1. 406 MHz EPIRB False Alerts Study NOAA/SARSAT Conference 2010
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

2. EPIRB False Alerts Study
Study was research project by:
Larry Yarbrough, CAPT, USCG (Ret)
USCG District 7 (dpi)
Newton Anderson,
USCG Auxiliary
Greg Johnson
USCG Sector Charleston
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

3. Why does US Coast Guard care about EPIRB False Alerts?
96% 406 MHz EPIRB Alerts are false
85% Resolved by RCCs with registration and good detective work
Projected increase in the 406 HMz Beacon population will bring increase in number of false alerts
The RCCs in this study are all US Coast Guard Command Centers with SAR responsibilities for maritime geographical areas, and SAR assets under their control.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

4. L. T. Yarbrough/ USCG, D7 dpi
406 MHz Beacon Population
Forecast of Registered Beacons in the U.S. Beacon Registration Data Base (RGBD)
Bacons/Year
2010
2015
EPIRBs
215,000
288,000
PLBs
292,000
470,000
ELTs
137,000
342,000
SSAS Beacons
500
1,000
Numbers from the Spring of Provided by NOAA SARSAT at the Beacon Manufacturer’s Workshop
Beacons/Year
ELTs 137, ,000
EPIRBs 215, ,000
PLBs 292, ,000
SSAS beacons ,000
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

5. Why does US Coast Guard care about EPIRB False Alerts?
$4.5million in A/C time and fuel on 406 MHz EPIRB false alerts in 2009
SAR crews put at risk
SAR assets less available for actual distress
Fatigues and dulls the SAR system
How many times do you cry wolf, before you have dulled the system.
USCG spent over $12 per day in aircraft cost on false alerts.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

6. L. T. Yarbrough/ USCG, D7 dpi
Another way to look at what it is costing the US Coast Guard to respond to EPIRB Alerts that are not actual distress.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

7. EPIRB False Alerts Study
Study data limited to:
US Registered 406 MHz EPIRBs
transmitting a 406 MHz False Alert
where secondary data collection was accomplished, through RCC telephone interview of vessels owner or operator at the time of the alert
Study Population came from all USMCC alerts passed to US Coast Guard RCCs
USMCC is the US Mission Control Center.
The questions asked are below. This data was tabulated, along with comments from the SAR controller who handled the case.
MISLE #: Site ID#:
Confirm Hex ID:
Contact information for follow-up:
Vessel Name:
VIN:
Homeport:
Phone Nr:
Name:
Make / Model of EPIRB:
Did they know EPIRB had activated?
Was EPIRB in its bracket when it activated?
Was Switch in the On or Off position?
Was the EPIRB wet when it activated?
Was the EPIRB hit or bumped?
What is the battery expiration date?
Any visible damage to EPIRB?
Other information?
Was Owner/Operator advised that EPIRB needs service after every activation?
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

8. L. T. Yarbrough/ USCG, D7 dpi
EPIRB False Alerts
1 May - 31 Dec 2007
USMCC received MHz EPIRB alerts
5% (83) were Distress Alerts
1494 False Alerts (non-distress and ceased/undetermined alerts)
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

9. L. T. Yarbrough/ USCG, D7 dpi
EPIRB False Alerts
1494 False Alerts (non-distress and ceased/undetermined alerts)
15% - (232) Were False Alerts with enough data collected to develop evidence of circumstances causing alert transmission
When you wake a Beacon owner at 3 AM, and tell him he has to go down to his boat and turn off his EPIRB, you may not get the most enthusiastic cooperation. In fact some folks turned out to be darn right grumpy. This was a natural limitation on our data collection.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

10. How Long does a False Alerts Last?
This slide is a study of the elapsed time from first detection to last detection. Each bar on the graph represents the number of alerts.
The red line shows the cumulative % of False Alerts who’s duration was less than the duration time points selected.
As this slide illustrates, most EPIRBs (70%) had stopped transmitting an alert before there was an opportunity for the owner to notified and take action to secure the beacon (about 30minutes).
40 or 17% had a total detection time of less than 1 minute.
77 or 33% had a detection time of >5 minutes, and
105 or 45% were detection events lasting less than 10 minutes.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

11. L. T. Yarbrough/ USCG, D7 dpi
EPIRB False Alerts
False Alerts with enough data collected to develop evidence of circumstances causing alert transmission
Of the 232 Activations only 35 were by EPIRBS with 3 or more activation in past 18 months.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

12. Operator Induced False Alerts
10% (24) were attributed to Testing without following manufactures instructions, or other deliberate non-emergency activations
6% (13) were EPIRBs deliberately taken out of bracket and naked of any control of the wet sensor
13 were stored or transported out of their bracket (Naked) by the owner. They were in ditch bags, car trunks, garages, chart drawers, etc.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

