Junkers Ju 188
Ju 188 | |
---|---|
Role | Tactical bomber/reconnaissance aircraft
|
Manufacturer | Junkers |
First flight | 19 June 1941 (Ju 88 V27) August 1943 (Ju 188 V1) |
Introduction | February 1943 |
Retired | 1951 (France) |
Primary users | Nazi Germany France and United Kingdom (post-war) |
Number built | over 1,000 |
Developed from | Junkers Ju 88 |
Variants | Junkers Ju 388 |
The Junkers Ju 188 "Rächer" (avenger) was a German Luftwaffe high-performance medium bomber built during World War II, the planned follow-up to the Ju 88 with better performance and payload. It was produced only in limited numbers, due both to the presence of improved versions of the Ju 88, as well as the increasingly effective Allied strategic bombing campaign against German industry and the resulting focus on fighter production.
Background
In 1936, Junkers submitted proposals for the
At the same time, they offered modified versions of each as the Ju 85B and Ju 88B, again similar to the original designs but using an "egg shaped"
The
To address the immediate need, the Ju 88B project was re-submitted as a stop-gap. For this version, they used the latest short-wing Ju 88 A-1 airframe as a baseline with the Ju 88B's new stepless cockpit design, with the new Junkers Jumo 213 engine, which had recently started bench testing and was expected to deliver 1,500 PS (1,100 kW; 1,500 hp) and required a redesigned annular radiator system for engine and oil cooling.
The RLM also stipulated that the aircraft should also be able to accept the BMW 801 radial engine in a Kraftei (power-egg) unitized installation, with no modification to the engine nacelles.[1] The RLM was not impressed with the new design, as it offered only small improvements over the Ju 88A model in service but suggested that Junkers continue with the prototype work anyway and that they consider fitting the design with the BMW 139 radial. This engine was cancelled only a few weeks later and all designs based on it moved to the newer and more powerful BMW 801.
Prototypes, Ju 88 B-0
The prototype Ju 88B V1, D-AUVS, flew for the first time with the 801A/B engines in early 1940. The fuselage and tail surfaces were identical to the Ju 88 A-1, which presented a problem: with the extra power, 1,560 PS (1,150 kW; 1,540 hp), the design could now carry considerably more load than the small bomb bay could fit. An additional external shackle was then added to each wing well outside the engines, although using the rack would seriously hamper performance.
During the summer, a pre-production run of 10 Ju 88 B-0 based on the pre-production Ju 88 A-4 airframes were delivered. The A-4 used a longer wing of 20.08 m (65.9 ft) span from new rounded wingtips for better altitude performance, when compared to the initial Ju 88A-1's shorter 18.26 m (59.9 ft) span, but attention to streamlining and new pointed
Service tests were all successful, and the pilots generally lauded the new cockpit design. However, the RLM still remained unconvinced that the small improvement in performance over the existing A-5's and future A-4's was worth investing time in. Instead, the pre-production models were modified as long-range reconnaissance aircraft by removing the guns, bombsights, and external bomb shackles, and fitting fuel tanks into the bomb bay.
Several of the airframes were retained by Junkers for further development. One of these was fitted with the slightly updated 801L engines and a small power-operated turret on the extreme top of the cockpit mounting a 13 mm (0.512 in) MG 131 machine gun.
Variants
By 1942, it was becoming clear that Junkers' candidate for the important
The sole Ju 88 E-0 was modified with another 13 mm (0.512 in) MG 131 firing rearward just below the turret, one firing forward through the nose and twin 7.92 mm (0.312 in)
In October 1942, the Ju 188 was chosen for production. A second prototype was delivered in January, which moved the outer bomb shackles to a position inboard of the engines. Both started testing the dive bombing system installed in the 88 A-4 in February. The RLM then asked for another change, allowing the aircraft to mount either the BMW 801 or Jumo 213 engines as a complete Kraftei or "power egg" common engine installation, that would simply be bolted on and hooked up. Concerns about the Jumo 213, now years overdue, were offset by this engine's better altitude performance, so it made sense to delay the aircraft slightly if that meant it could switch to the 213 as soon as they became available. The second Ju 188 prototype was flown in at
Ju 188 A & E
The Ju 188 was designed to be fitted with either the 1,750 PS (1,290 kW; 1,730 hp) Jumo 213A or 1,700 PS (1,250 kW; 1,680 hp) BMW 801 G-2 engines without any changes to the airframe, with the exclusion of the re-design for Jumo-powered examples, of the annular radiators from their Jumo 211 layout for the A-series to better match the more powerful 213's cooling needs, while using similar broad-chord three-blade propellers as the A-series did. It was intended that both would be known as A models but the naming was later changed: the Ju 188A model powered by the 213 and the Ju 188E by the 801.
