Version Overview: Ju 388

Ju 388 J Destroyer/Nightfighter

Ju388J-1.gif (34287 Byte)

Version

Power Plant

vmax

Range at vRmax

Service Ceiling

Weight (empty)

Gross Weight

Ju 388 J-1 9-8801 J-0
with
BMW 801 G
at H = 11,6 km

day:
621 km/h

night:
589 km/h

at H = 11 km

day:
2200 km

night:
2160 km



day:
12850 m

night:
12550 m



day:
10135 kg

night:
10230 kg



day:
13275 kg

night:
13310 kg

Ju 388 J-2 9-8222 A/B
with
Jumo 222 A/B/3
at H = 7,2 km

day:
650 km/h

night:
626 km/h

at H = 8 km

day:
2000 km

night:
1850 km



day:
11900 m

night:
11600 m



day:
11120 kg

night:
11235 kg



day:
14177 kg

night:
14362 kg

Ju 388 J-2 with
Jumo 222 E/F
at H = 11,5 km

day:
710 km/h

night:
685 km/h

at H = 11 km

day:
1680 km

night:
2570 km



day:
13600 m

night:
13350 m



day:
11540 kg

night:
11565 kg



day:
14510 kg

night:
14690 kg

Ju 388 J-3 9-8213 D
with
Jumo 213 E
at H = 10,2 km

day:
617 km/h

night:
585 km/h

at H = 9,2 km

day:
2230 km

night:
2040 km



day:
12500 m

night:
12050 m



day:
10050 kg

night:
10140 kg



day:
13110 kg

night:
13220 kg

Differences:
Day:        2 MK 103 or 2 MG 151 in addition to FHL 131 Z
Night:      2 MK 108 and 2 MG 151 plus 2 vertical MK 108 in addition to FHL 131 Z

Ju 388 J-1 (N)

Configuration III, with tail turret

November 16, 1944

Kobü-Entwurf-Leistungsdaten

Nr.: 388/846/2a

Engines:

801 TJ-0 with

Fimag intercooler

Take-off power                                   PS

Combat power in H = 0 km             PS

Combat power in H = 12,3 km        PS

1615 + 11 kg

1472 + 8 kg

1430 + 62 kg

Usage:

Night fighter with

vertical armament, flame damper and radar

Weight (empty)                                 kg

Crew                                                    kg

Fuel                                                      kg

Oil                                                        kg

Ammunition                                      kg

10485

400

2490

260

340

Take-off weight                                  kg

Flächenbelastung                            kg/m²

mittl. Fluggewicht                             kg

13965

250

12730

vmax in H = 0 km                             km/h

vmax in H = 12 km                           km/h

402

583

Flugzeit in H km [1]                          Std.

bei vReise max in H = 11 km             km/h            

3,02 (11)

538

3,03 (8)

520

Flugzeit in H km [1]                         Std.

bei vReise gedr.  in H = 11 km           km/h

3,69 (11)

480

3,45 (8)

405

wst 2-mot. in H = 0 b. GA                  m/s

Steigzeit (bis km)                               min

HD 2-mot. bei GA                                 m

HD 2-mot. nach Steigflug                   m

HD 2-mot. bei Gm                                 m

HD 1-mot. bei Gm                                 m

wst 1-mot in H = 0 km [2]                  m/s

6,3

34,5 (11) 21 (8)

12500

12750

13000

6100

1,2

Roll-/Startstrecke                                 m

800/1200

[1]   einschl. 1 Std. Flug mit Kampfleistungeinschl. 1 Std. Flug mit Kampfleistung

[2]  bei 1000 Ltr. Kraftstoffvorrat u. gesamter Heckstandmunition

Configuration III: Serienzustand ohne Kutonase mit verstellbarer Spreizklappe und Fimag-Ladeluftkühler. Einheitsgewicht des Kraftstoffs: 0,78, Mitnahme von 3280 l. Als Suchgerät wurde eine SN-2 Morgensternantenne mit eingebautem Naxos verwendet. Zerstörersatz mit 2 MG 151 und 2 MK 101 sowie 2 MG 151 schräg. Heckstand FHL 131 Z als Abwehrbewaffnung.

