Junkers Ju 287

Ju 287

Role	Bomber prototype
Manufacturer	Junkers
Designer	Philipp von Doepp
First flight	8 August 1944
Number built	2
Variants	OKB-1 EF 131

The Junkers Ju 287 was an aerodynamic testbed built in Nazi Germany to develop the technology required for a multi-engine jet bomber. It was powered by four Junkers Jumo 004 engines, featured a revolutionary forward-swept wing, and apart from the wing was assembled largely from components scavenged from other aircraft. It was one of the very few jet propelled aircraft ever built with a fixed landing gear.

The unfinished second and third prototypes, which far more accurately reflected the design of the eventual production bomber, were captured by the Red Army in the closing stages of World War II and the design was further developed in the Soviet Union after the end of the war.

Development

The Ju 287 was intended to provide the Luftwaffe with a bomber that could avoid interception by outrunning enemy fighters. The swept-forward wing was suggested by the project's head designer, Dr. Hans Wocke as a way of providing extra lift at low airspeeds - necessary because of the poor responsiveness of early turbojets at the vulnerable times of takeoff and landing. A further structural advantage of the forward-swept wing was that it would allow for a single massive weapons bay forward of the main wing spar. Prior to the assembly of the first Ju 287, an He 177 A-5 (designated as a 177 prototype, V38) was modified at the Letov plant in Prague to examine the technical characteristics of this single large bomb bay design.

Side view (Model)

The first prototype was intended to evaluate the concept, and was assembled from the fuselage of an He 177 A-5, the tail of a Ju 388, main undercarriage from a Ju 352, and nosewheels taken from crashed B-24 Liberators, all of which were fixed to lower weight and complexity, and equipped with spats to reduce drag. Two of the Jumo 004 engines were hung in nacelles (pods) under the wings, with the other two mounted in nacelles added to the sides of the forward fuselage.

Flight tests began on 16 August 1944 (pilot: Siegfried Holzbaur^[1]), with the aircraft displaying extremely good handling characteristics, as well as revealing some of the problems of the forward-swept wing under some flight conditions. The most notable of these drawbacks was 'wing warping', or excessive inflight flexing of the main spar and wing assembly. Tests suggested that the warping problem would be eliminated by concentrating greater engine mass under the wings. This technical improvement would be incorporated in the subsequent prototypes. The 287 was intended to be powered by four Heinkel-Hirth HeS 011 engines, but because of the development problems experienced with that engine, the BMW 003 was selected in its place. The second and third prototypes, V2 and V3, were to have employed six of these engines, in a triple cluster under each wing. Both were to feature the all-new fuselage and tail design intended for the production bomber, the Ju 287A-1. V3 was to have served as the pre-production template, carrying defensive armament, a pressurised cockpit and full operational equipment.

Work on the Ju 287 programme, along with all other pending German bomber projects (including Junkers' other ongoing heavy bomber design, the piston-engined Ju 488) came to a halt in July 1944,^[2] but Junkers was allowed to go forward with the flight testing regime on the V1 prototype. The wing section for the V2 had been completed by that time. Seventeen test flights were undertaken in total, which passed without notable incident. Minor problems, however, did arise with the turbojet engines and the RATO booster units, which proved to be unreliable over sustained periods. This initial test phase was designed purely to assess the low-speed handling qualities of the forward-swept wing, but despite this the V1 was dived at full jet power on at least one occasion, attaining a speed in the medium dive-angle employed of 660kph. To gain data on airflow patterns, small woolen tufts were glued to the airframe and the "behavior" of these tufts during flight was captured by a cine camera mounted on a sturdy tripod directly ahead of the plane's tailfin. After the seventeenth and last flight in late autumn of 1944, the V1 was placed in storage and the Ju 287 programme came to what was then believed to be its end. However, in March 1945, for reasons that are not entirely clear, the 287 programme was restarted, with the RLM issuing a requirement for mass production of the jet bomber (100 airframes a month) as soon as possible. The V1 prototype was taken out of storage and transferred to the Luftwaffe evaluation centre at Rechlin, but was destroyed in an Allied bombing raid before it could take to the air again. Construction on the V2 and V3 prototypes was resumed at the Junkers factory near Leipzig, and intended future variant designs (meant for service in 1946) were dusted off. These included the Ju 287B-1, seeing a return to the original powerplant choice of four 1,300 kg (2,900 lb) thrust HeS 011 turbojets; and the B-2, which was to have employed two 3,500 kg (7,700 lb) thrust BMW 018 turbofans. While the Heinkel turbojet was in the pre-production phase at war's end, work on BMW's radical and massively powerful turbine engine never proceeded past the blueprint stage. The final Ju 287 variant design to be mooted was a Mistel combination-plane ground attack version, comprising an unmanned explosives-packed "drone" 287 and a manned Me 262 fighter attached to the top of the bomber by a strut assembly. The cockpit of the 287 would be replaced by a massive impact-fused warhead. Takeoff and flight control of the combination would be under the direction of the 262's pilot. The 262 would disengage from the 287 drone as the Mistel neared its target, the pilot of the fighter remotely steering the 287 for the terminal phase of its strike mission.

