In December 1941, Sergente Maggiore Luigi Modesti served in the 155^a Squadriglia, 3^o Gruppo CT. This unit was at the time equipped with Fiat CR.42s.

At 11:40 on 1 December, a patrol of three CR.42s of the 155^a Squadriglia, 3^o Gruppo, led by Sottotenente Bruno Ciapparelli, took off from Sorman for a defence patrol over a convoy. The wingmen were Sergente Maggiore Modesti and Sergente Gino Bonato. The Fiats were patrolling at an altitude varying between 300 and 700 metres. Above the convoy a formation of three Bristol Blenheims was intercepted. Two of these were thought to have been shot down while the third had probably been shot down. 1278 rounds were fired from 12.7 mm machine guns and 1289 rounds from 7.7 mm ones.
The Italian pilots complained that the obsolete characteristics of the CR.42 didn’t allow for an effective escort of the convoys. The CR.42 fighter escort had to remain very close to the convoy to prevent the enemy bombers, which were faster than the CR.42, from being able to get away. Nevertheless, this didn't enable them to intercept enemy aircraft before the latter carried out an attack on escorted ships. In fact, the escorted tanker was hit and sank.
According to AIR 22.364:

”6 Blenheims (18 Sqn. Malta) were despatched to attack a tanker of 10,000 tons, escorted by a destroyer, and an air escort of 4 CR.42s and Ca.310. The ship was located in position 65 miles ESE of Melita. 2 bombs hit the superstructure and branched off; two others hit the funnel but no results were observed… the tanker was found well down by the stern...”

During the night of 25-26 May 1942, LG 143, at Gasr el Arid, was heavily attacked in an effort by the Luftwaffe and Regia Aeronautica to destroy as many WDAF fighters as possible before the start of Rommel’s offensive against the Gazala-Bir Hacheim line. The raiders approached before midnight on 25 May and included were nine CR.42s of the 3^o Gruppo (23:30-02:30), which made a low-level attack on Gambut, releasing around 50 small bombs and strafing. One of the CR.42s were shot down by Flying Officer John Selby (Hurricane Ic BM975/F) from 73 Squadron. This was Sergente Maggiore Modesti (153^a Squadriglia), who ended up as a PoW.

Modesti ended the war with 2 shared biplane victories.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	1941
	01/12/41	11:40-	1/3	Blenheim (a)	Shared destroyed	Fiat CR.42		65m ESE Melta	155a Squadriglia
	01/12/41	11:40-	1/3	Blenheim (a)	Shared destroyed	Fiat CR.42		65m ESE Melta	155a Squadriglia
	01/12/41	11:40-	1/3	Blenheim (a)	Shared probably destroyed	Fiat CR.42		65m ESE Melta	155a Squadriglia

Biplane victories: 2 shared destroyed, 1 shared probably destroyed.
TOTAL: 2 shared destroyed, 1 shared probably destroyed.
(a) Claimed in combat with Blenheims from 18 Squadron, which didn’t suffer any losses.

Sources:
A History of the Mediterranean Air War 1940-1945: Volume One – Christopher Shores and Giovanni Massimello with Russell Guest, 2012 Grub Street, London, ISBN 978-1908117076
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