 

Ju 388 K Bomber

Version

Power Plant

vmax

Range at vRmax

Service Ceiling

Weight (empty)

Gross Weight

Ju 388 K-1 9-8801 J-0
with
BMW 801 G
at H = 11,6 km
610 km/h
at H = 11 km
1770 km
12850 m 10250 kg 14275 kg
Ju 388 K-2 9-8222 A/B
with
Jumo 222 A/B
at H = 12 km
635 km/h
at H = 8 km
2080 km
11700 m 11215 kg 16000 kg
Ju 388 K-2 with
Jumo 222 E/F
at H = 11,5 km
695 km/h
at H = 11 km
1800 km
13500 m 11545 kg 15930 kg
Ju 388 K-3 9-8213 D
with
Jumo 213 E
at H = 10,2 km
593 km/h
at H = 9,2 km
2160 km
12450 m 10085 kg 14400 kg

 

Ju 388 L Reconnaissance

Version

Power Plant

vmax

Range at vRmax

Service Ceiling

Weight (empty)

Gross Weight

Ju 388 L-1 9-8801 J-0
with
BMW 801 G
at H = 11,6 km
620 km/h
at H = 11 km
3100 km
12800 m 10150 kg 13890 kg
Ju 388 L-2 9-8222 A/B
with
Jumo 222 A/B/3
at H = 7,2 km
650 km/h
at H = 8 km
2860 km
11800 m 11225 kg 14840 kg
Ju 388 L-2 with
Jumo 222 E/F
at H = 11,5 km
712 km/h
at H = 11 km
2450 km
13500 m 11565 kg 15180 kg
Ju 388 L-3 9-8213 D
with
Jumo 213 E
at H = 10,2 km
608 km/h
at H = 9,2 km
3150 km
12400 m 10060 kg 13675 kg

Annotations

This overview is based on the genuine manufacturer's file F-388.00-02 dated June 14, 1944 (Ju 388 J/K) and August 2, 1944 (Ju 388 L), if not explicitly specified otherwise.

The data contained should not be trusted too much, as they are obviously only an overview of planned versions. It seems all of the series aircraft were Ju 388 L-1. I will have to certify in the future whether there were prototypes of other versions. These data were calculated and not measured. This is why the data for range and maximum speed of the L-1 differ slightly from those on the main page.

Regarding the range data, two things should be considered: First, there was a day and a night reconnaissance option for the L-1 series. Both options differed considerably in fuel capacity. Second, flight test reports by the Germans indicate that the BMW 801 engines consumed more fuel than specified by the manufacturer. I found evidence of this in the JFM message FlA. 601/44 dated September 18th, 1944. It was found by indirect measurements that the engines installed in the Ju 388 L-0 V 7 at the time, c/n 385220 (right) and c/n 385256 (left) were

consuming fuel at a rate of ca. 570 l per hour and engine up to altitudes of 8.0 km. BMW gives a value of 430 l/h.

On the same topic, the JFM message FlA. 742/44 dated 12/15/1944 states that

a 10% decrease in range has to be expected..

This was evident from data released the day before with FlA. 741/44. In the experiments described, the fuel consumption of the Ju 388 V 7 was determined in-flight while climbing up at different numbers of revolution. The engines installed were the same, but it should be mentioned that the left engine had a BMW radiator, while the right engine was equipped with a Fimag radiator (air intake outside).
The results were alarming, and thus, four engines with air intakes outside were tested for fuel consumption on the ground. The results of these measurements were included in FlA. 742/44 as table and are found below:

  Sparleistung Höchste Sparleistung
  engine c/n 385/
275
385/
274
387/
776
387/
837
385/
275
385/
274
387/
776
387/
837
consumption l/h 196 224 200 180 260 287 278 256
number of revolutions revs/min 1785 1838 1780 1775 2058 2110 2080 1930
charger pressure ata 1,00 1,00 0,98 0,98 1,14 1,14 1,12 1,12
charger air temperature °C 42 46 35 36 44 47 36 37
exhaust pressure ata 1,07 1,07 1,08 1,09 1,10 1,10 1,12 1,13
injected fuel mm3/
stroke
268 290 267 241 302 324 318 307
expected " 240 - 255 295 - 305

 

  Höchste Dauerleistung Kampfleistung
  engine c/n 385/
275
385/
274
387/
776
387/
837
385/
275
385/
274
387/
776
387/
837
consumption l/h 464 480 468 466 598 634 649 600
number of revolutions revs/min 2310 2325 2320 2320 2460 2470 2430 2430
charger pressure ata 1,28 1,28 1,26 1,265 1,45 1,45 1,43 1,43
charger air temperature °C 46 48 38 38 50 52 43 42
exhaust pressure ata 1,16 1,15 1,18 1,19 1,22 1,22 1,25 1,27
injected fuel mm3/
stroke
478 491 482 478 580 611 636 588
expected " 438 - 470 540 - 580

The engines with the serial numbers 385 275 (flown 8 h 30 min) and 385 274 (7 h 30 min) were attached to the Junkers Ju 388 K0-156 (WNr. 230 156 ?), while the brand new engines with the serial numbers 387 776 and 387 837 had just been installed in the Ju 388 V4, a K-subtype. This correlation of aircraft and engines was made possible by a short BMW report by BMW's EZA/2 dated December 9, 1944. The same report also says that the conversion of the Ju 388 K0 - 156 (c/n 230 156) has been finished and that the aircraft is ready for service.


The US-Report on the Ju 388 states that "although various subtype were found in Germany after the capitulation, the JU-388 L-l version was found to be the most representative model, and this model was selected for examination and analysis. " I will try to verify whether there have been series or protoype aircraft of other versions. The data in the table above are calculated data, not measured data. This is why there are slightly different values for top speed and range  for the L-1 on the main page. Regarding the range, two things have to be taken into consideration: a) there were day and night versions of the L-1 with considerably different fuel capacities  and b) Junkes complained to BMW that the actual fuel consumption of the TJ-0 engines was higher than planned. The top speed obtained during flight tests in the USA was 383 mph at 40,300 feet, which corresponds to 616 km/h at an altitude of 12.283 m.

 

Engines

Ju 388 with Jumo 213

Several aircraft were converted to Jumo 213 for evaluation purposes. The most famous of these is without doubt the Ju 388 V32, Werknummer 300 295, T9+DL. Serving with the 3./Versuchsverband O.K.L., it was a L-0 aircraft converted to Jumo 213 E (Triebwerk 9-8213 D) by the Luftwaffe. A first test run was conducted 9/12/44, and the first of 23 test flights took place 9/16/44. During these flights, the plane was airborne for 9 h 40 min and obtained a maximum speed of 565 kph (351 mph) and a ceiling of 10,200 m (33,440 ft). The test program abruptly ended when the V32 crashed 1/5/45 for unknown reasons, killing the crew of three. All this information can be found in a report of the 3./Versuchsverband O.K.L. (Br.B.Nr. 28/45 geh.) dated 2/27/45.

