Avionics Bending: L-1011 Autopilot - Pitch Mode and Heading Panel - Part 3

L-1011 Autopilot - Vertical Speed Select

The VERT SPEED window and Vertical Speed Select thumb wheel are two pretty interesting components of the Heading/Pitch Mode Panel oft he Lockheed L-1011 autopilot. The Vertical Speed is indicated using a tape that is motorized and the thumbwheel allows adjustment of the value once the VERTICAL SPEED (VS) mode is selected on the panel.

The module takes +12 and -12V bipolar power. For todays hack I have worked on reading the vertical speed select values as output by the panel. The values are between -5V for 4000 feet per minute climb and -10V for 8000 feet per minute descent. I love the face that 8000 fpm can actually be selected on the L-1011 autopilot ... makes sense for an emergency descent ... of course, would probably also make about 80% of the 280+ people behind you loose their lunch. :)

Here is short video of the values produce by the panel ... for detail information please also see the chart below: