on Unconventional Aircraft”
USAF Director of Intelligence,
12 January 1950
(
The letter by Major General Charles P. Cabell was sent to the following persons: Commanding Generals, Major Air Commands, Z. I. and Overseas; All United States Air Attaches:
http://www.bluebookarchive.org/page.aspx?PageCode=NARA-PBB89-381
Quote from the document:
BY COMMAND OF THE CHIEF OF STAFF: C. P. Cabell (sig)”
Cabell later became a full general.