Junkers Ju52 Tante Ju. Part 1. Compiler: Luis German Dzib Aquilar

By 1932, the German airline, Lufthansa, had sufficiently recovered from the economic woes of the 1920’s to put in service a three-engine civil transport plane, the Junkers Ju 52/3m.Based on a short-lived single engine model, the Ju 52 first flew in April 1931 and quickly became the workhorse of both the airline and the reviving Luftwaffe, with a standard passenger-carrying load of 17. During the Spanish Civil War, the Ju 52 ferried more than 10,000 Moorish troops from Morocco to Spain, as well as dropping 6000 tons of bombs.

With three BMW engines of 725 horsepower each, the Ju 52 had a maximum speed of 171 mph and a range of 800 miles. For air defense and tactical ground support the bomber carried two 7.92 machineguns and could be fitted with a variety of bomb racks as the need arose; the plane's trademark corrugated skin produced a very solid airframe.

By the beginning of World War Two over 1,000 Ju 52’s were in service; eventually a total of 5,000 planes would fly the Nazi colors performing every imaginable mission from troop transport to mine-laying on all fronts. During the war some thirteen ‘variations on a theme’ saw improved radios, interchangeable float/ski/wheel landing gear (indicating the wide range of Luftwaffe requirements), better armor and engines, and heavier defensive armament.

In Spain, Casa built 170 Ju 52s for the Spanish air force, under the designation Casa 352, and even France built the airplane, under the designation AAC.1 Toucan.

Demonstrating the plane’s strength, three aircraft sold to Swiss Air remained in service until 1981 and are still flying in private hands today. Several others still fly charter and sightseeing flights throughout the world. (1)

Design and development

The Ju 52 was similar to the company's previous Junkers W 33, although larger. In 1930, Ernst Zindel and his team designed the Ju 52 at the Junkers works at Dessau. The aircraft's unusual corrugated duralumin metal skin, pioneered by Junkers during World War I, strengthened the whole structure.

The Ju 52 had a low cantilever wing, the midsection of which was built into the fuselage, forming its underside. ⁽²⁾ It was formed around four pairs of circular cross-section duralumin spars with a corrugated surface that provided torsional stiffening. A narrow control surface, with its outer section functioning as the aileron, and the inner section functioning as a flap, ran along the whole trailing edge of each wing panel, well separated from it. The inner flap section lowered the stalling speed and the arrangement became known as the Doppelflügel, or "double wing". (3)

Lufthansa's 21st-century airworthy heritage Ju 52/3mg2e (Wk-Nr 5489) in flight, showing the Doppelflügel, "double wing" trailing edge control surfaces.

The outer sections of this operated differentially as ailerons, projecting slightly beyond the wingtips with control horns. The strutted horizontal stabilizer carried horn-balanced elevators which again projected and showed a significant gap between them and the stabilizer, which was adjustable in-flight. All stabilizer surfaces were corrugated.

The fuselage was of rectangular section with a domed decking, all covered with corrugated light alloy. There was a port side passenger door just aft of the wings, with windows stretching forward to the pilots' cockpit. The main undercarriage was fixed and divided; some aircraft had wheel fairings, others not. There was a fixed tailskid, or a later tailwheel. Some aircraft were fitted with floats or skis instead of the main wheels.

In its original configuration, designated the Ju 52/1m, the Ju 52 was a single-engined aircraft, powered by either a BMW or Junkers liquid-cooled engine. However, the single-engine model was underpowered, and after seven prototypes had been completed, all subsequent Ju 52s were built with three radial engines as the Ju 52/3m (drei motoren — "three engines"). Originally powered by three Pratt & Whitney R-1690 Hornet radial engines, later production models mainly received 574 kW (770 hp) BMW 132 engines, a licence-built refinement of the Pratt & Whitney design. Export models were also built with 447 kW (600 hp) Pratt & Whitney R-1340 Wasp and 578 kW (775 hp) Bristol Pegasus VI engines. The two wing-mounted radial engines of the Ju 52/3m had half-chord cowlings and in planform view (from above/below) appeared to be splayed outwards, being mounted at an almost perpendicular angle to the tapered wing's sweptback leading edge. The central engine had a cowling like a Townend ring as the fuselage behind it was increasing in diameter, though some later aircraft had deeper cowlings. Production Ju 52/3m aircraft flown by LuftHansa before World War II, as well as Luftwaffe-flown Ju 52s flown during the war, usually used an air-start system to turn over their trio of radial engines, using a common compressed air supply that also operated the main wheels' brakes.

