Possession of an automatic landing capability does not automatically confer the ability to operate in reduced visibilities and the use of decision heights (DH) below 200'. The Vulcan had a single channel autopilot that could only confer a fail passive capability and would require a visual segment in the approach in order that centreline tracking could be confirmed. The best that could have been achieved with the equipment as fitted would equate to Category 2 capability, i.e. a DH not below 100' above Touch Down Zone Elevation (TDZE). The required visual reference at DH for a CAT 2 approach are to see 3 approach lights (there are other options but this keeps it simple). The problem with the Vulcan would have been that the viusal cut-oof from the cockpit would have made acquisition of the closest light marginal and significantly reduced the chance of a sucessful approach in the normal Cat2 runway Visual Range (RVR) of 300 mtrs. The only way to increase the success rate would have been to raise the minimum RVR to say 400mtrs and given that the minimum RVR for a normal Cat 1 manual landing was 600 mtrs then the additional capability increase was of marginal value. Remember as well that the system envisaged for the v-aircraft required ground installation of leader cables, it was not a pure ILS system as used today.
In summary, the development of autoland and work done on low vis ops by the Blind Landing Experimental Unit was ground breaking and showed what could be achieved. The technology was developed and procedures established, but this was still a long way away from an operational capability available to all service crews.
YS