©1998 Scott E. Lanis ELTs: Everything You Wanted to know- and MORE BASIC GROUND ELT LOCATION COURSE (CLASSROOM)

©1998 Scott E. Lanis OBJECTIVES  By the end of this course, you should:  Know what an ELT is, and how it can be activated  Understand why an ELT signal is an emergency  Describe how CAP is called out on an electronic search  Be familiar with these fundamentals: Plotting a SARSAT hit on a map (latitude/longitude) Direction finding - Little L-Per™ Operation Triangulation Body shielding Aircraft coordination/LORAN/GPS operations Ground Vehicle Operations

©1998 Scott E. Lanis Is An Aircraft Missing?  How would we know?  Radio distress call  Monitored aircraft drops from RADAR  Overdue Flight Plan  Report from friends/relatives  ELT Signal (maybe!)

©1998 Scott E. Lanis How does CAP Search for Missing Aircraft?  Purely Visual Searches  Very Difficult: often few clues  Air - most effective to cover ground  Ground  Electronic Searches - “Quick” (24 hrs)  Air - best reception and range  Ground - autonomous search is slower and more difficult  Advanced Technology  Few of these resources available directly to CAP  Synthetic Aperture Radar (SAR), Thermal/Infrared Imagery, Other Remote Sensing (satellites/reconnaissance aircraft)

©1998 Scott E. Lanis What Will A Crashed Airplane Look Like?

©1998 Scott E. Lanis Air To Ground Coordination  The most effective way to search  The only way CAP stays in the SAR business  The plan:  CAP aircraft locates crash (visual / electronic)  Coordinates to bring ground team on scene Radio (transmit the Lat-Longs from LORAN/GPS!) Radio Out Lat-Long (LORAN/GPS)  Ground Team effects rescue

©1998 Scott E. Lanis Aircraft Limitations  Weather  Can’t pinpoint signal  Row of hangers

©1998 Scott E. Lanis Ground Search Types for Missing Aircraft  Ramp Search  Ensure the missing aircraft has not landed safely  Can be conducted by both air and ground crews  Bastard Search  Ensure the missing person isn’t in a favorite hangout  “You bastard!”

©1998 Scott E. Lanis How does a search start?  There is the possibility of a missing aircraft  Radio distress call, aircraft drops from RADAR, overdue flight plan, report from friends/relatives, ELT Signal  AFRCC performs a telephone search  Airport managers, towers, etc.  Missing Aircraft Confirmed!  AFRCC activates the appropriate CAP wing

©1998 Scott E. Lanis What if only an ELT signal is Received?  AFRCC Telephone Search  Airports: “Do you hear it too?”  Likely false alarm at this point; signal silenced by crews on airport  CAP called sooner if “after hours”  No one else answers the phone!  Is there another indicator of a missing aircraft?  If not, AFRCC will wait to see if the signal terminates  Tests  Inadvertent actuations terminated

©1998 Scott E. Lanis Huh? What is an ELT anyway?  Emergency Locator Transmitter  It’s an automatic radio beacon!  3 Frequencies of Operation  MHz (VHF)  AND 243 MHz (UHF) (Military Guard)  MHz (new)  Most aircraft have ELTs installed

©1998 Scott E. Lanis General Types of ELTs  Aircraft (General Aviation)  Military (“beepers” or “beacons”)  Personal (PELTs or PLBs)  Marine EPIRBs  Advanced (406/GPS)

©1998 Scott E. Lanis Typical Aircraft ELT Operation  3 Switch positions--on, arm/standby, and off  G-switch activated (Generally 9G)  Activates ELT upon impact when armed  May be manually operated by placing the switch in in the ‘ON’ position

©1998 Scott E. Lanis Can you test an ELT?  Yes, with restrictions:  First 5 minutes of the hour, no more than 3 sweeps  Battery must be replaced after:  One cumulative hour of use or  50% of useful life has expired  FAR §91.207(c)  Does not apply to our Practice Beacons  Call nearest FSS in advance: 1 (800) WX-BRIEF  Give a contact phone-interference happens on !

