That’s another thing about this that sounds absurd.
What are the chances that a fist or hammer banging on carbon fiber at 12000 feet down would generate sound waves audible to a flying aircraft?
It’s ridiculous.
Most searches by air use sonar buoys. Planes airdrop them.
Our Subhunter aircraft are the Lockheed P-3 Orion(turboprop) and its successor the Boeing P-8 Poseidon (turbofan).