Teniente Isidro Comas Altadill served in 1-E-3 during the Spanish Civil War.

On 5 July 1938, a patrol formed by capitán Ángel Salas, Comas Altadill and Abundio Cesteros took off to seek out enemy aircraft operating over the Villel front, to the south of Teruel. Anti-aircraft fire indicated the position of an enemy formation and, closing gradually, Comas Altadill and Cesteros each claimed an I-16.
Flying over the Teruel front, capitán Eduardo Claudín Moncada, CO Grupo N^o 21 (I-16), perished when his Mosca reportedly was hit by Nationalist anti-aircraft fire and crashed in enemy-held territory near Villaestar.
His posthumous promotion to mayor was dated 7 July 1938.
Claudín was replaced by Manuel Zarauza Clavero as CO Grupo N^o 21. His appointment was dated 23 July 1938, and he remained in this position until the fall of Catalonia four months later. Zarauza usually flew Mosca ‘CM-225’, which was assigned to the grupo staff.

Comas Altadill ended the Spanish Civil War with 3 victories claimed while flying the Fiat CR.32.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1938
1	05/07/38		1	I-16 (a)	Destroyed	CR.32		Villel front	1-E-3
2	??/??/3?		1	Enemy aircraft	Destroyed	CR.32		Spain	2-G-3
3	??/??/3?		1	Enemy aircraft	Destroyed	CR.32		Spain	2-G-3

Biplane victories: 3 destroyed.
TOTAL: 3 destroyed.
(a) Nationalist pilots claimed 2 I-16s but only 1 I-16 seems to have been lost.

Sources:
Air War over Spain - Jesus Salas Larrazabal, 1974 Ian Allan Ltd, Shepperton, Surrey, ISBN 0-7110-0521-4
Fiat CR.32 Aces of the Spanish Civil War - Alfredo Logoluso, 2010 Osprey Publishing, Oxford, ISBN 978-1-84603-983-6
Additional information kindly provided by Alfredo Logoluso and Ondrej Repka.