The Junkers factory building the V2 and V3 was overrun by the Red Army in late April 1945; at that time, the V2 was 80% complete, and construction of the V3 had just begun. Wocke and his staff, along with the two incomplete prototypes, were taken to the Soviet Union. There, the third prototype (returned to its original Junkers in-house designation, EF 131) was eventually finished and flown on 23 May 1947, but by that time, jet development had already overtaken the Ju 287. A final much-enlarged derivative, the EF 140, was tested in prototype form in 1949 but soon abandoned.

Specifications (Ju 287 V1)

Top view (Model)

Data from ^[3]

General characteristics

Crew: two
Length: 18.30 m (60 ft 0 in)
Wingspan: 20.11 m (66 ft 0 in)
Height: 4.70 m (15 ft 5 in)
Wing area: 61 m² (660 sq ft)
Empty weight: 12,500 kg (27,558 lb)
Gross weight: 20,000 kg (44,092 lb)
Powerplant: 4 × Junkers Jumo 004B-1 turbojet engines, 8.825 kN (1,984 lbf) thrust each :::Ju 287 V2 and Ju 287 V3: 6 x Junkers Jumo 004B-1

Performance

Maximum speed: 558 km/h; 302 kn (347 mph) at 6,000 m (19,685 ft)
Cruise speed: 512 km/h; 276 kn (318 mph) at 7,000 m (22,966 ft)
Range: 1,570 km (976 mi; 848 nmi)
Service ceiling: 9,400 m (30,840 ft)
Rate of climb: 9.67 m/s (1,904 ft/min)

References

Notes

↑ Wochenbericht der Erprobungsstelle Rechlin der Woche vom 6. bis zum 12. August 1944
↑ Ford, Roger (2013). Germany's Secret Weapons of World War II. London, United Kingdom: Amber Books. p. 224. ISBN 9781909160569. |access-date= requires |url= (help)
↑ Green 1970, pp. 493–496.

Bibliography

Green, William. Warplanes of the Third Reich. New York: Doubleday & Company Inc., 1970. ISBN 0-385-05782-2.
Hitchcock, Thomas H. Junkers 287 (Monogram Close-Up 1). Acton, Massachusetts: Monogram Aviation Publications, 1974. ISBN 0-914144-01-4.
Ransom, Stephen, Peter Korrell and Peter D. Evans.Junkers Ju 287. Hersham, UK: Ian Allan, 2008. ISBN 978-1-903223-92-5.

External links

Wikimedia Commons has media related to Junkers Ju 287.

Ju 287
Ju 287 Mistel

Junkers aircraft

Company	J 1 J 2 J 3 J 4 J 5 J 6 J 7 J 8 J 9 J 10 J 11 J 12 F 13 J 15 K 16 K 17 J 18 T 19 A 20 H 21 / J 21 / T 21 J 22 T 23 G 23 F 24 / G 24 A 25 T 26 T 27 J 28 T 29 K 30 G 31 A 32 W 33 W 34 A 35 S 36 K 37 G 38 K 39 K 47 A 48 A 50 K 51 K 53

Idflieg	CL.I D.I E.I J.I

RLM	Ju 46 Ju 49 Ju 52 Ju 60 Ju 85 Ju 86 Ju 87 Ju 88 Ju 89 Ju 90 Ju 160 Ju 187 Ju 188 Ju 248 Ju 252 Ju 268 Ju 287 Ju 288 Ju 290 Ju 322 Ju 352 Ju 388 Ju 390 Ju 488 Ju 635

