Supertanker Update The Evergreen Supertanker has completed its development program and achieved several major milestones in 2006. On October 27 the B747 Supertanker received its FAA STC (Supplemental Type Certificate). The aircraft also received its Part 137 (Agricultural Aircraft Operations) certification on November 6, 2006.
The Supertanker is pretty sophisticated, and it seems they've done a test progrqam and produced and ops manual.
See Evergreen's FAQ page.
Seat-of-the-pants is not acceptable proceure with this kind of wing loading (IMHO). The DC 10 crew DID NOT KNOW they had struck trees until the observer told them they had indeed done so.