Caproni Ca . 135 The Caproni Ca . 135 was an Italian medium bomber designed in Bergamo in Italy by Cesare Pallavicino . It flew for the first time in 1935 , and entered service with the Peruvian Air Force in 1937 , and with the " Regia Aeronautica " ( Italian Royal Air Force ) in January 1938 . Origins . General Valle ( Chief of Staff of the " Regia Aeronautica " ) initiated the " R - plan " - a program designed to modernize Italy ' s air force , and to give it a strength of 3 , 000 aircraft by 1940 . In late 1934 a competition was held for a bomber with the following specifications : The ceiling and range specifications were not met , but the speed was exceeded by almost all the machines entered . At the end of the competition , the " winners " were the Ca . 135 ( with 204 aircraft ordered ) , the Fiat BR . 20 ( 204 ) , the Piaggio P . 32 ( 144 ) , the Savoia - Marchetti SM . 79 ( 96 ) , the CANT Z . 1007 ( 49 ) , and the Piaggio P . 32 ( 12 ) . This array of aircraft was proof of the anarchy , clientelarism , and inefficiency that afflicted the Italian aviation industry . Worse was the continuous waste of resources by the " Regia Aeronautica " ( Italian Royal Air Force ) . Orders were given for aircraft that were already obsolete . The winners of the competition were not always the best - the BR . 20 was overlooked in favour of the SM . 79 , an aircraft which was not even entered in the competition . Design . The Ca . 135 was to be built at Caproni ' s main Taliedo factory in Milan , which is why the type had a designation in the main Caproni sequence , rather than in the Caproni - Bergamaschi Ca . 300 series . However , the project was retained at Ponte San Pietro and the prototype , completed during 1934 - 35 , ( a long construction time for the period ) , was first flown on 1 April . The project chief was Cesare Pallavicino of CAB ( " Caproni Aereonautica Bergamasca " ) . Although the new bomber was in the " century series " of Caproni aircraft , it resembled the Caproni Ca . 310 , with its rounded nose , two engines , low - slung fuselage and wings with a very long chord . Several versions were fitted with different engines and some had noticeable performance differences . The prototype was powered by two ( at 4 , 000 m / 13 , 123 ft ) Isotta Fraschini Asso XI . RC radial engines initially fitted with two bladed wooden propellers . It had a length of , a wingspan of , and a wing surface of . It weighed empty and had a useful load . Structurally , it was built of mixed materials , with a stressed - skin forward fuselage and a wood and fabric - covered steel - tube rear section ; the wings being of metal and wood , using fabric and wood as a covering . The wings were more than ⅓ of the total length , and had two spars of wooden construction , covered with plywood and metal . The strength coefficient was 7 . 5 . The tail surfaces were built of wood covered with metal and plywood . The fuel system , with two tanks in the inner wings , held a total of 2 , 200 L ( 581 US gal ) . The Ca . 135 ' s fuselage shape was quite different from , for example , that of the Fiat BR . 20 . If the latter resembled the American B - 25 Mitchell , the Ca . 135 , with its low fuselage more resembled the American B - 26 Marauder . Its long nose accommodated the bomb - aimer ( bombardier ) and a front turret ( similar to the Piaggio P . 108 and later British bombers ) . The front part of the nose was detachable to allow a quick exit from the aircraft . It also had two doors in the cockpit roof , giving the pilots the chance to escape in an emergency . The right - hand seat could fold up to assist entry to the nose . A single 12 . 7 mm ( 0 . 5 in ) in a turret in mid - fuselage , was manned by the co - pilot . A seat for the flight engineer was later fitted . The wireless operator ' s station , in the aft fuselage , was fitted with the AR350 / AR5 ( the standard for Italian bombers ) , a radiogoniometer ( P63N ) , an OMI AGR . 90 photographic - planimetric machine or the similar AGR 61 . The aircraft was also equipped with an APR 3 camera which although not fixed , was normally operated through a small window . The wireless operator also had a 12 . 