I’m trying to nail down the timing using the Webtrak map. It’s the only resource that shows all four Cessnas at WVI. Based on the the callouts, it almost looks like the 150 had just begun the base turn when the 340 made his 3 mile call. It’s likely within +-3 seconds.
The 340 was actually doing 200 knots groundspeed (!) for a few seconds right about the time of the 3-mile call. So forget 180 at that point. He was coming out of a slight overshoot right of course and about to correct back onto final. There was a Cessna 172 on the go just over the runway, the accident 152 initiating his base turn, and a 182 1 mile south of the airport on the missed, crossing left to right.
Here is the approximate sight picture in Google Earth using ADS-B position data from FlightRadar24, adsbexchange, and Webtrak. The accident 152 is the orange dot, 90FL (pattern) is green, and 9BE (missed VOR-A) is blue. Note that the dots are not proportional to aircraft size.
The first is the positions at 21:54:15Z, about the time of the 3-mile call. Distance to threshold 3.2 miles. Speed 198 knots.
The second is the positions 33 seconds later, at 21:54:48Z, about the time of the 1-mile call. Distance to threshold 1.4 miles. Speed 179 knots.
Note that it is physically impossible for the initiation of the one mile call to have occurred at or less than 1 mile from the threshold as it took exactly 20 seconds to traverse from the 1-mile to threshold distance to the point of impact (.95 miles away), yet communications from either of the two accident aircraft continued for 26 seconds after the initiation of the 1-mile callout.
Lastly, the positions 10 seconds prior to impact. 10 seconds is the amount of time the FAA has determined that it takes to spot, identify, realize the threat, react to it, and have the aircraft respond. Speed 182 knots.
Note that at this speed, there weren't a lot of good escape options for the 340. The 182 (blue) was still moving left to right, climbing, and had not yet begun the turn to the west. The 172 was straight ahead, climbing on the departure leg, and the 152 on a collision course on left base. An abrupt right turn would have put him close to the path of the 182, if nothing else changed with the 182's flight path (and he wouldn't know what the 182 was going to do). You could ostensibly stay low under the 182, but there's rising terrain to almost 500' to the northwest. The only other option is a HARD turn to the north, but now you're into potential structural limitations.
I will also say this: the 340 would have been above the horizon throughout the 152's base to final turn. It's a LOT to ask any pilot to assume 7 miles, 2 miles, and .95 miles would be traversed as quickly as they were. But I guarantee I would have been looking hard when the 3 mile call came. Even if I'd started my base a few seconds prior, I might unstart it and fly away from final. Mental math would have kicked in and realized something's not right. I wonder if there were more communications that the LiveATC scanner didn't pick up.
Either way, bad setup. I'm going to go with my original notion - the 340 has the vast preponderance of blame, but there has to be a little on the 152. See and avoid and quick reactions could have prevented this once the spidey senses kicked in, even if he wasn't at fault for initiating the base turn. Don't let that become the focus over the utter bo**ocks flying of the 340, more of a footnote.
