Junker Ju 288

The Junkers Ju 88 was a German World War II Luftwaffe twin-engined multirole combat aircraft.

Junkers Aircraft and Motor Works (JFM) designed the plane in the mid-1930s as a so-called fast bomber that would be too fast for fighters of its era to intercept.

It suffered from technical problems during its development and early operational periods but became one of the most versatile combat aircraft of the war.

Like a number of other Luftwaffe bombers, it served as a bomber, dive bomber, night fighter, torpedo bomber, reconnaissance aircraft, heavy fighter and at the end of the war, as a flying bomb.

Despite a protracted development, it became one of the Luftwaffe's most important aircraft.

The assembly line ran constantly from 1936 to 1945 and more than 15,000 Ju 88s were built in dozens of variants, more than any other twin-engine German aircraft of the period.

Throughout production the basic structure of the aircraft remained unchanged.

In August 1935, the German Ministry of Aviation submitted its requirements for an unarmed, three-seat, high-speed bomber with a payload of 800–1,000 kg (1,760–2,200 lb).

Design of the Ju-88 began with a study (EF59) which evolved into two parallel designs, Ju-85 and Ju-88.

The Ju 85 was a twin-engined bomber aircraft prototype, designed by Junkers in 1935.

The Ministry of Aviation requested the aircraft, which differed from the Ju 88 due to the use of a twin fin tail unit.

The aircraft was never put into service.

Design was initiated by Junkers Chief Designer Ernst Zindel.

He was assisted by Wilhelm Heinrich Evers and American engineer Alfred Gassner.

Evers and Gassner had worked together at Fokker Aircraft Corporation of America where Gassner had been Chief Engineer.

Junkers presented their initial design in June 1936, and were given clearance to build two prototypes (Werknummer 4941 and 4942).

The first two aircraft were to have a range of 2,000 km (1,240 mi) and were to be powered by two DB 600s.

Three further aircraft, Werknummer 4943, 4944 and 4945, were to be powered by Jumo 211 engines

The first two prototypes, Ju 88 V1 and V2, differed from the V3, V4 and V5 in that the latter three models were equipped with three defensive armament positions to the rear of the cockpit, and were able to carry two 1,000 kg (2,200 lb) bombs, one under each inner wing panel.

The aircraft's first flight was made by the prototype Ju 88 V1, which bore the civil registration D-AQEN, on 21 December 1936. When it first flew, it managed about 580 km/h (360 mph) and Hermann Göring, head of the Luftwaffe was ecstatic. It was an aircraft that could finally fulfill the promise of the Schnellbomber, a high-speed bomber. The streamlined fuselage was modeled after its contemporary, the Dornier Do 17, but with fewer defensive guns because the belief still held that it could outrun late 1930s-era fighters.

The fifth prototype set a 1,000 km (620 mi) closed-circuit record in March 1939, carrying a 2,000 kg (4,410 lb) payload at a speed of 517 km/h (320 mph).

Standard Ju 88 main landing gear installation, from the V6 prototype onwards The first five prototypes had conventionally-operating dual-strut leg rearwards-retracting main gear, but starting with the V6 prototype, a main gear design debuted that twisted the new, single-leg main gear strut through 90° during the retraction sequence, much like that of the American Curtiss P-40 Warhawk fighter.

This feature allowed the main wheels to end up above the lower end of the strut when fully retracted [N 1] and was adopted as standard for all future production Ju 88s, and only minimally modified for the later Ju 188 and 388 developments of it.

These single-leg landing gear struts also made use of stacks of conical Belleville washers inside them as their main form of suspension for takeoffs and landings. By 1938, radical modifications from the first prototype began to produce a "heavy" dive bomber.

The wings were strengthened, dive brakes were added, the fuselage was extended and the number of crewmen was increased to four.

Due to these advances, the Ju 88 was to enter the war as a medium bomber. Annular radiator on a wrecked Ju 88 The choice of annular radiators for engine cooling on the Ju 88, which placed these radiators immediately forward of each engine and directly behind each propeller, allowed the cooling lines for the engine coolant and oil-cooling radiators (integrated within the annular design) to be as short as possible, with integral port and starboard air intakes for cooling the exhaust headers, the starboard inlet also supplying the inlet air for the supercharger.

