(2)  
All electrical power is supplied from electronic bus-1 to the autopilot through circuit breakers located on the main load control center (P6-2). On GJ B-2501 THRU B-2505, an additional circuit breaker, powered from the 115V ac standby bus, is installed for airplanes with derived rate pitch and roll channels. On GJ ALL EXCEPT B-2501 THRU B-2505, 115V ac power is routed from the standby bus to the control channels via vertical gyro or auxiliary vertical gyro, for airplanes with derived rate pitch and roll channels. Circuit breakers are labeled for the component or control channel that is supplied with power, and also for either 115 volts ac or 28 volts dc power.

(3)  
The control panel is located on the glare shield above the center panel where it is accessible to both the captain and first officer. The control panel contains the controls to enable the captain and first officer to engage the aileron and elevator axes and to select various modes of operation. These controls are the aileron and elevator engage switches, the mode select switch, the navigation-heading select switch, and the pitch mode select switch.

(a)  
The aileron and elevator engage switches, labeled AIL and ELEV are two position switches. The positions are DISENGAGED and ENGAGED. The switches have a latch that holds the switch to the DISENGAGED position. If certain engage interlocks are satisfied, a solenoid releases the latch so that the switch may be moved to the ENGAGED position. When in the ENGAGED position, if certain other interlocks are satisfied, the solenoid will hold the switch engaged. If the interlocks are broken, the solenoid will release the switch to the DISENGAGED position. The engage interlocks are so arranged that the roll (AIL) engage switch does not require engagement before the pitch (ELEV) engage switch will engage.

(b)  
The mode select switch is a four-position rotary switch that is spring-loaded to the MAN position and solenoid held in the other positions. The positions are heading off (HDG OFF), manual (MAN), omnirange/localizer (VOR LOC) and automatic approach (AUTO APP). Certain interlocks must be satisfied for the switch solenoid to remain energized in each position except manual. 

(c)  
The pitch mode select switch is a three-position rotary switch with a center OFF position. The switch is solenoid held in the altitude hold (ALT HOLD) position so that it may be automatically released upon glide slope engagement. The turbulence (TURB) position is selected by rotating the switch counterclockwise.

(d)  
The navigation (NAV)-heading select (HDG SEL) switch is a 3-position toggle switch, spring loaded to the center off (heading hold) position and solenoid held in the HDG SEL or NAV position. The switch will automatically return to the center position from the HDG SEL position if a lateral radio beam (VOR or localizer) is engaged or if the CWS is out of detent. The switch will hold in the NAV position only when the mode select switch is in the MAN position and a valid OMEGA navigation signal is present.

(4)  
The approach progress displays are located on the captain’s and first officer’s instrument panels. The displays are annunciators utilizing colored lights to indicate when certain switching functions have taken place within the autopilot.

(5)  
The disengage and warning light reset switches are located on the outboard horn of each control wheel. The normally-closed contacts of the switches are in the engage interlock circuits, and if either switch is actuated, the autopilot will disengage. The normally-open contacts of the switches are used to reset the disengage warning light circuit. If the autopilot is disengaged using the control wheel switch, the warning lights will be reset at the same time, therefore; the lights will not flash.

(6)  
The disengage warning lights are located on the captain’s and first officer’s instrument panels. The lights are covered with a red cap. The light assembly incorporates a light reset push-to-test switch. When the light is pushed in, the warning light circuit is reset and the lights flash. The lights will extinguish when the light is released. If either light is held in, both lights should flash until the light is released. The lights will illuminate steadily if any one of the autopilot or yaw damper system self-test switches are in any position other than OFF.

(7)  
The stabilizer out of trim warning light is an amber light located on the center instrument panel (P2). The light is controlled by the stabilizer trim monitor in the pitch control channel and will illuminate whenever an out of trim condition exists between the stabilizer and elevator for more than approximately 12 seconds.

5C8 
22-11-0 Page 12  BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.  Feb 20/86 

Feb 15/78 22-11-0 Page 13
　
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