Narrative:

I was orbiting at 4500 ft on a law enforcement mission. I had been on station for about 10 mins and had completed about 2 orbits. I had dialed in the approach frequency for socal as I was going to ask for VFR advisories. The aircraft is equipped with a ryan 9900B tcad. I heard an alert tone in my headset while in a l-hand orbit. I continued the orbit scanning for traffic. As I continued the turn and scan, the target continued climbing towards my altitude and location. When I could not locate the target, I banked right to continue to look. As I raised the left wing, I immediately saw an air carrier jet approximately 1/10 mi away, climbing through my altitude. I continued a hard right bank to avoid the wake turbulence. I do not know why the airline was allowed so close to my position. I had a working transponder, but had not yet begun receiving radar advisories. The tcad helped greatly in helping me locate the target but the closure rate between the target was too great to allow me time to locate the target prior to it getting as close as it did. Possible solutions to prevent this from recurring are: 1) VFR aircraft (me) request radar advisories anytime I am operating in the vicinity of an airport (even in class east airspace). 2) acrs departing a radar equipped airport should have constant communication with the controller during the time the aircraft departs class C airspace, while transiting through class east airspace, until they are handed over to another controller (once in class B airspace). 3) when looking for converging traffic, immediately lift one wing, scan, then life the other. This may have allowed me to see the air carrier sooner.

Related reports:

Google
 

Original NASA ASRS Text

Title: A LAW ENFORCEMENT PLT IN A C182 EXPERIENCED AN NMAC WITH AN ACR WHILE ORBITING DURING A POLICE ACTION.

Narrative: I WAS ORBITING AT 4500 FT ON A LAW ENFORCEMENT MISSION. I HAD BEEN ON STATION FOR ABOUT 10 MINS AND HAD COMPLETED ABOUT 2 ORBITS. I HAD DIALED IN THE APCH FREQ FOR SOCAL AS I WAS GOING TO ASK FOR VFR ADVISORIES. THE ACFT IS EQUIPPED WITH A RYAN 9900B TCAD. I HEARD AN ALERT TONE IN MY HEADSET WHILE IN A L-HAND ORBIT. I CONTINUED THE ORBIT SCANNING FOR TFC. AS I CONTINUED THE TURN AND SCAN, THE TARGET CONTINUED CLBING TOWARDS MY ALT AND LOCATION. WHEN I COULD NOT LOCATE THE TARGET, I BANKED R TO CONTINUE TO LOOK. AS I RAISED THE L WING, I IMMEDIATELY SAW AN ACR JET APPROX 1/10 MI AWAY, CLBING THROUGH MY ALT. I CONTINUED A HARD R BANK TO AVOID THE WAKE TURB. I DO NOT KNOW WHY THE AIRLINE WAS ALLOWED SO CLOSE TO MY POS. I HAD A WORKING XPONDER, BUT HAD NOT YET BEGUN RECEIVING RADAR ADVISORIES. THE TCAD HELPED GREATLY IN HELPING ME LOCATE THE TARGET BUT THE CLOSURE RATE BTWN THE TARGET WAS TOO GREAT TO ALLOW ME TIME TO LOCATE THE TARGET PRIOR TO IT GETTING AS CLOSE AS IT DID. POSSIBLE SOLUTIONS TO PREVENT THIS FROM RECURRING ARE: 1) VFR ACFT (ME) REQUEST RADAR ADVISORIES ANYTIME I AM OPERATING IN THE VICINITY OF AN ARPT (EVEN IN CLASS E AIRSPACE). 2) ACRS DEPARTING A RADAR EQUIPPED ARPT SHOULD HAVE CONSTANT COM WITH THE CTLR DURING THE TIME THE ACFT DEPARTS CLASS C AIRSPACE, WHILE TRANSITING THROUGH CLASS E AIRSPACE, UNTIL THEY ARE HANDED OVER TO ANOTHER CTLR (ONCE IN CLASS B AIRSPACE). 3) WHEN LOOKING FOR CONVERGING TFC, IMMEDIATELY LIFT ONE WING, SCAN, THEN LIFE THE OTHER. THIS MAY HAVE ALLOWED ME TO SEE THE ACR SOONER.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.