Narrative:

About 5 mins after departure, I noticed another aircraft at my 11-12 O'clock position, same altitude. I had leveled off at about 2100 ft MSL. Upon spotting the other aircraft (it was well lit, with a bright spot on its right side), I began to watch it closely because I sensed no relative motion. After about 10 more seconds, still no relative motion, so I rocked my wings, still nothing. At this point I took evasive action and turned slightly towards the aircraft and dove about 500 ft. The aircraft passed directly over me by about 400 ft and slightly to the right. I circled the area to see if I could spot the other aircraft, but only noticed a helicopter to the north a few mins later working an area. Shortly after that, I heard the chopper call out to the fixed wing. The observer then admonished me to be more careful in the area and to announce my intentions on the CTAF. (Technically, we were outside the CTAF at the time, but it doesn't hurt to do so.) not desiring a second 'aerial confrontation,' I apologized for any potential conflict and continued on my way to emt. The rest of the flight was uneventful. Once on the ground, I reached the crew on duty -- yup, the pilot and observer I had encountered 'visually' and on 'frequency.' I explained that I had wanted to touch base for safety reasons to understand what had happened. The observer essentially told me they had been totally occupied, and didn't notice me until the last second. The pilot told him, 'hold on!' then put the bird into a steep climb. To say it scared the both of them is an understatement. Apparently they had been cruising along at about 1800 ft MSL when they saw me. Ironically, they passed through my altitude as I passed through theirs. But here's the best tip from this story: the observer urged me to use an air-to-air frequency used by aircraft at the lower altitudes, ie, 1000 ft MSL to about 2500 ft MSL -- 123.025. It is used by low flying folks. The kicker is that in the 15+ yrs of flying in the los angeles basin, I have never been instructed on using this. The observer said that often times they are very busy in the air and that announcing on this frequency would help in seeing and avoiding conflicting traffic!

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Original NASA ASRS Text

Title: NMAC BTWN A HELI AND LIGHT FIXED WING IN VFR CONDITIONS AT NIGHT NEAR BUR, CA.

Narrative: ABOUT 5 MINS AFTER DEP, I NOTICED ANOTHER ACFT AT MY 11-12 O'CLOCK POS, SAME ALT. I HAD LEVELED OFF AT ABOUT 2100 FT MSL. UPON SPOTTING THE OTHER ACFT (IT WAS WELL LIT, WITH A BRIGHT SPOT ON ITS R SIDE), I BEGAN TO WATCH IT CLOSELY BECAUSE I SENSED NO RELATIVE MOTION. AFTER ABOUT 10 MORE SECONDS, STILL NO RELATIVE MOTION, SO I ROCKED MY WINGS, STILL NOTHING. AT THIS POINT I TOOK EVASIVE ACTION AND TURNED SLIGHTLY TOWARDS THE ACFT AND DOVE ABOUT 500 FT. THE ACFT PASSED DIRECTLY OVER ME BY ABOUT 400 FT AND SLIGHTLY TO THE R. I CIRCLED THE AREA TO SEE IF I COULD SPOT THE OTHER ACFT, BUT ONLY NOTICED A HELI TO THE N A FEW MINS LATER WORKING AN AREA. SHORTLY AFTER THAT, I HEARD THE CHOPPER CALL OUT TO THE FIXED WING. THE OBSERVER THEN ADMONISHED ME TO BE MORE CAREFUL IN THE AREA AND TO ANNOUNCE MY INTENTIONS ON THE CTAF. (TECHNICALLY, WE WERE OUTSIDE THE CTAF AT THE TIME, BUT IT DOESN'T HURT TO DO SO.) NOT DESIRING A SECOND 'AERIAL CONFRONTATION,' I APOLOGIZED FOR ANY POTENTIAL CONFLICT AND CONTINUED ON MY WAY TO EMT. THE REST OF THE FLT WAS UNEVENTFUL. ONCE ON THE GND, I REACHED THE CREW ON DUTY -- YUP, THE PLT AND OBSERVER I HAD ENCOUNTERED 'VISUALLY' AND ON 'FREQ.' I EXPLAINED THAT I HAD WANTED TO TOUCH BASE FOR SAFETY REASONS TO UNDERSTAND WHAT HAD HAPPENED. THE OBSERVER ESSENTIALLY TOLD ME THEY HAD BEEN TOTALLY OCCUPIED, AND DIDN'T NOTICE ME UNTIL THE LAST SECOND. THE PLT TOLD HIM, 'HOLD ON!' THEN PUT THE BIRD INTO A STEEP CLB. TO SAY IT SCARED THE BOTH OF THEM IS AN UNDERSTATEMENT. APPARENTLY THEY HAD BEEN CRUISING ALONG AT ABOUT 1800 FT MSL WHEN THEY SAW ME. IRONICALLY, THEY PASSED THROUGH MY ALT AS I PASSED THROUGH THEIRS. BUT HERE'S THE BEST TIP FROM THIS STORY: THE OBSERVER URGED ME TO USE AN AIR-TO-AIR FREQ USED BY ACFT AT THE LOWER ALTS, IE, 1000 FT MSL TO ABOUT 2500 FT MSL -- 123.025. IT IS USED BY LOW FLYING FOLKS. THE KICKER IS THAT IN THE 15+ YRS OF FLYING IN THE LOS ANGELES BASIN, I HAVE NEVER BEEN INSTRUCTED ON USING THIS. THE OBSERVER SAID THAT OFTEN TIMES THEY ARE VERY BUSY IN THE AIR AND THAT ANNOUNCING ON THIS FREQ WOULD HELP IN SEEING AND AVOIDING CONFLICTING TFC!

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.