Tango100..
SirStel is not obliged to register Fastjet at Companies House... and there are numerous good reasons why he may have chosen not to.
Firstly, he may choose to register the company in a state other than the UK but, more likely, he may already have a company registered as the proposed airline's proprietor..eg ScareBus2011 Limited .. Thus the operation becomes ScareBus2011 trading as Fastjet...
Just my two penn'uth... fascinating all the same... I bet he plays a mean game of poker! Cheers..TP