13. False Alert and EPIRB in Bracket
161 reported to be in their bracket,
Of these;
95 reported to be wet,
35 reported to have been bumped,
15 report being knocked from bracket .
4 reported icing (tabulated data stopped at end of December, however during the winter of 07/08 a total of 15 icing involved False Alerts were logged in the IHDB).
26 reported rain storm or heavy weather,
22 reported washing boat
Note: An EPIRB False Alert may have exhibited more than one symptom.
19 reported damaged
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

14. L. T. Yarbrough/ USCG, D7 dpi
EPIRB False Alerts
69% (161) Caused by Failure of “The bracket decoupling function” to control the EPIRB
Observed with Category I and II
Manufactures, makes and models in the US registration data base were proportionally represented by False Alerts
These false activations tend to be transitory or short duration events.
I assume the bracket decoupling function gained control of the beacon and stopped the transmission in a short period of time.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

15. L. T. Yarbrough/ USCG, D7 dpi
EPIRB False Alerts
69% (161) Activated when bracket should have prevented activation
Failure of “The bracket decoupling function” to control the EPIRB
161 reported to be in their bracket.
Of these;
95 reported to be wet,
35 reported to have been bumped,
15 report being knocked from bracket
4 reported icing (collection stopped at end of December)
26 reported rain storm or heavy weather,
22 reported washing boat
Note: An EPIRB False Alert may have exhibited more than one symptom.
13 were in a ditch bag, trunk or garage
19 reported damaged
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

16. Bracket problems observed in field by Coast Guard personnel
Loose straps or mechanical holding device
Missing pads or guides to hold beacons in place
Missing or corroded magnets
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

17. Bracket problems observed in field by Coast Guard personal (continued)
Beacons being placed improperly in brackets by users
Brackets not mounted in accordance with manufactures recommendations
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

18. L. T. Yarbrough/ USCG, D7 dpi
RTCM Standard
“The satellite EPIRB should not be accidentally activated or deactivated by conditions normally encountered in the maritime environment.”
The IEC Global maritime distress and safety system (GMDSS)-
Part 2: COSPAS-SARSAT EPIRB – Satellite emergency position indicating radio
Beacon operating on 406 MHZ – Operational and performance requirements,
Methods of testing and required test results.
3.3.1 Prevention of inadvertent activation
The satellite EPIRB shall:
(A.810(19)/A2.3.1 be fitted With adequate means to prevent inadvertent activation and deactivation.
not automatically active when water washes over it while in its release mechanism.
Beacons are tested prior to be authorized for production and sale. Tests include a fire hose spraying 680 gal / min for 5 minutes.
Shock and vibration
(A.810(19)/A2.6.2) Be capable, while mounted on board, of operating properly over the ranges of shock and vibration and other environmental conditions normally encountered above deck on sea-going vessels.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

19. L. T. Yarbrough/ USCG, D7 dpi
RTCM Standard
“The bracket decoupling function will guard against false alarms should the water-activation mechanism malfunction to an “on” mode. It will also prevent inadvertent activation due to the water activation mechanism becoming wet due to heavy seas or rain. … Both Category 1 and Category 2 satellite EPIRBs should have these features.”
The IEC Global maritime distress and safety system (GMDSS)-
Part 2: COSPAS-SARSAT EPIRB – Satellite emergency position indicating radio
Beacon operating on 406 MHZ – Operational and performance requirements,
Methods of testing and required test results.
3.3.1 Prevention of inadvertent activation
The satellite EPIRB shall:
(A.810(19)/A2.3.1 be fitted With adequate means to prevent inadvertent activation and deactivation.
not automatically active when water washes over it while in its release mechanism.
Shock and vibration
(A.810(19)/A2.6.2) Be capable, while mounted on board, of operating properly over the ranges of shock and vibration and other environmental conditions normally encountered above deck on sea-going vessels.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

20. Approval Water Testing
All EPIRBS must have a Bracket to control the “Water Activation Circuit”. These EPIRB and Bracket combination must go through testing prior to being authorized for production and/or sale.
Part of the testing is to be subjected to a stream from a hose directed at the unit for a period of 5 min. The nozzle of the hose shall have a nominal diameter of 63.5 mm and water –delivery rate of approximately 2300 liters (680 gal) of water per min.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

21. EPIRB Operational Requirements
Not be activated or deactivated by conditions encountered in maritime environment
69% Of
False Alerts
Bracket
Interface Failure
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

22. L. T. Yarbrough/ USCG, D7 dpi
False Alert Workload
How to reduce your False Alert Workload
Push Beacon Registration at every opportunity.
Did you tell them what was wrong with their registration? Do they know bad registration information may cost their life someday?
Did you tell them to service their beacon and bracket?
Did you tell Sector Prevention about identified repeat offenders?
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

23. L. T. Yarbrough/ USCG, D7 dpi
False Alerts
False Alerts are a drain on the health of the EPIRB Distress Alerting System
There is no one cause of EPIRB False Alerts, and there is no one fix for the problem However …
Correctly identifying the cause of the False Alert in the IHDB can lead to a better system.
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi

24. L. T. Yarbrough/ USCG, D7 dpi
Questions?
Feb 2010
L. T. Yarbrough/ USCG, D7 dpi