7 mm ( 0 . 5 in ) machine gun in the ventral position . All this equipment made him very busy ; as a result , an extra man was often carried . The aircraft had very wide glazed surfaces in the nose , cockpit , and the central and aft fuselage ; much more than in other Italian aircraft . The aircraft was fitted with three machine guns , of 12 . 7 mm ( 0 . 5 in ) calibre in the turrets , and a 7 . 7 mm ( 0 . 303 in ) calibre gun in the nose . All had 500 rounds , except the 7 . 7 mm ( 0 . 303 in ) which had 350 . Bombload , like most Italian bombers , was less than impressive in terms of total weight , but was relatively flexible , depending on the role - from anti - ship to close air support : The aircraft had a better bomb capacity than most of its contemporaries ( the SM . 79 could carry : 2 × 500 kg / 1 , 100 , 5 × 250 kg / 550 lb , 12 × 100 kg / 220 lb or 50 kg / 110 lb bombs , or 700 × 1 – 2 kg / 2 - 4 lb bomblets ) . Performance . The aircraft was underpowered , with a maximum speed of at and a high minimum speed of , ( there were no slat s , and maybe not even flaps ) . Ceiling was only and the endurance , at 70 % of throttle , was . All - up weight was too high , with total of , not as expected . The total payload of was shared between the crew ( 320 + kg / 705 + lb ) , weapons ( 200 kg / 441 lb ) , radios and other equipment ( 100 kg / 220 lb ) , fuel ( 2 , 200 L / 581 US gal ) , oil ( 1 , 500 kg / 3 , 307 lb ) , oxygen and bombs . There was almost no chance of carrying a full load of fuel with the maximum bombload , ( other Italian bombers were generally capable of a 3 , 300 - 3 , 600 kg / 7 , 275 - 7 , 937 lb payload ) . The lack of power made take - offs when over - loaded , impossible . Indeed , even with a normal load , take - offs were problematic . Take - off and landing distances were and . The range was good enough to assure with 550 kg ( 1 , 210 lb ) and with 1 , 200 kg ( 2 , 650 lb ) . The production version was fitted with two inline liquid - cooled Asso XI RC . 40 engines , each giving at 4 , 000 m ( 13 , 120 ft ) . Aerodynamic drag was reduced , with three - bladed metal propellers that were theoretically more efficient . These new engines gave the aircraft a maximum speed of at 4 , 000 m ( 13 , 120 ft ) . It could climb to 2 , 000 m ( 6 , 560 ft ) in 5 . 5 minutes , 4 , 000 m ( 13 , 120 ft ) in 12 . 1 minutes and 5 , 000 m ( 16 , 400 ft ) in 16 . 9 minutes . Despite this , the aircraft was still underpowered , so the 1939 Ca . 135Mod , fitted with Piaggio P . XI engines , was developed . Operational service . The aircraft arrived late in respect to the others ( like the BR . 20 ) , and with totally unsatisfactory technology . Despite this there was an order for 32 aircraft from the " Regia Aeronautica " on 19 June 1937 . They started to enter service in January 1938 , over a year after the BR and SM bombers . Spanish Civil War . In 1938 seven aircraft were earmarked for the " Aviazione Legionaria " to serve in the Spanish Civil War . These " Tipo Spagna " ( " Spanish Type " ) aircraft were refitted with Fiat A . 80 R . C . 41 engines , rated at . Crews from 11 Wing were sent to Taliedo ( just outside Milan ) , to take the first seven aircraft - designated Ca . 135S - to Spain . One was damaged on take - off , the other six flew to Ciampino near Rome , where two suffered damage on landing . After repairs and some modifications , the seven aircraft were not ready to leave for Spain until late 1938 . During the flight two were forced by icing to return to Italy and three crashed into the sea . Only two arrived at Palma de Mallorca , where they remained unused for six months . Italy . Production of the aircraft was initially 32 aircraft , of which eight were Ca . 135Ss , some were converted into the Ca . 135Mod . The first Ca . 135Bis were built in 1938 . They were fitted with 746 kW ( 1 , 000 hp ) Piaggio P . XI RC . 40 engines , with Piaggio P . 1001 three - blade metal propellers . Length was 17 . 7 m ( 58 . 1 ft ) , wingspan 18 . 8 m ( 61 . 7 ft ) , and wing surface 60 m² ( 646 ft² ) . Armament was still only two 12 . 7 mm ( 0 . 