A6 was a designation applied to a variant of the A5 test rocket which used different propellants.[24]
Some sources indicate that it was also applied to a speculative proposal for a manned reconnaissance version of the A4b winged variant
of the A4. This A6 was initially proposed to the German Air Ministry as an uninterceptable reconnaissance craft. It would be launched
vertically by rocket, taking it to an apogee of 95 km (59 mi); after re-entering the atmosphere it would enter a supersonic glide phase,
when its single ramjet would be ignited. It was hoped that this would provide 15 to 20 minutes of cruise at 2,900 km/h (1,800 mph) and
would allow the aircraft to return to its base and make a conventional runway landing assisted by a drag chute.
However, the Air Ministry had no requirement for such an aircraft and the proposal was rejected. Similar concepts (though unmanned) were
produced after the war in the form of the USA's SM-64 Navaho missile and the USSR's Burya, both intercontinental cruise missiles with
ramjet propulsion.