"I'll nominate the Handley Page Hampden as a clunker. Any design which loses almost half its total production doing the very thing it was designed to do leaves a lot to be desired!"
True but that is stellar performance compared to the The Blackburn Botha, was judged not suitable for operational deployment at all (after equipping one squadron)and when used as a trainer turned out to be fairly lethal to the crews it was supposed to be training.
" It was considered to have poor lateral stability, while the view to the side or rearward was virtually non-existent owing to the location of the aircraft's engines, with the poor view making the aircraft "useless as a GR [General Reconnaissance] aircraft". Finally, the Botha was also underpowered."
"In service, the Botha proved to be severely underpowered and unstable and there were a number of fatal crashes in 1940."
" At this point, the Air Staff made the ill-advised decision to transfer the surviving aircraft to training units, which inevitably resulted in further casualties."
No. 608 of coastal command received it's first Bothas in July of 1940, Flew it's first operational sortie on Aug 10th, flew it's LAST operational sortie Nov 6th 1940 and then took until March 1941 to revert BACK to the Avro Anson.
For 580 aircraft built that is a pretty dismal operational history for a torpedo bomber.
The may have lost a lot of Hampdens but at least they accomplished something.