5 in ) guns and one 7 . 7 mm ( 0 . 303 in ) , but the nose was redesigned to be more aerodynamic . Another 32 aircraft were ordered and built between 1939 and June 1940 . They were not successful aircraft , being heavily criticized by the Italian pilots . Unable to be used operationally , they were sent to flying schools , and then exported to Hungary . The first batch of Ca . 135s flown by 11 Wing were phased out by late 1938 . 25 were still available at Jesi airfield , but only four were airworthy . The others were probably in maintenance for engine replacement . There were at least 15 Ca . 135Ss and Ca . 135Mods at the Malpensa flying school in 1940 , the poor condition of these aircraft meant that they were scrapped in November 1941 . With the scrapping of the first batch and the selling of the second , all 64 Ca . 135s left the service of the " Regia Aeronautica " without performing a single operational mission . Hungary . In the 1938 Imperial Japanese Army Air Force evaluation , the Ca . 135 P . XI had lost to the Fiat BR . 20 , but the Magyar Királyi Honvéd Légierő ( MKHL ; the Royal Hungarian Air Force ) , Hungarian Air Force , nonetheless ordered it . It is likely that these Hungarian Ca . 135s had Manfred Weiss WM K - 14 engines in place of the Piaggio P . XIs , since Hungary used these engines in its versions of the Reggiane Re . 2000 and the Heinkel He 70 . Both the Piaggio P . XI and the Manfred Weiss WM K - 14 were licensed versions of the French Gnome - Rhône 14K Mistral Major . The Hungarians operated up to 100 Ca . 135s with some success against the Soviet Union on the Eastern Front in 1941 and 1942 , once Hungary had committed its forces in that sector during World War II . These aircraft constituted almost the entire Hungarian heavy bomber force . They were ordered after Hungarians returned 33 out of 36 Caproni Ca . 310s acquired between May and September 1939 . Because of an Italian credit for 300 million " lire " and the impossibility of acquiring modern German aircraft , Honvéd air force acquired the new , more powerful , Ca . 135 . The second Ca . 135 series was delivered between 1940 and 1941 , after an order originally submitted in 1937 . It was only confirmed in 1939 , after a trial was carried out by Hungarian pilots at Guidonia . " Regia Aeronautica " had rejected the Ca . 135s on account of its technical shortcomings and the aircraft had been taken off production . But in Hungarian service this bomber proved quite satisfactory . When Hungary declared war to the Soviet Union , in June 1941 , Honvéd air force was almost entirely equipped with Italian aircraft . The bombers had their baptisme of fire on 27 June 1941 , the day of Hungarian declaration of war . That day , Sen Lt Istvan Azakonyi , on his Ca . 135 from the 4 / III Bomber Group , managed to destroy an important bridge with a ' trial drop ' of two bombs . The Ca . 135s equipped the 3 . / III Group of 3rd Bomber Wing , based in Debrecen , a bomber unit of the Hungarian air formation commanded by Lt Col Béla Orosz , that had been tasked to provide air support to the Hungarian Rapid Corps , subordinated to German 17th Army . These bombers entered in action on 11 August , when six Capronis , commanded by Sen Lt Szakonyi , took off to bomb a 2 km ( 6 , 560 ft ) bridge across the Bug River of the city of Nikolayev , on the Black sea . One Ca . 135 had to turn back due to engine problems , but the other five , escorted by Hungarian Fiat CR . 42 s and Reggiane Re . 2000 s , continued eastwards . Szakonyi ' s Caproni was hit by AA fire and lost his port engine but the squadron commander remained in action . One of his pilots , Capt . Eszenyi , destroyed the bridge , and Szakonyi bombed the Nikolayev train station . On the way back the Capronis were intercepted by Soviet Polikarpov I - 16 fighters . The escorting Hungarian fighters shot down five I - 16 , while the crippled Szakonyi ' s Ca . 135 managed to destroy another three Polikarpovs . After the German 11th Army captured Nikolayev , on 16 August , the commander of Luftflotte 4 , Col Gen Lohr , decorated the successful Hungarian crews at Sutyska . The Ca . 