The Junkers EF77 was a further developement of the Junkers Ju52 started in 1938.
The RLM Type Allocator List reserved the "77" for Junkers, probably for the EF77.
Initially the EF77 design Eichholtz did not find Lufthansa's interest, as it did not show much
advantages against the Ju52. The EF77 with its three BMW 132 engines was capable for 21 passengers,
just three more than the Ju52. The wing span was approximately 23 metres rectangle design,
while the fuselage length was designed for about 20 metres.
In late 1939 the design was improved at the Prague Junkers Office for up to
30 passengers and had a range of maximum 2000km at 350 to 400km/h. Lufthansa was
interested in this design as well as the RLM and
the project was finally finished during WWII as Junkers Ju252.