Mario Bonzano was born on 1 September 1906 and was from Alessandria.

On 1 October 1928, he was commissioned (in Servizio Permanente Effettivo).

He took part in the campaign in Italian East Africa (A.O.I.) and was decorated for this.

Later, he took part in the Spanish Civil War.

Capitano Bonzano took command of the 18^a Squadriglia, XXIII Gruppo, on 30 July 1938.

To support the campaign to capture Barcelona in December 1938, virtually all the CR.32 units in Spain were committed. This included the 7^a Escuadra de Caza, commanded by comandante Joaquín García Morato and comprising Grupos 2-G-3 and 3-G-3, based at Escatron. The 3^o Stormo Caccia of the Aviazione Legionaria, led by Colonnello Venceslao D’Aurelio, was transferred from Caspe to Sariñena at the beginning of the offensive. XVI Gruppo, led by Arrigo Tessari, and including 24^a, 25^a and 26^a Squadriglie led by Capitani Giuseppe Majone, Meille and Travaglini, respectively, remained at Caspe, however. XXIII Gruppo, commanded by Maggiore Aldo Remondino, and including 18^a, 19^a and 20^a Squadriglie led by Capitani Bonzano, Giulio Crosara and Andrea Favini, respectively, was also based at Sariñena. Finally, the Squadriglia Autonoma Caccia Mitragliamento, led by Capitano Giorgio Iannicelli, flew from Caspe too.

On 8 January 1939, Capitano Bonzano was replaced as CO of the 18^a Squadriglia by Capitano Vezio Mezzetti.

After commanding 18^a Squadriglia, Bonzano led an experimental unit attached to XXIII Gruppo Caccia that tested and evaluated the Fiat G.50 in Spain after that 12 aircraft had been shipped there.
They arrived too late to see combat with l-15s or l-16s, however. This was perhaps a fortunate thing as the G.50 was both underpowered and defective in design..

In Spain, Bonzano claimed one individual victory and 14 shared (confirmed and probables).

On 7 October 1939, Maggiore Armando François took command over the 9^o Gruppo after Capitano Bonzano.

Bonzano took part in the Battle of Britain as part of the Corpo Aereo Italiano (CAI). Here he commanded the 20^o Gruppo (known as 20./JG 56 by Luftwaffe), which was split into 351^a, 352^a and 353^a Squadriglia, based first at Ursel and then later at Maldegem and equipped with Fiat G.50bis.
The fighters of the 20^o Gruppo C.T. brought with them 45 Fiat G.50bis and six Caproni Ca.133s. Each Squadriglia flew in five groups of three aircraft with two Ca.133s bring in the rest of the pilots and some of the crew of the squadriglia. Under Maggiore Bonzano, the Gruppo flew from Roma-Ciampino on 22 September to Treviso. In Treviso they were forced to stay on the ground due to fog and only on 6 October could the Gruppo fly on to Bolzano. Eleven days later they flew over the Alps and landed in Munich. The next two stages saw the Gruppo flying to Frankfurt, first, and then to its final base at Maldegem airfield. Only one Fiat G.50bis was left behind having to force-land with carburation problems.

Bonzano was promoted to Tenente Colonnello on 27 Februari 1941.