135 on the Eastern front had frequent malfuncions and its insufficient combat load - carrying capability set high demands on the mechanics maintaining it . A 50 per cent operational readiness of the Capronis was to be seen as a great achievvement . The first Hungarian Flying formation on the Eastern Front was withdrawn in September 1941 , for recuperation , re - equipment and rest . In 1942 the Hungarians sent the 2nd Air Brigade to provide tactical support and reconnaissance sorties to Hungarian 2nd Army , deployed on the Don . The only bombardment unit , the 4 / 1 Bomber squadron , was equipped with 17 Ca . 135s . The 4° squadron operated these aircraft until late 1942 , when the survivors , worn out , were used as training aircraft . The Hungarians did not love the Ca . 135Bis , but it was all they had , and so they had to make best out of it . One of the squadrons , the I / 4 , ( originally equipped with eight aircraft ) , soon lost one on landing . It was replaced by another four aircraft . This squadron , up to October 1941 , carried out 265 attacks , flew 1 , 040 sorties , and dropped around 1 , 450 tonnes ( 1 , 600 tons ) of bombs , evidently helped by the short range ( 200 – 300 km / 120 - 190 mi ) that allowed them to use the aircraft ' s maximum bomb load . Two aircraft were shot down , another two were lost in accidents and 11 crewmen were killed . The daily average , over these four months , was over 8 missions flown and 13 tonnes ( 14 tons ) of bombs dropped . Peru . Design and production . Early in 1936 , Capronis representative in Lima , Peru , approached the Peruvian Navy and Aviation Ministry regarding the possible Peruvian purchase of Ca . 135 aircraft . Peru had been considering the replacement of its unsatisfactory Caproni Ca . 111 bombers since 1935 , and the Italian Air Ministry approved of the foreign sale of the Ca . 135 . Consequently , Peru ordered six Ca . 135s from Caproni in May 1936 . Peruvian Aviation Corps Commander Ergasto Silva Guillen led a Peruvian delegation to Italy to evaluate the Ca . 135 and to ensure that there was no repeat of the what the Peruvians considered to be the " Ca . 111 fiasco " . Caproni test pilot Ettore Wengi made a demonstration flight for the Peruvians which left Silva unimpressed ; he viewed the Ca . 135 as underpowered and lacking in defensive armament and wrote a letter to the Caproni company insisting on modifications to the aircraft and threatening to cancel the Peruvian order if they were not made . Caproni company founder Gianni Caproni ( 1886 – 1957 ) personally promised that the changes would be made . The resulting version of the aircraft , the Ca . 135 " Tipo Peru " ( " Peruvian Type " ) , had more powerful engines — Isotta Fraschini Asso XI R . C . 40 " Spinto " ( " Driven " ) engines , uprated versions of the Isotta Fraschini R . C . 40 Asso delivering 559 kilowatts ( 750 horsepower ) at sea level and 671 kilowatts ( 900 horsepower ) at 4 , 000 meters ( 13 , 123 ft ) - - and modified engine cowlings with additional openings to accommodate the additional air intakes of the new engines . The new engines gave the Ca . 135 better performance that met the Peruvian requirements , and also allowed an increase in the aircrafts bomb load to 2 , 000 kilograms ( 4 , 409 pounds ) . Defensive armament was improved by the installation of a 12 . 7 - millimeter ( 0 . 5 - inch ) machine gun in a semi - open dorsal turret equipped with a wind deflector shield to protect the gunner and another 12 . 7 - millimeter machine gun in a retractable ventral turret . Both turrets had a 360 - degree field of fire , although the ventral turret produced excessive aerodynamic drag when extended and was recommended for use only in emergencies . All six Ca . 135 " Tipo Peru " aircraft were completed in early July 1937 . After test flights by Wengi and acceptance by the Peruvian delegation , they were disassembled and shipped to Callao , Peru . Personnel of the Caproni companys Peruvian subsidiary , " Caproni Peruana S . A . " , promptly began their reassembly at Las Palmas . The first Ca . 