-Junkers Ju 52-
The Junkers Ju 52 (nicknamed Tante Ju—"Auntie Ju" and Eisen Annie—"Iron Annie") was a German transport aircraft manufactured from 1932 to 1945. It saw both civilian and military service during the 1930s and 1940s. In a civilian role, it flew with over 12 air carriers including Swissair and Lufthansa as an airliner and freight hauler. In a military role, it flew with the Luftwaffe as a troop and cargo transport and briefly as a medium bomber. The Ju 52 continued in postwar service with military and civilian air fleets well into the 1980s.
The Ju 52 was similar to the company's previous Junkers W33, 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 mid-section of which was built into the fuselage, forming its underside. 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".
Ju 52/3mg2e (Wk-Nr 5489) in flight, showing the Doppelflügel, "double wing".The outer sections of this operated differentially as ailerons, projecting slightly beyond the wing tips 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' cabin. The main undercarriage was fixed and divided; some aircraft had wheel fairings, others not. There was a fixed tail skid, or later tail wheel. 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 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 Wasp R-1340 and 578 kW (775 hp) Bristol Pegasus VI engines. The two wing-mounted radial engines of the Ju 52/3m had full-chord cowlings and were noticeably toed-out, from being mounted at an almost perpendicular angle to the wing's tapered leading edge. The central engine had a half-chord 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.
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. Two bomb-bays were fitted, capable of holding up to 1,500 kg (3,300 ) 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. 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.
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 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.
The Ju-52 Stats
Specifications (Junkers Ju 52/3m g7e)
Crew: 3 (two pilots, radio operator)
Capacity: 18 troops
Length: 18.90 m (62 ft 0 in)
Wingspan: 29.25 m (95 ft 10 in)
Height: 4.5 m (14 ft 10 in)
Wing area: 110.5 m² (1,190 ft²)
Empty weight: 6,510 kg (14,325 lb)
Loaded weight: 9,200 kg (20,270 lb)
Max takeoff weight: 10,990 kg (24,200 lb)
Powerplant: 3× BMW 132T radial engines, 533 kW (715 hp) each
Maximum speed: 265 km/h (165 mph) at sea level
Cruise speed: 211 km/h (132 mph)
Range: 870 km (540 mi)
Service ceiling: 5,490 m (18,000 ft)
Rate of climb: 17 minutes to 3,050 m (10,000 ft)
* 1 × 13 mm (.51 in) MG 131 machine gun in a dorsal position
* 2 × 7.92 mm (.312 in) MG 15 machine guns
* up to 454 kg (1,000 lb) of bombs (some variants)