The Junkers Ju 88 is a German World War II Luftwaffe twin-engine multirole combat aircraft.
Junkers Aircraft and Motor Works designed the plane in the mid-1930s as a so-called Schnell 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 (1,800–2,200 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 (1,200 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 modelled 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 (4,400 lb) payload at a speed of 517 km/h (321 mph).
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 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 take-offs 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.
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.
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 and 500 kg (550 and 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.
Variants
Ju 88A
Junkers Ju 88 A-4
Main bomber type with Jumo 211 engines.
Ju 88 A-0
Pre-production aircraft.
Ju 88 A-1
Initial production variant.
895 kW (1,200 hp) Jumo 211B-1 engines
Ju 88 A-2
Jumo 211 G-1 engines.
Ju 88 A-3
Conversion trainer.
Dual controls and throttles, various instruments duplicated.
Ju 88 A-4
Improved variant.
Longer wingspan, due to redesigned wingtips.
Stronger defensive armament.
Power provided by Jumo 211 J-1 or J-2 engines producing 1,050 kW (1,410 hp), driving wooden bladed propellers.
Reinforced undercarriage.
Provision for four external bomb racks.
Ju 88 A-5.
This version actually predates the A-4.
Earlier models of Ju 88 upgraded with longer wings and other equipment.
Jumo 211B-1, G-1 or H-1 engines all rated at 890 kW (1,200 hp) for take-off.
Ju 88 A-6
Was equipped with a balloon cable fender.
A counterweight was mounted in the rear fuselage.
Extremely vulnerable to fighter interception, most reverted to the normal A-5 version, fender and counterweight removed.
Ju 88 A-7
Dual control trainer based on the A-5
Ju 88 A-8
This version had balloon cable cutting capabilities, crew reduced to three, Jumo 211F-1 engines
Ju 88 A-11
Factory built tropical version
Ju 88 A-12
Dual control trainer.
Ventral gondola, dive brakes and all armament removed.
Ju 88 A-13
Low level assault version.
Dive brakes and bomb sight removed.
Additional armour for crew, engines and fuel tanks.
Armament consisted of bombs and up to 16 MG 17 housed in pods.
Ju 88 A-14
An improved A-4 version, more armour for the crew, Kuto-Nase balloon cable cutters, MG FF cannon in the ventral gondola, bomb sight removed.
Ju 88 A-15
Based on the A-4, it featured an enlarged wooden bomb bay, capable of holding 3 tons of bombs.
Ventral gondola removed, only two defensive MGs.
It was rejected as the bomb bay “bulge” caused too much drag and a thus a reduction in speed.
Ju 88 A-16
Dual control trainer based on the A-14
Ju 88 A-17
Dedicated torpedo bomber, no ventral gondola.
One PVC torpedo rack under each wing replaced the two bomb racks.
A long housing on the starboard side of the nose contained the torpedo aiming mechanisms.
Crew of three.
Ju 88B
Prototype with all-new fully glazed “stepless” crew compartment nose, developed into Junkers Ju 188.
Ju 88 B-0
10 pre-production aircraft with “stepless” fully glazed nose.
Ju 88C
Zerstörer, fighter-bomber and night fighter, based on A-series, but with sheet metal nose.
Ju 88 C-1
Heavy fighter, 20 converted from A-1, Jumo 211 engines
Ju 88 C-2
Heavy fighter, 20 converted from A-5
Ju 88 C-3
Heavy fighter with BMW engines, none built
Ju 88 C-4
Heavy fighter, reconnaissance variant, based on A-5.
60 built and 60 converted from A-5
Ju 88 C-5
Heavy fighter, like C-4 but with BMW 801 engines, up to four converted
Ju 88 C-6
Heavy fighter and Night fighter, based on A-4, Jumo 211J engines with 1,044 kW (1,401 hp), 900 built
Ju 88D
Long-range photo-reconnaissance variants, based on the Ju 88 A-4/A-5.
Ju 88 D-1
Long-range photo-reconnaissance variant based on Ju 88 A-4.
Ju 88 D-2
Long-range photo-reconnaissance variant based on Ju 88 A-5.
Ju 88 D-3
Tropicalized D-1.
Ju 88 D-4
Tropicalized D-2.
Ju 88 D-5
as D-1 but with VDM metal propellers instead of Junkers wooden propellers
Ju 88G
Night fighter, new fuselage with A-series’ ventral Bola (Bodenlafette) gondola omitted, tail section from Ju 188, aerodynamically improved conformal gun pod for a quartet of forward-firing 20 mm (0.787 in) calibre, MG 151/20 auto cannons below the former bomb bay.
Ju 88 G-1
BMW 801 radial engines with 1,250 kW (1,677 hp), FuG 220 Lichtenstein SN-2 radar
Ju 88 G-6
Junkers Jumo 213A inverted V12 engines with 1,287 kW (1,726 hp), used either FuG 220 Lichtenstein SN-2 90 MHz or FuG 218 Neptun 158/187 MHz frequency radar, either with the usual Hirschgeweih eight-dipole aerial setup or experimentally with the more aerodynamic Morgernstern tripled crossed-dipole aerials.
Some very-late-war aircraft equipped with experimental FuG 240 Berlin cavity magnetron based 3 GHz radar, with dish antenna in bulbous solid nose.
Optional with Schräge Musik upward firing guns with two 20 or 30 mm (0.787 or 1.18 in) guns.
Ju 88 G-7
Identical to G-6, but with Jumo 213E high-altitude engines, planned for use with FuG 218/220 with Morgenstern array or FuG 240.