135 was reassembled within two weeks , and the first flights in Peru took place when the six bombers were turned over to the Peruvian Aviation Corps new 2nd Heavy Bomber Squadron on 10 September 1937 . Operational service . After their pilots had undergone two months of intensive training by Italian officers , five 2nd Heavy Bomber Squadron Ca . 135s flew to their permanent base , the Lieutenant Commander Ruiz base , at Chiclayo , Peru , on 5 November 1937 , while the sixth bomber remained at Las Palmas to train additional personnel . Once at Chiclayo , the five Ca . 135s became the 2nd Bombardment Group , joining the Ca . 111 bombers of the 1st Bombardment Group as part of the 1st Aviation Squadron . In 1940 a reorganization resulted in the Ca . 135s being assigned to the 13th , 14th , and 15th " Escuadrilla " s alongside Ca . 111 bombers , although later in the year the Ca . 111s were reclassified as transport aircraft and reassigned to transport squadrons , at which point the 14th and 15th " Ecuadrilla " s were disbanded and all Ca . 135s were assigned to the 13th " Escuadrilla " . In service , the Ca . 135 " Tipo Peru " soon came under criticism , with Peruvian pilots complaining that the bombers yawed to the right on take - off and had poor lateral stability ; in addition , their engines proved unreliable in service , and the bombers suffered an excessive number of oil and hydraulic leaks . " Caproni Peruana S . A . " noted these problems and made plans to correct them in a version of the Ca . 135 to be manufactured in Peru , although in the end no Ca . 135s were built in Peru . As the result of a growing border crisis with Ecuador in 1941 , the bomber squadrons of the Peruvian Aviation Corps were ordered into operational readiness , although engine problems kept them from having more than two aircraft out of each squadron ' s assigned five bombers airworthy at any given time . However , the Peruvian bombers were able to train at a bombing range north of Chiclayo . When the Ecuadorian - Peruvian War broke out on 5 July 1941 , the Ca . 135s remained behind at the Lieutenant Commander Ruiz base while other bombers moved to forward airfield s , the greater range of the Ca . 135s allowing them to avoid the need to move to forward air bases . However , Peruvian bombing missions were limited to tactical attacks on Ecuadorian troops in the front lines and facilities and forces supporting them directly , a type of attack to which Ca . 135s were unsuited . Instead , the Ca . 135s conducted unescorted reconnaissance flights over Ecuadorian territory and transport flights to the airfields at Piura and Talara , Peru . On 10 July 1941 , during a transport flight , one of the Ca . 135s was forced down by engine problems in an area inaccessible to ground vehicles about from Piura ; although suffering only minor damage , its disassembly for transportation to a repair facility was infeasible , so it was stripped and abandoned . After the war ended on 31 July 1942 , the five surviving Ca . 135s remained at Chiclayo . They soon were removed from service , disassembled , and carted away on flatbed truck s driven by American military personnel from El Pato airbase . By October 1942 , the last of the Peruvian Ca . 135s had disappeared . Although they are rumored to have been burned in the desert or buried somewhere around the El Pato air base , their final fate is unrecorded . Modified aircraft . A single Ca . 135 P . XI was modified by Caproni . It incorporated a dihedral tailplane and 1 , 044 kW ( 1 , 400 hp ) Alfa Romeo 135 RC . 32 Tornado radial engines , and given the designation Ca . 135 bis / Alfa . The newer and more powerful engines pushed the maximum speed of the aircraft to more than 480 km / h ( 300 mph ) . The final variant was also a one - off , known as the Ca . 135 " Raid " , it was used to set records and win air races . It was built in 1937 to the order of the Brazilian pilot de Barros . It was powered by two Isotta Fraschini Asso XI and provided with additional fuel capacity for a greatly extended range . While attempting a flight from Italy to Brazil in 1937 , de Barros and the Ca . 135 " Raid " disappeared over North Africa , in another disaster for the image of the aircraft .