VirginSkid you are quite wrong. Unlike IT, advertising, marketing and other employment within the business world, you are not required to 'big yourself up' in a covering letter for an aviation CV.
Your qualities will be assessed in an interview and a simulator session, plus probably a number of group exercises. All the covering letter needs to do is confirm what post you are applying for, and include your contact details. It may be slightly less formal and in more colloquial English than the CV itself.
However, you are right that careful research (particularly here on Pprune) will reveal all that you need to know, both about CVs themselves and their covering letters.
Scroggs