IFF and Vietnam

From: "Richard and Emily Bell" <rlbell@sympatico.ca>

> The unavailability of reliable IFF forced the US to

No, but an Australian Destroyer got hit by an air-to-air missile.

You see, the Charles F Adams class has a big SPS-52 radar antenna,
that rotates. In fog, this was classified by an F-4's radar as
a helicopter based on the rotary doppler. The F-4 pilot correctly
called base to make absolutely certain there was no possibility
of a friendly helo operating off the coast, then shot an AIM-7B
Sparrow missile at the target.
For once, the AIM-7 worked. Most didn't. This one hit the radar,