Original Flight Hardware: Auto Pilot and Flight Director Engage Panel

The autopilot system of the Lockheed L-1011 was a very sophisticated system for its time. The avionic flight control system (AFCS) provides automatic modes of control throughout the total flight profile from takeoff run to landing roll. TheAFCS consists of 4 major subsystems:

1. Autopilot/Flight Director System (APFDS)
2. Stability Augmentation System (SAS)
3. Speed Control System (SCS)
4. Flight Control Electronic System (FCES)

The panel in today's posting, is the APFDS ENGAGE PANEL. It is located in the center of the glare-shield console.

The AUTOPILOT SWITCH has two solenoid-held switch positions besides the OFF position. Only one switch can be engaged at a time except when A/L (auto-land) mode is selected:

CWS

Engages A/P (only one can be engaged at a time) in the Control Wheel Steering mode to provide the following

• Pitch attitude hold up to +/- 18DEG
• Heading hold (if bank angle less than 3DEG)
• Roll attitude between 3DEG and 35DEG
• Auto pitch trim is operative except when force is being applied to control wheel/column.
• Control wheel electric trim is available
• Only Altitude Hold is available as an A/P command mode.

CMD

Has all the same functions as the CWS mode, but further has:

• Second AP can be engaged when A/L mode is selected
• any compatible NAV, HEADING/PITCH modes may be engaged
• auto pitch trim is operative

There are two flight director switches on the panel. One for the captain and one for the first officer. The modes of the flight director switch are:

• OFF - ADI command "V" bars biased out of view
• ON - Engages command bar display in the respective ADI. When the A/P is off, the V bars will simply display the roll attiude an the pitch attitude hold as set on the panels. With the A/P in CWD or CWS and no modes engaged, the V-bars display wings level or roll attitude and pitch attitude hold.
• SYNC - provides manual synchronziation of V-bars to heading or roll attitude when A/P is OFF.

The TURB (Turbulence) switch when pressed the first time reduces pitch and roll gains to 1/2, but does not change SAS. It disengages the auto-throttle system and all modes except GO-AROUND and A/L after A/L tracking has occurred. The switch also trips the autopilot to CWS if in CMD and removes the command bars from the ADI. The TURB mode is disengaged by pressing the switch again.




Panel Location