EPIRB’s How They Work & DF-430 On the C-130H Will cover: How EPIRBS work Some about your DF-430 Beacon Alerts in the CC and some about false alerts January 2010

How the System Works L Yarbrough/D7 CFVS

LEOSAR & GEOSAR Satellites GEOSAR Geostationary Satellites – 25,000 miles up. Same platform as weather satellites. 406 Beacon detect. No independent location data. LEOSAR Low Earth Orbit Satellites - 528 miles up. Polar orbit, with all points in the foot print at least once every 100 minutes. Center path of footprint 17 minutes wide, needs three full transmissions to calculate Doppler location. L Yarbrough/D7 CFVS

Maritime Distress Beacon Types of Beacons Maritime Distress Beacon EPIRBs 406 MHz (w/ 121.5 homer) Automatic activation when out of bracket and wet. Floats upright to transmit Strobe light Min 48 hour transmit Some GPS enabled L Yarbrough/D7 CFVS

Distress Beacon for Personal Use (Land Rescue) Types of Beacons Distress Beacon for Personal Use (Land Rescue) PLBs 406 MHz (w/ 121.5 homer) Manual activation Carried on persons May or may not float Held out of water to transmit NO Strobe light required Min 24 hour transmit Some GPS Enabled L Yarbrough/D7 CFVS

Aviation Distress Beacon Types of Beacons Aviation Distress Beacon ELTs Transmit on 121.5 (most) or 406 MHz Integrated 121.5 MHz homer Crash activation Floats upright to transmit No Strobe light Min 48 hour transmit L Yarbrough/D7 CFVS

Maritime Satellite Emergency Position-Indicating RadioBeacon EPIRB L Yarbrough/D7 CFVS

EPIRB Operational Requirements EPIRB 406 MHz Signal - 5 Watts Short bursts at approximately 50 second intervals (varies between 47.5 and 52.5 s), with a transmission time of 440 ms or 520 ms. Transmits in the 406.0 to 406.1 MHz band. Transmission consists: unmodulated carrier, for 160 ms, short synchronization signal, signal inverted for test, Digital message that provides stored information (identification, nationality, type of user), Optionally, current information like, type of emergency and estimated location. Designed to prevent inadvertent activation L Yarbrough/D7 CFVS

Hex ID EPIRB’s identification, when decoded into its 15 character hexadecimal representation, which is the EPIRB’s unique identifier number. http://www.cospas-sarsat.org/Beacons/decode.htm Normally readout in 3 groups of 5 characters. Example: ABCDE 12345 ABCDE HexID only uses 0 through 9 plus A through F. L Yarbrough/D7 CFVS

Battery Replacement Required at Expiration date or if EPIRB activated for any reason besides test. Useful Life = power for all required testing + 48 hrs operation. L Yarbrough/D7 CFVS

EPIRB Operational Requirements Positive visual and/or audible indication that EPIRB is activated (strobe light flashing). Easily manually deployed, activate, and deactivated, and transferred to survival craft. Not be activated or deactivated by conditions encountered in maritime environment. L Yarbrough/D7 CFVS

EPIRB Control Ready – EPIRB should be ON in the water unless in its bracket. Sometimes labeled “OFF”. ON – EPIRB operates regardless of location or orientation. Unconditional “ON” position. (Requires two physical actions) Test – Self-test Function. L Yarbrough/D7 CFVS

Prevention of Inadvertent Activation Must be fitted with means to prevent inadvertent activation and deactivation. Not automatically activate when water washes over while in bracket. Most EPIRBs use bracket with magnet to disable activation circuit. L Yarbrough/D7 CFVS

EPIRB Deactivation Remove beacon from water and dry off or replace in bracket Move switch to OFF or Ready position If the above failed then: Remove cover and disconnect battery L Yarbrough/D7 CFVS

EPIRB Activation How Or By definition it transmits: out of bracket and wet, by manual switch, in or out of bracket, Or Self test L Yarbrough/D7 CFVS

