In November 1941, Sottotenente Piero Bertonass served in the 375^a Squadriglia, 160^o Gruppo CT, which was equipped with Fiat CR.42s and based in Libya.

At 13:55 on 25 November, Sottotenente Bertonasso was on a defence patrol over Benghazi, when he spotted and successfully machine-gunned a Bristol Blenheim.

In the beginning of March 1942, Regia Aeronautica spotted Chad-based Free French forces led by Général Jacques-Philippe Leclerc intruding into the Fezzan desert area, in the southern part of Libya, to harass Italian garrisons in order to distract forces from the northern front. The Leclerc column was formed by four independent patrols, the aerial support being provided by the Groupe Bretagne, composed of Nates and Rennes Escadrilles. The former was led by Lieutenant Jean Mahé and had four Martin Marylands (ex-French Martin 167s, known simply as ‘Glenns’) and a Potez 540. The latter, commanded by Lieutenant Marcel Finance, had five Lysanders and three Potez 29s.
Leclerc had moved from Chad on 17 February and ten days later surprised and overwhelmed the small garrison of Uigh el Kebir. Here he established his command post and on 28 February his forces managed to capture the Gatrun and Tegerri garrisons, but a patrol led by Capitaine Jacques Massu met strong resistance at Umm el Araneb and was forced to retreat.
As a result of the French aerial activity in Fezzan, Maggiore Michele Mandara, CO 160^o Gruppo CT, deployed four CR.42s to Sebha, led by Tenente Eduardo Sorvillo (394^a Squadriglia). The other three pilots were Sergente Maggiore Duilio Bernardi (393^a Squadriglia), Sottotenente Bertonasso (375^a Squadriglia) and Sergente Maggiore Antonino Malavasi (394^a Squadriglia). A single S.79 of 175^a Squadriglia RST was also sent as reinforcement, flown by Tenente Giuseppe Pellizzotti.
The CR.42s undertook their first sortie from Sebha on 6 March, hunting French vehicles between there and Zuila, but without result.

On 7 March, the four CR.42s at Sebha moved to Umm el Araneb. After a reconnaissance to Gatrun, while on the ground at Umm el Araneb, they were bombed and strafed by the French Lysander P9197 of the Rennes Escadrilla, flown by Lieutenant Marcel Finance. The fighter of Tenente Eduardo Sorvillo (MM7627/394-8) was set on fire, the pilot suffering severe injuries, while Sottotenente Bertonasso’s CR.42 was slightly damaged.
The pair of Fiats still serviceable took off immediately, flown by Sergente Maggiore Duilio Bernardi and Sergente Maggiore Antonino Malavasi to hunt for the hostile aircraft. Sergente Maggiore Malavasi found the Lysander and fired at it repeatedly, forcing it to land in the desert trailing smoke. Lieutenant Finance took the gunner Sergent Chef Fernand Leroy, who had been wounded in the leg, out of the Lysander and sought the cover of the smoke. It proved only to be a smoke bomb hit by a bullet from Malavasi’s guns.
Meanwhile, Malavasi flew for some time over the grounded aircraft without attacking it further. Convinced that he had inflicted irreparable damage, he then departed. This allowed Finance, having got the gunner back on board, to take off and fly back to Uigh el Kebir.
Malavasi reported the mission as between 14:00 and 14:40.
At Umm el Araneb meantime, the wounded Sorvillo was put in an S.79 called to the spot and flown to Castel Benito.
The S.79 (MM21465) flown by Tenente Pellizzotti subsequently crashed at Sebha for unknown reasons, all crew being killed.

On 8 March, two more 160^o Gruppo CR.42s were flown down to Sebha by Tenente Raoul Francinetti and Sergente Maggiore Aurelio Munich to replace the two which had been destroyed. Meanwhile, however, all the French aircraft left the area, retiring to their base at Faya in Chad, leaving Leclerc’s patrol without air cover.
The next day, on 9 March, Tenente Francinetti and Sergente Maggiore Munich strafed Capitaine Massu’s patrol, leaving one vehicle in flames and others damaged. Francinetti’s CR.42 was slightly damaged by small-arms fire.
In the afternoon Tenente Francinetti, Sergente Maggiore Malavasi and Sergente Maggiore Munich again attacked Massu’s troops, this time near Uigh el Kebir, ten small trucks were claimed destroyed and others damaged.
On 30 March an Italian patrol of 3^o Compagnia Sahariana found the wreck of eight French vehicles. At this point the first Fezzan Campaign was at an end, French forces returning to Chad and the Italians garrisons being re-established.

Bertonasso ended the war with one damaged biplane victory.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1941
	25/11/41	13:55	1	Blenheim	Damaged	Fiat CR.42		Benghazi	375a Squadriglia

Biplane victories: 1 damaged.
TOTAL: 1 damaged.

Sources:
A History of the Mediterranean Air War 1940-1945: Volume Two – Christopher Shores and Giovanni Massimello with Russell Guest, Frank Olynyk & Winfried Bock, 2012 Grub Street, London, ISBN-13: 9781909166127
La Battaglie Aeree In Africa Settentrionale: Novembre-Dicembre 1941 – Michele Palermo, IBN, ISBN 88-7565-102-7
Additional information kindly provided by Pierpaolo Maglio