The heavy bomber project Junkers Ju 290 Z (for
"Zwilling", German for "Twin") was inteded for getting a maximum bombload
delivered to enemy targets. In order to avoid a
completely new design, the development team used the already proven method (see
Heinkel He 111 Z) to link up two existing airframes. So it was planned to connect two Junkers Ju 290 A-7's via an newly
designed wing-center section. All other components, like undercarriage,
empennage, fuselage (incl. accessories) were to be retained
unchanged.
In order to strengthen the defensive capabilities
of this colossus, it was envisaged to install a "parasite fighter"
(Messerschmitt Me 328 B, equipped with two ram-jet engines) on top of the
right-hand fuselage, to be started by a catapult device.
Whether this was intended as single-use-only
device, or if an in-flight recovery system was to be used, can't be deduced from
existing data.
Nevertheless, its clear that this twin-fuselage
bomber (equipped with eight radial engines) would have been the largest
land-based plane ever built. Due to its size and unhandiness on ground, it would
have caused a lot of logistics problems, which would have been hard to overcome
due to Germany's detoriating war situation.
As the Junkers Ju 390 V1 (Prototype 1) was
developed, built and successfully tested in parallel, the Ju 290 Z-project was
put back on to the shelf.