The Junkers Ju 288 was one entry in the “Bomber B” competition of 1939, designed to provide the Luftwaffe with a long range high performance medium bomber. The entire program and every aircraft designed for it was essentially doomed by the insistence of the use of two engines rather than four, as the promising engines then under development failed to live up to expectations. The Jumo 222 project failed to produce a reliable engine (although a small number of engines were produced), while the DB 604 was cancelled in September 1942. This left Junkers searching for suitable engines, and relying on under-powered BMW 801 radial engines to power the prototypes.
Design work began during 1939. A full scale mock up was begun in December 1939. It was inspected in May 1940, and official approval for a prototype given in June. By this time Junkers had already begun work on the aircraft. Early tests using Ju 88 airframes with revised nose and tail units had begin in the spring of 1940, while work on the Ju 188 V1 had started in February 1940. This first prototype has the shortest wing used on the Ju 288, at 60ft 3.25in, and was powered by the BMW radial engines.
The A series went through eight prototypes. The V2 saw the wingspan increased to 65ft 3.25in. It was badly underpowered, and in late 1941 did not perform well when tested against the Ju 88. The V3 of June 1941 saw the remote tail turret added. The V4 had the dive brakes removed – the Ju 288 was clearly too large to act as a dive bomber.
The V5 was the first prototype to use the original Jumo 222A engines. These engines provided 2,500hp, giving the V5 1,800hp more power than the earlier aircraft, but the engine was still not reliable. It was again used on the V-6, with a 74ft 4in wingspan, but was unavailable for the V7. The V8 was the final prototype for the A-series, which very nearly entered production, but was then cancelled in favour of the B series.
The B-series saw the crew increased from three to four. It received a wider nose, which eliminated the straight sided profile of the A series. It had a bigger tail plan, and retained the 74ft 4in wing of the V-6, which was to have been reduced in size for the A-1. In October 1941 Junkers received an order to begin mass production of the B series, but on 1 November that order was reduced to one for 35 aircraft while a search for more powerful engines began.
The V10 was powered by BMW 810TJ engines, with exhaust driven turbo-superchargers, but these engines only developed 1715hp. Finally, a potential solution appeared to have been found with the Daimler Benz DB606, a twinned engine produced by pairing two DB 601s. These provided 2,700hp and did eventually enter series production, but were not reliable. In the He 177 they were prone to burst into flames for a wide variety of reasons.
Despite this, early in 1942 Junkers were told to prepare for series production of a DB 606 powered Ju 288C. The first prototype for the C-series was completed in August 1942 as the Ju 288 V101 (although was the 15th prototype). It had a wider forward fuselage and a fourth gun turret. It would have had a bomb load of around 6,000lb and a projected top speed of 400mph. Work now began on preparing for mass production of the aircraft, but in June 1943 the RLM suddenly decided to cancel the project, on the grounds that the Bomber B specifications were now no longer valid. They were now four years out of date, and the war had moved on dramatically from 1939-40.
In 1944 interest revived in the strategic bomber. The Junkers contender in this utterly deluded project was the Ju 488, a four engined bomber that would have used the tail of the Ju 288. Work on this aircraft began far to late for it to have any chance of seeing service.