The Jumo 213 E was intended to become the standard engine of the Ju 388 J-3 :

 

Ju 388 J-3 (N) mit FlaV

24.11.1944

Kobü-Entwurf-Leistungsdaten

Nr.: 388/851

Engines:

9-213 E

Take-off power                                   PS

Combat power in H = 0 km             PS

Combat power in H = 10,2 km        PS

1750 + 103 kg

1580 + 85 kg

1270 + 140 kg

Deployment

w/o ext. tank

+ MW 50

w. 1 ext. tank

+ MW 50

Weight (empty)                                 kg

Crew                                                    kg

Fuel                                                      kg

Drop Tank + fitting                            kg

MW 50                                                  kg

Oil                                                         kg

Ammunition                                       kg

10410

400

2410

280

260

340

10410

400

2950

60

280

260

340

Take-off weight                                  kg

Flächenbelastung                             kg/m²     

mittl. Fluggewicht                             kg

14100

252

12750

14700

262

13055

vmax in H = 0 km                               km/h

vmax in H = 10,2 km                          km/h

vNot  + MW 50 m. FlaV in H=8,2     km/h

439

576

626

438

573

624

vNot  +MW 50 o. FlaV in H=9,1        km/h

647

645

Flugzeit in H = 9,2 km                         h

bei vReise max                                        km/h

3,74

516

3,65

509

Flugzeit in H = 9,2 km                         h

bei vReise gedr.                                      km/h

4,65

438

4,30

446

wst 2-mot. in H = 0 bei GA                 m/s

Steigzeit bis H = 9,2 km                    min

HD 2-mot. bei GA                                  m

HD 2-mot. bei Gm                                  m

HD 1-mot. bei Gm                                  m

wst 1-mot in H = 0 km                        m/s

7,85

27,7

11100

11800

2300

*,**

7,00

34,0

10550

11650

2000

*,**

Roll-/Startstrecke                                 m

670/920

750/1010

 

Ju 388 with Jumo 222

On Novemer 13, 1944, Junkers issued an order to build six Ju 388 test aircraft equipped with Triebwerk 9-8222 A/B (Jumo 222 engines), after the number of such test aircraft had been cut from eight to three in the meantime. The 4-blade VS 19 airscrew with a diameter of 4 m should be installed. The test aircraft should be converted from K-0 series aircraft. The main differences in comparison with the L-0 series should, apart from the obviously necessary changes for the installation of the Jumo 222, include an enhanced landing gear (wheels 1400 x 410), a Kärcher fuel powered heater per wing for de-icing, additional lubricant oil tanks (Rüstsatz B 13) and a drop tank with a capacity of 900 l. The armament consisted of a MG 131 machine gun at the back of the cockpit. As the installation of camera equipment was not intended, hence the bomb bay could be closed permanently.

 

Ju 388 with DB 603

There are hints that the Ju 388 should also be powered by the DB 603 engine. A JFM memorandum dated August 25, 1944 which refers to a meeting at VDM on August 8, 1944, deals with possible airscrews for the Ju 388 with DB 603 U (Unit 9-8603 F). Two alternatives were discussed:

  1. two six-blade aluminum airscrews, each consisting of  two three-blade airscrews (Weight 365 kg)
  2. two four-blade airscrews made of tempered wood (Weight 235 kg)

However, the cg shift would have required 200 kg of ballast, making the version with six blades 460 kg heavier than the four-blade-version. In addition to this, increased efforts in manufacturing and assembling suggested not using the six-blade airscrew. Consequently, the decision was made to use the four-blade wooden airscrew. The same memorandum also lays down the use of the four-blade aluminum airscrew 9-12188 A already used on the BMW 801 TJ with the DB 603 L and DB 603 E/F. This airscrew had a diameter of 3,726 m.

 

Ju 388 with mixed jet/piston engines?

In late September 1943, Genst.6.Abt. requested the installation of jet engines in the following aircraft types used for the Reich's defence, in the following order:

a) Me 410
b) Ju 188 R und Ju 88 G
c) Ju 388 J

Due to their importance, these measures should be conducted with utmost urgency. Obviously, 1,000 jet engines a month were to be installed as additional power plants in the aircraft [1].

