Whether the cover letter is in the email or attached probably doesn't matter, just so long as the reader can instantly derive a phone number and residential address. What does matter is to keep it short and to the point. Ditto with the resume'. One page of each - with aviation background only - has more chance of grabbing a busy Chief Pilot's attention for the two minutes that he can spare. If you only have 2000 hours or a few years in the industry there is no point in extending the resume' to 5 pages of padding, like where you went to school and how long you worked as a dish-pig at Macca's because chances are the 'delete' key will be used before the time-pressed reader gets to the aviation bit.