Military use 1932–1945

The Colombian Air Force used three Ju 52/3mde bombers equipped as floatplanes during the Colombia-Peru War in 1932–1933. After the war, the air force acquired three other Ju 52mge as transports; the type remained in service until after World War II.

Bolivia acquired four Ju 52s in the course of the Chaco War (1932–1935), mainly for medical evacuation and air supply. During the conflict, the Ju 52s alone transported more than 4,400 tons of cargo to the front. ⁽⁴⁾

In 1934, Junkers received orders to produce a bomber version of the Ju 52/3m to serve as interim equipment for the bomber units of the still-secret Luftwaffe until it could be replaced by the purpose designed Dornier Do 11. ⁽⁵⁾ Two bomb bays were fitted, capable of holding up to 1,500 kg (3,300 lb) of bombs, while defensive armament consisted of two 7.92mm MG 15 machine guns, one in an open dorsal position, and one in a retractable "dustbin" ventral position, which could be manually winched down from the fuselage to protect the aircraft from attacks from below. The bomber could be easily converted to serve in the transport role. ⁽⁶⁾ The Dornier Do 11 was a failure, however, and the Junkers ended up being acquired in much larger numbers than at first expected, with the type being the Luftwaffe's main bomber until more modern aircraft such as the Heinkel He 111, Junkers Ju 86 and Dornier Do 17 entered into service. ⁽⁷⁾⁽⁸⁾ The Ju 52 first saw military service in the Spanish Civil War against the Spanish Republic. It was one of the first aircraft delivered to the fraction of the army in revolt in July 1936 as both a bomber and transport. In the former role, it participated in the bombing of Guernica. No more of the bomber variant were built after this war, though it was again used as a bomber during the bombing of Warsaw ⁽⁹⁾ during the Invasion of Poland of September 1939. The Luftwaffe then relied on the Ju 52 for transport roles during World War II, including paratroop drops.

World War II

While in use by the Deutsche Lufthansa the Ju 52 had proved to be an extremely reliable passenger airplane and was, therefore, adopted by the Luftwaffe as a standard aircraft model. In 1938, the 7th Air Division had five air transport groups with 250 Ju 52s. The Luftwaffe had 552 Ju 52s at the start of World War II. Even though it was built in great numbers, the Ju.52 was technically obsolete. Between 1939 and 1944, 2.804 Ju 52s were delivered to the Luftwaffe (1939: 145; 1940: 388; 1941: 502; 1942: 503; 1943: 887; and 1944: 379). The production of Ju 52s continued until approximately the summer of 1944; when the war came to an end, there were still 100 to 200 available.

Fallschirmjäger jumping from Ju 52

The Ju 52 could carry eighteen fully equipped soldiers, or twelve stretchers when used as an air ambulance. Transported material was loaded and unloaded through side doors by means of a ramp. Air dropped supplies were jettisoned through two double chutes; supply containers were dropped by parachute through the bomb-bay doors, and paratroopers jumped through the side doors. Half-track motorcycles (kettenkraftrad) and parachute troops' supply canisters were secured under the fuselage at the bomb bay exits and were dropped with four parachutes. A tow coupling was built into the tail-skid for use in towing freight gliders. The Ju 52 could tow up to two DFS 230 gliders.

Heavy losses in combat

The first major operation for the aircraft was in Operation Weserübung, the attack on Denmark and Norway on 9 April 1940. Fifty-two Ju 52s from 1. and 8. Staffel in Kampfgeschwader 1 transported a company of Fallschirmjäger and a battalion of infantry to the northern part of Jutland, and captured the airfield at Aalborg, vital to support the operation in southern Norway. Several hundred Ju 52s were used to transport troops to Norway in the first days of this campaign.

