I went downstairs to the hotel restaurant and ran into a friend who
recounted a recent experience he had. He was inbound to LAX on the Civet
arrival to rwy 25R at night. His FO coupled the autopilot to the ILS about
30 miles out. Approach control pointed out traffic from the northeast that
was to join the ILS for the north side's parallel runway. Everything was
routine. They were told to switch over to the tower's frequency. Then they
saw a bright flash from an explosion on the north side of the terminal. Both
of them thought there had been a crash.

From here everything happened rapidly. They were staring so hard out the
front that they didn't notice the parallel traffic went through the
northside localizer and was heading right at them. Then the TCAS went crazy
telling them to pull up. Then the autopilot let out with it's loud series of
chirps. Then the captain yelled at the FO to pull up because there was no
response to the TCAS. The FO yelled back that he thought the captain had the
controls. The captain looked out his window to see an A-340 less than 200'
below them and it was racked up at big bank angle trying to get back on
final for the north runway. Then a frantic radio call came from ATC asking
if they were still there.

The subsequent investigation revealed an interesting chain of events. The
flash came from an exploding electrical transformer. The localizer,
glideslope, and ATC radios failed momentarily until back-up power came
online. When the localizer signal failed, the A-340's autopilot didn't have
anything to intercept and stayed on the intercept angle, which is why it
went through the final approach into the south runway's final approach. When
the localizer failed, my friend's autopilot didn't kick-off, but changed
from approach mode into heading and pitch mode which mimics the ILS in
smooth air. The FO heard the autopilot chirps along with the TCAS warnings
and figured the captain had assumed control from him. The captain heard the
same noises but figured the FO had kicked off the AP to perform the TCAS
instructions.

It was close. Stay safe.

D.