Ju 88 assembly line, 1941 As the outbreak of WW II in Europe approached, by the time Luftwaffe planners like Ernst Udet had their opportunities to have their own "pet" features added (including dive-bombing by Udet), the Ju 88's top speed had dropped to around 450 km/h (280 mph). The Ju 88 V7 was fitted with cable-cutting equipment to combat the potential threat of British barrage balloons, and was successfully tested in this role.

The V7 then had the Ju 88 A-1 "beetle's eye" faceted nose glazing installed, complete with the Bola undernose ventral defensive machine gun emplacement, and was put through a series of dive-bombing tests with 250 kg (550 lb) and 500 kg (1,100 lb) bombs, and in early 1940, with 1,000 kg (2,200 lb) bombs.

The Ju 88 V8 (Stammkennzeichen of DG+BF, Wrk Nr 4948) flew on October 3, 1938.

The A-0 series was developed through the V9 and V10 prototypes.

The A-1 series prototypes were Wrk Nrs 0003, 0004 and 0005.

The A-1s were given the Jumo 211B-1 or G powerplants.

Dr. Heinrich Koppenberg (managing director of Jumo) assured Göring in the autumn of 1938 that 300 Ju 88s per month was definitely possible.

Göring was in favour of the A-1 variant for mass production.

Production was delayed drastically by developmental problems.

Although planned for a service introduction in 1938, the Ju 88 finally entered squadron service (with only 12 aircraft) on the first day of the invasion of Poland in 1939.

Production was painfully slow, with only one Ju 88 manufactured per week, as problems continually kept cropping up.

The Ju 88C series of heavy fighter was also designed very early in 1940, but kept secret from Göring, as he only wanted bombers. Dive bomber Three Ju 88s in flight over Astypalaia, Greece, 1943 In October 1937 Generalluftzeugmeister Ernst Udet had ordered the development of the Ju 88 as a heavy dive bomber.

This decision was influenced by the success of the Ju 87 Stuka in this role.

The Junkers development center at Dessau gave priority to the study of pull-out systems and dive brakes.

The first prototype to be tested as a dive bomber was the Ju 88 V4 followed by the V5 and V6. These models became the planned prototype for the A-1 series.

The V5 made its maiden flight on 13 April 1938, and the V6 on 28 June 1938. Both the V5 and V6 were fitted with four-blade propellers, an extra bomb bay and a central "control system".

As a dive bomber, the Ju 88 was capable of pinpoint deliveries of heavy loads; however, despite all the modifications, dive bombing still proved too stressful for the airframe, and in 1943, tactics were changed so that bombs were delivered from a shallower, 45° diving angle. Aircraft and bomb sights were accordingly modified and dive brakes were removed.

With an advanced Stuvi dive-bombsight, accuracy remained very good for its time.

Maximum bomb load of the A-4 was 3,000 kg (6,600 lb), but in practice, standard bomb load was 1,500–2,000 kg (3,310–4,410 lb).

Junkers later used the A-4 airframe for the A-17 torpedo carrier.

However, the variant lacked the undernose Bola gondola for a ventral gun position.

Ju 88 preparing for take off, Tunisia, c. 1942–43 Fighter-bomber The Ju 88C series of standard fighter-bomber versions from the C-2 onwards culminated in the Ju 88 C-6, applying experience acquired with the A-4 bomber, equipped with the same Jumo 211J engines but replacing the "beetle's eye" nose glazing with a smoothly curved all-metal nose, pierced only by the barrels of its forward-firing offensive armament.

The C-6 was used mostly as fighter-bomber and therefore assigned to bomber units.

As a reaction to the increasing number of attacks on German shipping, especially on U-boats in the Bay of Biscay, from July 1942 it started flying anti-shipping patrols and escort missions from bases in France.

V./Kampfgeschwader 40 being formed to operate the C-6. The aircraft of V./KG 40 (which was redesignated I./Zerstörergeschwader 1 in 1943[16]) were a significant threat to antisubmarine aircraft and operated as escort fighters for the more vulnerable Focke-Wulf Fw 200 Condor maritime patrol bombers.

Between July 1942 and July 1944, the Ju 88s of KG 40 and ZG 1 were credited with 109 confirmed air-to-air victories, at a cost of 117 losses.

] They were finally deployed against the Allied Invasion of Normandy in June 1944, incurring heavy losses for little effect before being disbanded on 5 August 1944