Hi,
Not one I knew about before but I found this:
http://books.google.com/books?id=uj3...dundee&f=false
I'm not a fan of google books but in this case it proves useful. A Hudson dropped three 250lb anti submarine bombs which, for once, did their job.
There are a couple of other "friendly fire" incidents against submarines that I'm aware of:
An attack on HMS Snapper was made by the RAF on 3rd December 1939. Arriving back in port, the unhappy captain reported that not only had he been attacked by his own side but, despite a direct hit on his conning tower, the only damage was four broken light bulbs in the control room.
On 5th September 1939 a Coastal Command Anson K8845 of 235 Squadron made four attack runs on HMS Seahorse, without result.
The anti-submarine bomb was replaced by the far more effective aerial dropped depth charge.
Allan