[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: [email protected].
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