Interesting. My copy of
FASWC doesn't have a mention of Otte or Gloecken on 3 May 1917

. CGAS obviously is not clear about the circumstances of the deaths, other than to link them with operational service.
My thoughts about FA249 have nevertheless collapsed. The airfield at Charmois is hundreds of Kilometres from Craonne. La Ferme de Charmois is another place entirely. A circumstance I should possibly have seen
best regards
Keith