Narrative:

I observed on radar an aa-5 tiger approaching my airspace from the south on the mini route which is a VFR published corridor tracking the SMO128 radial northbound and southbound. In this case; the tiger was approaching from the south and another aircraft was also in the vicinity approaching my airspace from the south. The two aircraft were in hhr airspace and it appeared as if hhr was attempting to achieve longitudinal separation using visual separation between the two aircraft. This type of sequence occurs frequently when multiple aircraft are requesting the mini route from both directions. Hhr controller called my position via the shout line. I answered the line; and he said to watch out for the unknown aircraft because he was suppose to maintain visual separation from the tiger and follow him northbound. The two aircraft were not yet in bravo airspace. They were both going at a similar speed as well. I then attempted to contact the tiger with no response. I then realized that although I thought I hung up the shout line; it didn't truly hang up and I was reaching out to aircraft on the shout line instead of on frequency. After realizing that I was offline; I hung up the shout line and attempted to reach out to from what I recall was the tiger. I then told him to make a right 360. The wrong aircraft readback the clearance; so both aircraft starting making a right 360. The targets were separating nonetheless; so I continued to separate the aircraft by issuing a climb clearance to the tiger to maintain VFR at 3;000. By this time; both aircraft were achieving separation both vertically and longitudinally. The unknown aircraft stated that he nearly collided with the tiger and that they were 1 foot apart. This near miss occurred as the hhr controller coordinated with me regarding the developing conflict. I recommend that hhr; lax; and smo get briefings to advise us to ensure separation prior to issuing frequency changes to aircraft. In this particular situation; the hhr controller; in my opinion; tried but did not succeed in separating the aircraft prior to issuing a frequency change. It is possible that it was a pilot deviation because the hhr controller did state that the unknown aircraft was suppose to be following the tiger; but wasn't doing what he was told to do. Then the same pilot from what I recall advised me that he had a near miss with the tiger. By issuing the 360 turn; it was an attempt to turn the aircraft target that was on the east side of the airspace in order to ensure separation; but matters became worse when the wrong aircraft read the clearance back and both aircraft started making a right 360 turn.

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Original NASA ASRS Text

Title: LAX Controller described a NMAC involving two HHR departures; the second supposedly following the first. The reporter suggested that adjacent Towers insure separation before transferring aircraft to LAX for transition.

Narrative: I observed on RADAR an AA-5 Tiger approaching my airspace from the south on the mini route which is a VFR published corridor tracking the SMO128 radial northbound and southbound. In this case; the Tiger was approaching from the south and another aircraft was also in the vicinity approaching my airspace from the south. The two aircraft were in HHR airspace and it appeared as if HHR was attempting to achieve longitudinal separation using visual separation between the two aircraft. This type of sequence occurs frequently when multiple aircraft are requesting the mini route from both directions. HHR Controller called my position via the shout line. I answered the line; and he said to watch out for the unknown aircraft because he was suppose to maintain visual separation from the Tiger and follow him northbound. The two aircraft were not yet in Bravo airspace. They were both going at a similar speed as well. I then attempted to contact the Tiger with no response. I then realized that although I thought I hung up the shout line; it didn't truly hang up and I was reaching out to aircraft on the shout line instead of on frequency. After realizing that I was offline; I hung up the shout line and attempted to reach out to from what I recall was the Tiger. I then told him to make a right 360. The wrong aircraft readback the clearance; so both aircraft starting making a right 360. The targets were separating nonetheless; so I continued to separate the aircraft by issuing a climb clearance to the Tiger to maintain VFR at 3;000. By this time; both aircraft were achieving separation both vertically and longitudinally. The unknown aircraft stated that he nearly collided with the Tiger and that they were 1 foot apart. This near miss occurred as the HHR Controller coordinated with me regarding the developing conflict. I recommend that HHR; LAX; and SMO get briefings to advise us to ensure separation PRIOR to issuing frequency changes to aircraft. In this particular situation; the HHR Controller; in my opinion; tried but did not succeed in separating the aircraft prior to issuing a frequency change. It is possible that it was a pilot deviation because the HHR Controller did state that the unknown aircraft was suppose to be following the Tiger; but wasn't doing what he was told to do. Then the same pilot from what I recall advised me that he had a near miss with the Tiger. By issuing the 360 turn; it was an attempt to turn the aircraft target that was on the east side of the airspace in order to ensure separation; but matters became worse when the wrong aircraft read the clearance back and both aircraft started making a right 360 turn.

Data retrieved from NASA's ASRS site as of July 2013 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.