Related Rule
South Africa
Practice Relating to Rule 48. Attacks against Persons Parachuting from an Aircraft in Distress
South Africa’s LOAC Manual (1996) states:
Parachutists are presumed to be on military mission and may therefore be targeted during descent. An exception to this presumption is where the parachutists are the crew of a disabled aircraft; they are presumed to be out of combat and may not be targeted unless they show an intent to resist. 
South Africa, Presentation on the South African Approach to International Humanitarian Law, Appendix A, Chapter 4: International Humanitarian Law (The Law of Armed Conflict), National Defence Force, 1996, § 33.
South Africa’s Revised Civic Education Manual (2004) states:
Parachutists are presumed to be on a military mission and may therefore be targeted during descent. An exception to this presumption is where the parachutists are the crew of a disabled aircraft; they are presumed to be out of combat and may not be targeted unless they show an intent to resist. 
South Africa, Revised Civic Education Manual, South African National Defence Force, 2004, Chapter 4, § 55.