Narrative:

There is a natural corridor defined by the mountain range which causes VFR traffic to funnel along the valley toward the 'soled' intersection when departing the los angeles area to the northeast. Due to the terrain their altitude is generally climbing toward 7500' MSL. IFR traffic approaching bur from the east cross the 'janny' intersection at 8000' MSL. They are then turned south and descended to 7000' while crossing that VFR corridor. Even though forward visibility is usually good, vertical visibility below is reduced to almost nothing by haze in the valley. The mountains further compound the problem by blanketing climbing radar targets until the are above 7000'. Our turn to the south put us in a left bank which blocked our vision on the right side until we rolled out. That was the point at which the traffic Y xed from right to left about 150' directly below our nose. We had half of our TCAS system installed so it wasn't operational yet. I'll be glad when we have it in all of the aircraft. In the mean time, the density of aircraft around los angeles is so great now that I think we need arsa type corridors all the way out to about the 50 mi range where the jets are above 10000'. Small turbo-charged aircraft can come up from nowhere so fast that they need to be talking to someone.

Google
 

Original NASA ASRS Text

Title: NMAC BETWEEN LIGHT GA ACFT AND ACR MLG 15 NORTH OF BUR.

Narrative: THERE IS A NATURAL CORRIDOR DEFINED BY THE MOUNTAIN RANGE WHICH CAUSES VFR TFC TO FUNNEL ALONG THE VALLEY TOWARD THE 'SOLED' INTXN WHEN DEPARTING THE LOS ANGELES AREA TO THE NE. DUE TO THE TERRAIN THEIR ALT IS GENERALLY CLBING TOWARD 7500' MSL. IFR TFC APCHING BUR FROM THE E CROSS THE 'JANNY' INTXN AT 8000' MSL. THEY ARE THEN TURNED S AND DSNDED TO 7000' WHILE XING THAT VFR CORRIDOR. EVEN THOUGH FORWARD VISIBILITY IS USUALLY GOOD, VERT VISIBILITY BELOW IS REDUCED TO ALMOST NOTHING BY HAZE IN THE VALLEY. THE MOUNTAINS FURTHER COMPOUND THE PROB BY BLANKETING CLBING RADAR TARGETS UNTIL THE ARE ABOVE 7000'. OUR TURN TO THE S PUT US IN A L BANK WHICH BLOCKED OUR VISION ON THE R SIDE UNTIL WE ROLLED OUT. THAT WAS THE POINT AT WHICH THE TFC Y XED FROM R TO L ABOUT 150' DIRECTLY BELOW OUR NOSE. WE HAD HALF OF OUR TCAS SYS INSTALLED SO IT WASN'T OPERATIONAL YET. I'LL BE GLAD WHEN WE HAVE IT IN ALL OF THE ACFT. IN THE MEAN TIME, THE DENSITY OF ACFT AROUND LOS ANGELES IS SO GREAT NOW THAT I THINK WE NEED ARSA TYPE CORRIDORS ALL THE WAY OUT TO ABOUT THE 50 MI RANGE WHERE THE JETS ARE ABOVE 10000'. SMALL TURBO-CHARGED ACFT CAN COME UP FROM NOWHERE SO FAST THAT THEY NEED TO BE TALKING TO SOMEONE.

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.