"EF" (experimental)	EF 61 EF 126 EF 127 EF 128 EF 131 EF 132 EF 140 EF 150

Reich Air Ministry aircraft designations

1 to 100	B 9 Gö 9 Do 10 Do 11 Wn 11 Do 12 Do 13 Do 14 Do 15 Wn 15 Do 16 Wn 16 Do 17 Do 18 Do 19 Do 20 Do 22 Do 23 Do 24 Kl 25 Do 26 Kl 26 M 27 Do 29 Kl 31 Kl 32 W 33 L 33 W 34 Kl 35 Kl 36 HD 37 HD 38 G 38 DFS 39 BV 40 DFS 40 A 40 Fw 42 He 42 Fw 43 HD 43 Fw 44 He 45 He 46 Ju 46 Fw 47 Ju 47 K 47 A 48 He 49 Ju 49 He 50 A 50 He 51 K 51 Ju 52 K 53 NR 54 Fw 55 NR 55 Fw 56 Fw 57 Fw 58 He 58 He 59 He 60 Ju 60 Fw 61 He 61 Fw 62 He 62 He 63 Ar 64 He 64 Ar 65 He 65 Ar 66 He 66 Ar 67 Ar 68 Ar 69 He 70 He 71 He 72 He 74 Ar 76 Ar 77 Ar 79 Ar 80 Ar 81 Ju 85 Ju 86 Ju 87 Ju 88 Ju 89 Ju 90 Ar 95 Ar 96 Fi 97 Fi 98 Fi 99 He 100

101 to 200	Al 101 Al 102 Al 103 Fi 103 Fh 104 Kl 105 Kl 106 Kl 107 Bf 108 Bf 109 Bf 110 He 111 He 112 He 113 He 114 He 115 He 116 Hs 117 He 118 He 119 He 120 Hs 121 Hs 122 Hs 123 Hs 124 Hs 125 Hs 126 Hs 127 Hs 128 Hs 129 Hs 130 Bü 131 Hs 132 Bü 133 Bü 134 Ha 135 Ha 136 Hü 136 Ha 137 BV 138 Ha 139 Ha 140 BV 141 BV 142 BV 143 BV 144 Go 145 Go 146 Go 147 Ju 147 Go 149 Go 150 Kl 151 Ta 152 Kl 152 Ta 153 Ta 154 BV 155 Fi 156 Fi 157 Fi 158 Fw 159 Ju 160 Bf 161 He 162 Bf 162 Bf 163 Me 163 Me 164 Fi 166 FK 166 Fi 167 Fi 168 He 170 He 172 He 176 He 177 He 178 Bü 180 Bü 181 Bü 182 Ta 183 Fl 184 Fl 185 Fw 186 Ju 186 Fw 187 Ju 187 Ju 188 Fw 189 Fw 190 Fw 191 Ao 192 DFS 193 DFS 194 Ar 195 Ar 196 Ar 197 Ar 198 Ar 199 Fw 200

201 to 300	Si 201 Si 202 DFS 203 Si 204 Fw 206 Me 208 Me 209 Me 209 (1943) Me 210 Hü 211 Do 212 Do 214 Do 215 Do 216 Do 217 Hs 217 He 219 He 220 BV 222 Fa 223 Fa 224 Ao 225 Fa 225 BV 226 Ho 226 FGP 227 DFS 228 Ho 229 DFS 230 Ar 231 Ar 232 Ar 233 Ar 234 Do 235 BV 237 BV 238 Fw 238 Ar 239 Ar 240 Go 241 Go 242 Go 244 BV 246 Ju 248 BV 250 Fw 250 Ho 250 Ho 251 Ho 252 Ju 252 Fi 253 Ho 253 Ta 254 Ho 254 Fi 256 Sk 257 Fw 261 Me 261 Me 262 Me 263 Me 264 Fl 265 Me 265 Fa 266 Ho 267 Ju 268 Fa 269 He 270 We 271 Fw 272 He 274 He 275 He 277 He 278 He 280 Fl 282 Fa 283 Ta 283 Fa 284 Fl 285 Ju 286 Ju 287 Ju 288 Ju 290 Me 290 As 292 Hs 293 Hs 294 Hs 295 Ar 296 Hs 296 Hs 297 Hs 298 Fw 300

301-	Me 309 Me 310 Do 317 Do 318 He 319 Me 321 Ju 322 Me 323 Me 328 Me 329 Fa 330 DFS 331 DFS 332 Fi 333 Me 334 Do 335 Fa 336 Fl 339 E.340 WNF 342 He 343 Rk 344 So 344 Go 345 DFS 346 Rk 347 Ba 349 Ju 352 Me 362 Me 364 Ju 388 Ju 390 Fw 391 Ar 396 Ta 400 Me 409 Me 410 Do 417 He 419 ZMe 423 Ar 430 Ka 430 Ar 432 Do 435 Ar 440 Ju 452 Me 462 Ju 488 Fw 491 Me 509 Me 510 He 519 ZSO 523 Ar 532 Do 535 E.555 Me 609 Ar 632 Do 635

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