©1998 Scott E. Lanis Inadvertent Activation of an ELT May Occur From:  Excessively hard landing  Inadvertent change of switch position  Removal of the unit  activating the switch or G-switch  Malfunction  switch short  battery leakage

©1998 Scott E. Lanis Who is listening?  SARSAT/COSPAS  FAA Facilities  FSS, Centers, Towers  Airliners  Only if pilot chooses  Military Aircraft  243 MHz Required  General Aviation Aircraft  That’s us! Help the system work: monitor MHz  Signal report is relayed to AFRCC

©1998 Scott E. Lanis SARSAT/COSPAS

©1998 Scott E. Lanis How SARSAT Works  Receive 121.5, 243, 406 MHz Signals  Orbiting and Geostationary Satellites  Orbiting: SARSAT/COSPAS  High Inclination (polar) orbits  Geostationary: GOES Weather Satellites  SAR payloads for 406 only  Operated by Canada, France, Russia, USA  They give us digital lat-long coordinates  CAP Mission Coordinator plots these and assigns assets  Ground teams must interpret for land navigation

©1998 Scott E. Lanis System Operation Details  SARSAT/COSPAS in polar orbit  Calculates location of signal by measuring Doppler shift  This yields a latitude and a distance

©1998 Scott E. Lanis Narrowing The Search (SARSAT/COSPAS Only)  First pass  Ambiguity

©1998 Scott E. Lanis Where Is It?  Second Pass  average minute wait  Ambiguity resolved  5-12 Nautical Mile Average Error

©1998 Scott E. Lanis How Do Different ELTs Stack Up?  MHz ELT  12 NM Radius, 452 Sq Mi  Ave. 6 Hour Notification  60 Milliwatt Transmitter  406 MHz ELT  2 NM Radius, 12.5 Sq Mi  Ave. 1 Hour Notification  25 Milliwatt Beacon  406 ELT with GPS .05 NM Radius,.008 Sq Mi  Ave. 5 minute Notification  25 Milliwatt Beacon

©1998 Scott E. Lanis System Review  ELT, PLB, EPIRB Signal Received  AFRCC gets coordinates from SARSAT  Appropriate CAP Wing is activated

©1998 Scott E. Lanis False Alarms  97% of received ELTs are false alarms  MHz: 1 in 1000 is an actual emergency (0.1%)  406 MHz: 1 in 8 is an actual emergency (12.5%)  Why is a False Alarm a big deal?  SARSAT can only monitor 10 ELTs at once (within footprint)  bent-pipe repeater  VERY easy to overload the system  Blocks emergency communications  Blocks the real emergency!

©1998 Scott E. Lanis How Should We Treat An ELT?  As an EMERGENCY!  You can’t know which ones are Distress ELTs  And even the false ones are good training!

©1998 Scott E. Lanis Transportation to Target  Ground Teams generally will use vehicles for transportation to and from mission base  Aircraft Coordination will get the Ground Team to the target the fastest  If no aircraft is available:  Vehicles provide enough speed and range to triangulate  Close range may be required for signal acquisition

©1998 Scott E. Lanis Direction Finding  DF unit Measures equal strengths of signal not wholly accurate, but good enough!  Therefore, when needle is centered, ELT could be either direction  Needle always POINTS to the ELT (DF=Direct to the Flipping target)  Use a TURN to TELL if the ELT is in front or behind you

©1998 Scott E. Lanis DFing with the Little L-Per™  6 Steps: use the full procedure every time!  Turn the unit to Receive, check proper frequency and volume  Turn the Sensitivity Knob to HALF SCALE This will prevent oversense and a good starting point  Turn the unit to DF (Direct to the Flipping target)  Turn at least one FULL circle, stopping and calling, “Center!”  Check: Use Turn to Tell: the needle will point Direct to the Flipping target  Use your compass, shoot an azimuth to get a bearing to the ELT

