A. N. Zeitsoff served as a volunteer in the Spanish Civil War.

In March 1936 he served in Kosokov’s Escuadrilla, which was equipped with I-15 Chatos.

At 11:30 on 16 March his patrol flew a sortie from Soto Madrid. In the Brihuega-Valdesor-Pajares sector the patrol met a formation of Fiat CR.32s. In the ensuing combat Albert Baumler shared a CR.32 with Zeitsoff. It seems that totally two CR.32s were claimed in this combat for no losses.

Zeitsoff ended the war with 1 shared biplane victory.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1937
	16/03/37	11:30	½	CR.32	Shared destroyed	I-15		Brihuega-Valdesor-Pajares	Kosokov Escuadrilla

Biplane victories: 1 shared destroyed.
TOTAL: 1 shared destroyed.

Sources:
Air War over Spain - Jesus Salas Larrazabal, 1974 Ian Allan Ltd, Shepperton, Surrey, ISBN 0-7110-0521-4
Flyers of Fortune
Några leva än - F. G. Tinker, 1939 T. V. Scheutz Bokförlag AB, Stockholm
Polikarpov Fighters in action Pt. 1 - Hans-Heiri Stapfer, 1995 Squadron/Signal Publications, Carrollton, ISBN 0-89747-343-4
Stars & Bars - Frank Olynyk, 1995 Grub Street, London, ISBN 1-898697-17-5