The G-7 was also to be installed with wings from the Junkers Ju 188.
Ju 88G-3, 4 and 8 not produced.
Ju 88H
Long-range photoreconnaissance, fighter variants, based on the stretched Ju 88G-series fuselage.
Ju 88 H-1
Long-range maritime reconnaissance variant, equipped with a FuG 200 Hohentwiel radar and a trio of remotely controlled cameras in the aft fuselage.
Ju 88 H-2
Fighter variant intended to attack Allied long range convoy escort aircraft armed with six Forward firing MG 151/20.
Ju 88 H-3
Ultra-long-range maritime reconnaissance variant similar to H-1.
Ju 88 H-4
Destroyer variant
Ju 88P
Anti-tank and bomber destroyer variant with single Bordkanone series 75 mm (2.95 in), 50 mm (1.97 in), or twin 37 mm (1.46 in) calibre cannon in conformal ventral fuselage gun pod mount, which mandated removal of the Bola gondola under the cockpit section, conversion of A-series bomber.
Produced in small series only, they were perceived as a failure for both anti-tank and anti-bomber use.
Ju 88 P-1
Heavy-gun variant fitted with single 75 mm (2.95 in) Bordkanone BK 7,5 cannon in ventral gun pod.
Appeared in mid-1942 in small numbers.
Ju 88 P-2
Heavy-gun variant with twin 37 mm (1.46 in) Bordkanone BK 37 cannon in ventral gun pod.
Ju 88 P-3
Heavy-gun variant with twin 37 mm (1.46 in) Bordkanone BK 37 cannon in ventral gun pod, and additional armour.
Ju 88 P-4
Heavy-gun variant with single 50 mm (1.97 in) Bordkanone BK 5 cannon in ventral gun pod.
There were 32 built.
Ju 88 P-5
Proposed heavy-gun variant with single 88 mm (3.46 in), none known to have ever been built.
Ju 88R
C-series night fighters with BMW 801 engines.
Ju 88S
High-speed bomber series based on Ju 88 A-4 but with ventral Bola gondola omitted, smoothly glazed nose with radial-ribbed supports instead of the “beetle’s eye” of the A-version, and GM-1 nitrous-oxide boost, fastest of all variants.
Ju 88 S-0
Fitted with two BMW 801 G-2 engines, single 13 mm (0.512 in) dorsal gun and 14 SD65 65 kg (143 lb) bombs.
Ju 88 S-1
Fitted with two BMW 801 G-2 engines, the GM-1 boost system and could carry two SD1000 1,000 kg (2,200 lb) bombs externally.
Ju 88 S-2
Fitted with two turbocharged BMW 801J engines, wooden bomb bay extension as used on the Ju 88 A-15.
Ju 88 S-3
Fitted with two 1,671 kW (2,241 hp) Jumo 213A engines and GM-1 boost system.
Ju 88T
Three-seat photo-reconnaissance version of S-series.
Ju 88 T-1
Based on the Ju 88 S-1 but with bomb bays fitted for extra fuel or GM-1 tanks.
Ju 88 T-3
Based on the Ju 88 S-3.
Specifications
Crew
4
Length
14.4 m (47 ft 3 in)
Wingspan
20 m (65 ft 7 in)
Height
4.8 m (15 ft 9 in)
Wing area
54.5 m2 (587 sq ft)
Empty weight
9,860 kg (21,737 lb)
Gross weight
12,105 kg (26,686 lb)
Max take-off weight
14,000 kg (30,865 lb)
Powerplant
2 × Junkers Jumo 211J-1 or 211J-2,
V-12 liquid-cooled inverted piston engine,
1,000 kW (1,340 hp) each for take-off
1,010 kW (1,350 hp) at 250 m (820 ft)
790 kW (1,060 hp) at 5,200 m (17,000 ft)
Propellers
3-bladed VDM variable-pitch propeller
Performance
Maximum speed
470 km/h (290 mph, 250 kn) at 5,300 m (17,390 ft) and 12,500 kg (27,557 lb)
Cruise speed
370 km/h (230 mph, 200 kn) at 5,300 m (17,390 ft) economical cruising speed
Range
1,790 km (1,110 mi, 970 nmi) with 2,896 l (765 US gal; 637 imp gal)
Ferry range
2,730 km (1,700 mi, 1,470 nmi) with 4,028 l (1,064 US gal; 886 imp gal)
Service ceiling
8,200 m (26,900 ft)
Time to altitude
5,400 m (17,700 ft) in 23 minutes
Wing loading
220 kg/m2 (45 lb/sq ft)
Power/mass
0.100 hp/lb (0.164 kW/kg)
Armament
Guns
1 × 7.92 mm MG 81J machine gun on flexible mount in front windscreen, firing forward with 1,000 rounds.
1 × 7.92 mm MG 81J machine gun on flexible mount in lower fuselage nose glazing, firing forward with 1,000 rounds.
2 × 7.92 mm MG 81J machine guns on flexible mount in the rear of the cockpit canopy, firing aft with 1,000 rounds each.
1 × 7.92 mm MG 81Z twin machine gun on flexible mount in the rear ventral Bola position, firing aft with 1,000 rounds.
Bombs
Up to 1,400 kilograms (3,100 lb) of ordnance internally in two bomb bays rated at 900 kg (2,000 lb) and 500 kg (1,100 lb) or up to 3,000 kg (6,600 lb) externally.
Carrying bombs externally increased weight and drag and impaired the aircraft’s performance.
Carrying the maximum load usually required rocket-assisted take-off.
