators with ELTs secured with hook and loop fasteners in 
their aircraft to voluntarily switch to a metal strap type restraint 
method.

    Issued in Washington, DC, on June 30, 2015.
Susan J.M. Cabler,
Acting Manager, Design, Manufacturing, & Airworthiness Division, 
Aircraft Certification Service.
[FR Doc. 2015-16557 Filed 7-6-15; 8:45 am]
BILLING CODE 4910-13-P


