Fantastic! Your Y1B-17 manual is now the earliest known Air Force manual with a procedure. November 1936/ Feb. 1937. I will have to revise something I wrote accordingly. Previously I listed a B-17 manual from July 1937.
This is relevant to the often-repeated, but wrong, statement that checklists were invented for the B-17 bomber after a crash. This claim appears in dozens of post 2000 articles about medical checklists and related topics. (They were first used in a USN manual, several years earlier.) I will credit you in a footnote. Do you want to go by Micdrow, or your real name?
Now, if only I could find an early DC-2 or DC-3 manual…