1 Emergency Services Electronic Searches Mission Pilot CAPR Attachment 10 Paragraph b Richard Shulak Wasatch Sqdn. RMR-UT-008 January 2000

2 Used to augment search Track line search (route) Parallel track search Standard equipment can be used CAP planes equipped with DF ELTs on or 243 mhz Electronic Searches

3 Homing Method Used with DF equipment Start at 5000 to ft AGL Keep needle centered Determine if heading towards or away from target Crossover indications Problems Stray signals Other aircraft Low altitude reflections

4 Signal Null Search

5 Signal Null Methods Requires two conditions Metal wings Requires several nulls to locate target Null direction differs for different wing and antenna configurations High wing Low wing Calibrate using DG Use lower altitudes as you approach suspect area No nulls Descend to search altitude

6 Signal Null Search Crew Requirements 1. Crew skilled in executing steep turns Close to the ground Possibility of a spin No recovery possible Not recommended below 1000 to 2000 ft AGL 2. Know aircraft position when null occurs Plot vectors

7 Signal Null Search Crew Requirements 3. Lost signal procedures Return to last known signal Requires charting 4. Approach to the search area Watch for other aircraft Non CAP aircraft may be involved

8 Aural Search Methods

9 Aural Search Method Procedure Assumption that area of equal beacon strength is circular Procedure Observer plots position when signal is first heard Pilot turns 90 degrees Either left or right All subsequent turns are made in the same direction (left or right) Continue until signal fades (SF). Do not touch volume

10 Aural Search Method Procedure Pilot executes 180 degree turn Plot the new signal heard point (SH) Fly until signal fades (SF) Generates second vector Pilot flies to indicated point and executes low altitude search Notes Calculations are approximate Bisectors seldom intersect over target

11 Metered Search

12 Metered Search Requires a signal strength meter Procedure Find two points of equal strength Fly to mid point At mid point, turn left or right If signal drops, turn 180 degrees Observer plots two more points of equal strength Turn and fly to max reading Start low level search

13 Electronic Searches Conclusions Requires training Works best in flat terrain Signals reflect Can cause DF equipment to indicate different directions Flying higher can help In mountainous areas, canyons, crevices etc will block signals In above examples, plotting where signals are heard and lost can help identify possible ELT locations