EPIRB Activation What Happens; Beacon starts transmitting its Unique Hex ID in a 406 MHz digital message, 121.5 MHz homer with an audible warble, Strobe Light starts flashing. Beacon will not start transmissions until one full timing cycle has elapsed (+50 sec). Some with GPS will wait up to 5 minutes to allow for GPS position acquisition. L Yarbrough/D7 CFVS

Rockwell Collins DF-430

DF-430 Bearings Bearing are relative Bearing Accuracy – less than 3° (Heads up, not compass). Bearing Accuracy – less than 3° Bearing Stability - +/- 5° (means less needle swing, a more stable point) Bearing Range – continuous 360° L Yarbrough/D7 CFVS

Bearing Inhibit Bearing Inhibit – during on-board transmission, the bearing computation is frozen (DF LOCK is displayed during on-board transmissions) L Yarbrough/D7 CFVS

SLDMBs ARGOS (401.650) is the frequency for your SLDMB. L Yarbrough/D7 CFVS

DF Bearing Pointer DF pointer only updates on receipt of next 406 MHz EPIRB burst transmission. Will seem jerky. EPIRB transmission only every ~50 sec. Burst transmission only half sec duration. Bust transmission is just a short (.5 sec) buz in the headset. L Yarbrough/D7 CFVS

Figure-of-Merit (FOM) Values DF-430 will display a FOM value in range of 0-255. Practical application is as a secondary level of confidence the aircraft is tracking towards target. L Yarbrough/D7 CFVS

406 MHz Detection Range Altitude (ft) Detection Range (nm) 25,000 133 22,500 129 20,000 124 17,500 119 15,000 113 12,500 106 10,000 99 7,500 88 5,000 76 2,500 57 1,500 23 L Yarbrough/D7 CFVS

Operational Considerations Transit in SAR Scan, unless tasking indicates a need to monitor a tactical freq. Greatest range/ earliest detection opportunity at higher altitudes. If a 406 signal is detected, DF needle will point. L Yarbrough/D7 CFVS

406 Beacon Tests Every 406 MHz Beacon is supposed to be tested (using the self-test function) once every month. Each test transmits one live 406 burst. Wait at least two bursts before you react to a 406 Det. L Yarbrough/D7 CFVS

What Does the CC/RCC do with a 406 Alert? EPIRB Prosecution What Does the CC/RCC do with a 406 Alert?

Registered/Unlocated 406MHZ EPIRB 1. RCC or RSC on receipt of unlocated registered 406 EPIRB: a. Place case in the DISTRESS phase. b. Assume SMC. c. Determine status of vessel from contact number listed, available databases, etc. L Yarbrough/D7 CFVS

Registered/Unlocated 406MHZ EPIRB (cont) 2. If vessel is determined to be safe underway or in port: a. Close case. A case will be claimed for all 406 alerts prosecuted L Yarbrough/D7 CFVS

Registered/Unlocated 406MHZ EPIRB (cont) 3. If vessel is underway and cannot be contacted: a. Issue UMIB for Home Port and general area in which vessel is believed to be operating. b. Contact AMVER Ships and request callouts for the vessel. c. Contact USMCC and request satellite forecast for the geographic area. L Yarbrough/D7 CFVS

Registered/Unlocated 406MHZ EPIRB (cont) 3. If vessel is underway and cannot be contacted: d. If the next forecast satellite pass does not locate the beacon consider sending an SRU to the area to attempt to hail the vessel or DF on 406/121.5MHZ homing signal. Continue investigating to try to determine last known position/probable track of vessel for additional searches. L Yarbrough/D7 CFVS

Registered/Unlocated 406MHZ EPIRB (cont) 3. If vessel is underway and cannot be contacted: e. If vessel cannot be located after reasonable search is conducted, search will be suspended. L Yarbrough/D7 CFVS

