Some more details about the various Ju-288a data aviable.
There are, in part, conflicting data aviable on the net.
Ju-288 (initial proposal, also termed Junkers EF-73).
This design was closer to the Ju-88A. It had the same rear fuselage with the Ju-88A tail section and a smaller wing. Two JUMO-222A (2 x 1840 KW) were proposed to drive the airplane. Under development from 1937 to 1940. Another version was proposed to be propelled by two JUMO-224A Diesel with ultra long range (marine purposes). No prototypes.
Span: 15.70m
wing area: 48.0m²
speed: 675 km/h at 8,000m
internal bombload: 4,000kg (=2 x SC2000)
max. take off weight: 14,600kg
Range figures as given by Junkers appear to be to high (the RLM concerns about this and I guess they were right in their suspect) and are not reproduced here until more data is aviable
Ju-288A (scheduled for serial production late in 1941, initial variant, studied 1939 to 1941)
The design had to be changed owing to a larger requirement of internal bombload from the RLM. Driven by two derated JUMO-222A/B (2 x 1440 KW) but other engines were under consderation, too (see above). The Ju-288V1 was buildt according to these requirements, the Ju-288V5 was buildt as a full pre production prototype, driven by JUMO-222A/B.
Span: 18.29m
wing area: 54.0m²
speed: 660 km/h at 8000m
bombload: 5000kg (=2 x SC 2500 internal)
max. take off weight: 15600kg
range: 3850km
Ju-288A modified (scheduled for serial production late in 1941, modified variant, studied 1941 to 1942)
The design had to be changed owing to a larger requirement of internal bombload from the RLM. Driven by two derated JUMO-222A/B (2 x 1440 KW) but other engines were under consideration, too (see above). The big difference to the Ju-288A above is the bigger wingsize. The Ju-288V2-V4 were buildt as prototypes following these specifiations.
span: 20.06m
wing area: 60.0 m²
speed: 645 km/h at 8000km
bombload: 5000kg (two SC2500 internal) (+ 1200kg external drop tanks or +1000kg external bombs, optional)
max take off weight: 17300kg
range: 3600km
Now the RLM changed once more requirements, calling for an even larger endurance, requiring yet another, even bigger wing (span= 22.0m, wing area = 64.0m², beeing represented by the Ju-288V6-V8 and Ju-288V12, leading to the Ju-288B design stage) and eventually a fourth crewmember (Ju-288V9-11) in a wider cockpit. Simultaneously, the power requirement for the JUMO-222A/B was increased to 1844 KW, which -as it was hoped, would compensate for the larger airplane.
I was somehow suprised to see that they required so much larger payloads from the initial proposal EF-73. Even driven with only 1044 KW JUMO-211J instead, the A/C should be fast (~580 km/h) and nimble and represents (in my eyes) a more capable plane than Bf-110 and Ju-88/-188 with regard to utility and load taking vs range capability.