| Smiths Electronic Pilot control diagram, showing differences between S.E.P. 1 and S.E.P. 2 |
The S.E.P. 2 autopilot followed in 1952. It improved on the original Smiths Electronic Pilot, being faster, 40 lbs lighter, with new functions, and a new control box, specified by B.O.A.C. The new controls combined the original joystick and control panel in a single unit, bolted to the centre pedestal, and accessible to both pilots.
The illustration shows the difference between the S.E.P. 1 and 2. Where the S.E.P. 1 was self-contained, the S.E.P. 2 interacted with other
instruments. It had the ability to maintain the current altitude, using a barometer; to maintain speed by varying pitch; to turn onto and maintain a compass heading, or V.O.R. radial; and automatic approach, via localiser and glide-slope beams. As yet, there were no auto-throttles, so speed could only be adjusted by altering pitch, but it was already a far more comprehensive system. It was specified for the Comet 2.