The first three production Ju 188 E-1 machines were delivered with BMW engines in February 1943, followed by another seven in March and eight in April. A conversion testing unit was formed up in May and after testing were attached to an operational unit, with the first mission, an attack by three Ju 188E-1s on a factory in
Although the A and E models were to have been delivered at the same time, the Jumo engine was still not ready; the first Jumo powered Ju 188 A-1 versions were shipped only shortly after the BMW versions, albeit at a much slower rate. By the time deliveries were finally picking up in late 1943, the Jumo was available in a new MW 50 methanol-water injection "boosted" version that delivered 1,648 kW (2,241 PS; 2,210 hp) for takeoff. With this engine, the planes were known as the Ju 188 A-2 and started deliveries in early 1944.[8]
A modified version mounting a small, low-UHF-band
for naval strike missions was delivered as the Ju 188 E-2, and with the Jumo as the Ju 188 A-3. The only other difference was the removal of the outer pair of wing bomb shackles. For all its good points, the Ju 188 was only a small improvement over the Ju 88. The bombload and bomb bay was no larger than the earlier aircraft; although a larger load could be carried externally, it reduced performance. Even then the performance was rather poor considering all the effort - only 523 km/h (325 mph) or less. The dorsal turret had only one gun, yet the type retained the single-gun flexible position only a few centimeters away from it; various projects finally to provide the 188 with tail armament were abandoned.Delivery problems of the Jumo 213 were never entirely solved and the only model to be built in large numbers were the E series with the BMW 801. Even then so few were available that they were generally given out to Ju 88 units, who flew them on "special" missions where the longer range or better performance would be helpful. Some 500 Ju 188A and E variants were produced before production ceased in the summer of 1944.[8]
Ju 188 C
It was planned all along to skip over a "B model" to avoid confusion with the original Ju 88 B but in the original plan the A and E models would be called As and the Ju 188 C would be the next model. The C series was built to the extent of a single example, by modifying one of the few A-1 machines. A new power-operated, remotely operated FA 15 turret was mounted in the tail and had two 13 mm (0.512 in) MG 131s, aimed with a double-periscope (top and bottom) system mounted in the cockpit. This modification would have greatly improved defensive firepower, always lacking on German designs but reliability was so poor it was decided to abandon the system.
Ju 188 D & F
In early 1944, it was decided to focus on reconnaissance versions of the A and E models. The airframe was modified with the removal of the bomb aimer and forward gun and additional fuel cells were added to extend the range to 3,400 km (2,100 mi). The Ju 188 D-1 was otherwise similar to the A-1 and the Ju 188 D-2 had nose radar for naval reconnaissance. Similar conversions of the E models were the Ju 188 F-1 and Ju 188 F-2.
Ju 188 G & H
One problem with the Ju 88 that carried into the 188 was the lack of internal room for bomb storage. Both carried the majority of their bombload on racks under the wing, where it greatly affected performance. This was to have been addressed in the G and H models, which extended the fuselage downward for more room with the addition of a wooden pannier. The modification also left enough room at the tail to fit a manned turret in place of the C model's remote-control one but this system proved to be just as limited as the remote-control FA 15. It was so small that only the smallest men could fit into it and left them with no room to escape in an emergency. The RLM rejected the manned turret and planned on mounting the FA 15 even if it were unreliable.[7] Oddly, the designs still possessed the Bola undernose feature for a rear-facing gunner, when this would no longer be needed and its removal would have greatly streamlined the aircraft. With the Jumo 213s now being sent to fighter production, the Ju 188G-2 was to use the BMW 801 only, with the reconnaissance conversion known as the Ju 188 H-2. Neither entered production before the war ended; the Ju 188G remained at the prototype stage.[9] Tail empennages of the few Ju 188G prototypes built were used in construction of the first two Ju 287 prototypes.[10]
Ju 188 R
In the summer of 1944, three E models were modified as night fighters with the addition of radar and either four 20 mm MG 151/20s or two 30 mm (1.18 in) MK 103 cannons in the nose. The better visibility of the 188 was not useful in night fighting and because the added drag of the radar washed out any speed difference, the Ju 188 R-0 was not ordered.
