S.74, the aced out ace

 

    There are aircraft that have a charm of their own, as if their technical and operational life followed a parabola similar to the biographical history of notable people. The S.74, the subject of this translation, was born old. The market had decreed that it was aced-out even before he had shown what it had to offer. But it still had something to show. The above painting of an S.74 is by Danilo Renzulli.

    The Savoia Marchetti S.74

    The outclassed airplane on a class of its own

    By Pietro Mazzardi (translated by L. Pavese)

    
    There are aircraft that have a charm of their own, as if their technical and operational life followed a parabola similar to the biographical history of notable people. Granted, an airplane is just a machine but the S.74, designed and built by Savoia Marchetti, was a very capable aircraft and the only Italian four-engines passenger airplane that had a notable operational life.

    Everything began in 1934, when chief engineer Dr. Alessandro Marchetti began designing a four-engine airliner as a development of the previous S.72. The development had been made necessary by the extension of the Italian commercial routes that now reached the colonies of Northern and Eastern Africa.

    The Italian Ala Littoria airline that, at that time, was on a par with the British Imperial Airways, needed a long range aircraft which should also be easy to maintain. Hence the overall rustic design of the S.74, with the choice of a fixed landing gear, a high cantilever wing, nevertheless with a capacious fuselage that offered a high level of comfort for the standard of the time.

    The dimensions were a length of about 70 feet (without the long nose-mounted Pitot tube), a wingspan of 97 feet (the wing was adapted from the S.72’s) and a wing area of 1276 square feet. The empty weight was 19,620 pounds and the maximum take off weight was 30,865 pounds.

    Initially, the first two S.74s, registered I-URBE and I-ALPE flew with the CV 700 (690 hp) Piaggio P.X R engines, while on the third aircraft registered I-ROMA the CV 845 (833 hp) Bristol Pegasus III engines were installed. The top declared speed was 200 mph, with a 174 mph cruise speed. In the period straddling 1937-1938, the engines of three examples built were replaced by the Alfa Romeo 126RC.34's developing CV 780 (769 hp) with three-blade, in-flight variable pitch propellers (the Alfa Romeo engine was based on the British Bristol Jupiter engine, T/N).

I-URBE, the first S.74

    The S.74 was designed with a mixed construction airframe with a wooden three-spar wing covered with fabric covered plywood and a welded steel tube fuselage. The nose had an elliptical section with a structure of welded tubes covered with duralumin. The cockpit was elevated with respect to the floor of the cabin and housed the four-men crew consisting of two pilots and behind them the radio operator and the flight engineer. The latter could reach the engines through a tunnel built inside the wing.

The cockpit of the S.74

 The fuselage had a rectangular section with rounded corners covered with painted fabric.

    The passenger cabin, characterized by a single continuous window, was thermically and acoustically insulated. It housed twenty-seven seats (one double row of seats on the right side and a single one on the left) and was equipped with a toilet. An oxygen delivering system with individual outlets, for high altitude flight, was planned. Under the floor, in the belly of the fuselage, there was a series of baggage holds accessible through well placed external doors. 

    The robust and hefty fixed landing gear was equipped with elastic shock absorbers.

    The first S.74 built, n.c. 21001, I-URBE, for the first flights was equipped with two-blade wooden propellers. It was test-flown on November 16,1934 by Alessandro Passaleva. It was followed by the I-ALPE (n.c. 21002), delivered on June 6, 1935 and by the I-ROMA (n.c. 21003) delivered on December 5, 1935.

    The I-URBE was the first S.74 to wear the livery of Ala Littoria, and on April 27, 1935 made an experimental Rome to Paris flight commanded by test pilot Tesei with General Aldo Pellegrini, head of the Ufficio Avazione Civile e Traffico aereo (Italian Civil Aviation and Air Traffic Bureau), Umberto Klinger, president of Ala Littoria and the reserve pilots Strazzer and Suster, demonstrating a good level of efficiency.

