The safe performance of parachute entries into hostile territory by Special Forces personnel is addressed in a U.S. Army manual (large pdf).
Military free-fall (MFF) parachute operations “are used when enemy air defense systems, terrain restrictions, or politically sensitive environments prevent low altitude penetration or when mission needs require a clandestine insertion.”
“This field manual presents a series of concise, proven techniques and guidelines that are essential to safe, successful MFF operations.”
See “Special Forces Military Free-Fall Operations,” Field Manual FM 3-05.211, April 2005 (295 pages, 14 MB).
The unclassified Special Forces manual has not been approved for public release, but a copy was obtained by Secrecy News.
Before posting the document on the Federation of American Scientists web site, we turned to M, a friendly parachutist who is attuned to national security classification concerns, and asked whether there was any reason not to do so.
“I reviewed the manual carefully and consulted with a couple of people and I didn’t see anything that would suggest that any portion of the report requires special protection,” he said.