At 10:00 (Axis time) on 3 September 1941, 23 G.50bis of 20^o Gruppo took off, led by Tenente Colonnello Bonzano, to make a strafing attack in the Sidi Barrani area. They arrived over LG 05 at 11:35 (GMT), strafing 1 SAAF Squadron’s Hurricanes and damaging three of these, also riddling every tent with machine-gun fire. The Italian pilots believed that they had destroyed eight aircraft and many vehicles on the ground here. As quickly as possible six Hurricanes took off but were too late to engage the raiders.
Ten miles away at LG 02, 2 SAAF Squadron had four aircraft on standing patrol and seven on immediate readiness. A telephone warning sent the latter Tomahawks into the air within 90 seconds, the last of these hardly being airborne before the raiders swept in, some of them as low as 150ft. The South African pilots identified the attackers as 27 in number, and at once attacked. Lieutenant Charles Whaites made the first claim for one G.50, which he saw spin into the ground two miles from the camp. The second claim was made by Lieutenant N. J. Cullum, who witnessed his target go into the ground at high speed, while a third was “shot to pieces” by fire from five Tomahawks before being given the ‘coup de grace’ by Lieutenant W. P. Stanford (Tomahawk AK442) and John Wells, who reported that it had crashed five miles west of Sidi Barrani. All these were seen by ground personnel on the airfields. Further claims were made by Lieutenants J. W. Sayers and Rolfe Gernecke who each claimed one shot down onto an escarpment to the west, while Lieutenant A. D. Farralls’s claimed victim reportedly fell into the sea. The only casualty to the squadron was Lieutenant L. A. Stones’ aircraft (Tomahawk AM376) which was hit by Bofors AA fire from the airfields, and was forced to crash-land.
The Italian pilots reported being engaged by Tomahawks and Hurricanes following completion of their strafing attack and became involved in a 25-minutes combat during which claims were made for 14 of the intercepting fighters shot down, plus three more probable and four damaged for the loss of four G.50bis. It seems that six more G.50bis suffered fairly severe damage during this engagement. Claiming pilot from 20^o Gruppo was Tenente Colonnello Bonzano (1 Tomahawk and 1 and 1 probable Hurricane). Claiming pilots from 151^a Squadriglia were Capitano Giampiero Del Prete (1 and 1 shared Hurricane), Sergente Maggiore Gugliélmo Gorgone (1 Tomahawk), Sottotenente Pietro Menaldi (1 shared Hurricane), Sergente Maggiore Alberto Porcarelli (1 Tomahawk) and Maresciallo Federico Tassinari (1 Tomahawk). Claiming pilots from 352^a Squadriglia were Sergente Maggiore Otello Bonelli (1 Hurricane), Capitano Luigi Borgogno (1 damaged Hurricane), Sergente Maggiore Renato De Silvestri (1 damaged Hurricane), Maresciallo Maurizio Iannucci (1 damaged Hurricane), Sergente Giuseppe Mirrione (1 Hurricane), Sottotenente Giorgio Oberwerger (1 damaged Hurricane), Sergente Maggiore Francesco Pecchiari (1 Hurricane) and Sergente Maggiore Francesco Visentin (1 probable Hurricane). Claiming pilots from 353^a Squadriglia were Sergente Maggiore Ersio Caponigro (1 and 1 probable Hurricane), Sergente Maggiore Tullio Covre (1 Hurricane), Sergente Spiridione Guiducci (1 Hurricane), Sergente Alcide Leoni (1 shared Hurricane) and Capitano Riccardo Roveda (1 Hurricane). The four lost G.50bis was one from 353^a Squadriglia (MM5939 shot down; Sergente Maggiore Bruno Baldacci KIA) and four from 352^a Squadriglia (MM5933 shot down, crash-landed; Sottotenente Vittorio Muratori KIA) (MM5947 shot down, crash-landed; Sergente Giovanni Vescovi KIA) (G.50bis shot down, crash-landed; Sergente Maggiore Renato De Silvestri PoW).
In consequence of this action, Tenente Colonnello Bonzano received the immediate award of the Medaglia d’argento al valor militare.

