Maresciallo Acerbi took part in the Spanish Civil War and served in the 25^a Squadriglia, XVI Gruppo.

On 31 August 1938, CR.32s from the XVI Gruppo was indirectly escorting S.79 and BR.20 bombers to the front of Gandesa. At the end of the bombing, the fighters stayed in the area for interdiction. As in the previous week, the 25^a Squadriglia had the duty to cover at 7,000m while the fighters from 26^a and 24^a Squadriglie flew at 5,500m.
The XVI Gruppo had taken off from Caspe at 16:30 and the eight CR.32s from the 25^a Squadriglia flew in four sections of two aircraft:
1st section – Capitano Roberto Fassi (CO) and Tenente Pietro Raimondi
2nd section – Sottotenente Mario Visintini and Sergente Giuseppe Marini
3rd section – Sottotenente Bongiovanni and Sottotenente Mario Pinna
4th section – Sottotenente Emilio Marchi and Maresciallo Acerbi
Around 18:00, Capitano Giuseppe Majone (CO 24^a Squadriglia) spotted six SBs in two formations of three each heading from the Segre river towards Villalba.
They were soon attacked by the Italian fighters. Suddenly, a dozen of escorting I-16s dived on the CR.32s of the 24^a Squadriglia, but they were in turn jumped by the 25^a Squadriglia, which soon was joined by all the Fiats. In the ensuing dogfight Italians claimed two Ratas destroyed and one probable, that were officially shared among the three Squadriglie, though one of the kills was unofficially credited to Capitano Fassi. Sottotenente Visintini (25^a Squadriglia) shot at four I-16s, one of which “effectively and by short distance” and saw a Rata falling in flames, which considering the place and the time should be the one shot down by Capitano Fassi. Visintini’s Fiat was however damaged in the action.
As a result, the commander of the XVI Gruppo, Tenente Colonnello Arrigo Tessari, proposed that each Squadriglia should be creited with one shared destroyed I-16.

During his time in Spain, Acerbi was credited with one shared victory.

Acerbi ended the war with one shared biplane victory.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1938
	31/08/38	18:00-	1/8	I-16	Shared destroyed	Fiat CR.32		Gandesa	25a Squadriglia

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

Sources:
Courage Alone - Chris Dunning, 1998 Hikoki Publications, Aldershot, ISBN 1-902109-02-3
Fiat CR.32 Aces of the Spanish Civil War - Alfredo Logoluso, 2010 Osprey Publishing, Oxford, ISBN 978-1-84603-983-6
Regia Aeronautica: The Italian Air Force 1923-1945 - An Operational History - Chris Dunning, 2009 Ian Allan Publishing, Hersham, Surrey, ISBN 978-1-906537-02-9
Additional information kindly provided by Stefano Lazzaro and Ludovico Slongo.