High-altitude versions
In 1943, it was planned to upgrade all versions with even more wing area and a pressurized cockpit for high-altitude work. A single basic airframe would be offered in three versions, the Ju 188J heavy fighter, Ju 188K bomber, and the Ju 188L reconnaissance version. As with the streamlined Ju 88S, all three late model Ju 188 designs did away with the Bola gondola, leading to a cleaner nose profile, and the bomber and reconnaissance versions mounted their loads in a long pannier under the central fuselage instead of the deeper fuselage of the G and H models.
Simpler versions of these with no defensive armament and even longer wings became the Ju 188S fighter and Ju 188T intruder. With Jumo 213E-1 engines 2,050 PS (1,510 kW; 2,020 hp) at take-off and 1,690 PS (1,240 kW; 1,670 hp) at 9,500 m (31,200 ft), the Ju 188T could reach 700 km/h (430 mph). Operating at this altitude, the Ju 188S could carry only 800 kg (1,800 lb) of bombs.
Before any of these could start production, the entire lineup was renamed the Ju 388, the vastly improved performance warranting a different 8-388 airframe number from the RLM for the design.[7]
Operators
- French Air Force(Postwar)
- Aviation Navaleoperated several captured Ju 188s post war.
- Royal Air Force operated at least two captured machines post war, an A-2 and A-3 (Wrk Nr 190335 of 9./KG 26). The A-3 surrendered to British forces after landing at Fraserburgh on 2 May 1945.[7]
Specifications (Ju 188E-1)
Data from The warplanes of the Third Reich.[11]
General characteristics
- Crew: 4
- Length: 14.95 m (49 ft 0.5 in)
- Wingspan: 22.00 m (72 ft 2 in)
- Height: 4.45 m (14 ft 7 in)
- Wing area: 56.0 m2 (602.7 sq ft)
- Empty weight: 9,990 kg (22,024 lb)
- Max takeoff weight: 15,195 kg (33,499 lb)
- Powerplant: 2 × BMW 801D-214-cylinder air-cooled radial piston engines, 1,300 kW (1,700 hp) each for take-off
- 1,070 kW (1,440 hp) at 5,700 m (18,700 ft)
- Propellers: 3-bladed constant-speed propellers
Performance
- Maximum speed: 500 km/h (310 mph, 270 kn) at 6,000 m (19,685 ft)
- Cruise speed: 375 km/h (233 mph, 202 kn) at 5,000 m (16,400 ft)
- Service ceiling: 9,350 m (30,665 ft) with 2,000 kg (4,400 lb)
- Time to altitude: 6,100 m (20,000 ft) in 17 minutes 42 seconds
- Wing loading: 258.9 kg/m2 (53.0 lb/sq ft)
- Power/mass: 0.175 kW/kg (0.106 hp/lb)
Armament
- Guns: 1 × 20 mm (0.787 in) MG 151/20 cannon
- 3 × 13 mm (0.512 in) MG 131 machine guns
- Bombs: 3,000 kg (6,600 lb)
See also
Related development
Aircraft of comparable role, configuration, and era
Related lists
Notes
- ^ Dressel and Griehl 1994, p.95.
- ISBN 978-0-8021-2560-6.
- ^ Dressel and Griehl 1994, p.97.
- ^ Air International April 1982, p.183.
- ^ Air International April 1982, p.184.
- ^ Dressel and Griehl 1994, p. 96.
- ^ a b c d Dressel and Griehl 1994, p. 99.
- ^ a b Dressel and Griehl 1994, p. 98.
- ^ "Luftwaffe Resource Center - Bombers - A Warbirds Resource Group Site".
- ^ Lommel, Horst, 2004. Junkers Ju 287: The World's First Swept-Wing Jet Aircraft. Atglen, PA: Shiffer Publishing, Ltd.
- ISBN 0385057822.
References
- Dressel, Joachim and Manfred Griehl. Bombers of the Luftwaffe. London: DAG Publications, 1994. ISBN 1-85409-140-9.
- "The Fortuitous 'Avenger'......Junkers' One Eighty-Eight". ISSN 0306-5634. pp. 179–187.
External links
- "Ju-88's Successor." Popular Science, March 1944, p. 79. Cutaway drawing of Ju-188.