Narrative:

I left smo with a student pilot in a small aircraft. We flew a standard departure, with a right turn to a heading of 315 degrees, which took us along the shoreline. We stayed onshore, because the bases seemed to be thicker offshore. We reached 1600- 1700 MSL when my student looked to his left and pointed. I then saw a small transport fly under our aircraft from the left to right wing. The tail appeared much closer to us. I contacted smo tower and reported that a small transport had just flown 20-30 ft under us. I had to repeat this twice. In this area, most of the attention is given to flying the aircraft, climbing to a higher altitude, looking for arrival traffic entering pattern from left to right and aircraft coming from the VFR TCA shoreline route. I heard the small transport being cleared for takeoff, but never thought it would be at our altitude. A twin engine should be able to climb at a much greater rate than a single and therefore should not conflict with it. Neither the small transport nor I were informed by the tower that we were on a collision course, which leads me to believe that the controller wasnþt watching the departure end of his radar screen. This isnþt the first time that aircraft have come close to each other in this area when landing and departing on runway 21.

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Original NASA ASRS Text

Title: SMA WITH INSTRUCTOR AND SPI HAS NMAC WITH SMT DEPARTING AFTER FROM SAME ARPT.

Narrative: I LEFT SMO WITH A STUDENT PLT IN A SMA. WE FLEW A STANDARD DEP, WITH A R TURN TO A HDG OF 315 DEGS, WHICH TOOK US ALONG THE SHORELINE. WE STAYED ONSHORE, BECAUSE THE BASES SEEMED TO BE THICKER OFFSHORE. WE REACHED 1600- 1700 MSL WHEN MY STUDENT LOOKED TO HIS L AND POINTED. I THEN SAW A SMT FLY UNDER OUR ACFT FROM THE L TO R WING. THE TAIL APPEARED MUCH CLOSER TO US. I CONTACTED SMO TWR AND RPTED THAT A SMT HAD JUST FLOWN 20-30 FT UNDER US. I HAD TO REPEAT THIS TWICE. IN THIS AREA, MOST OF THE ATTN IS GIVEN TO FLYING THE ACFT, CLBING TO A HIGHER ALT, LOOKING FOR ARR TFC ENTERING PATTERN FROM L TO R AND ACFT COMING FROM THE VFR TCA SHORELINE RTE. I HEARD THE SMT BEING CLRED FOR TKOF, BUT NEVER THOUGHT IT WOULD BE AT OUR ALT. A TWIN ENG SHOULD BE ABLE TO CLB AT A MUCH GREATER RATE THAN A SINGLE AND THEREFORE SHOULD NOT CONFLICT WITH IT. NEITHER THE SMT NOR I WERE INFORMED BY THE TWR THAT WE WERE ON A COLLISION COURSE, WHICH LEADS ME TO BELIEVE THAT THE CTLR WASNþT WATCHING THE DEP END OF HIS RADAR SCREEN. THIS ISNþT THE FIRST TIME THAT ACFT HAVE COME CLOSE TO EACH OTHER IN THIS AREA WHEN LNDG AND DEPARTING ON RWY 21.

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.