©1998 Scott E. Lanis Direct to the Flipping, Turn to Tell

©1998 Scott E. Lanis  REC  1/2  DF  Center  Turn  Shoot

©1998 Scott E. Lanis Little L-Per™ Receive Mode  Measures Signal Strength only  From a direction of the arrows on the antenna (to your left)  Use it with multiple centers (more than 2) to verify strongest path  Due Reflections  That’s most likely the true direction to the ELT

©1998 Scott E. Lanis Reflections  Caused by flat surfaces  Hangars are notorious  Rock wall, cliff, or mountains  To beat reflections  Check sensitivity half scale often  Use RECeive mode  Rubber ducky antenna  Off-frequency tuning  Usually strongest DF center is not a reflection

©1998 Scott E. Lanis Triangulation  Best method for ground troops to get an accurate fix when search aircraft support is unavailable  You must be able to receive the signal  Center up DF unit on the signal  Take the magnetic bearing (shoot an azimuth)  Correct for magnetic variation East is least, West is best  Plot your bearings (draw a line) on map  The ELT should be where the lines cross!

©1998 Scott E. Lanis Let’s See That

©1998 Scott E. Lanis Body Shielding The BEST method of beating reflections at close range  Can use L-Per™  Radio Shack JETSTREAM radio is better and CHEAP!  At extremely close range, a 2m VHF radio unsquelched may work This works ok when trying to figure out a particular aircraft on a flight line, it will probably not identify a particular hangar  Body blocks out the signal  Called a NULL  Null should be at your BACK

©1998 Scott E. Lanis Off-Frequency Tuning  Decrease sensitivity when:  Sensitivity (L-Per™) is at the minimum and signal is still too strong (full scale on receive)  You don’t get a null during body shielding  You don’t have a sensitivity knob (Jetstream)  Shortening (Jetstream) or removing (Little L-Per™) the antenna will also decrease sensitivity  Off-Frequency tuning may be used any time you have too much signal, but this technique is especially effective during body shielding

©1998 Scott E. Lanis Hey, I Can’t Hear the Signal!  ELTs are limited to Line of Sight propagation  You don’t always need to hear the ELT  Carrier wave may be broadcasting with no audible sweep  Especially true in low batteries, or odd transmissions  You can tell by DEFLECTION  Good needle deflection generally indicates a signal that is strong enough to DF

©1998 Scott E. Lanis What Else Can Affect An ELT Signal?  Power lines  EM Radiation  If you get an actual ELT during a practice search, shut down all practice beacons. The signal on may be frequency shifted from your practice beacon! (often due to powerlines)  Fence Line (signal can follow)  Coffee Can/Stovepipe effect  Hangars  Moving Target

©1998 Scott E. Lanis How Does An Aircraft Perform An Electronic Search?  Aircraft use the same type of methods as used on the ground  DF mode (most common)  Wing Null Method (body shielding with the wing!)  Signal Strength  Aural Search (rare)

©1998 Scott E. Lanis Before Going Home, Silence The Signal!  Sometimes that’s the only goal!  Methods of disabling an ELT:  Switch off (not always effective!)  Foil tent  Grounding wire  Remove battery  Remove antenna  The Sheriff is required for forcible entry  Most folks will be very cooperative  Ensure the aircraft operator is notified you disabled the ELT!

©1998 Scott E. Lanis Summary  You Should Now:  Know what an ELT is and how it can be activated  Understand why an ELT signal is an emergency  Describe how CAP is called out on an electronic search  Be familiar with these fundamentals: Plotting a SARSAT hit on a map (latitude/longitude) Direction finding - Little L-Per™ Operation Triangulation Body shielding Aircraft coordination/LORAN/GPS operations Ground Vehicle Operations

©1998 Scott E. Lanis QUESTIONS?