Related Rule
Practice Relating to Rule 48. Attacks against Persons Parachuting from an Aircraft in Distress
Croatia’s Commanders’ Manual (1992) states: “A combatant who is recognized (or should be recognized) as being out of combat (… descending by parachute in distress) may not be attacked.” 
Croatia, Basic Rules of the Law of Armed Conflicts – Commanders’ Manual, Republic of Croatia, Ministry of Defence, 1992, § 72.