    After the aircraft passed all the technical tests, the prestigious route Rome-Marseille-Lyon-Paris was launched on July 18, 1935. The service continued until the Fall with daily flights. The price of the ticket was Italian £ 800.

    Subsequently, the S.74's were flown on the Rome to Brindisi route on propaganda flights and in flights to Italian Libya. In fact, beginning from 1938, the S.74s operated with Comando Aeronautica della Libya (Italian Air Force Command, Libya) based on the Tobruk T2 airfield, preserving their civilian livery, but with the T2 code on the fuselage.

    On December 22, 1937, the I-ROMA piloted by Giuseppe Tesei and Lino Rosci on the circuit Santa Marinella-Napoli-Montecalvo established the world speed record on a 1000 kilometers close track, with a load of 10 metric tons at the average speed of km/h 322, 098. The aircraft was reconfigured for its normal airline duties immediately after the record flights.

    Regardless of the record, however, it was clear that in comparison with the new French and German airliners the S.74 was not “state of the art.” The French and German aviation industries had been building aircraft with more modern and advanced criteria, developing all-metal aircraft: a choice that was mandated by rationality but also by the harsher Central and Northern European climate. By the mid 1930s, the French offered on the international market some very competitive models such as the Bloch 120, the Dewoitine D.333/338 and the Potez 62. And the German transport airplanes, the twin-engine Ju.86, and the four-engine Ju.90 produced by Junkers, and especially the Ju.52 — that would become one the protagonists of WWII — were greatly appreciated in Europe as well as in Latin America.

The British aircraft industry had focused on the development of passenger airplanes suitable for the very long routes of Imperial Airways to the overseas colonies. For this task the Britons built the H.P. 42, a large four-engine biplane, capable of very long range flights, slow but very reliable, which remained in service for almost ten years, at every latitude, without a single deadly accident; the high wing Armstrong Whitworth A.W.15 Atalanta, very similar to the S.74 but smaller, with four 340 hp engines and capable of carrying only ten passengers was instead short-lived. But the all-wood 1937 De Havilland DH.91 Albatross was a very noteworthy product.

The American industry also could not be ignored, because in the United States the modern all-metal construction was already a concrete reality; and the American aircraft designs anticipated the aesthetics of the aviation of the future.

     The quality, the power and the reliability of the American engines oriented the designers towards the twin-engine formula without hesitations. The leading manufacturers were three: Lockheed, with its Vega, Electra and Ventura twin-engine aircraft; even though they were relatively small ten-passenger airplanes. Boeing with the good Model 247; but above all the futuristic and revolutionary Douglas DC-2. Even the German Lufthansa had betrayed the German national products by introducing former KLM’s and CLS’ DC-2’s in its fleet.

The Lufthansa's DC-2 D-ABEQ

   

    And so, the S.74 was not successful on the international market; and in any case its outdated structural construction would have made it unsuitable for the northern European skies. 

The Italian aircraft was built in only three examples, which towards the end of the 1930s they were all destined to Ala Littoria’s long routes to Italian Africa on which the type had already proved itself very reliable.

    Just a few days after the Italian declaration of war, on June 16, 1940 the three S.74s based at Rome Littorio airport were impounded by the government and put at the disposal of the Servizi Aerei Speciali. The three airplanes were painted in a camouflage scheme and were given military registrations. After an early and brief assignment to the 616th Squadriglia Autonoma Trasporti (Autonomous Transport Flight), in July they were flown again to Berka, Libya to form the Sezione Autonoma S.74 ( S.74 Autonomous Section). Subsequently, they were integrated into the 604th Squadriglia of the 145th Gruppo Autonomo Trasporti of the Comando Aeronautica Libia Est (Eastern Libya Transport Command) and operated from various bases: Berka, Bengasi and from the T2 airfield in Tobruk.

The camouflaged I-URBE

    The three four-engine airplanes in military camouflage got the following fuselage identification codes:


    I-URBE 604-8 M.M. 60364 (former M.M. 424 nc.21001)

    I-ALPE 604-11 M.M. 60366 (former M.M. 425 nc. 21002)

    I-ROMA 604- 9 M.M. 60365 (former M.M. 423 nc. 21003)

Three bad quality photographs of the militarized S.74's
with the codes of the 604th Squadriglia. The upper images
 show the engine cowlings painted in yellow.  
 

