Narrative:

At the time; smo was under about a 1;000 foot MSL marine layer (i.e. Low cloud stratus layer) extending from the west to just east and encompassing both north and south of the runway. I was flying under an IFR flight plan and had already been cleared for the approach. Because the tower was closed and because I could see that I could see the airport (coming from the east looking at runway 21) I cancelled IFR and continued inbound on the visual making appropriate calls on the CTAF. As I got to a 1 mile final (which was called out on CTAF); aircraft Y began turning base to final and asked where I actually was as he did not have me in sight. I advised him that I was at his 2 o'clock. It would appear that he never had me in sight as he continued his turn to final. He ended cutting me off ending up just left and about 50 feet above/in front of me. I informed him that he had cut me off; but he continued on course and descending. Because of the situation; I decided the best course to avoid a collision was to make a right turn. I also noted that the marine layer cloud edge extended out to the position where I made the turn (3/4 mile final) I then proceeded to continue that right turn into a 360 to rejoin the final and then landed. It is notable that because of the marine layer; the likely student pilot in the aircraft Y; should never have even been flying the 'standard' pattern' (i.e. Left traffic 21) as it was not legal to do so because the VFR requirements for the overlying echo airspace could not be met (i.e. 1;000 feet above the clouds) due to the height of the marine layer. Thus; his descent to turn base at around the freeway clearly violated VFR minimums. I did inform the person who runs the school of the situation. He informed me that he himself had an near midair collision just the very day before. Had the tower been operating on normal or slightly longer hours at the time; such incidents would not have been able to occur. The currency reduced tower hours should be extended as soon as possible; in order to prevent an accident as the airspace is very busy; and can be challenging in the event of a marine layer; which precludes the use of the pattern.

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Original NASA ASRS Text

Title: GA pilot reported a NMAC on final to SMO airport. Tower closure was cited as a contributing factor.

Narrative: At the time; SMO was under about a 1;000 foot MSL marine layer (i.e. low cloud stratus layer) extending from the west to just east and encompassing both north and south of the runway. I was flying under an IFR flight plan and had already been cleared for the approach. Because the Tower was closed and because I could see that I could see the airport (coming from the east looking at Runway 21) I cancelled IFR and continued inbound on the visual making appropriate calls on the CTAF. As I got to a 1 mile final (which was called out on CTAF); Aircraft Y began turning base to final and asked where I actually was as he did not have me in sight. I advised him that I was at his 2 o'clock. It would appear that he never had me in sight as he continued his turn to final. He ended cutting me off ending up just left and about 50 feet above/in front of me. I informed him that he had cut me off; but he continued on course and descending. Because of the situation; I decided the best course to avoid a collision was to make a right turn. I also noted that the marine layer cloud edge extended out to the position where I made the turn (3/4 mile final) I then proceeded to continue that right turn into a 360 to rejoin the final and then landed. It is notable that because of the marine layer; the likely student pilot in the Aircraft Y; should never have even been flying the 'standard' pattern' (i.e. left traffic 21) as it was not legal to do so because the VFR requirements for the overlying Echo airspace could not be met (i.e. 1;000 feet above the clouds) due to the height of the marine layer. Thus; his descent to turn base at around the freeway clearly violated VFR minimums. I did inform the person who runs the school of the situation. He informed me that he himself had an NMAC just the very day before. Had the Tower been operating on normal or slightly longer hours at the time; such incidents would not have been able to occur. The currency reduced Tower hours should be extended ASAP; in order to prevent an accident as the airspace is very busy; and can be challenging in the event of a marine layer; which precludes the use of the pattern.

Data retrieved from NASA's ASRS site 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.