At 11:00 on 5 December 1941, 27 German Ju 87s together with nine Italian aircraft of the 239^a Squadriglia took off to attack units and depots of enemy motor vehicles 12 km east of Gobi.
The close cover was composed of 14 G.50s of the 20^o Gruppo (five of the 352^a Squadriglia, six of the 353^a Squadriglia and three of the 151^a Squadriglia) led by Tenente Colonnello Bonzano and headed for the area south-east of Gobi. The G.50s took off at 11:05 and joined with the Stukas above Gazala at 11:35. The close cover was completed with 13 MC.200s of the 153^o Gruppo, whose diary mentions an attack in the Bir El Esem area. There were also two MC.200s of the 157^o Gruppo.
Finally, according to Commonwealth sources, twelve Bf 109s of I. and II./JG 27 provided the top cover.
The G.50s were placed in two groups: six of the 353^a Squadriglia on the right of the Stukas and eight on the left (the five of the 352^a Squadriglia and the three of the 151^a Squadriglia flying at an altitude of 3,500 m.
The Bf 109s of the top cover engaged enemy fighters south of El Adem before reaching the target. The German operational report mentions the first clash with twenty enemy fighters. The latter broke off after several short attacks. Italian sources noted that this first group of enemy fighters was machine gunning our motor vehicles in the Bir El Garaat area.
Meanwhile the target was reached at 11:45.
A formation of 15 enemy fighters was encountered after Bir El Gobi before the dive. They turned without attacking, presumably to get into a more favourable position.
The Ju 87s began the dive and as usual were followed by the close cover. As soon as they got together at 1,000m the battle with the above-mentioned 15 enemy fighters began (these must have been Tomahawks of 250 Squadron) and with others that were at a lower altitude. It is not clear who they belonged to (112 Squadron) was higher up.
Of the five pilots from the 352^a Squadriglia, Capitano Luigi Borgogno managed to shoot down a P-40, after having got over a critical moment at a low altitude hemmed in by several enemy aircraft. Maresciallo Otello Bonelli found himself in some difficulties against two enemy aircraft and received some rounds on the empennages. However, he got free of one of the enemy fighters and having jousted with the other managed to shoot it down. Sergente Maggiore Francesco Pecchiari also machine gunned several enemy aircraft and shot down one. On engaging an enemy aircraft, Sottotenente Giorgio Oberwerger was in a favourable position but had to abandon it before being able to line it up because he was in his turn threatened by the attentions of a fighter, which was later found out to be a Bf 109. The five pilots of the 352^a Squadriglia returned to base without any problems at 12:45.
The three pilots of the 151^a Squadriglia were all heavily engaged. Sottotenente Lanfranco Baschiera machine-gunned a P-40 and saw it turn over near the ground but was unable to check how the duel had gone. He fought with two other enemy aircraft, machine-gunning one (totally he used 166 rounds). Sergente Maggiore Luigi Manelli and Maresciallo Ennio Tarantola (15m south of El Adem) both claimed enemy fighters which they then saw burning on the ground. Both hit other aircraft hard (totally using 222 and 544 rounds respectively). Sergente Maggiore Manelli landed at South Gazala w.th the engine overheating; the other two returned to base without problems at 12:50.
Another four fighters were claimed by the pilots of the 353^a Squadriglia; Tenente Colonnello Bonzano, Capitano Riccardo Roveda, Sergente Maggiore Tullio Covre (south-east of El Adem) and Sergente Spiridione Guiducci while Sergente Manini machined-gunned another two. It was a fierce battle that split up into individual duels. About half of the G.50s managed to disengage themselves and re-join the escort of the Stukas. At the end of the dive other P- 40s attacked the Stukas (presumably 112 Squadron). The battle also continued on the way back. Tenente Colonnello Bonzano landed at South Gazala with his plane badly damaged, hit on the fuel and oil tanks. Altogether the pilots of the 20^o Gruppo claimed nine enemy planes shot down and 12 machine-gunned.
The diary of the 153^o Gruppo was very concise; during the dive they were attacked over the target by a wave of planes greater than the one before, which attacked time after time in a mass. The close cover and semi top cover (presumably Italian units) managed to free the bomber formation from the grip the enemy had them in, machine-gunning the enemy aircraft that tried to put themselves on the tail of the bombers and fighter escort. However, it was not possible to check the results. A MC.200 that had been hit on the radiator landed at Gazala.
The German operational report noted that most of the bombs fell on the target and numerous fires were observed. Losses among the Stukas were very heavy; totally six Ju 87s. The 239^a Squadriglia lost three ”Picchiatellis”:
