CIRCULAR LETTER
MSC/Circ.1039
GUIDELINES FOR SHORE-BASED MAINTENANCE OF SATELLITE EPIRBS
(adopted
on 21 May 2002)
1.1
The purpose of these Guidelines is to establish standardised procedures and
minimum levels of service for the testing and maintenance of satellite EPIRBs
to ensure maximum reliability whilst minimising the risk of false distress
alerting.
1.2
The Guidelines are intended to be applicable both to 406 MHz EPIRBs and to
L-band EPIRBs, as either type may be carried to comply with the requirements of
SOLAS IV/7.1.6. EPIRBs may include 121.5MHz transmitters, or Global Navigation
Satellite System (GNSS) receivers.
1.3
The Guidelines also apply to service exchange EPIRBs. These should be properly
encoded to match the appropriate registration database.
2. Shore-Based Maintenance (SBM) Provider.
2.1
The SBM Provider should:
.1 have a quality control
system audited by a competent authority in respect of its servicing operation;
.2 have access to adequate
calibrated test equipment and facilities to carry out the SBM in accordance
with these Guidelines;
.3 have access to batteries
and other spare parts to the original equipment specification;
.4 have access to up-to-date
technical manuals, service bulletins and the latest software versions as
provided by the original equipment manufacturer;
.5 keep records of
maintenance, available for inspection by the Administration as may be required;
.6 ensure that all personnel
responsible for supervising and for carrying out the maintenance procedures are
adequately trained and fully competent to perform their duties; and
.7 issue of a shore-based
maintenance report with a list of the test results and maintenance performed.
3. Prevention of False Distress Alerts.
3.1
Throughout the testing and maintenance process, great care must be taken to
avoid the transmission of false distress alerts. The transmissions may be
picked up by aircraft as well as satellites.
3.2
A radio-frequency-screened room or enclosure should be used for all maintenance
procedures involving, or likely to involve, any transmission from an EPIRB.
3.3
Provision of a 121.5MHz monitor receiver is required; this will pick up the
homing transmitter and give a warning if the EPIRB is accidentally activated
outside the screened enclosure.
3.4
If a distress signal is transmitted accidentally, the local RCC should be
contacted immediately and informed of the coordinates of the test site.
4. Maintenance Service interval.
4.1
All satellite EPIRBs should be inspected and tested in accordance with
MSC/Circ.882.
4.2
Shore-based maintenance of satellite EPIRBs as defined in paragraph 1.2 should
be carried out in accordance with these Guidelines at intervals specified by
the Flag Administration, and not exceeding 5 years. It is recommended that the
maintenance be performed at the time when the battery is to be changed.
5.1
Prior to carrying out any maintenance and, upon completion, a self-test should
be performed, following the instructions on the equipment, and the results
noted.
5.2
Attention is drawn to paragraph 3 on the Prevention of False Distress Alerts.
Avoidance of live transmissions is required to prevent unnecessary loading of
the satellite channels.
5.3
Verify that the self-test mode operates properly. This check could be performed
by holding the switch in self-test mode position for 1 minute after the first
self-test mode burst transmission. All transmissions should cease after
releasing the self-test mode switch. Additionally, for 406 MHz satellite EPIRBs
which received the COSPAS-SARSAT type approval after October 1998 (Type
Approval certificates 106 and higher) the number of self-test bursts should be
verified to be no more than one.
6.1
The main battery should be changed in accordance with the manufacturer's
recommendations, including the replacement of any other routine service parts
(e.g. seals, memory battery, desiccant).
6.2
The removed batteries should be disposed of in accordance with the
manufacturer's and/or national/local recommendations.
6.3
After having changed the battery, the new expiration date should be displayed
on the exterior surface of the EPIRB.
7. Satellite distress transmission.
7.1
The satellite EPIRB should be activated in its normal transmitting mode (i.e.
not just self-test). Attention is drawn to paragraph 3 on the Prevention of
False Distress Alerts. Where seawater contacts are fitted, these should be
connected together to activate the EPIRB.
7.2
The transmitted signal should be checked with a suitable test receiver to
verify the signal integrity and coding.
7.3
The frequency of the transmitted signal should be recorded and verified to be
within the limits required by the specification to which it is approved.
7.4
The output power of the transmitter should be checked in the self-test mode. A
simple method of the emission verification, such as a low sensitivity receiver
placed at an unobstructed distance of at least 3 m from the EPIRB antenna, may
be used for this check. The original equipment manufacturer may suggest an
appropriate method to verify the output power. Attention is drawn to paragraph
3 on the Prevention of False Distress Alerts..
8. 121.5 MHz homing transmission.
8.1
The satellite EPIRB should be activated in it's normal transmitting mode (i.e.
not just self-test). Attention is drawn to paragraph 3 on the Prevention of
False Distress Alerts. Where seawater contacts are fitted, these should be
connected together to activate the EPIRB.
8.2
The transmitted signal should be checked with a suitable test receiver for the
characteristic swept tone modulation.
9. Global Navigation Satellite System (GNSS).
9.1
Some satellite EPIRBs are designed to transmit a position derived from a GNSS
receiver, which may be internal or external to the EPIRB.
9.2
The original equipment (EPIRB) manufacturer should be consulted for a method of
testing the correct operation of this function, e.g.: by using a GNSS
repeater/simulator or external input. This test may involve a live transmission
from the EPIRB and should be performed in a screened room or enclosure in
accordance with paragraph 3.2. Attention is drawn to paragraph 3 on the
Prevention of False Distress Alerts.
9.3
A test receiver should be used to verify that the signal transmitted by the
satellite EPIRB contains the correctly encoded position data derived from the
GNSS receiver. Attention is drawn to paragraph 3 on the Prevention of False
Distress Alerts.
10.1
The satellite EPIRB should be inspected for any signs of damage or cracks to
the casing, or of water ingress. Any damaged item should be replaced in
accordance with the manufacturers recommended procedures.
10.2
The satellite EPIRB should be tested for waterproof integrity at the end of the
SBM. The equipment manufacturer may suggest an appropriate method to test the
integrity of the EPIRB.
10.3
One method involves immersing the equipment in hot water (20 - 30°C above
ambient) for a period of one minute. It can be readily seen if there are any
problems with the seals, as the air inside the beacon expands and escapes as a
stream of bubbles. Ibis test should not be carried out with cool water, as the
water may be drawn into the equipment without showing significant release of
air