Hi
the problem of losses done by own A/A unit during IX 1939 is quite serious.
Not only PZL.23 but other Polish planes had been hit by own fire. There was such psychosy of fear. Any plane over us - the enemy. Second quiet low knowledge about shapes of own enemy planes.
German flak did not have many chanches to open fire to enemy planes. There were not so many air attack done by Polish planes on enemy positions. Most dangerous was Me 109s and Me 110, which shot down about 100 Polish planes in 17 days.
If we talking about Soviet side in IX 1939, and common soldiers, they did shot to anythig, which they had seen. There were several cases of shot down own planes (mostly U-2) by A/A fire. It was serious. So since 25 IX 1939 it was given for RKKA soldiers a special order to forbide them to open A/A fire to any kind of plane.
In my book I have written about a few cases of shoting by Soviet A/A fire own planes (a few VVS RKKA airmen were killed or wounded). The same was with Polish planes which were shot down by such A/A fire.
Regrads
mw
The case of shoting own plane it is not any kind of national habit but rather simple the common lack of knowledge about onw Plane among Polish and Soviet soldiers plus big fear/stress of war.