CAA class one revalidation
 

I understand that a U.K. CAA Class one revalidation can be done up to 45 days before the expiry of the current class one medical. I wonder though if something is found like an abnormal ecg that needs further investigation, is the the existing medical still valid? ie can you still fly and get any investigations done in the 45 days leading up to the expiry of the existing one?

On any occasion when you are "incapacitated" you cannot fly until "capacitated" again. The same would happen if you were drunk or had a bout of flu.

Depends on the NAA and the fault. Some NAAs will allow continued operation pending investigation, some won't. Once the fault is found it has to addressed.