    During the extensive war operations the three S.74s reached the most remote places in Libya, carrying supplies to the farthest outposts like Giarabub (Jaghbub) near the Libyan-Egyptian border and Koufra, well within the Fezzan; or evacuating civilians from Cyrenaica, landing and taking off from dirt airstrips that were barely marked on the flight charts.

    After their militarization, the S.74s had been modified removing the rows of three seats, replaced by two long rows of side-by-side seats along the sides of the fuselage, with their backs against the windows. Unfortunately, the general configuration did not allow the installation of any defensive armament.

    In August 1941, the S.74 604-8 was attacked in broad daylight by a British Bristol Blenheim north of the island of Pantelleria. The Italian pilot managed to disengage and bring the aircraft to safety with all its load. But from that moment on, the pilots of the 604th were forced to operate almost exclusively at night to avoid unpleasant encounters.

    In that very difficult context, the S.74'S performed very well on the most spartan airfields, and slowly earned themselves the reputation of providential rescuers of the Italian soldiers deployed in the most remote and vulnerable oasis. Giarabub in particular: 200 kilometers from the coast, in the heart of the desert of Cyrenaica, where the Italian soldiers led by Colonel Salvatore Castagna resisted the siege by the Australians of the Western Desert Force until March 23, 1941 when they had to surrender. Before the fall of the “Lyons of Giarabub", an S.74 of the 604th Flight from Tobruk carried out a support mission, transporting material and ammunition, and managed to evacuate several wounded soldiers under the fire of the Australians.

    Later, the S.74's together with the SM.82's and the FIAT G.12's, distinguished themselves transferring to North Africa several companies of the Regio Esercito (Italian Royal Army) from the “Folgore,” “Pistoia,” “La Spezia” and “Superga” divisions, departing from the Sicilian airfields of Sciacca, Gerbini and Castelvetrano.

    The first S.74 to be destroyed was the 604-11 I-ALPE. It took off from Castel Benito, Libya on October 23, 1941, commanded by Maresciallo Pilota (Warrant Officer) Franco Ferrari, with 26 military and civilian passengers on board. When it reached the Sicilian land, due to bad visibility the S.74 crashed on a mountain near Licodia Eubea (Catania). There were no survivors.

    On November 2, 1941 it was the S.74 I-URBE 604-8 to be destroyed on the ground, together with eight other airplanes, by a British air attack on Castel Benito in Libya.

    The S.74 I-ROMA 604-9 managed to carry out a long cycle of operations between Sicily and Libya, even if it was in very difficult circumstances. On December 11, 1941 on the airfield of Castelvetrano, a CANT Z.1007 bomber of the 33rd Bomber Group that was returning at night from a bombing mission over Malta struck the parked S.74 on landing. The damage was repaired. On April 4, 1942, the I-ROMA suffered some sixty hits when the airfield was attacked by British Blenheims.

    During the summer of 1942, it carried out a long series of flights between Derna, Bu-Amud and Fuka, near El-Alamein. With nine flights, the I-ROMA carried 373 paratroopers of the “Folgore” division with all their weapons. The aircraft was damaged and repaired several times, and eventually reached Castel Benito.

A picture of the 604-9, I-ROMA

 

    On January 7, 1943 it returned to Italy, where it took refuge at the Roma-Centocelle airbase and it was assigned to the Gruppo Complementare dei Servizi Aerei Speciali. 

    But the end came eventually for I-ROMA too, when it was irremediably damaged by the July 19, 1943 American bombing of the Roma-Littorio airport.

This article appeared originally on the Italian magazine Ali Antiche.

The magazine is a publication of the G.A.V.S., an Italian organization devoted to the preservation of Italian aviation heritage.

Your comments, as usual, will be greatly appreciated.

Thank you,

Leonardo Pavese