(Editor's Note: This story has been updated to include a prepared statement received from the Air Force.) The Air Force plans to choose a light-attack aircraft by the end of fiscal year 2019, and is only considering bids from Textron and Sierra Nevada, according to a recent presolicitation notice. In a prepared statement Monday, service spokeswoman Ann Stefanek said the Air Force shared a draft request for proposals with the Sierra Nevada-Embraer team and Textron after the light-attack experiment...