Sergente Mangano (KIA) and 1^o Avieri Faienza (PoW)
Sottotenente Steffanina (PoW) and 1^o Avieri Spada
Sergente Lanfredi (badly WIA) landed near Gazala.
The heavy anti-aircraft fire hit another three Italian Stukas. The German operational report mentions three German Ju 87s missing. The surviving six returned to base at 13:10.
I./StGW WNr. 6063, forced landing, 50% damage; crew unhurt
II./StGW WNr. 6023, forced landing, 60% damage; crew unhurt
3./StGW WNr. 6153 forced landing, 100% damage; it was destroyed by the bombs of a Ju 87 that was diving down above it and Feldwebel Hans Bremkamp and gunner Wihelm Heger KIA.
All six had probably been hit by enemy fighters.
Finally the clash of the Bf 109Fs from JG 27 with 30-40 Curtisses was reported; it was noted that five of the latter had been shot down as well as a probable:
Unteroffizier Horst Reuter of 5./JG 27, who claimed one at 11:43 south-east of Bir el Gobi
Leutnant Franz Külp of 6./JG 27, who claimed one at 11:45 over Bir el Gobi
Oberleutnant Gustav Rödel of 4./JG 27, who claimed one at 11:55 north-west of Bir el Gobi
Hautpmann Wolfgang Redlich of 1./JG 27, who claimed one at 12:05 south of Bir el Gobi
Unteroffizier Josef Grimm of 1./JG 27, who claimed one south of Bir el Gobi
II./JG 27 lost (100%) Bf 109F-4 trop WNr. 8429, which was hit in the radiator but the pilot was unhurt, l./JG 27 lost (50%) Bf 109F-4 trop WNr. 8523, above Bir el Gobi, pilot unhurt and plane recovered. Bf 109F-4 trop WNr. 8453 was damaged during the take-off (70%), but the pilot was unhurt.
Squadron Leader Clive “Killer” Caldwell (AK498) led the Commonwealth formation from 250 and 112 Squadrons. 112 Squadron with seven Tomahawks had taken off at 10:50 and returned to base between 12:00-12:25, was the top cover for 250 Squadron with eleven Tomahawks, which had taken off at 11:00. The patrol area was about 10 miles west of El Gobi and was reached at 11:40, when an RT communication warned of the arrival of a large enemy formation from the north-west, at about the same altitude as the two Squadrons (7,000 feet). Both the squadrons immediately gained height and, in the space of a minute, the formation of Stukas (thought to be 40 aircraft) protected by the fighter escort was seen on the right, at the same altitude, south of El Adem. The bombers were flying in sections of three planes, stepped on the left and very close to each other.
112 Squadron had to deal with the Bf 109s, while 250 Squadron attacked the Stukas and the close escort. The sections were also close to each other. Squadron Leader Caldwell thought that they were an easy target but on the other hand it was the best defensive tactic to use, both for the weapons and for the fighter escort. The latter was identified well above the Stukas. The commander led the attack on the Stukas with 250 Squadron in line astern, while 112 Squadron engaged the escort. The attack was delivered from the stern quarter. Before Squadron Leader Caldwell started firing another pilot (presumably Sergeant ‘Mac’ Twemlow) on his right started firing into the mass of planes from 500 yards. A Stuka that had been hit started to fall leaving a trail of smoke. Caldwell also opened fire from about 300 yards with all his guns blazing on the section leader of the rear section of three. The deflection was not very effective but numbers 2 and 3 were hit, one of which caught fire immediately. The latter came down leaving a trail of smoke and was burnt up after losing 1,000 feet of altitude. Then Caldwell attacked the section leader of a rear section of three on the right of the formation. He opened fire with all his guns from behind and below from a very short distance. The enemy plane turned over with the right wing root in flames. While Caldwell went down to the left to attack the leader of a section of two planes, the latter jettisoned his bombs by making a sharp nose-up manoeuvre to the right, but was immediately shot down by a Tomahawk. Then Caldwell unleashed a short burst at a wingman that was diving. Nevertheless he managed to remain close to its tail by going flat out and side slipping down to 2,000 feet; again he opened fire from a short distance and the Stuka caught fire on the left wing root, coming down in flames near to lorries full of troops. The latter got out of the way so as not to be hit by the plane. Caldwell regained altitude up to 2,000 feet managing to attack from below, again from a short distance, another Stuka that was shot down in flames. While he was turning he noticed a G.50 500 feet higher up and attacked it, opening fire from a short distance. Unfortunately, all his guns stopped firing. At this point the Italian pilot noticed Caldwell and disengaged by turning over sharply and then diving. A second G.50 saw Caldwell and appeared to want to attack him, but gave up the idea before getting within firing range. Caldwell counted that about 12 planes had come down in flames or left trails of smoke until they crashed into the ground. As well as this he saw three explode in flight. Besides he thought that the Stukas had jettisoned their bombs before reaching their target. In the end he claimed as many as five Ju.87s shot down and a G.50 that was damaged (claimed as a MC.200).