And indeed, BMW's department "EZS" made performance calculations for different propulsion concepts in 1943. As early as February 1943, EZS-Report No. 11 theoretically analyzed the effective thrust of piston, turboprop and jet engines in a Ju 88 aircraft. It was found that turboprops and jet engines were clearly superior. EZS-Report No. 25 concluded that the installation of two additional jet engines would increase the maximum speed of the Ju 88 by 120 kph at the design ceiling. Above, the increase in speed was even larger, while the decrease in range became smaller.
EZS-Report No. 33 published in November 1943 is of particular interest, as it deals with the question whether the tactical tasks of a fast long-range reconnaissance  plane could be fulfilled with normal piston engines and additional jet engines instead of turbo-supercharged piston engines. Therefore, the performance of a Ju 388 L-1 with BMW 801 TJ and a Ju 88 H-1 with BMW 801 TG and two additional BMW 003 A-1 jet engines was made. At low and medium altitudes, this combination featured significant speed advantages in comparison to the BMW 801 TJ, but smaller ranges. Above 12,500 m, turbo-supercharged engines were found to be superior both in terms of speed and range to to the mixed propulsion in spite of additional GM1 use with the BMW 801 TG. Consequently, turbo-supercharged engines were recommended for fast high altitude reconnaissance planes, while the jet/piston engine combination was preferred for special missions. In the EZS-Report No. 36 (December 1943), conventional piston engines were compared to the turboprop engine BMW 028 for aircraft in the Ju 388's weight range (12.61 - 13.62 t). The BMW 028 yielded superior velocities at all altitudes, but lead to a decrease in range [2]. 

The actual use of additional jet engines in Ju 388 aircraft has not been proven yet. The E'Stelle Werneuchen, however, suggested around November 1944 to equip a Ju 88 G-6 with two additional jet engines for hunting the DH 98 "Mosquito". In Rechlin, this suggestion was examined at least theoretically under Test Number 1888. Without drop tanks, but with SN2-antennae and flame suppression gear, the aircraft would have had a maximum speed of 615 kph at 6,100 m. With an additional 900 l drop tank and a takeoff weight of 14.4 t, fuel would have been sufficient for one hour of flying with maximum thrust and additional jet engines and another hour at maximum continuous thrust without jet engines [3]. 

As late as January 1945, two Ju 88 test aircraft (V67 and V72) were flight-tested with additional Jumo 004 B engines [4]. However, these were more likely flying "engine test stands", as the test flights were made to test individual components of the Jumo 004 B. Moreover, Ju 88 V72 still had Jumo 211 engines.
As "pure" jet aircraft like Me 262 and Ar 234 were flight-tested and built in parallel to the Ju 388, it seems reasonable that jet-engine related activities focussed on these aircraft, while the intermediate solution of equipping conventional aircraft like the Ju 388 with additional jet engines was abandoned.

[1] Letter GL/C-E 2 I Nr. 9919/43, 3/27/1943
[2] BMW, Summary of  EZS-Reports No. 11, No. 25, No. 33, dated 10/26/1943, and No. 36, dated 2/5/1944, NASM MF R2026
[3] Weekly Report of  E'Stelle Rechlin for the time from Nov. 11. - Nov. 18, 1944 (11/18/1944), BA-MA RL 36/86
[4] Monthly Report of the Flight Department of the  Otto-Mader-Werk (OMW), dated 2/4/1945, NASM MF R8083 F656.
This section was originally planned for the Ju 388-Book but had to be removed due to space constraints.

 

Ju 388 in Japan?

In August 1944, a Japanese delegation led by military attaché Brigadier General Otani visited the Junkers facilities at Dessau. On this occasion, Otani expressed his interest in a license production of the Ju 388 and the Ju 390. After several delays and numerous difficulties, e.g. the availability of drawing paper, complete drawing sets for the Ju 388 and the Ju 390 were eventually handed over to the Japanese. They also obtained the rights for a license production of the Jumo 222 and the FA 15. Most likely, the planned delivery of all these documents to Japan via submarine failed.

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© 29.12.2010 by Christoph Vernaleken. This article may not be published - as whole or in excerpts - in any form without written permission of the author