Throw in a "dude" or two in the resig letter to seal the recommendation from the old company. Professional pilots apparently use the word "dude" a lot so you might as well throw a few of them in a cover (or resignation) letter.
If I was a completely overpaid asshole that ran an airline, I'd hire you.
I'd pay you sh!t wages also. And laugh my ass all the way to the bank.
Thanks to the f*ckhead corporate assholes who make our jobs great!!!