(I'm quite late on reporting this incident from over 2 years ago, but just spotted it).

In Sept 2019, four hikers were on the 2nd day of a 5 day hike in Wollemi National Park, New South Wales, Australia, when one fell and sustained multiple fractures.

They used a PLB to call for help, and a signal mirror to help the responding plane to pinpoint them.

The full story is here, 2nd column, 2nd story from top:
https://aiea.org.au/kinetic-technology-international-pty-ltd-1507767692811468/

The signal mirror part is in this section:

"I checked the time after activating the PLB and it was about 10.05am. Help Arrives: At about 1:30pm a fixed wing plane arrived in the area and began to circle.

We used the signal mirror provided with the PLB and a small smoke fire to attempt to signal our precise location. Shortly after the plane left a rescue helicopter arrived at our location. I check my watch and it was 2:05pm."

Great save!

Boater adrift in the Caribbean for 24 days while other boats passed by - rescued after flashing plane with signal mirror.

News articles:
UK Daily Mail Article (Archive link)
NPR Article (Archive link)
UK Daily MIrror (Archive link)

This is a very good reminder that "old tech" is still very good.

I'm in the middle of the mid west and don't expect I'll need a dramatic rescue anytime in my future but I've still got a signal mirror in my kit.