The Netherlands

Later, Ju 52's participated in the attack on the Netherlands on 10 May 1940, where they were deployed in the first large-scale air attack with paratroops in history during the Battle for The Hague. No fewer than 295 Ju 52s were lost in that venture and in other places in the country, due to varying circumstances, among which were accurate and effective Dutch anti-aircraft defenses and German mistakes in using soggy airfields not able to support the heavy craft. ⁽¹⁰⁾ On 10 May alone, 278 were downed or disabled, making this day unequaled in military history as no-where else were so many planes lost of one type on one day, including the Battle of Britain. (In total on that day, 512 planes went down, another never challenged world record). ⁽¹¹⁾

Thus, almost an entire year's production was lost in one day in the Netherlands. The lack of sufficient numbers of aircraft most probably heavily influenced the decision not to invade England following the Battle of Britain. ⁽¹⁰⁾

 

After Holland

After the campaign in the West, the air transport units were brought up to their pre-Holland strength and were assembled at airfields in the Lyon, Lille, and Arras areas in August 1940. ⁽¹²⁾ Probably this was done using new and repaired aircraft augmented by other transport planes like the FW-200 Condor and the Ju 90.

A Ju 52 approaching Stalingrad, 1942

The next major use of the Ju 52 was in the Balkans campaign, most famously in the Battle of Crete in May 1941. Lightly armed, and with a top speed of only 265 km/h (165 mph) – half that of a contemporary Hurricane – the Ju 52 was very vulnerable to fighter attack and an escort was always necessary when flying in a combat zone. Many Ju 52's were shot down by anti-aircraft guns and fighters while transporting supplies, most notably during the desperate attempt to resupply the trapped German Sixth Army during the final stages of the Battle of Stalingrad in the winter of 1942–1943.

During the North African Campaign, the Ju 52 was the mainstay reinforcement and resupply transport for the Germans, starting with 20 to 50 flights a day to Tunisia from Sicily in November 1942, building to 150 landings a day in early April as the Axis situation became more desperate. The Allied air forces developed a counter-air operation over a two-month period and implemented Operation Flax on 5 April 1943, destroying 11 Ju 52s in the air near Cap Bon and many more during bombing attacks on its Sicilian airfields, leaving only 29 flyable. ⁽¹³⁾ That began two catastrophic weeks in which more than 140 were lost in air interceptions, ⁽¹⁴⁾ culminated on 18 April with the infamous "Palm Sunday Massacre" in which 24 Ju 52's were shot down and another 35 staggered back to Sicily and crash-landed. ⁽¹⁵⁾

A minesweeper Ju 52 equipped with degaussing ring

The seaplane version, equipped with two large floats, served during the Norwegian Campaign in 1940, and later in the Mediterranean theatre. Some Ju 52's, both floatplanes and landplanes, were also used as minesweepers, known as Minensuch — literally, "mine-search" aircraft in German — fitted with a 14 m diameter current-carrying degaussing ring under the airframe to create a magnetic field that triggered submerged naval mines. ⁽¹⁶⁾

Hitler's personal transport

Hitler used a Deutsche LuftHansa Ju 52 for campaigning in the 1932 German election, preferring flying to transport by train. After he became Chancellor of Germany in 1933, Hans Baur became his personal pilot, and Hitler was provided with a personal Ju 52. NamedImmelmann II after the World War I ace Max Immelmann, it carried the registration D-2600. ⁽¹⁷⁾ As his power and importance grew, Hitler's personal air force grew to nearly 50 aircraft, based at Berlin Tempelhof Airport and made up of mainly Ju 52s, which also flew other members of his cabinet and war staff. In September 1939 at Baur's suggestion, his personal Ju 52 Immelmann II was replaced by the four-engine Focke-Wulf Fw 200 Condor, although Immelman II remained his backup aircraft for the rest of World War II.

Hitler´s transport, Junkers JU 52. Flying over Nürnberg.

Chiang Kai-shek's personal transport

Eurasia was the main Chinese Airliner Company in the 1930s and Ju 52 was the main airliner plane. One of them was commandeered by the Chinese Nationalist Party Government and became Chiang Kai-shek's personal transport.

A Ju 52 of Eurasia, 1930s in China

 Compiled by Luis German Dzib Aquilar