Two points & two recommendations
The Japanese used a few autogyros for ASW
en.wikipedia.org
In OTL The problems arising from attacking a (near) surfaced Uboat were some of the first successes of Operational Research.
They determined that an air-dropped depth-charge needed a lower depth setting to maximise the chance of a kill
(it had previously been set to the average depth that a UBoat was found at but this missed "the low hanging fruit")
The technical difficulties in achieving the "25 ft fuse',
and the effect of the "rocket spear" for use against surfaced UB and the "homing torpedo" for use versus deeply dived targets,
are discussed in a book by Alfred Price
Aircraft versus submarine: The evolution of the anti-submarine aircraft, 1912 to 1972 [Price, Alfred] on Amazon.com. *FREE* shipping on qualifying offers. Aircraft versus submarine: The evolution of the anti-submarine aircraft, 1912 to 1972
www.amazon.com
Aside: Price also wrote a wonderful study of the "wizard war" of electronics during the bombing campaign (from both sides)
Instruments of Darkness: The History of Electronic Warfare, 1939–1945 - Kindle edition by Price, Alfred. Download it once and read it on your Kindle device, PC, phones or tablets. Use features like bookmarks, note taking and highlighting while reading Instruments of Darkness: The History of...
www.amazon.com
Both are well worth study (if now a little dated)
I first read them as an impoverished engineer some 40 odd years ago 👨🦳