Ball Airlines and Embry-Riddle both used Nines in 1927. Construction of Nine typical of the time--welded steel tubing with all-wood wing structure, entirely fabric covered. Standard finish was silver-painted fabric with blue paint on exposed metal parts. In response to frequent accidents caused by aircraft of uncertain airworthiness and pilots of questionable qualifications, Air Commerce Department Regulations of 31 Dec 26 enacted requiring all aircraft manufacturers to secure Approved Type Certificate (ATC) for product. Manufacturers had to submit strength calculations and demonstrate through static tests on a prototype that minimum airworthiness standards met. Tests by US Army at McCook Field showed the Nine could withstand a load factor of 7.5 against a minimum of 6.5; received ATC No.11.