The Geneva Convention of 1929:
Art. 3. In the case of armed conflict of an international character occurring in the territory of one of the High Contracting Parties, each Party to the conflict shall be bound to apply, as a minimum, the following provisions:
(1) Persons taking no active part in the hostilities, including members of armed forces who have laid down their arms and those placed hors de combat by sickness, wounds, detention, or any other cause, shall in all circumstances be treated humanely, without any adverse distinction founded on race, colour, religion or faith, sex, birth or wealth, or any other similar criteria. To this end, the following acts are and shall remain prohibited at any time and in any place whatsoever with respect to the above-mentioned persons: (a) violence to life and person, in particular murder of all kinds, mutilation, cruel treatment and torture; (b) taking of hostages; (c) outrages upon personal dignity, in particular, humiliating and degrading treatment; (d) the passing of sentences and the carrying out of executions without previous judgement pronounced by a regularly constituted court, affording all the judicial guarantees which are recognized as indispensable by civilized peoples.
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The above provision clearly applies to a pilot who has punched out of his instrumentality of war.
During the war crimes trial of Generaloberst Nickolaus Von Falkenhorst, conducted by the British Military Court, Brunswick July 29th through August 2nd, 1946, a directive issued by Adolph Hitler on December 18th, 1942 was entered into evidence. Hitler's directive is instrumental here as it contains a carve out exception reflected in the contemporary international law.
Paragraph 1
" For some time our enemies have been using in their warfare, methods which are outside the international Geneva Conventions. Especially brutal and treacherous is the behaviour of the so-called Commandos who, as is established, are partially recruited even from freed criminals in enemy countries. Their capture orders divulge that they are directed not only to shackle prisoners but also to kill defenceless prisoners on the spot at the moment in which they believe that the latter, as prisoners, represent a burden in the further pursuance of their purpose or can otherwise be a hindrance. Finally, orders have been found in which the killing of prisoners has been demanded in principle.
Paragraph 2
" For this reason it was already announced in an addendum to the Armed Forces Report of 7th October, 1942, that in the future Germany in the face of these sabotage troops of the British and their accomplices will resort to the same procedure, i.e., that they will be ruthlessly mowed down by the German troops in combat wherever they may appear.
p.21
Paragraph 3
" I therefore Order, from now on all opponents brought to battle by German troops in so-called commando operations in Europe or Africa, even when it is outwardly a matter of soldiers in uniform or demolition parties with or without weapons, are to be exterminated to the last man in battle or while in flight. In these cases it is immaterial whether they are landed for their operations by ship or aeroplane or descend by parachute. Even should these individuals on their being discovered, make as if to surrender, all quarter is to be denied them on principle. A detailed report is to be sent to the O.K.W. on each separate case for publication in the Wehrmacht communique."
Paragraph 4
" If individual members of such commandos working as agents, saboteurs, etc., fall into the hands of the Wehrmacht by other means, e.g. through the police in any of the countries occupied by us, they are to be handed over to the S.D. immediately. It is strictly forbidden to hold them in military custody, e.g. in PW camps, etc., even as a temporary measure."
Paragraph 5
" This order does not apply to the treatment of any enemy soldier who in the course of normal hostilities (large scale offensive actions, landing operations and air-born operations) are captured in open battle or give themselves up. Nor does this order apply to enemy soldiers falling into our hands after battles at sea or enemy soldiers trying to save their lives by parachute after battles."
Paragraph 6
" In the case of non-execution of this order, I shall make responsible before the Court Martial all commanders and officers who have either failed to carry out their duty in instructing the troops in this order, or who acted contrary to this order in carrying it out.
Signed Adolf Hitler."
The above directive is remarkably harsh and unyielding. Yet, it carves out "safe harbors" that specifically include enemy soldiers parachuting from their planes in order to save their lives. Paragraph 5 is an "in spite of" clause. It is included so that the sweeping brutal directive will not invade the existing, recognized rule of warfare as it applies to pilots who have bailed out. This existing, recognized rule was set out in the 1929 Geneva Convention in Article 3, Paragraph 1(and those placed hors de combat by sickness, wounds, detention, or any other cause).