Modes

The following autopilot modes are selectable at the autopilot control panel of the SP-150:

• TURN KNOB

• NAV LOC

• AUTO G/S

• MAN G/S

• ALT SEL

• HDG SEL

• AUX NAV

• MACH HOLD

• IAS HOLD

• VERT SPEED

• PITCH HOLD

TURN KNOB

The NAV SELECTOR is spring loaded to this position. The turn knob mode is used to manually control the airplane in roll by the TURN knob. Pitch is controlled by the VERT SPEED wheel. Pitch control will be inoperative if altitude hold is engaged.

The autopilot holds the heading and vertical speed existing at the time of engagement. If the airplane is in a turn, the autopilot will level the wings and hold the heading assumed at the time the wings are leveld.

NAV LOC

The navigation localizer mode provides automatic capture on tracking of a VOR radial or localizer course, correcting for crosswind. Prior to capturing the VOR radial or a localizer course selected on the captain's HSI the airplane will continue on the selected heading until approximately five degrees from the VOR radial or 2.5 degrees from the localizer course. It will then capture and track the VOR radial or LOC course. After capture (annunciator green), the captain's HSI heading bug will have no effect.

If the turn knob is used or the VOR frequency changed, the mode selector will return to MAN.

To couple the GNS530, GTN750 or GNS-XLS you need to set the HSI source switch to GPS and select NAV/LOC mode on autopilot to engage tracking.

AUTO GS

The automatic glideslope mode provides automatic capture and tracking of the localizer and glideslope. Glideslope capture can occur either before or after localizer capture.

Tracking and capture of the localizer is the same as in the NAV LOC mode.

If the turn knob is used or the ILS frequency changed, the mode selector will return to MAN.

MAN GS

The manual glideslope mode functions the same as the AUTO GS mode except that when it is selected, the airplane will climb or descend to immediately capture the glideslope.

ALT SEL

In the altitude select mode provides intercept and capture of a selected altitude. After an altitude is entered in the selected altitude display, and the pilot activates the altitude select mode (by pressing the ALT SEL button), the altitude ARM light on the autopilot control panel, and the APD ALT SEL light illuminate amber. The autopilot is now aremd to capture the selected altitude. Prior to altitude capture, pitch control is available through one of the modes on the PITCH SELECTOR.

When altitude capture is initiated, the amber ARM light is extinguished, the green ENG (engage) light is illuminated, and the APD ALT SEL light changes from amber to green, indicating that the leveloff maneuver has been initiated.

When the airplane is withing approx. 50 ft of the selected altitude, the autopilot control panel green ENG light and the APD green ALT SEL light are extinguished and the APD green ALT HOLD light illuminates, indicating that altitude capture has taken place. After altitude capture the mode will disengage when the glideslope is automatically or manually captured.

HDG SEL

The heading, or heading select mode is used to control airplane heading with the heading bug on the captain's HSI. If the turn controller is used while the HDG SEL mode is selected, the mode selector will return to TURN KNOB.

The heading select mode is activated by pressing the HDG SEL button. When activated the airplane will turn to capture the heading selected by the captain's HSI heading bug. When the heading is captured, the heading select ENG light on the control panel, and the APD HDG light will illuminate green.

AUX NAV

The auxiliary navigation mode provides automatic capture and tracking of a INS course correcting for crosswind.

To engage autopilot tracking of the INS course you have to turn on the AUX NAV mode. Please remember that the HSI is not coupled to the INS and is therefore still available for radio navigation.

PITCH SELECTOR

The PITCH SELECTOR is spring-loaded to VERT SPEED. If selected to one of the other pitch modes, IAS HOLD or PITCH HOLD, the selector will return to VERT SPEED when the glideslope is captured, altitude select is engaged or the VERT SPEED control wheel is manually rotated.

VERT SPEED

In this mode, the autopilot will vary the pitch attitude to maintain the vertical speed selected on the VERT SPEED control wheel. The VERT SPEED control is marked in 1000 fpm graduations.

IAS HOLD

In this mode the autopilot will vary pitch and attitude to maintain the indicated airspeed existing at the time IAS HOLD is selected.

PITCH HOLD

The autopiplot maintains the pitch attitude existing at the time PITCH HOLD is selected.