Flight Development of the VC10 toward Automatic Landing Capability: A description of the flight trials of the VC10 using autoflare and the instrumentation involved

The automatic flight control system of the Standard and Super VC10 was designed to be capable of development to full blind landing. To meet this requirement the system had to be capable of failure survival and this includes associated services such as power supplies and flying controls. The method of autopilot failure survival chosen was to provide two monitored systems which are fail soft, i.e. there is negligible aircraft disturbance after a failure. Then auto changeover between the systems provides failure survival when it is necessary. The arguments for this type of system are expanded in the article on p. 49 by A. R. Colwell.