Owner manual

ACR ELECTRONICS, INC / ARTEX PRODUCTS

DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL

G406-4 (453-5012)

25-62-21

Page 56 of 86

JUL 31/12

SUBTASK 25-62-21-990-005

E. RTCA

(1) DO-204, § 3.1.8 guidelines for mounting a ELT:

(a) The ELT shall be mounted to primary aircraft load carrying structures, such as trusses,

bulkheads, longerons, spars, or floor beams.

(b) The mounts shall have a maximum static local deflection no greater than 0.1 inches (2.5

mm) when a force of 100 lbs (450 newtons) 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 1 foot (0.3 meters) nor more than 3 feet (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

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.

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

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.