You all know I've done some interesting things while trying to get the attention of a chief pilot. But when applying for an advertised position (such a luxury the current economy offers: people are actually advertising piloting jobs), I always adhere strictly to the application instructions given in the posting. I will fax my resume to the specified person's attention. I will mail it to their head office in Carp, Ontario. (Hands up if you've ever planned a cross country trip to Carp, under an invigilator's watchful eye.) If a job I wanted demanded it, I would deliver it naked on horseback at midnight. That would have to be a pretty good job, though.
Most commonly these days they ask for a resume by e-mail. I generally attach the resume to the e-mail as a Microsoft Word document, with the body of the e-mail being a brief cover letter highlighting the qualifications I believe most likely to induce them to open and print out the attachment. But sometimes they ask applicants to e-mail "a resume and cover letter". That means they are actually looking for a cover letter, and I imagine the applications all printed off in a pile on the table in the chief pilot's office. Obviously I don't want mine to be the one with an e-mail header and uucp routing at the top, competing against properly formatted letters. So I write a cover letter in Word, explaining how every facet of my personality, skills and experience matches their needs as though I was manufactured for the company. And then I attach both cover letter and resume to the e-mail.
But I'm not going to send a blank e-mail with just the attachments. I need to put something in the body of the e-mail. So yes, I have to write a cover letter for my cover letter. Silly, isn't it? I've thought of repeating the entire cover letter in the e-mail, and adding the sentence "This letter is attached as a Microsoft Word file." I usually just summarize the cover letter.
By the way, if you're writing an e-mail intending to attach something, always add all the attachments before you write the e-mail. Nothing kills your claim of meticulous attention to detail faster than a follow up e-mail saying "oops, here are the attachments I forgot."