Registered/Unlocated 406MHZ EPIRB (cont) 4. If SRU is tasked to search for vessel: a. Proceed to LKP/tasked search area. Make callouts for vessel and attempt to DF homing beacon on 406/121.5MHZ. L Yarbrough/D7 CFVS

Registered/Unlocated 406MHZ EPIRB (cont) 4. If SRU is tasked to search for vessel: b. If signal cannot be DF’d once on scene and unless otherwise tasked, aircraft shall complete a VS search at radius of 12NM. Vessels shall complete the same search at 3NM. L Yarbrough/D7 CFVS

“A” solution located 406MHZ EPIRB 1. RCC or RSC on receipt “A” solution located 406MHZ EPIRB: a. Place case in the DISTRESS phase. b. Assumed SMC. c. Determine status of vessel from contact number listed (if registered), available databases, etc. L Yarbrough/D7 CFVS

“A” solution located 406MHZ EPIRB (cont) 2. RCC or RSC if vessel is determined to be safe/underway or in port: a. Close case. L Yarbrough/D7 CFVS

“A” solution located 406MHZ EPIRB (cont) 3. RCC or RSC if vessel is underway and cannot be contacted: a. Issue UMIB for general area in which vessel is believed to be operating. b. Contact AMVER ships in vicinity and request callouts for vessel. c. Dispatch SRU to located vessel and determine status. SRU’s should be tasked to DF on the signal. L Yarbrough/D7 CFVS

“A” solution located 406MHZ EPIRB (cont) 3. RCC or RSC if vessel is underway and cannot be contacted: d. If vessel cannot be located after reasonable search is conducted, search will be suspended. L Yarbrough/D7 CFVS

“A” solution located 406MHZ EPIRB (cont) 4. SRU if tasked to search for vessel: a. Proceed to position/tasked search area. Make callouts for vessel and attempt to DF homing beacon on 406/121.5MHZ. b. If a signal cannot be DF’d once on scene and unless otherwise tasked, aircraft shall complete a VS search at radius of 12NM. Vessels shall complete the same search at 3NM. L Yarbrough/D7 CFVS

“B” solution with alert probability less than or equal to 20% 1. RCC or RSC on receipt “B” solution with probability less than or equal to 20%: Place case in the UNCERTAINTY phase. Assume SMC. Coordinate investigation with RCC responsible for “A” solution. If investigation determines “B” solution is the likely position, respond in same manner as an “A” solution. L Yarbrough/D7 CFVS

“B” solution with alert probability greater than 20% 1. RCC or RSC on receipt “B” solution with probability greater than 20%: a. Place case in the ALERT phase. b. Assumed SMC. c. Coordinate investigation with RCC responsible for “A” solution. If investigation determines “B” solution is the likely position, respond in same manner as an “A” solution. L Yarbrough/D7 CFVS

Unregistered/Unlocated EPIRB alerts: 1. RCC or RSC investigate identity of vessel through vessel data bases. 2. RCC or RSC contact RCC country of vessel registered and attempt to determine vessel’s status. L Yarbrough/D7 CFVS

False Alerts

False Alerts If a false alert is determined upon arrival on-scene complete the following actions: Have vessel de-activate the beacon. Have vessel provide the beacon “HexID” Have vessel provide the reason beacon alerted and include in MISLE Reporting. Advise vessel that EPIRB and bracket require servicing and battery replacement. Relay to tasking authority as required. L Yarbrough/D7 CFVS

Operator Induced False Alerts 10% were Testing without following manufactures instructions, or other deliberate non-emergency activations 6% 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. L Yarbrough/D7 CFVS

EPIRB False Alerts 69% Caused by Failure of “The bracket decoupling function” to control the EPIRB 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. L Yarbrough/D7 CFVS

Why didn’t I get a 406 Detection or How Long do 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. L Yarbrough/D7 CFVS

Questions? (305) 415 6868 Larry.T.Yarbrough@uscg.mil L Yarbrough/D7 CFVS