Skootsman, if I understand it correctly, your dad needs advice about travelling with a CPAP machine. It MUST be taken hand baggage, and my experience with Easyjet is that they are very sympathetic and will often allow a piece of medical equipment to be carried in addition to the one piece of handbaggage allowed.
Your dad will not be using the equipment in flight so that will not worry them at all.
Easyjet's website desribes what is allowed
here
Quote removed due to copyright reasons and link provided above. Dazbo HT Mod
So your dad will need a doctor's letter stating that he needs to use his machine every night and that it is vital to his health. It will help if the doctor can mention the name of the manufacturer and the reference of the machine eg ResMed S9 or Respironics RemStar.
Do advise your dad that although security are very used to seeing these machines, it is quite normal for them to 'divert' them in the security scan and then take a swab (always negative!!!). Taking the swab will neither harm the equipment nor the user subsequently using it!