A corporate jet on the VOR A approach to SMO experienced an NMAC with a light aircraft flying a VFR traffic pattern to the same runway. Visibility less than advertised on ATIS was cited as a contributing factor.
Synopsis
A corporate jet on the VOR A approach to SMO experienced an NMAC with a light aircraft flying a VFR traffic pattern to the same runway. Visibility less than advertised on ATIS was cited as a contributing factor.
Narrative
I was the non flying pilot [Captain] in the left seat. We were vectored onto the VOR GPS A approach into SMO. We were given a bad vector and were high as we started the approach. We soon caught up and we were set once we crossed the FAF BEVEY. As we started the approach the weather was clear but deteriorated to the west on the approach so we briefed the missed approach again. The weather over the airport was 1000 broken to overcast with haze. The flight visibility was four to five miles. We switched to SMO Tower. We were told to report the runway 'in sight'. Crossing BEVEY we descended to MDA of 1200. I saw the runway and reported it in sight. We were cleared to land. The pilot flying started to turn to the right to line the plane up with the center line of the runway. As the PAPI started to come in he left MDA. There was a plane on downwind that was told to extend and follow us in. The Tower then asked this other plane where he was. He said he was on base. This was at the same time we were leaving MDA. We were approximately 900-1000 feet descending.We got a TCAS TA. I looked for the traffic but could not spot him in the haze but TCAS showed him 400 feet below right underneath us. Very soon after the TA we got an RA. I immediately called for a go-around. I confirmed with Tower that they wanted us to fly the published missed approach and we did. Approach asked why we went missed and I told them we got an RA. They vectored us back in for the same approach. While getting vectored for the second approach we got a TA but no RA from a different airplane than before. We landed and had to contact the tower on the phone. I told them that we got a RA and that complying with it kept us from making a safe landing so I just went missed.The haze and low ceiling made having VFR traffic in the pattern follow IFR traffic dangerous. Tower was reporting 1000ft scattered and 9 miles. But; it was broken to overcast with haze and the visibility was four to five miles. We could see the runway through the haze but it was hard to pick out detail or buildings on the field until we were very close. It was all but impossible to pick out other traffic. We never saw the plane that cut us off on final. I feel as a crew we made the right choice to go around and not try to save the landing. Even if we would have seen the plane and avoided him we would have landed fast and long on a short downhill runway.
Second reporter narrative
The initial ATIS we received going into SMO reporting 1000 feet scattered ceiling and 9 miles visibility was wrong. We did not see the airport until approximately 4 miles out and when we went missed the cloud layer we climbed through was overcast not scattered. The new ATIS that SMO put out just after we went missed was more accurate with the ceiling but still wrong when reporting 7 miles of visibility. In my flying career I have had 7 TCAS RA's and 6 of those have come in the Los Angeles area.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.