Chivalry was not uniformly practiced, nor respected, during WW I, Hollywood depictions not withstanding. Some of the aces were rather notorious, in fact, for strafing downed pilots, and chasing crippled planes was also quite common.

Living to fight another day, is a key concept in all forms of warfare. Expecting a player to stick around when practically dead and/or outnumbered, but not yet being low enough on fuel to escape with honor, is strategically unsound.

Those who feel strongly about the issue, could always opt to form squadrons with those who feel the same to limit the odds of this happening.

Your mileage may vary,

markrendl