ARTEX PRODUCTS / ACR ELECTRONICS, INC.
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
ELT 1000 (P/N: A3-06-2749-1)
Y1-03-0259 Rev. U
Company Confidential
Page 38 of 62
F.
RTCA
1)
DO-204A, § 3.1.8 guidelines for mounting an ELT:
a)
The ELT unit shall be mounted to primary aircraft load-carrying structures, such as trusses, bulkheads,
longerons, spars, or floor beams (not aircraft skin) or a structure that meets the requirements of the
following test:
b)
The mounts shall have a maximum static local deflection no greater than 2.5 mm when a force of 450
newtons (100 lbf) is applied to the mount in the most flexible direction. Deflection measurements shall be
made with reference to another part of the aircraft not less than 0.3 meters nor more than 1.0 meters from
the mounting location.
2)
DO-182, § 6.2.2.b recommends that:
a)
To maximize the probability of the ELT transmitting a detectable signal after a crash, all ELT system
components, which must survive a crash intact, e.g. transmitter and external antenna, should be attached
to the airframe in such a manner that the attachment system can support a 100 g load, (ELT weight x 100,
ELT antenna weight x 100, etc.) applied through the center of gravity of the component (ELT, antenna,
etc.) in the plus and minus directions of the three principal axes of the aircraft.
b)
Post-crash critical components of the ELT system, e.g. transmitter and external antenna, should be
mounted as close to each other as possible.
c)
The antenna coax cable should not cross any production breaks, e.g., major structure sections, such that
the ELT and antenna are in the same section of the aircraft and as close together as possible.
d)
If the ELT and external antenna are on opposite sides of an airframe production break, the components
should be secured to each other by a tether that can support a 100 g load (ELT weight x 100). The
interconnecting antenna-to-ELT coax cable should have sufficient slack on both ends that it will not be
subjected to any tensile load and should be tied loosely to the tether.
