In 1967, I was a member of the RCAF Golden Centennaires and we shared the airspace at the Abbotsford Airshow with the Blue Angels. One of their old Chiefs related this tale to me:
Back when the Angels were flying Bearcats, they were in transit from Alameda, California, and flying in formation between two layers of cloud. One of their sharp-eyed numbers spotted a PBY Catalina lumbering along toward them, lower but also between the layers. He tipped off the lead and the lead immediately had the entire formation roll inverted. They flew past the PBY that way.
Once past, the flight rolled back up then did a long 360 to watch the PBY. Apparently, to their amusement, the PBY was being "horsed" all over the sky in an attempt to get it the right way up. I guess the PBY crew just didn't believe their instruments.
Maybe it's a good thing the crew wasn't able to get it over. I've worked on PBYs and I'm sure the wings would have immediately folded up and brought an quick end to that flight."
Read the type remarks on page 6766.