Sergeant Twemlow was in his turn attacked by a G.50 but managed to disengage himself. He was credited with a Ju 87 shot down and two more as probable. Sergeant “Bob” Whittle (AN313) claimed two Ju 87s, with one more initially claimed as probably shot down but this was later upgraded to a “confirmed” after that it had been found crash-landed. Sergeant “Bill” Cable claimed two and one damaged Ju 87. Flight Lieutenant I. F. Rose claimed a probable Bf 109. Pilot Officer Francis Albert Creighton (AM274) claimed one Ju 87 and one damaged Bf 109. It is also possible that R. E. Bary claimed a damaged Bf 109. Totally 250 Squadron claimed twelve Ju 87s shot down, two probables and one damaged, one damaged G.50, one probably destroyed and one damaged Bf 109.
250 Squadron lost four aircraft when Pilot Officer Cole was shot down and wounded as was Sergeant McWilliam, both returning the next day. Sergeant James Ross Gilmour (RAF no. 1365007) and 19-year old Sergeant Edmondson Peter Greenhow (RAF no. 1059800) were both shot down and killed.
112 Squadron reported taking off at 11:20 led by Flight Lieutenant Charles Ambrose (AK475) and including Flying Officer John Soden (AK377), Pilot Officer Neville Duke (AN337/GA-F), Sergeant Rudy Leu (AK354), Pilot Officer “Jack” Bartle (AN372/GA-Q), Pilot Officer Neville Bowker (AK509) and Pilot Officer Joseph Sabourin (AK457). The seven Tomahawks were flying at a higher altitude, at 9,000-10,000 feet, and sighted the enemy formation at about their own altitude, slightly to the left, at 12:00. They saw 30-40 Ju 87s in sections of three with the close cover of 20-25 G.50s and C.200s, mixed up with Stukas in a slightly higher position; while the top cover, composed of twelve Bf 109s, was flying some hundreds of feet higher, divided into two groups of six on both the sides of the formation.
Pilot Officer Sabourin, who mentions a general dogfight, was credited with the shooting down of a Bf 109E, a G.50 and a Ju 87. He saw his rounds enter the cockpit, then these planes came down going into an uncontrollable spin; the first enveloped in smoke and the second in flames. The Stuka came down in the El Adem area. Besides this, he damaged a G.50, a Bf 109E and a Bf 109F. He noted that the wingtips of the enemy aircraft were painted white. Sabourin’s plane was slightly damaged by a round.
Sergeant Leu attacked a MC.200 from out of the sun, which spun in and was claimed destroyed. He also attacked a Bf 109F, which "seemed to falter in the air" and then dive, but he did not see it crash but it was credited as a probable.
Pilot Officer Bartle also reported an attack from above and behind. He shot down a Ju 87 and a G.50. He reported that he was on the tail of a G.50 above El Adem, at a distance of 200 yards, when the latter was shot down by enemy anti-aircraft fire.
Pilot Officer Bowker claimed three Ju 87s, two of which exploded in flight, and damaged a G.50 south of El Adem. He noticed that the Ju 87s had a very dark camouflage scheme without the classic crosses. After shooting down a Ju 87, the other two planes of the section closed up tightly low down and continued on the route heading for the target.
In the Tobruk-El Adem area, Flight Lieutenant Ambrose observed many rounds entering the fuselage of a MC.200, so the latter started a shallow dive flying in an irregular way; it was declared probably shot down. He hit the fuselage of a G.50 with several rounds and he declared it damaged (it was later upgraded to a probable). Finally he commented that the two Italian fighters tried to no avail to get away with a shallow dive after making a full circle.
Flying Officer Soden attacked the tail of a Bf.109 from above; the latter tried to turn against him, but he managed to hit him making him lose the engine cowling and the canopy. He claimed it as a probable. After this, he attacked the stern of the Ju 87s from below. He claimed a Stuka shot down; the tail came away while it came down.
The Stukas appeared to be black and the Bf.109s dark green with a light green shade.
Altogether 112 Squadron claimed to have shot down six Ju 87s, two G.50s, one Bf 109E and one MC.200, two Bf 109F were claimed as probably destroyed as was one G.50 and one MC.200 with two G.50s and two Bf 109s as damaged.
Pilot Officer Duke belly-landed at Tobruk having been hit in the leg by an explosive shell. His radio had failed and his cockpit had sanded up so that he hadn't seen his attacker until cannon shells started hitting his aircraft. He wrote:

“Oh dear, shot down again. Met the Hun Circus again and all the types piled in and got ten down. I stayed up to stave the 109s off but got hit in the right elevator which was carried away, and in the starboard wing where all the trailing edge up to the aileron was shot off.
Spun down from 10.000 ft to about 2-3,000. Undid the straps, etc, preparatory to baling out, but it seemed to fly OK. Made north for Tobruk at ground level. Crash-landed at 150 mph as I could not keep nose up at slower speed; got thrown about the cockpit, and found I’d been hit in the right leg by cannon shell splinters. Hopped out pretty quick. Pinched the compass and clock from the machine as spoils of war!
The chaps were pretty surprised to see me again at Tobruk. I was whisked off to the hospital and X-rayed but the wounds were not very bad. Lucky enough to get a lift back in a Blenheim same evening. Shot down twice within five days – so flying down to Cairo for a few days’ leave.”

In 1943, he was servicing as CO of the 41^o Stormo.

Bonzano ended the war with 1 biplane victory and a total of 4.

Claims:

Kill no.	Date	Time	Number	Type	Result	Plane type	Serial no.	Locality	Unit
	193?
1	??/??/3?		1	Enemy aircraft	Destroyed	Fiat CR.32		Spain	18a Squadriglia
	1941
2	03/09/41	11:35-	1	Tomahawk (a)	Destroyed	Fiat G.50bis		Sidi Barrani area	20o Gruppo
3	03/09/41	11:35-	1	Hurricane (a)	Destroyed	Fiat G.50bis		Sidi Barrani area	20o Gruppo
	03/09/41	11:35-	1	Hurricane (a)	Probably destroyed	Fiat G.50bis		Sidi Barrani area	20o Gruppo
4	05/12/41	11:45-12:45	1	Tomahawk (b)	Destroyed	Fiat G.50bis		S El adem	20o Gruppo

Biplane victories: 1 destroyed.
TOTAL: 4 destroyed, 1 probably destroyed.
(a) Claimed in combat with Tomahawks from 2 SAAF Squadron, which claimed 6 G.50bis for the loss of 1 Tomahawk. 20^o Gruppo claimed 14 fighters (Tomahawks and Hurricanes), 3 probables and 4 damaged for the loss of 4 G.50bis (6 more severely damaged).
(b) Claimed in combat with 112 and 250 Squadrons, which claimed 22 destroyed, 7 probables and 8 damaged while losing 5 P-40s. Fighters from Regia Aeronautica and I. and II/JG 27 claimed 14 P-40s for the loss of 6 Ju 87s and several fighters damaged.

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
Annuario Ufficiale Delle Forze Armate Del Regno D’Italia Anno 1943. Part III Regia Aeronautica – 1943 Istituto Poligrafico Dello Stato, Roma
Courage Alone - Chris Dunning, 1998 Hikoki Publications, Aldershot, ISBN 1-902109-02-3
Elenco Nominativo dei Militari dell’ A. M. Decorati al V. M. Durante it Periodo 1929 - 1945 1 Volume A - L
Fiat CR.32 Aces of the Spanish Civil War - Alfredo Logoluso, 2010 Osprey Publishing, Oxford, ISBN 978-1-84603-983-6
La Battaglie Aeree In Africa Settentrionale: Novembre-Dicembre 1941 – Michele Palermo, IBN, ISBN 88-7565-102-7
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