Does anyone know if there are any legal requirements to achieve any particular single-engine climb performance in a light twin - preferably on-going requirements,
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What I'm specifically looking for is something which I can either show to an engineer and say "this aircraft does not meet this requirement, therefore it needs fixing", or alternatively show to a pilot and say "this aircraft meets this requirement, so it's ok to fly".
Surely the answer is "the Approved Flight Manual". I don't know what the tolerances are for SE climb, but if it doesn't do what the AFM says it does, it needs fixing.